KB2LJJ Radio Mods Database and Manuals
Contents
1. Service Bulletin no 962 17 1 1990 The TS 950SD RX to TX switching time in semi break in is approximately 10 mS At the key down the transceiver momentarily sees an open circuit because the linear s keying relay has not engaged As a result the transceiver s protection circuit turns on causing the output power to be reduced The following modification will make the RX to RX switching time in semi break in approximately 30 mS This modification does not affect full break in switching Increasing the switching time to 30 mS may restrict certain long distance high speed communications Required parts Digital transistor QTY 2 DTC124ES 100 Kohm resistor RD1I4BB2E104J 2 2 uF 50 V electrolytic capacitor CEO4EW 1H2R2M Disconnect the power cord and antenna Remove the top and bottom covers 18 screws Remove the top screw from each side of the front panel assembly Loosen the bottom screw on each side of the front panel assembly http www kb2 jj com data kenwood ts 950 htm 5 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Pull the front panel assembly forward to expose the Digital and Control boards Remove the two screws that secure Control board B 3 to the top of the chassis and swing the board out of the way Remove the 4 screws from Control board A 3 and rotate the board down Disconnect the right hand plugs as necessary to expose the foil side of the Control board Install the circuit2. Kenwood Communication inc Service Bulletin no 998 3 August 1992 Occasionally the TS 950SDX will transmit instantaneously when the mode is switched from SSB to CW with the VOX turned on The frequency of occurrence depends upon the setting of the VOX GAIN and DELAY controls Cause A small amount of RF feedback is felt on analog switches IC5 and IC6 in the AF unit This RF causes the timing circuit to actuate briefly when the mode is changed with VOX ON Warning This radio uses micro sized surface mount component and or multi layer circuit boards If you are not familiar with the techniques for service of this type of equipment do not attempt this modification yourself You will invalidate your warranty if you attempt to modify the equipment and damage the radio If you are at all in doubt about your qualification to perform this modification you should seek qualified assistance Required parts C191 4 7 uF 25 V electrolytic capacitor CWO4EW 1 W4R7M Procedure Unplug the DSP unit from the rear of the transceiver Remove the top and bottom covers 18 screws Turn the units so the bottom is up The AF unit is located in the front left hand corner Remove the 8 screws securing the AF unit to the chassis Add C191 in the position indicated in figure 2 Reverse steps 1 5 to reassemble http www kb21jj com data kenwood ts 950 htm 16 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals AF
3. KB2LJJ Radio Mods Database and Manuals TS 950S Final bias circuit change Author Kenwood Communication inc Service Bulletin no 990 28 1 1992 It is possible to exceed the maximum Vcbo rating of the MRF429 transistors used in the TS 950S SD if the unit is operated at excessive transmit power levels greater then the normal factory output power setting This results in a collector to base short on the MRF429 This causes excessive current to be drawn thru R17 and or R18 of the final bias circuit This can cause a large amount of smoke from the overloaded resistors It does not normally cause damage to surrounding components You might wish to check Q7 VR2 Q8 and the fuse just as a precaution R17 and R18 are carbon type resistors 27 ohms 2 w Carbon resistors can emit quite a bit of smoke when overload in this manner and can be the cause of considerable concern by the operator In order to case operator concern we recommend replacing R17 and R18 on the final unit X45 3330 00 with ceramic resistors whenever replacing the final transistors These special resistors have been designed to open quickly if the current rating is exceeded This prevents smoking and the odors associated with burning resistors Parts required 27 ohm 2 watt ceramic resistor R92 1286 05 Precautions The MRF 429 transistors generally fail one of two ways The collector base junction opens R17 and R18 are not damage when this occurs If the MR
4. http www kb2 jj com data kenwood ts 950 htm 28 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950SDX click noise with NOTCH ON Kenwood Communication inc Service Bulletin no 1026 7 June 1993 Symptom A click noise might be generated when receiving a strong signal S 0 or above when the NOTCH is ON and the Notch Control is turned away from the notch point Corrective action Lengthening the AGC release time of the IF Amp just before the NOTCH circuits will correct this symptom The enclosed modification has been designed to change the time constant only when the NOTCH circuit is activated Do not install this modification on sets that do not exhibit this symptom as the AGC FAST time constant affected by this change Cut the printed circuit foil pattern between the test point TP and gate 2 of Q2 as shown Install the 47 Kohm chip resistor from TP tp gate 2 of Q2 Add a 0 047 uF ceramic capacitor as shown in the accompanying illustration Add the DTC124ES transistor as show Note The 047 uF capacitor and the digital transistor must be connected together as shown and installed so that they do not touch the sorrounding board patterns Install a jumper wire from the base of the digital transistor to pin number 6 of CN14 Parts required Qty Description Kenwood Part No Circuit description 1 0 047 uF capacitor CK45B1H473Z NA 1 Digital transistor DTC124ES NA 1 47 Kohm chip resistor RK73FB2A473J N
5. MAKE begins If the two overlap then the weighting is too heavy If they don t touch then it s too light If the weighting in this mode SEMI BREAK IN is too light increase the value of CV if it is too heavy reduce the value of CV a bit until you obtain a weighting ratio of approximately 50 Set the FULL SEMI switch to FULL While sending a string of DITs adjust the value of RT until the space between the end of one DIT and the start of the next DIT is the same length as the length of the DIT itself Once you have successfully set the weighting you are finished If you did not use a PC mount pot for RT you must now remove the temporary pot and leads measure the value of the pot and replace it with a fixed resistor of the same approximate value If required reinstall the QSK mod PC board Tilt the front panel back into place vertical slide it back toward the main chassis and secure it in place with two screws at the top on each side Retighten until snug only the two hinge screws Replace the top and bottom covers of the radio and reattach the two cables from the DSP unit on the bottom of the radio You are done Whew Please note This document would not have been possible without the assistance of Bob Wolbert K6XX who designed the original modification If you find errors in this document please contact me so that I may make corrections to the instructions Revised 13 April 2001 Better QSK Waveforms by Bo
6. chip resistor RK73FB2A151J Procedure Change the value of R258 in the SIG unit X57 4130 00 from 68 ohm to 150 ohm This will increase the available adjustment range of the PROC IN control This will make it much easier to properly adjust the control and thus avoid overdriving the speech processor circuit http www kb2 jj com data kenwood ts 950 htm 20 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Unit Foil Side View Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance Time required for this modification is 30 minutes or less TS 950SDX 3rd order IMD standardization Kenwood Communication inc Service Bulletin no 1009 25 January 1993 Symptom 3rd order IMD figures have been noted that do not meet out standard value of 32 to 35 dB Cause We have found that this symptom can be caused by either improper blas to the final transistor and or because of distortion inducted by the 73 05 MHz IF mixer circuit Parts required R195 R197 R198 150 ohm chip resistor RK73FB2A151J QTY 3 R204 4 7 Kohm chip resistor RK73FB2A472J QTY 1 R19 R20 22 ohm carbon resistor RCOSGF2H220J QTY 2 Procedure On the Final unit X54 3450 00 change R19 and R20 from 10 ohm to 22 ohm Figu
7. on the oscilloscope cross as shown in figure 3 http www kb21jj com data kenwood ts 950 htm 31 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Switch to LSBV Press the 8 83 MHz filer key until 6 KHz appears in the display Leave the 455 KHz filter set at 2 7 KHz Select a dial frequency of 1 853 0 MHz Adjust the TX VFO SUB encoder control until the waveforms displayed on the oscilloscope cross as shown in figure 3 Select MENU 01 Switch to USB Press the 8 83 MHz filter key until 2 7 KHz appears in the display Leave the 455 KHz filter set at 2 7 KHz Select a dial frequency of 1 850 0 MHz Adjust the TX VFO SUB encoder control until the waveforms displayed on the oscilloscope cross as shown in figure 3 Select LSB Select a dial frequency of 1 853 0 MHz Both filters should remain at 2 7 KHz Adjust the TX VFO SUB encoder control until the waveforms displayed on the oscilloscope cross as shown in figure 3 Note This completes the adjustment To return to the normal display and save these setting you should press the CLR key one time Transceiver under Test O To tour 2 Fig Fig 2 Fig 4 Time required for this modification is 60 minutes or less http www kb2 jj com data kenwood ts 950 htm 32 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950SDX Sub band residual noise Kenwood Communication inc Service Bulletin no 1050 28 March 1994 Symptom T
8. pins In the following step pin numbering will begin with the leftmost of these six pads and progress to the right Wires will be connected to pins 2 3 amp Connections to Back Side of Keyer PO Board m n F Sa a A j e j a t i ante 4 z i r x i P a j W i To E pe ee i x i ALIN 6 respectively 5V0C a M A 9 _ Key YEL E J Y a Lead r z Remove 1 8 max of insulation from the three unterminated leads coming from the QSK mod PC board tin the leads note the insulation may recede as the ends are tinned and clip the tinned leads to a length of 1 8 Attach the wire from pin 1 Key Out on the QSK Mod PC board to pin 2 on the keyer PC board BE SURE to attach the lead so the rest of the wire faces the INSIDE of the PC board Attach the wire from pin 2 QSK Full on the QSK Mod PC board to pin 3 on the keyer PC board ri i Key Dut BRN ASH RED GND GRA Attach the wire from pin 5 GND on the QSK Mod PC Figure 5 board to pin 6 on the keyer PC board Position the keyer PC board so that it can be reinstalled onto the header blocks on its motherboard Arrange the wires from the QSK mod PC board such that they are well clear of the header holes on the now right side of the keyer board and so they exit from the top rear of the QSK mod PC board Reinstall the keyer PC board Reinstall the two multi wire header plugs removed from the keyer PC board in step 19 above Cut a
9. proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance Time required for this modification is 30 minutes or less TS 950 Infinite SWR at beginning of transmission Kenwood Communication inc Service Bulletin no 1020 14 May 1993 Symptom During Full Break in operation the SWR meter shows infinite SWR at the beginning of transmission This results in a reduction of the transmitter power followed by a gradual increase to normal full power This symptom does not occur with the antenna tuner set to THRU Cause Normally the RCB line should be 0 Vdc at the beginning of transmit operations We have found that this does not always occur The length of time required for transmit power to return to normally is directly related to the time constant of capacitor C128 on the RXB line Correct action Removing this capacitor corrects the above symptom but might affect the receiver sensitivity at a dial frequency of 100 KHz This action is only recommended if the symptom is actually present Do not modify the unit if the symptom is absent http www kb21jj com data kenwood ts 950 htm 26 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification
10. screws Locate the Signal board on the bottom of the transceiver This is the front right board of the 4 boards on the bottom of the transceiver Disconnect the 3 flex cables and remove the 6 mounting screws from the Signal board Carefully lift the board and rotate it toward the AF unit front left board to expose the foil side of the Signal board Loosen the wire harness as necessary to rotate the board The following will be performed on the foil side of the Signal board Cut the foil between pin 3 of CN18 and chip resistor R229 Desolder and remove R229 Solder a 10 ohm chip resistor across the cut foil Solder a 39 ohm chip resistor in place of R229 it will be slightly offset due to the installation of the 10 ohm resistor Solder a 4 7 ohm resistor to the collector of a 2SC2458 Y transistor Shorten the lead length to accommodate the following installation and insulate the leads with shrink tubing Solder the exposed end of the 4 7 ohm resistor to chip capacitor C167 Solder the base and emitter leads as shown in the accompanying diagram Solder a 10 Kohm resistor to the circuit as shown http www kb2 jj com data kenwood ts 950 htm 3 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals CNL PRS ADD 10 OHM INSTALL R229 REMOVE ADD 4 7 OHM R229 W ADD 10K OHM F are ie A pahia a T F i r TE af j TE Fak TH ie a i r Fata P i i Somaya Seta K EF
11. the bottom of the transceiver This is the back left board of the four boards on the bottom of the transceiver Remove the screws from the AF unit and disconnect the plugs as necessary to turn the board over to expose the foil side of the board Replace Q6 with a 2SD1757K S Solder a 22 AWG jumper wire as shown in figure 1 AF UNIT X49 3020 00 VCO amp S8 3638 88 This modification may be covered under warranty Time required to perform the modification is 1 hour or less TS 950S SD TX image on 18 115 MHz Service Bulletin no 982 6 2 1991 http www kb2 jj com data kenwood ts 950 htm 10 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Some TS 950SD owners have reported a transmit image at 18 115 MHz that cause the receiving station to hear distortion on the carrier If the operating frequency is shift 3 KHz above or below 18 115 MHz the image disappears This modification will lower the image level from 30 dB worse case to better then 40 dB by installing a trap on the 455 KHz I F Required parts 4 pF Trimmer capacitor C05 0308 05 40 pF Trimmer capacitor C05 0309 05 2 2 uH coil L40 2292 14 Modification Disconnect the power cord and antenna Remove the top and bottom covers 18 screws Locate the I F board on the bottom of the transceiver This is the back right board of the 4 boards on the bottom of the transceiver Figure 1 Locate L36 by connector CN17 on the I F boar
12. 1993 Symptom A transmitter spur might be present at a dial frequency of xx xx1 MHz This spur fo 1 KHz is quite small 55 dB relative to fo but might become noticeable when the transceiver is used with a linear amplifier Cause The transmitted signal enters pin 5 of IC11 which is in the last PLL loop in the AF unit due to RF feedback This pin is the input for the 10 MHz Ref Osc signal from the CAR unit IC11 is the source of the spurious signal since both the band and 10 MHz frequencies are divided by the 500 KHz comparison frequency supplies by IC11 Correct action To reduce this RF feedback increase the Ref Osc level from 2 V to 7 V ms by adding the accompanying circuit to the input of KUL Parts required Qty Description Kenwood Part No Circuit description 1 12 uH Ferri inductor L40 1201 17 NA 1 10 pF Chip capacitor CC73FCH1H100J NA 1 16 pF Chip capacitor CC73FCHIHI60J NA tit Chip Cap fren ZEL TuM F Ea 7 Ants E eeh Tae ETE ig B a a Dda Ce Tel eed Sh easy ee Lao PET ae pao Ade mie f an hi a Add AF Unit X49 3020 00 Ref Ose Foil Side View Input Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance Time required for this modification is 30 minutes or less
13. 3 piece of insulated wire preferably the same color and type of wire as used for the 15VDC V lead coming from the QSK mod PC board 5 pin connector Strip 1 8 of insulation from each end of this wire and tin both ends To one end of this wire attach a single pin receptacle and insert it into a single pin housing This will mate with the single pin plug which was created in step 6 of the instructions Attach the unterminated end of this wire to the 15VDC pad on the PC board immediately above the keyer PC board see Figures 1 amp 6 for the location of the PC board and for the proper pad to connect to Also confirm this connection in your TS 950 manual schematic section ly Above Keyer PCB oe ne gt 15VDC Pwr Conn to Board Figure 6 me a mmediate Connect all of the single pin connectors to their respective pins 15VDC and two connections Figure 6 front amp rear of the AUX Key In line This should complete installation of the QSK Waveform Mod However you will still need to tweak the component values for CV and RT and possibly CT as well With any luck at all you won t have to change the value of CT however If you installed a 1 Meg PC mount trimmer pot at RT skip to step 33 Temporarily detach the QSK mod PC board from its mounting and tack solder two 1 leads into the holes reserved for RT and attach a 1 Meg potentiometer to be referred to as RT during the testing period to these leads Reinstall th
14. A Cut the foil s pattern then add a 47 K chip resistor i Signal Unit X57 4130 00 Foil Side View http www kb2ljj com data kenwood ts 950 htm 29 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance Time required for this modification is 30 minutes or less TS 950SDX YG 455S 1 Installation note Kenwood Communication inc Service Bulletin no 1043 28 March 1994 Symptom When the YG 455S 1 is installed the LSB audio is slightly off pitch This characteristic is corrected using the Service Adjustment menu Early models of this transceiver did not make this adjustment available the individual operator unless they had access to a service manual Countermeasures A menu option has been added to Menu 07 on late versions of the transceiver which allows the individual operator to correct this audio shift This has been accomplished by changing the program of the ROM chip IC 19 on the Digital unit X46 3130 1 2 and by updating the operators manuals Installing the new ROM on early versions of this transceiver will allow the operator the same convenience as provided on later serial numbered sets Parts required Qty Description Old p
15. A He This modification is covered under the 1 year warranty Time required to perform the modification is 1 hour or less TS 950SD N B Gate switching noise Trio Kenwood Communication inc Service Bulletin no 961 11 1 1990 Switching noise from the main band noise blanker circuit may be induced on the 15V line and pass through the AF amplifier to the speaker The following modification will correct this condition Note This modification has already been performed on models starting with serial number 104xxxx Required parts 120 ohm 1 8 watt resistor RD14BB2B121J 100 uF 16 V electrolytic capacitor CE04EW1C101M Disconnect the power cord and antenna Remove the top and bottom covers 18 screws http www kb2ljj com data kenwood ts 950 htm 4 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Locate the AF board This is the front left board of the 4 boards on the bottom of the transceiver This work will be done on the component side of the AF board Cut the foil shown in the accompanying diagrams Add a 120 ohm resistor between the emitter of Q48 and the 15 V line Add a 100 uF 16 V capacitor between the 15 V line and ground Reassemble the transceiver Ip NB2 X59 335 80 0000000000 This modification is covered under the 1 year warranty Time required to perform the modification is 1 2 hour TS 950SD Early protection with TL 922A Trio Kenwood Communication inc
16. B minimum full CCW Sub NB set for blanking Sub RX ON Sub RX frequency out of band This results in quiet intermod free blanking The only problem seems to be a limitation on the spacing between the main and sub receiver frequencies of 500 kHz maximum but this isn t a big issue You can listen to the sub receiver output to confirm that there isn t an interfering signal there For information on powerful ac line synchronous blankers see http www ussc com turner syn_blank html http www ussc com turner syn_blank html http www ussc com turner BLANKER1 GIF http www ussc com turner BLANKER1 GIF http www lwca org library articles jtreed gate gate 1b htm http www lwca org library articles jtreed gate gate1b htm These are blankers that use the AC line itself to set phase and blanking width and are used with VLF receivers where line noise can be a big problem http www kb2 jj com data kenwood ts 950 htm 45 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals 1 T N The KB2LJJ takes no responsibility for any damage during the modification or for any wrong information made on this modification http www kb2 jj com data kenwood ts 950 htm 46 di 46 01 09 2009 0 15 19
17. B2LJJ Radio Mods Database and Manuals Press the MENU key one time to exit the MANU mode Turn off the POWER SW Turn ON the POWER SW while depressing the MENU key Select MENU 69 by tuning the M CH knob Press the DOWN key until OFF appears in the display Press the MENU key one time to exit the MENU mode This operation turns off the internal chatter absorption filter circuit Time required for this modification is 15 minutes or less TS 950 Hum with monitor ON Author Kenwood Communication inc Service Bulletin no 1016 12 May 1993 Symptom On early versions of the TS 950 series below serial number 106xxx a hum might be heard when the MONI function is active and headphones are connected to the PHONE jack No hum is experienced when the MONI circuit is OFF Cause This noise can only be found in the monitor circuit itself and not on the transmitted signal We have found that the VCO shield cover for the PLL unit might be contacting the shield plate for the filter unit This physical contact can allow a slight amount of vibration to be felt in the sub receiver section This vibration combined with too much gain in the sub receiver section contributes to the hum Parts required Qty Description Kenwood Part No Circuit description 4 Low profile PLL Unit cover screws N35 2640 05 NA Procedure On the IF unit X48 3060 00 adjust VR 1 to the point the audio output just decreases when the MONI circuit is activated Re
18. D THESE INSTRUCTIONS COMPLETELY BEFORE YOU HEAT UP THE SOLDERING IRON REFER TO THE SCHEMATICS IN YOUR TS 950xx MANUAL TO CONFIRM ALL CONNECTIONS BEFORE YOU ATTACH ANY WIRES TO A PC BOARD Step by Step Installation steps Remove the top and bottom covers of the TS 950SD and set them aside Don t forget to disconnect the two cables from the DSP unit before removing the bottom cover of the radio Place a protective blanket or other soft material beneath the front of the TS 950SD so that when the radio is moved and turned you will not damage the finish on the plastic portion of the front panel On each sides of the TS 950SD chassis just behind the front panel you will find two Phillips head screws which hold the front panel in place The bottommost of the two screws when loosened 2 3 turns acts as a hinge for that side of the front panel allowing it to first slide forward about 1 1 2 inches and then to tilt forward to expose the back of the front panel and the front of the sub front panel PC boards mounted to the main chassis The topmost of the two screws may be completely removed to allow the front panel to move Loosen the bottom screws remove the top screws and slide the front panel forward http www kb2 jj com data kenwood ts 950 htm 39 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals 9505D With Front Panel Hinged Out Internal Electronic 15V DC OSK Waveform Keyer PC Board Access Mod PC Board PP eae PP
19. F 429 s are operated at RF power levels higher then the absolute maximum Vcbo rating the collector base junction fails This causes excessive current to flow thru the base circuit If the MRF 429 s short collector to base with ceramic resistors there will be very little smoke before the resistor opens The outward appearance of the resistors will not change so you must make sure to check the resistors with an ohmmeter before installing new finals If R17 or R18 should open there will not be an appreciable change in the base circuit current It is essential however that these resistors be in good working order as they ensure stable operation of the final amplifiers R17 and R18 must be replaced whenever you replace the final transistors The ceramic resistors are easy to identify They are rectangular and white in color Replacement Procedure Replace the bad MRF 429 transistors Remove R17 and R18 from the component side of the Final circuit board Solder the ceramic resistor directly to the base and emitter of the final transistors The stability of the circuit is improved by soldering R17 and R18 directly to the base and emitter of the finals Do not install them in the old locations http www kb21jj com data kenwood ts 950 htm 14 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Final Unit X45 3330 00 Component Side View TS 950S Rear panel cooling fan Author Kenwood Communication inc Service Bu
20. KB2LJJ Radio Mods Database and Manuals Contact Downloads Radio Niods Database Niods Mianuals ancl Circuits R P L J J http www kb 21 com TS 950 Mods TS 950SD general coverage transmit mod Kenwood TS 950 Power On Functions Kenwood TS 950 SDX Allows sub rcvr to be on different band than Main receiver TS 950SD Speech processor noise TS 950SD N B Gate switching noise TS 950SD Early protection with TL 922A TS 950SD RX digital noise TS 950SD Two second TX power delay with MONI on TS 950 SD Receiver noise TS 950S SD TX image on 18 115 MHz TS 950S SD 80 meter spurious emission TS 950S Final bias circuit change TS 950S Rear panel cooling fan TS 950SDX Mode switching TS 950SDX No beep in headphones TS 950SDX Distorted DRU 2 TX audio TS 950SDX w K1EA Ver 8 Program Revised TS 950SDX Speech processor TS 950SDX 3rd order IMD standardization TS 950SDX Key click w bug type Keyer TS 950 Hum with monitor ON TS 950 Noise with Sub Band noise blanker ON TS 950 14 200 MHz transmit spur TS 950 Low power output after temp protection TS 950 Infinite SWR at beginning of transmission TS 950 Smoke from antenna tuner unit TS 950S SDX Transmit spur TS 950SDX click noise with NOTCH ON TS 950SDX YG 455S 1 Installation note TS 950SDX No VFO B after split TS 950SDX Carrier point adjustment TS 950SDX Sub band residual noise TS 950SD 18 115 MHz spur TS 950SDX Change of Gate resistor type Countermeasure against cold solder joi
21. P Peres a ment Brn ae i iar a fd er g i P r Tirena i s se Pore aie N bel hs Jape abe ib T EAT T pened ed ity aha he Eji i r rk H pes 2 rE SEER IS op ar oa be ha be Ah F Ei IN THE STEP WHICH FOLLOWS BE CAREFUL TO NOT ALLOW THE FRONT PANEL TO FLOP DOWN IN AN UNCONTROLLED MANNER Should this happen one or both of the thin white ribbon cables just to the right of center in Figure 1 may become unplugged and will require reinstallation In this case you must CAREFULLY pry out on the locking tabs which hold the locking mechanism of the socket and then lift the mechanism about 1 4 in order to be able to re insert the ribbon cable Once the cable is reinserted press the locking mechanism back into place Slide the entire radio forward such that the front of the radio extends off the front edge of the work surface allowing the front panel to rotate from its normal vertical position to a horizontal position If necessary take steps to support the front panel at an angle no greater than 90 to the vertical QSK Waveform Mod PC Board Mounting Detail Prepare a 6 length of 5 conductor i s cable to attach to the 5 pin connector on the PC board Note that the wires for the GND QSK and Key Out lines will be connected to the BACK side of the TS 950SD internal Keyer PC board while the V and the Key In pins of the 5 pin connector must be connected to other off board devices As such the V and AUX Key In wires shoul
22. Remove the RF board shield plate 4 screws Remove the 3 remaining screws from the RF board Remove the black screw that secures the DRIVE OUT RX ANT IN jack to the back panel Disconnect the right hand coax cables from the RF board and unplug connector 2 Slide the RF board forward and then rotate it towards the front of the transceiver to expose the foil side of the board Locate chip resistor R135 as shown in figure 1 Replace R135 with a 2 2 Kohm chip resistor Assemble the transceiver by reversing steps 8 RF BOARD Al FOIL SIDE VIEW E ieo o F mo r i d KI eyg DOOS anne Di y AN a E JGD D00 6 scene ESIA 7 FISSURE This modification is covered under the 1 year warranty Time required to perform the modification is 1 hour or less TS 950 SD Receiver noise Trio Kenwood Communication inc Service Bulletin no 971 29 5 1990 About mV noise is present at the speaker or headphone jack in the receive mode with the AF GAIN control set to minimum If the transceiver is in the CW mode a faint tone might also be heard through the headphones sidetone leakage The following modification will reduce the level of the noise and the tone http www kb2 jj com data kenwood ts 950 htm 9 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Required parts 2SD1257K S Disconnect the power cord and antenna Remove the top and bottom covers 18 screws Locate the RF unit on
23. Unit X49 3050 00 cist WOT asy change ta t Gaal Bi 4 7uF 25v VISE id Figure 1 PC Board View Component Side CNi2 Service Manual w CAD ae le CS is not seown in the a So 2 A ore sig nul ti Hote Fin labels for connector CHIO are Incorrect in the Service Manual Correct labeling is shown above Figure 2 This modification may be covered under warranty Time required for this modification is 1 hour or less TS 950SDX No beep in headphones enwood Communication inc Service Bulletin no 999 4 August 1992 Several owners of the TS 950SDX have reported the absence of an audio confirmation tone when using monaural headphones The tone is present when listening with stereo headphones but only from the right hand speaker element Cause In this design the SUB AF PA circuit supplies audio when using a monaural headphone and the MAIN AF PA supplies audio to the right speaker of a stereo headphone The audio confirmation tone is not applied to both the SUB AP PA and the MAIN AF PA To simplify circuit design the tone is only outed to the MAIN AF PA Unfortunately this left monaural users without a confirmation tone and stereo headphone users with a confirmation tone only in the right side of the headphones Correct action The following modification permits the user to hear the audio confirmation tone from both sides of a stereo headphone and from a monaural headphone
24. Warning This radio uses micro sized surface mount component and or multi layer circuit boards If you are not familiar with the techniques for service of this type of equipment do not attempt this modification yourself You will invalidate your warranty if you attempt to modify the equipment and damage the radio If you are at all in doubt about your qualification to perform this modification you should seek qualified assistance http www kb2 jj com data kenwood ts 950 htm 17 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Required parts R138 100 Kohm radial lead 4 watt resistor RD14BB2C104J Procedure Unplug the DSP Unit from the rear of the transceiver Remove the top and bottom covers 18 screws Remove one screw from each side of the front panel and tilt the front panel forward Add R138 from the wiper arm of VR1 to the negative side of C39 as shown in the accompanying diagram Reverse steps 1 3 to reassemble R120 OOK ohm ee Use inguiating fae eee aie tubing ae showr C6 CS to prevent shorts T Control Unit X53 3380 00 Foil Side View This modification may be covered under warranty Time required for this modification is hour or less TS 950SDX Distorted DRU 2 TX audio Communication inc Service Bulletin no 1001 4 November 1992 We have received several reports of minor distortion of the DRU 2 transmitted audio when used with the TS 950SDX Recordings made f
25. art No New PartNo Circuit Description 1 ROM 27C512BJDUF 27C512BJDUG_ IC 19 or 1 ROM 27C512RJIDVF 27C512BJDUG _ IC 19 1 Instruction manual B62 0229 30 B62 0229 40 Time required for this modification is 30 minutes or less TS 950SDX No VFO B after split Kenwood Communication inc Service Bulletin no 1045 28 March 1994 Symptom Using the following key sequence will result in a failure to receive on VFO B Select different frequencies for VFO A and B Example 14 019 for VFO A and 14 018 for VFO B Mode SSB 2 7 KHz FILTER for 455 KHz and 8 83 MHz Select VFO A to RX and VFO B to TX The press the TF W key Press the ENT key and select a frequency in the 7 MHz band For example 7 018 MHz for VFO A and 7 019 for VFO B Press the ENT key and reselect the 14 MHz band Change VFO B from TX to RX The FILTER display for 8 83 dissapears and reception is disabled on VFO B Countermeasure Press the 8 83 MHz FILTER select key one time or replace the ROM chip Parts required Qty Description Old part No New Part No Circuit Description 1 ROM 27C512BJDUG 27C512BJDUJ IC 19 or 1 ROM 27C512BJDVG 27C512RJDVJ IC 19 http www kb21jj com data kenwood ts 950 htm 30 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Time required for this modification is 30 minutes or less TS 950SDX Carrier point adjustment Kenwood Communication inc Service Bulletin no 1047 28 March 1994 Symptom The
26. b Wolbert KM http www kb2 jj com data kenwood ts 950 htm 43 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals 5 to 14 S68 TS 950 motel V n 1 5k T 0 1uF 1N400x 3 Key Output M D 12 Key Input E z B i as VN2222 2N7000 or equiv 2 E J N Channel MOSFET Cy 00luF min IHA j a IC 40018 Quad NOR Gate CMOS ask 4 10 onorr J gt 001 all 100k Figure 2 QSK Timing Compensation Circuit mounted inside the rig Circuit Copyright 1996 1990 Bob Wolbert KGXX Capacitors Connector s amp Notes TS 950 users note You must connect to a 15VDC supply line rather than to a 5VDC line Otherwise the VOX T R line may trigger falsely This mod must be 001 uF monolithic Mouser 21 RX510 used with an AUX Key input see http www k6xx com radio auxkeyin pdf 02uF monolithic Mouser 21 XR420 0 1 uF monolithic Mouser 21 XR310 Finally this mod will NOT function in the TS950 series unless a 1 4 stereo phone plug empty or otherwise is installed in the KEY jack an the back panel of the radio Optional 5 Pin 025 Rt Angle PC Mtg Shrouded male Header connector Mouser 571 1033613 mating plug is with Mouser 571 1022413 this mating plug requires five 571 875236 female receptacles You may find it helpful to have a couple single pin connectors for the DC and the KEY IN lines as well Mouser 571 7874992 single pin housings with 571 875236 receptacl
27. background audio tone is different between the LSB and the USB mode when no signal is present i e the carrier point is incorrect Occasionally this tone is still different after adjustment per the service manual specifically Item 9 on page 196 Countermeasure Change the adjustment procedure for Item 9 as follows Test Equipment Two RF signal generators with good frequency accuracy A two signal combiner An oscilloscope Preparation Adjust the two signal generators for equal output levels Connect the test equipment as shown in the accompanying diagram Set the frequency of SSG1 to 1 850 2 MHz Set the frequency of SSG2 to 1 852 8 MHz Fine tune the output levels of the two SSG s for a good two tone output on the oscilloscope Figure 3 Adjustment Procedure Connect the transceiver and the test equipment as shown in figure 2 Select the adjustment Mode on the transceiver by pressing and holding the 3 and 9 keys on the keypad while the POWER is turned on Set the output of the two signal generators for a 73 dBm level Set the SSB SLOPE TUNE control to the NORMAL position Set the AGC to AUTO Select MENU 00 using the M CH VFO knob Select USB mode Press the 8 83 MHz filter key until there is no indicator illuminated no filter Press the 455 KHz filter key until 2 7 K appears in the display Set the frequency to the transceiver to 1 850 0 MHz Adjust the TX VFO SUB encoder control until the waveforms displayed
28. d Figure 2 Install and solder into place a 4 pF trimmer capacitor across L36 Figure 3 Install a 2 2 uH coil and 40 pF trimmer capacitor in series from the output of L36 to ground The can of L31 can be used for ground Figure 3 Alignment Connect the TS 950S SD to a power meter and 50 ohm load If you are working on the TS 950S digital connect the DSP cables on the bottom cover to the back panel In the CW mode adjust the front panel power control for 150 Watt while the ALC level is just at the starting point on the meter This will create the highest image level condition Using a monitor receiver with narrow filters installed and AGC set to off tune the receiver to the image frequency Alternately adjust the two trimmer capacitors until the image cannot be heard This procedure may need to be repeated several times Push the wire harness around the I F board toward the chassis of the transceiver Assemble the transceiver http www kb2 jj com data kenwood ts 950 htm 11 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals LIS CHI R pma om iy a SS 5 La d 4 z ja Ley aan FIGURE 2 La6 amp 2uH C111 33pF ADD 2 2 uH AOD 4 _ F FIGURE 3 SCHEMATIC This modification may be covered under 1 year warranty Time required to perform this modification is hour or less TS 950S SD 80 meter spurious emission enwood Communication inc Service Bullet
29. d be cut to 3 4 and terminated with single pin receptacles or pins AMP AmpModu 0 25 pins receptacles and housings Mouser 571 1021073 571 875236 and 571 7874992 work well for this task Use a single pin receptacle and housing on the AUX Key In lead and a single pin insulated with heat shrink tubing on the V lead The mating connections will be used on the leads coming from the external sources Note that I added a slightly larger diameter heat shrink tubing cover to provide additional Figure 2 protec tion for the single pin connection allowing the heatshrink tubing to slip over the single pin housing thus protecting the single pin lead when it s not inserted into the mating single pin housing receptacle This added protection can be seen in the photo above connected to the pink wire in the lower left quadrant of the picture See a better example a bit later in this article when the connection of the AUX Key Input is connected to the i http www kb2 jj com data kenwood ts 950 htm 40 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals ACC2 connector Mount the QSK mod PC board to the underside of the top lip of the chassis front as AUX Key In shown in Figure 2 above and in Figure 1 on the first page of this document Lea d Rou ting 7 7 Vg Ba S Bn 1 Ji n To a 26 length of small diameter 22 24 insulated wire attach a single pin and insulate it in the manner
30. described above including the oversized heatshrink cover for the housing into which it will plug Attach this connector to the mating single pin housing receptacle coming from the AUX Key In lead of QSK Mod PC board Carefully run the free end of the 28 length of wire between the back of the front panel and the front of the facing PC boards out the bottom of the TS 950SD Carefully fold up front panel slide it into place and secure it in place with the two TOP screws There is no need to tighten the hinge screws at this time Carefully invert the TS 950 and turn it so the rear of the radio is now facing the front of your work surface Refer to Figure 3 and route the free end of the Key In lead along the side of the chassis to the rear of the chassis As you pass the tie wraps which secure the other wires into bundles take time to pass this Key In lead through the tie wraps as well When the AUX Key In lead has been properly routed lay it just inside the back edge of the chassis measure the length required to attach this lead to pin 2 of the ACC2 connector see Figure 4 SUBTRACT two inches 2 from the measured length and cut off any excess wire length To this end attach a single pin receptacle and slip it into a single pin header Attach a 00luF 50V min cap between pins 2 amp 4 of the ACC2 jack as shown in Figure 4 From the excess wire cut in step 13 measure and cut a 3 length Strip 1 8 of insulation from both ends a
31. e EPROM Carefully remove the IC from the socket Use an IC pull or very gently pry it out by slipping a small flat tool between the IC and the socket Do not use excessive pressure as you can damage the circuit board if you pry too hard Take the new EPROM and carefully install it in the now vacant socket Note that the notch on the end of the EPROM should be down Reverse steps 1 5 to reassemble Make certain you do not pinch any wires when you return the front panel to its vertical position You will need to reset the microprocessor after the radio is reassembled This is done by pressing and holding the A B key while the power is turned on and then release the key TS 950SDX Side view o Remove Loosen F d m l M e e a Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance Time required for this modification is 30 minutes or less TS 950SDX Speech processor Kenwood Communication inc Service Bulletin no 1007 25 January 1993 Symptom Reports of low COMP meter sensitivity or noise on the transmitted audio when using the speech processor is normally a result of misadjustment of the PROC IN control This control is very sensitive and is difficult to adjust properly Parts required 150 ohm
32. e PC board Place a 1 4 stereo plug into the KEY jack not the AUX Key In connection at ACC2 on the rear of the TS 950 You will NOT be able to send CW via the AUX Key In connection unless the regular KEY jack has a plug in it Run the TS 950 output coax run to a dummy load though a monitor scope or attached to an oscilloscope http www kb2 jj com data kenwood ts 950 htm 42 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Connect the output of your EXTERNAL CW keyer to the AUX Key Input at ACC2 pin 2 and ground You may need to use clip leads for this connection until you fabricate a jack to plug into ACC2 pin 2 Turn the TS 950 on and set the POWER control fully CCW Set the VOX PTT switch to VOX and FULL SEMI QSK to SEMI Set the external keyer speed to around 30 WPM and the weighting to 50 Send a string of DITs and slowly increase the POWER output control until an output envelope is shown on the monitor scope While watching the CW waveform on the scope adjust the Horizontal Sweep speed of the scope in order to stop two consecutive DITs on the screen HINT Increase the speed of the Horizontal Sweep to the point that one DIT wraps itself around the trace and you can then superimpose the BREAK of this DIT on top of the MAKE of the same DIT There will a bright line through the trace but you will be able to easily tell if the weighting is correct because a 50 weighting will cause the BREAK to end just as the
33. e through a strong S 9 10dB or more signal The receiver loses all control of the RF GAIN The control becomes virtually useless you either tune off the strong signal or the signal stops at which point the RG GAIN control again becomes usable Immediately switching the AGC back ON will also allow you to regain control of the RF GAIN but if you again return to AGC OFF and the signal is still present control is again lost Although I have not tried it I am told this problem can also occur in other receive modes as well The following document is a re typed version of the Kenwood Mod Any typos have been allowed to remain in the narrative of the document The schematic has been re drawn in order to allow you to follow the mod more easily not because the original drawing was in error but because it was somewhat difficult to follow the black amp white line drawing I have also included several photos of the Signal Unit PC board to assist you in locating the portion of the PC board which will require your attention Note that you will be dealing with SMT type devices which will require a significantly higher degree of care when working with them then would be required if non SMT devices were used This is result of progress in manufacturing You WILL have to use a soldering iron with a very small tip and you may have to use a magnifying lens to assist you in locating and removing the SMT devices not to mention installing the two jumpers requ
34. er 150 watts output the final FET may fail and short from Source to Gate If this occurs the bias resistors used in this circuit may be damaged and cause a large amount of smoke to be emitted from the final compartment Corrective Action Change the carbon type resistor used for R17 and R18 to the fuse type resistors specified below This will prevent an unpleasant odor and smoke from the final compartment Parts required Qty Description New Part No Circuit Description 2 100 ohm 2 watt fuse resistors R92 1310 05 R17 R18 Procedure Remove the old resistors from their locations an the circuit board and install the new resistors directly between the Gate and Source of the final transistors see the illustration below Ser ihe mew RETARD resis ee hetaeen he Gute iiti Sond F af he MRFS fina transisi Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance from your closest Kenwood Service Center Long Beach CA or Virginia Beach VA Time required for this modification is 60 minutes or less Countermeassure against cold solder joint at the resistor block CP1 CP4 in the PLL unit Phenomenon Sub band reception is deteriorate or receiving audio is intermittent distortion Transmission monitoring audio is d
35. es mate with 571 1021073 push in pin or with a single pin from Mouser 517 6111 TN Starting value Cv amp CT must be found by trial and error Start with 001 uF at Cv and increase if non QSK keying needs to be heavier For CT start with 02uF 022uF and about 500k for RT Or use a 1 M pot at RT and adjust it until the proper weighting is achieved Then replace the pot with a fixed resistor of equal value Note that pads are also provided for a permanently mounted trimpot Mouser 72 T7RYB 1 M or 594 75H 1 M if you wish to replace RT with a variable device altogether Wavelonn Mod a Ara oe a oe Rr or YET aee text py FubeSime 1 PAG board eyouts ij 5 GND 1h x 1 r l arara ij TE 4 m VOOC uF ia see iori 100K i YM2222 or ZN7000 Connector N Channel MOSFET see text Foil Side of PC board showing X Ray view of component placement All components mount an the NON FOIL side of board PC board design by Tom Hammond NOSS 03 18 2001 This modification can also be download 2 5 Mb as a PDF file by Tom Hammond N SS http www kb2ljj com data kenwood ts 950 htm 44 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950 SO2 Adjust Dave WONL HCSL leeson earthlink net The TS 950SDs I have use the Kenwood TCXO SO2 They have both drifted off frequency enough to notice so I wanted to reset the master oscillators The frequency adjustment is under the TCXO label under t
36. he N in Kenwood I peeled back the label and the adjustment was simple I tune in WWV at frequency 20 000 MHz mode AM filters 6 kHz marker on You can hear the beat note and adjust for zero beat I assume I m the only one that didn t know about this 73 de Dave W6ONL HC8L Using Subreceiver to Improve TS 950 Noise Blanker Dave Leeson WONL HCSL leeson earthlink net I was searching for a way to blank ac line noise without getting the distortion and intermodulation you get when you use the typical transceiver noise blanker I was researching Collins 316B 2 uses 40 MHz noise receiver and ac line synchronous blankers and was looking at the TS 950 blanker circuit to see how it was implemented when I realized that either the main or sub receiver can trigger the NB diodes for both receivers So this meant I could use the sub receiver to get the noise signal and it could be tuned to a quiet part of the band or even out of band By inspection of the circuit diagrams in the service manual it appears that the noise blanker function can be driven by either the main or sub receiver signal but that in either case the blanking is applied to both paths So one can turn on the sub receiver tune it to a quiet spot in or out of the active band and use the sub receiver blanking control rather than the main blanking control to get impulse blanking without distortion or intermodulation from in band signals To set up NB1 ON Main N
37. he level of residual noise AF VOL at Min on the SUB band is slightly higher than that of the MAIN band This is especially true at audio frequencies of around 50 Hz as viewed on a spectrum analyzer As a result the SUB receiver is more susceptable to motor noise such as might be generated by fans refrigerators etc Countermeasure Replacing the Control unit electrolytic capacitors C33 C34 and C39 with Tantalum capacitors and adding the bypass capacitor to the Switch unit reduces or eliminates this symptom Parts required Qty Description Kenwood Part No Circuit Description 1 0 1 uF 35 V Tantalum capacitor C92 0001 05 C33 1 1 0uF 16 V Tantalum capacitor C92 0004 05 C34 1 10uF 16 V Tantalum capacitor C92 0505 05 C39 1 01 u disc capacitor CK45B1H103Z NA X53 3480 00 4 2 Control Unit Foll Side View Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance from your closest Kenwood Service Center Long Beach CA or Virginia Beach VA Time required for this modification is 60 minutes or less TS 950SD 18 115 MHz spur Kenwood Communication inc Service Bulletin no 1052 28 March 1994 Symptom Transmitting on 18 1145 MHz causes a spur to appear at 18 1150 MHz with the antenna tuner on Corrective Actio
38. ime required for this modification is 30 minutes or less http www kb2 jj com data kenwood ts 950 htm 25 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950 Low power output after temp protection Kenwood Communication inc Service Bulletin no 1019 14 May 1993 Symptom After transmitting for approximately 2 hours at 50 duty with 150 watts output the temperature protection circuit activates reducing the output power to about 50 watts Normally full output power will be restored after the fans have had a chance to cool things down Occasionally the power output will not return to normal even after extended receive operations Cause The temperature sensor is attached to the main transformer and is set to activate at 80 C This setting was selected to reduce power before the internal fuse on the transformer opens Correct action After through testing we have found that the temperature sensor should be set to 90 C to allow proper return to full power transmit This setting will also allow the radio to be used at higher ambient room temperatures without worrying about the power output dropping in the middle of a QSO Parts required Qty Description Kenwood Part No Circuit description 1 90 C Thermal switch 59 1416 05 S1 Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the
39. in no 984 6 2 1991 Some TS 950S SD owners have reported a transmit spurious emission between 3 500 MHz and 3 520 MHz The modification will reduce the spurious emission to 65 dB Required parts 10 pF capacitor CC73FCH1H100J QTY 1 16 pF capacitor CC73FCHIHI60J QTY 1 12 uH coil L40 1201 17 QTY 1 2 6 X 4mm screws N09 0650 05 QTY 4 Disconnect the power cord and antenna Remove the top and bottom covers 18 screws Open the sub chassis to expose the PLL board figures 1 3 To open the sub chassis remove 4 top screws remove 3 back screws and unplug the RX ANT OUT and DRIVE In connectors Replace the four VCO shield plate screws with the type listed above Figure 3 http www kb2 jj com data kenwood ts 950 htm 12 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Close the sub chassis and secure it with the screws removed in step 3 Locate the A F board on the bottom of the transceiver Figure 4 Remove the board s mounting screws and disconnect the necessary connectors to expose the bottom of the board Locate the foil pattern area shown in Figure 5 This area is below IC11 Cut the foil pattern and add the components shown in Figure 6 Assemble the transceiver Remember to plug in the two connectors on the back panel UNPLUG PE mir out BHO OF TVE a Cni cCtOmE FIGURE 1 SHIELo FIGURE 3 FIGURE 5 FIGURE 6 http www kb2 jj com data kenwood ts 950 htm 13 di 46 01 09 2009 0 15 19
40. ired by the mod Fortunately NO additional components are required only a couple lengths of 24 to 30 insulated wire for the jumpers http www kb2 jj com data kenwood ts 950 htm 36 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Good luck Tom Hammond N SS nOss arrl net MODIFICATION NET 28 Nov 2001 MODEL TS 950S amp TS 950SD No RF Gain at AGC OFF and large input CONTENTS REFERENCE Phenomena AGC is turned OFF The RF GAIN is set maximum in the counterclockwise direction SSG is connected to the ANY pin The SSG input is about 10dBu A signal is received on the SSB mode and it is made sure that the S meter s pointer swings about S 3 The RF GAIN control is turned counterclockwise to set the S meter s swing to S 9 The SSG input is changed from 10dBu to 40dBu Then the S meter reading zero and the RF GAIN becomes disabled Cause Insufficient study on switching transistors Q 30 and Q 40 these transistors operate at AGC OFF of AGC amplifier Q 10 in the signal unit Countermeasure The circuit of the AGC amplifier Q 10 is the signal unit X57 3380 00 is modified Chip resistor R 135 it removed Chip resistor R 136 is removed Digital transistor Q 40 DTC124EK is removed Chip diode D25 RKZJ3 6B is changed to chip jumper W8 R92 0679 05 Short jumper W9 R92 1061 05 is added PT R99 fin O10 i Ty SIGNAL UNIT Jumper Added X57 3380 00 one ae Added shorting 15V jum
41. istorted If you find the malfunction at stated above take the following procedure Cause Cold solder joint od resistor block CP1 CP4 in the PLL unit X50 3170 00 In the manufacturing process the temperature in the reflow soldering furnace was lower than specified and the connection was insufficient http www kb2ljj com data kenwood ts 950 htm 35 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Temporary Add more solder to the resistor block CP1 Cp4 at all pins in meassure the PLL unit X50 3170 00 Permanent review the whole temperature control system of the reflow furnace to manufacture the Printed Circuit Board at more adequate temperature PC Board Component side view Add more solder to the resistor block Pi Piiot ell pins Lento ay 00 Kenwood TS 950S amp TS 950SD RF gain mod Kenwood amp NOSS This mod is courtesy of Kenwood The Kenwood TS 950S and TS 950SD HF transceivers are fine radios However many if not all of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF One common scenario goes something like this Tuning around any band in CW mode with the AGC turned OFF and using the RF GAIN to control received audio level RF Gain is set to allow moderately strong signals c S 9 to be received without excessive audio output comfortable listening level Tun
42. ivers when operating at a dial frequency of approximately 14 200 MHz This spur is seen approximately 40 to 50 dB down from the fundamental Cause The output from the mixer IC12 which generates the final PLL loop comparison frequency for the AF unit contains harmonic radiation at approximately 36 to 68 MHz Parts required Qty Description Kenwood Part No Circuit description 1 Broad band transformer L19 0346 05 L15 1 001 uF 50 V capacitor CK45B1H103K C127 Procedure Solder the primary of the transformer to pins 3 and 13 of IC12 You will have to bend the terminals slightly Solder the secondary of the transformer to pin 1 and 14 of IC12 Remove chip capacitor C127 from the foil side of the board Connect pin 14 of IC12 to the ground pattern Add the new C127 from pin 1 of IC12 to L10 as shown in the accompanying illustration Broad Band Transformer L15 7o ee ie Ph SII lal Na Add 001 uF Sov Ceramic Cap ae ee LI U U we hehe B 5 i Tl Ww 15 Remove chip capacitor C127 from foil side of board s Gima Add a short jumper _ ia r between pin 14 and L10 ground AF Unit X49 3020 00 Component Side View Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance T
43. lletin no 991 24 1 1992 The 50 watt power down circuit will begin to operate if the cooling fan on the rear panel fails to operate after 15 minutes of continuous transmission in order to protect the final amplifier circuit Failure of the fan will prevent the power down circuit from returning transmit power to normal levels since the transformer temperature remains high This trouble can sometimes be traced to a pinched burnt wire near resistor R17 of the AVR unit X43 3070 01 Causes If the red wire attached to the connector CN2 of the AVR unit is pinched between the chassis and ground the insulation might be damage and allow this line to be short to the chassis This wire supplies 15 Vdc to the fan motor thru resistor R17 Excessive current is drawn thru R17 under this circumstance approximately 1 5 A rather then the normal 5 A This can cause the resistor to become red hot and damage the surrounding circuit board since R17 is a metal oxide film resistor Corrective action R17 should be replaced with a ceramic resistor if this symptom is encountered Replacing the metal oxide film resistor with a ceramic resistor will prevent damage to the circuit board should the red lead become shorted Parts required 10 ohm 2 watt ceramic resistor R92 1285 05 Peg gt T eee sige be plached is http www kb2 jj com data kenwood ts 950 htm 15 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950SDX Mode switching
44. n Add the low pass filter shown in the accompanying diagram to the input circuit of mixer Q41 on the IF unit X48 3060 00 This filter will increase the attenuation by approximately 20 dB http www kb2 jj com data kenwood ts 950 htm 33 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Parts required Qty Description New Part No Circuit Description 1 220 uH inductor L40 2211 14 NA 1 220 pF chip capacitor CC73FSLIH221J NA i jT meme Tum mem mm eg a ee eee BE BSH 3222S Pett i F bon oE d om mo e om oa ae ee os gy eni a a a ce ee a o eE Ei d d P a E E FIGURE 2 L3G 2 2uH lens Ciil 33p_pF AGO 2 uH AOD 4 pF SCHEMATIC FIGURE 3 Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance from your closest Kenwood Service Center Long Beach CA or Virginia Beach VA Time required for this modification is 60 minutes or less TS 950SDX Change of Gate resistor type http www kb2 jj com data kenwood ts 950 htm 34 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Kenwood Communication inc Service Bulletin no 1053 28 March 1994 Symptom If the final amplifier is operated at excessive transmit levels ov
45. nd tin them On one end install a Figure 4 single pin receptacle and slip it into a single pin housing Solder the other end of this wire to pin 2 of the ACC2 on the back side of the jack To the unterminated end of the AUX Key In lead coming from the Pin GND Back side of AUX Key front panel install a single pin and insulate it with heatshrink tubing AGC2 Connector Line Conn Note that the heatshrink tubing is only shrunk at ONE END the end Figure 4 covering the pin itself is NOT shrunk to allow insertion of the pin into the mating single pin housing Turn the TS 950SD back around so the front panel is facing the front of the work surface and tilt the front panel to the horizontal position Refer to Figure 1 and locate the internal keyer PC board This PC board is not screw mounted It plugs onto two header blocks attached to the PC board in back of it To access the keyer PC board carefully rock it back and forth as you pull it away from the larger PC board The keyer PC board has two 2 multi wire header connectors attached to it Carefully remove both of the multi wire header connectors Turn the keyer PC board so it s back foil side faces you http www kb2ljj com data kenwood ts 950 htm 41 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Refer to Figure 5 At the bottom of the keyer PC board there are six 6 pads each immediately above a matching hole for the header plug
46. nt at the resistor block CP1 CP4 in the PLL unit Kenwood TS 950S amp TS 950SD RF gain mod http www kb21jj com data kenwood ts 950 htm 1 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Implementation of the KOXX QSK Waveform Mod in the TS 950SD TS 950 SO2 Adjust Using Sub receiver to Improve TS 950 Noise Blanker TS 950SD general coverage transmit mod 1 Remove power and ant 2 Remove top and bottom covers 3 Locate the digital unit 4 Cut diode d 17 5 Reassemble radio 6 Reset cpu Kenwood TS 950 Power On Functions Please notice that all functions only work if you switch off radio first Please push the named buttoms to start function when switching on the radio SUB SUB receiver capable of scanning to SUB scan push and hold the SUB key and press than the scan key ENT Set up ch 90 99 as amateur band vfos 160 10 m band possible each memory vfo will accept direct frequency entry like ICOM band stack memory 5 M VFO set up ch 80 89 to accept any memory data RX A Turn ON OFF SUB receiver marker on SM 230 Monitor in 100 kHz 250kHz and 25kHz sweep mode IC COMP stop transmit if Ic exceeds 1 7 A Power output limited to 10 Watt 8 83 RIT Both 8 83 MHz and 455 kHz IF Filters are selectable on transmit Each memory channel is also capable of storing this setting Memory protect Cutting D 129 on control unit protects memory contents from beeing erased rite p
47. per 0 Ohms R92 1061 05 ka ma hme CJ h3 iA D25 R135 R136 amp Q40 Removed X http www kb2ljj com data kenwood ts 950 htm 37 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Foil side view http www kb2 jj com data kenwood ts 950 htm 38 di 46 01 09 2009 0 15 19 Replace 025 with jumper D25 R135 R136 _ amp Q40 Removed Diagram redrawn for clanty by Tom Hammond Wess J8 Navembear 2001 JA Sy a Ee 3 o biased pa PEE or ae ARAA i ar Signal unit pc board X57 3380 00 Bottom OF TS 950SD KB2LJJ Radio Mods Database and Manuals After mod This modification can also be download 820 Kb as a PDF file by Tom Hammond NOSS Implementation of the K6XX QSK Waveform Mod in the TS 950SD Tom Hammond N SS nOss earthlink net by Tom Hammond N SS Bob Wolbert K6XX has come up with a really great modification to improve the CW waveform and character weighting in a number of commercially made Amateur Radio transceivers The original article on the mod and a separate article containing a PC board design with which to implement it are available at http www k6xx com ikanrite html This article describes the specific steps required to implement this mod in the Kenwood TS 950SD and assumes that the PC board design referenced above has been used to produce a PC board and that the PC board has been populated with the required components REA
48. place the screws on the VCO unit shield case with the new low profile screws Time required for this modification is 15 minutes or less http www kb21jj com data kenwood ts 950 htm 23 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950 Noise with Sub Band noise blanker ON Kenwood Communication inc Service Bulletin no 1017 13 May 1993 Symptom Noise is generated when NB1 is switched on for the sub receiver Cause Switching noise from the noise blanker gate enters the AF amplifier via the 15 V line causing the noise Parts required Qty Description Kenwood Part No Circuit description 1 100 uF 16 V electrolytic capacitor CEO4KW1C101M NA 1 120 ohm resistor RDI4BB2B121J NA Procedure Cut the pattern of the 15 V line on the IF unit X48 3060 00 component side near Q34 s emitter and add the 120 ohm resistor as shown in the accompanying diagram Add the electrolytic capacitor as shown in the diagram Quickly solder the negative lead to the metal shield of L28 X48 3060 00 Component Side View Time required for this modification is 15 minutes or less TS 950 14 200 MHz transmit spur http www kb2 jj com data kenwood ts 950 htm 24 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Kenwood Communication inc Service Bulletin no 1018 14 May 1993 Symptom A close in transmit spur might be present on early model TS 950 S serial number 1010xx and below transce
49. re 1 On the IF unit X48 3100 00 Figure 2 Change R195 from 56 ohm to 150 ohm Change R197 from 220 ohm to 150 ohm Change R198 from 220 ohm to 150 ohm Change R204 from 10 Kohm to 4 7 Kohm No additional adjustment or modification will be required http www kb2 jj com data kenwood ts 950 htm 21 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Final Unit X45 3450 00 Component Side View wa7K IF Unit X48 3100 00 Foil Side View Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance Time required for this modification is hour or less TS 950SDX Key click w bug type Keyer Kenwood Communication inc Service Bulletin no 1012 3 May 1993 Symptom A bug type Keyer used at high keying speeds might cause a key click or chattering noise on the transmitted signal When the internal electronic Keyer is used no such chattering noise is encountered Cause The internal chatter absorption filter circuit incorrectly tries to remove noise from the external Keyer Procedure Press the MENU key one time Select MENU no 12 by tuning the M CH knob Press the UP key until OFF appears in the display http www kb2 jj com data kenwood ts 950 htm 22 di 46 01 09 2009 0 15 19 K
50. rom incoming received sources do not appear to be distorted Cause This characteristic is caused by an impedance mismatch between the DRU 2 output and the input of the microphone amplifier circuit in the TS 950SDX The following modification will correct improve this characteristic Procedure On the Microphone Amplifier Unit X59 3710 01 which is part of Switch Unit A A41 3240 00 H 10 The Microphone Amplifier Unit is a small daughter board located on the switch assembly that has the Microphone Gain Power Output Control and the Speech Processor IN OUT controls http www kb2 jj com data kenwood ts 950 htm 18 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Change chip resistor R257 from 4 7 Kohm to 8 2 Kohm RK73FB2A822 J Change chip resistor R262 from 4 7 Kohm to 1 5 Kohm RK73FB2A152J Caution This modification requires soldering equipment rated for CMOS type circuits It also requires familiarity with surface mount soldering techniques If you do not have the proper equipment or knowledge do not attempt this modification yourself Seek qualified assistance t TERT TEPPI Tre ttt RUBER SARGA Golis nai immi eee nna n poma i ee a i baco na n ngo ES a OEE s Change t Change to ange to Lek 8 2K R257 Time required for this modification is 30 minutes or less TS 950SDX w K1EA Ver 8 Program Revised Kenwood Communication inc Service Bulletin no 1003 1 June 1993 We have recei
51. rotated Cut the two foils as shown in figure 2 Assemble the transceiver by reversing steps 1 7 Remember to install the mesh plate resolder the antenna connector and plug in the two connectors on the back panel http www kb21jj com data kenwood ts 950 htm 7 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals REMOVE 4 SCREWS UNPLUG RX ANT OUT AHO DRIVE IN CONNECTORS init HLN i EFA ip W e FIGURE 2 This modification is covered under the 1 year warranty Time required to perform the modification is 1 hour or less TS 950SD Two second TX power delay with MONI on Trio Kenwood Communication inc Service Bulletin no 964 22 1 1990 hen the MONI switch is turned on transmit power may not develop for two seconds after key down During this time the ALC meter will pin and the SWR meter will read high This will more likely develop on 18 MHz and 21 MHz bands The following modification will correct this condition Note This modification has already been performed on model from serial number 0120441 Required parts 2 2 Kohm chip resistor RK73FB2A222J Disconnect the power cord and antenna Remove the top and bottom covers 18 screws http www kb2 jj com data kenwood ts 950 htm 8 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Locate the RF unit on the bottom of the transceiver This is the back left board of the four boards on the bottom of the transceiver
52. rotect Cutting D 18 on Control Unit write protects all memory channels from Hanno DG8JZ Kenwood TS 950 SDX Allows sub rcevr to be on different band than Main receiver Allows sub rcvr to be on different band than Main receiver This is a Power On function mod Start with radio turned off Hold down buttons SUB M S RX SUB while turning on the power ON Now you can listen to 15M on sub revr with Main revr on 20M or any other band or visa versa Both receivers will be in the same mode USB LSB CW etc fey George KSGH TS 950SD Speech processor noise Author Trio Kenwood Communication inc http www kb21jj com data kenwood ts 950 htm 2 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Service Bulletin no 959 12 1 1990 hen the Processor In control is set to some level below 10 dB of compression a crackling noise can be induced on the transmit signal The following modification will reduce the noise After the modification has been performed the noise can only be heard when the Processor In control is set too low to be functional Note This modification has already been performed on models starting with serial number 0120441 Required parts Transistor PNP 2SC2458Y 4 7 ohm 1 6 watt resistor RD14CB2C4R7J 10 ohm chip resistor RK73FB2A100J 39 ohm chip resistor RK73FB2A390J 10 Kohm chip resistor RK73FB2A103J Disconnect the power cord and antenna Remove the top and bottom covers 18
53. shown in figure on the foil side of Control board A 3 Assemble the transceiver by reversing steps 1 7 EPP SS ae ee ee CHB 15 oreie 0s at CH8 3 FULL FIGURE 1 This modification is covered under the 1 year warranty Time required to perform the modification is hour or less TS 950SD RX digital noise http www kb2 jj com data kenwood ts 950 htm 6 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Trio Kenwood Communication inc Service Bulletin no 963 17 1 1990 Some early TS 950SD transceivers may exhibit a low Signal to Noise ratio on ten and fifteen meters In addition rotating the encoder may allow the user to hear a crackling noise in his headphones The following modification will correct this condition Note This modification has already been performed on model from serial number 101xxxx Disconnect the power cord and antenna Remove the top and bottom covers 18 screws Open the sub chassis as shown in figure remove 4 top screws remove 3 back panel screws unplug the RX ANT OUT and DRIVE IN connectors Remove the cover from the sub chassis 12 screws Figure 1 Remove the 9 screws from the Filter board Desolder the antenna connector wires at the antenna connector Do not damage the surge absorber Rotate the Filter unit to expose the foil side of the board Disconnect coax cables as necessary to rotate the board and remove the mesh plate as the board is
54. ved several reports of the transmitter unkeying when using the KIEA Contesting program This symptom only occurs when the TS 950SDX is used with version 8 of the KIEA program Apparently some of the more advanced control features of this new version of the program cause the radio to think the program has unkeying A new EPROM is available that corrects this transmitter drop out Parts required IC 19 Microprocessor 27C512RJDVF QTY 1 Procedure Remove the top and bottom covers of the TS 950SDX Carefully unplug the two DSP units cables from the rear of the transceiver The front panel of the radio is designed to allow it to be tilted forward for ease of service To tilt the front panel forward remove the screw at the top of the brackets that secure the front panel to the chassis Please refer to the Accompanying diagram There is one screw on each side of the front panel Next loosen the remaining screw at the bottom of each bracket http www kb21jj com data kenwood ts 950 htm 19 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals Gently pull the bottom of the front panel forward until it reaches the end of the slot in the bracket and gently pull the top of the front panel down Now look at the circuit board mounted vertically on the main chassis This is the Digital Unit X46 3130 11 Near the center of this board you will find the lithium battery for memory backup and a large IC installed in a socket This is th
55. yourself Seek qualified assistance al 2 l a I RF Unit X44 3100 00 Time required for this modification is 30 minutes or less TS 950 Smoke from antenna tuner unit Kenwood Communication inc Service Bulletin no 1021 14 May 1993 Symptom When tuning into an antenna with high SWR the SWR meter reading becomes unstable and a small amount of smoke is seen coming from the antenna tuner Cause One of the 3 x 4 self tapping screws that is used to secure the AT unit hinge can occasionally damage the insulation on the brown lead wire When the tuner is then load into a high SWR the high reflected voltage causes the lead to head up which further damages the insulation Eventually the insulation breaks down completely and the wire shorts to the screw causing the lead to overheat and smoke to emanate from the area Correct action Cut a 12 cm long piece of the fiberglass insulating sleeve and install it over the brown lead wire to prevent shorting Parts required Qty Description Kenwood Part No Circuit description 12 cm Fiberglass insulating sleeve 212 3502 05 W101 Note The insulating sleeve must be ordered in increments of 1 meter or greater Time required for this modification is 30 minutes or less http www kb2ljj com data kenwood ts 950 htm 27 di 46 01 09 2009 0 15 19 KB2LJJ Radio Mods Database and Manuals TS 950S SDX Transmit spur Kenwood Communication inc Service Bulletin no 1024 27 May
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