IC-7410 User Evaluation & Test Report
Contents
1. E LIE EEE LEGI PI 21111 LUE TH 02 PUJ LEN Hime LENE LEUTE RH EEG 1 FREQUENCY OFFSET 1 Hz FROM 14 83 MHz CARRIER MHz 36 Fig 21c Composite noise at 50 1 MHz 100W 18 dB SPOT FRQ 18 8 kHz 48 TTIT Hz 116 58 dBC Hz 1 FREQUENCY OFFSET 1 Hz FROM 56 18 MHz CARRIER MHz ANI 37 22 Spectral display of CW keying sidebands Again the spectrum analyzer is connected to the IC 7410 RF output via a 60 dB high power attenuator The 10 dBm reference level equates to 100W A series of dits is transmitted at the highest keying speed Test Conditions 14 1 MHz CW 100W output to 50Q load Equivalent keying speed 50 wpm KEY SPEED max using internal keyer CW rise time 4 ms default Spectrum analyzer RBW is 10 Hz video averaged sweep time lt 4 sec Figs 22a and 22b show the transmitter output 5 kHz from the carrier Note the comebacks at 4 kHz these increase in amplitude as keying rate is increased and decrease at longer rise time values They are at lt 70 dBc so they should not normally create an on air issue Fig 22a Keying sidebands at 50 wpm 4 ms rise time 14 1 MHz 100W ATTEN 3 18 16dB RL CENTER 14 1666 6MHz SPAN 16 66kHz RBW 16Hz 16Hz SHP 3 78sec 38 Fig 22b Keying sidebands at 50 wpm 8 ms rise time 14 1 MHz 100W2. e mail farson shaw ca http www ab4oj com August 17 2011 Copyright 2011 A Farson VA7OJ AB4OJ All rights reserved Appendix 1 Performance Tests on IC 7410 S N 02001066 As performed in my home RF lab July 11 21 2011 A Receiver Tests 1 MDS Minimum Discernible Signal is a measure of ultimate receiver sensitivity In this test MDS is defined as the RF input power which yields a 3 dB increase in the receiver noise floor as measured at the audio output Test Conditions ATT off NR off NB off Notch off AGC M SHARP 15 kHz roofing filter Levels in dBm Table 2 MDS 14 1 MHz 50 1 MHz Preamp SSB 24 kHz CW 500 Hz SSB 2 4 kHz CW 500 Hz SSB 2 4 kHz CW 500 Hz Off 128 137 127 134 126 131 1 136 142 135 142 134 139 2 139 146 137 143 136 143 la AM Sensitivity Here an AM test signal with 30 modulation at I kHz is applied to the RF input The RF input power which yields 10 dB S N N is recorded Table 3 Test Conditions ATT off NR off NB off Notch off AGC M Wide 9 kHz AM filter 15 kHz roofing filter Levels in dBm Table 3 AM Sensitivity Preamp 0 9 MHz 3 9 MHz 14 1 MHz off 108 109 107 1 115 117 115 2 116 118 116 Note No RF attenuation below 1 6 MHz Notes 1 The IC 7410 does not insert attenuation at f lt 1 6 MHz 2 The high frequency hiss observed when receiving a wea
3. 19 AM Sidebands for 90 Modulation 7418 02001066 Sidebands 25M 14 1 MHz 17 87 2818 DISCRETE SIDEBAND SEARCH RESULTS CARRIER FREQ 14 18 MHz CARRIER POWER 16 8 dBm OFFSET FREQ OFFSET OFFSET dBc dBc 398 kHz 6 7 6 8 1 337 kHz 44 5 52 2 2 996 kHz 32 7 32 7 4 004 kHz 59 5 61 0 5 003 kHz 49 8 49 8 FOUND 5 SETS OF SIDEBANDS 19 AM sidebands and THD with single tone modulation As in Test 18 above the spectrum analyzer is connected to the IC 7410 RF output via a 60 dB high power attenuator On the IC 7410 RF Power is adjusted for 25W resting carrier The line sampler is adjusted to set the carrier at a convenient 0 dBc reference A 1 kHz test tone is applied to the USB port from the tone generator program running on the laptop computer The spectrum analyzer records the carrier and sideband parameters Test Conditions 14100 kHz AM DATA OFF MOD USB USB Level 50 default On computer adjust USB Codec device volume for 7 dBc test tone level 90 modulation Fig 19 shows the carrier and sideband levels Calculated THD 0 2 28 20 Transmitter harmonics amp spectral purity Once again the spectrum analyzer is connected to the IC 7410 RF output via a 60 dB high power attenuator The 10 dBm reference level equates to 100W The spectrum analyzer s harmonic capture utility is started Test Conditions 3 6 14 1 and 50 1 MHz RTTY 100W output to 50Q load Utility start and stop fr
4. ATTEN 18 m j POM NU Metoda SWP 3 84sec 22a CW keying envelope The oscilloscope is terminated in 50Q and connected to the IC 7410 RF output via a 60 dB high power attenuator A series of dits is transmitted from the internal keyer at the highest keying speed 50 wpm in QSK mode F BK Test Conditions 14 1 CW 100W output to 500 load CW rise time 4 ms default v envelope at 50 wpm 4 ms rise time 39 22b CW QSK recovery test This test was devised to address Yahoo Group reports that CW QSK full break in does not work well when using the internal keyer at speeds gt 12 wpm If a string of dits is transmitted at speeds gt 12 wpm the receiver does not recover between dits The 7410 is terminated in a 500 100W load via RF power meter A test signal is injected into the signal path between the radio s antenna port and the power meter via a line sampler a 20 dB attenuator at the sampling port protects the signal generator from reverse power Test signal level is adjusted for S3 S5 at the receiver Test Conditions 14 010 MHz CW 500 Hz IF filter preamp off ATT off NR off NB off F BK on rise time 4 ms KEY SPEED at max CW Pitch at 12 o clock Test signal at 14 0101 MHz Sidetone 600 Hz received tone 500 Hz Starting at minimum KEY SPEED trans
5. Test Conditions 7410 tuned to 9999 6 kHz 3 6 kHz USB NR off NB off Preamp off ATT off AGC F RF input power 57 dBm composite each test signal 63 dBm Baseband spectrum analyzer reference level adjusted to place test signals at 10 dB line Fig 12 illustrates the test signals and 3 order IMD products Fig 12 Baseband spectral display of in band IMD products 1895 8 8 8 1 8 2 8 3 8 4 8 5 8 6 8 7 8 8 38 9 dB 1 1 1 1 U Og 5 0 N 1 1 o 100 110 1 ES a On the X axis 0 0 kHz 9999 6 kHz virtual carrier f is at 0 4 kHz 5 at 0 6 kHz The 3 order IMD products are at 0 2 and 0 8 kHz respectively Test Result In band IMD 10 82 72 dB 18 11 Two Tone 3 Order Dynamic Range DR amp Third Order Intercept The purpose of this test is to determine the range of signals which the receiver can tolerate while essentially generating no spurious responses In this test two signals of equal amplitude P and separated by a known offset Afare injected into the receiver input If the test signal frequencies are f and f the offset Af fo fi and the 3 order intermodulation products appear at 2 f fi and 2 f f The two test signals are combined in a passive hybrid combiner and applied to the receiver input via a step attenuator The receiver is tuned to the upper and lower 34
6. IMD products 2 f f and 2 f fz respectively which appear as a 600 Hz tone in the speaker The per signal input power level P is adjusted to raise the noise floor by 3 dB i e IMD products at MDS The Pi values for the upper and lower products are recorded and averaged Note If the audio output drops by less than 3 dB when one of the test signals is removed the measurement is noise limited indicated by NL in the table DR MDS Calculated IP 1 5 DR3 MDS Test Conditions 14 1 MHz CW mode 500 Hz filter AGC off ATT off NR off NB off CW Pitch 12 o clock DR in dB in dBm NL noise limited Table 14 DR and IP at 14 1 MHz Af in kHz DR in dB IP in dBm E Preamp off Preamp 1 Preamp 2 Roof 15 6 3 15 6 3 15 6 3 DR3 IP3 DR3 P3 DR3 P3 DR3 DR3 DR3 P3 DR3 IP3DR3 P3 DR3 3 79NL 80NL 80NL 81NL 78 26 79 2580NL 5 85 2 88 2 89 1 84 16 87 12 89 9 79 25 85 16 88 11 89 1 91 3 95 8 87 12 92 4 94 1 82 20 90 8 92 5 10 95 8 97 11 98 13 93 3 96 2 97 9 87 13 94 2 94 2 20 99 14 99 14 100 16 98 5 99 6 1001891 7 98 4 99 5 30 98 13 99 14 102 19 99 6 100 8 99 6 97 2 98 4 98 4 50 100 16 100 16 101 17 100 8 100 8 101 9 99 5 99 5 99 5 Reading depressed low level spur at 14 140 MHz 11 Two Tone 2 Order Dynamic Range DR2 amp Second Order
7. Intercept IP2 The purpose of this test is to determine the range of signals far removed from an amateur band which the receiver can tolerate while essentially generating no spurious responses within the amateur band In this test two widely separated signals of equal amplitude P are injected into the receiver input If the signal frequencies are f the 279 order intermodulation product appears at f f2 The test signals are chosen such that f f2 falls within an amateur band 19 The two test signals are combined in a passive hybrid combiner and applied to the receiver input via a step attenuator The receiver is tuned to the IMD product f f which appears as a 600 Hz tone in the speaker The per signal input power level P is adjusted to raise the noise floor by 3 dB i e IMD product at MDS The Pi value is then recorded DR P MDS Calculated IP 2 DR MDS Test Conditions f 6 1 MHz 8 1 MHz CW mode 500 Hz filter AGC off ATT off NR off NB off CW Pitch 12 o clock in dB IP in dBm Table 14 MDS in dBm DR in dB IP in dBm Preamp MDS 14 2 MHz DR IP off 137 7102 67 1 142 103 64 12 Roofing filter bandwidth approximate This is a non invasive test in which the widest available DSP IF filter 10 kHz AM is selected A CW test signal is applied at the S9 level 72 dBm The receiver is then de tuned above and below the cen
8. ce 8 5 1 8 1 5 2 8 2 5 3 8 13 Figure 8 SSB 2 4 kHz 120 dBm RF signal max NR 55 1 5111111114 U 129 T a a 5 eal 8 5 1 8 1 5 2 8 2 5 3 8 x 6 Manual Notch Filter MNF stopband attenuation and bandwidth In this test an RF signal is applied at a level slightly more than 70 dB above MDS The test signal is offset 1 kHz from the receive frequency to produce a test tone The MNF is carefully tuned to null out the tone completely at the receiver audio output The stopband attenuation is equal to the difference between the test signal power and MDS Test Conditions 14 100 MHz USB at 72 dBm S9 2 4 kHz Sharp AGC MID preamp off ATT 0 dB NR off NB off MNF on Twin PBT neutral Increase input level sufficiently to raise baseband level 3 dB above noise floor Results MNF nulls out signal completely Measured MDS was 127 dBm per Test 1 A 57 dBm test signal was applied Thus stopband attenuation 70dB 127 57 The receive frequency is now offset on either side of the null The frequencies at which the audio output rises by 6 dB are noted The 6 dB bandwidth is the difference between these two frequencies Table 10 MNF BW Wide 130 Hz Mid 94 Hz Narrow 67 Hz The figures
9. doubt Menus are selected by pressing the MENU key on the bottom left of the screen this key also serves as an EXIT key Menu selections with default values can be returned to default by pressing and holding their respective softkeys For several menu items the F 3 key serves this purpose even though it is not marked DEF The filter selection and adjustment procedure is similar to that on other Icom DSP radios Press and hold the FILTER key for 1 sec to adjust the filter bandwidth select CW SSB Sharp Soft shape factors and match the desired roofing filter to each IF filter and mode All IF filters are continuously adjustable Being a current IC 7700 owner and former 756Pro series owner I found that the IC 7410 s controls and menus fell readily to hand A user familiar with a radio such as the IC 756Pro3 or IC 746Pro should find the IC 7410 s learning curve minimal The IC 7410 s default settings are very usable allowing the radio to be placed in service with minimal initial set up 3 LCD display screen The 13 cm 5 inch diagonal monochrome LCD screen is 10 cm wide 1 cm wider than the IC 746Pro screen The display is very bright and crisp and presents all radio parameters The display layout is very similar to that of the IC 746Pro The IC 7410 offers a limited non real time spectrum scope very similar to that of the 746Pro The spectrum scope is initiated via menu and displays an approximate qualitative histogram of band occupa
10. operation at 65 70W PEP output The following are the settings I used in the SSB trials Table 1 Transmit Audio Settings PR 781 20m S9 60 WIDE OFF 1 3 HM 36 20m 59 6090 WIDE 64 2 4 PR 781 17m S5 QSB 60 MID 6 dB 1 3 The DSP based noise blanker is superb It does not distort the signal at all and can be left on at all times it is every bit as good as the IC 7700 or IC 7600 blanker It suppressed fast rising noise spikes and almost completely eliminated locally generated electrical noise As discussed in Section 10 above I found the NR very effective on SSB Even at 60 NR did not attenuate highs excessively NR is very effective in conjunction with NB Preamps 1 and 2 10 and 16 dB gain respectively brought weak stations up to very comfortable copy without S N degradation The SSB filters and Twin PBT were excellent as we have come to expect from other Icom DSP radios MN and AN were extremely helpful I was able to notch out single tones with MN also AN reduced the levels of multiple tones suppressing the higher pitched tone and reducing the level of the lower pitched tone by about 20 dB Overall the IC 7410 receiver seemed a little noisier than my IC 7700 in the sense that band noise was more obtrusive NR seemed slightly more effective on the 7700 than on the 7410 Still SSB operation on the 40 20 and 17m bands with a mix of strong and weak signals was
11. to an investigation of this issue A test was performed in which white noise was applied via the USB port and the RF envelope observed on an oscilloscope terminated in 50Q and connected to the IC 9100 RF output via a 50 dB high power attenuator Test Conditions 14100 kHz USB COMP off DATA OFF MOD USB USB MOD Level 50 default Test signal white noise WIDE TBW default value selected Supply voltage 13 8V Set 50W in RTTY mode Select USB then adjust USB Audio Codec device volume on computer for 50 ALC reading At 50W PEP a leading edge overshoot spike was observed about every two seconds even with P set to 50W The spike amplitude was 3 dB 100W These overshoot levels are sufficiently high to fault out or even damage many amplifiers The amplifier s ALC loop if fitted will not suppress the overshoot The ALC overshoot can be reduced to 1 5 dB by careful adjustment of baseband level Mic Gain or USB MOD Level as appropriate and Compression This adjustment requires observation of the RF envelope with an oscilloscope and is quite critical PEP output drops sharply as the overshoot is reduced Fig 15 shows a typical overshoot spike with baseband level set for 50W PEP Fig 15 ALC overshoot 1 vert div 100W PEP 24 18 Transmitter 2 tone IMD test In this test a 2 tone test signal is applied to the USB port from a tone generator program running on a laptop computer A spectrum analyzer is connecte
12. very comfortable and pleasant b CW I also held a 30 minute QSO with a station on 20m CW using a straight key QSK and semi break in There was no evidence of dit clipping With 500 and 250 Hz CW filters Sharp BPF and NR NB on ringing was minimal with Preamp off At 15 wpm I found full break in operation very smooth and pleasant with virtually instantaneous receiver recovery No keying artifacts were audible in the headphones Note See 19 2 below I then set up a 250 Hz filter Soft non BPF with NR on and Preamp off Again there was virtually no audible ringing and the received CW note was very smooth Activating Preamp 1 or 2 raised the noise level causing slight ringing which was more noticeable in the absence of signals c AM In a quick check of AM reception I listened to various MF and HF broadcast stations A local station on 690 kHz and a music broadcast on 6910 kHz sounded good on the IC 7410 s internal speaker but much clearer as one would expect on my external speaker or on the headset The 9 kHz AM filter offered the best frequency response but the 6 kHz setting sounded somewhat smoother and 3 kHz cut the highs excessively The IC 7410 s Twin PBT is fully functional in this mode Mid AGC was best for average to good signal conditions but Fast AGC handled rapid selective fading more effectively NR was quite effective in improving the S N ratio of weak AM signals Vote See 19 3 be
13. 7418 402001066 Harmonics 166W 50 1 MHz 17 87 2818 HARMONIC MEASUREMENT RESULTS FUNDAMENTAL SIGNAL 56 18 MHz 19 3 dBm HARMONIC LEUEL FREQUENCY 2 86 8 x 188 2 MHz 3 77 8 158 3 MHz 4 87 8 288 4 MHz 5 91 3 258 5 MHz 6 183 8 x 308 6 MHz 7 99 8 358 7 MHz 8 184 5 488 8 MHz x MEASURED LEUEL MAY BE NOISE OR LOST SIGNAL TOTAL HARMONIC DISTORTION x lt OF HARMONICS MEASURED gt 33 Fig 21b 16dB 0 0 START 56 6MHz STOP 1 2 SHP 21 21 Transmitted composite noise As before the spectrum analyzer is connected to the IC 7410 RF output via a 60 dB high power attenuator The spectrum analyzer s phase noise utility is started Figs 20a and 20b are the resulting composite noise plots Test Conditions 3 6 14 1 and 50 1 MHz RTTY 100W output to 50Q load Utility minimum maximum offset and spot frequencies configured as shown in Figs 21a 21b and 21c Note The limitation of this measurement method is that the measured noise power is close to the spectrum analyzer s own noise floor Fig 21a Composite noise at 3 6 MHz 100W dB SPOT FR 40 dBc Hz 116 83 dBC Hz AU LLL 1 1111 111 11 1 FREQUENCY OFFSET 1 Hz FROM 3 663 MHz CARRIER MHz 35 Fig 21b Composite noise at 14 1 MHz 100W 18 dB SPOT FRQ 18 8 kHz 48 dBc Hz 19 dBC Hz
14. IC 7410 User Evaluation amp Test Report By Adam Farson VA7OJ AB40J Iss 4 March 25 2012 Added reference to firmware upgradeability Introduction This report describes the evaluation of IC 7410 S N 02001066 from a user perspective Appendix I presents results of an RF lab test suite performed on the radio I was able to spend a number of days with the IC 7410 in my ham shack and thus had the opportunity to exercise the radio s principal features and evaluate its on air behavior 1 Physical feel of the IC 7410 Owners of current Icom IF DSP transceivers should find the IC 7410 very familiar and will immediately feel comfortable with it The front panel layout is quite similar to that of the IC 746Pro and IC 7400 except that the larger LCD display is immediately noticeable The learning curve will be minimal for IC 7600 IC 7700 or IC 7800 owners The main tuning knob has a knurled Neoprene ring similar to that of the IC 7600 it turns very smoothly without side play As in the IC 7600 the major rotary controls are arranged in two vertical rows on either side of the screen and keypad The concentric MIC GAIN RF POWER controls are in the left hand row The large monochrome LCD screen displays a very clear crisp image with excellent contrast and a paper white backlight The IC 7410 is solidly constructed and superbly finished It conveys a tight smooth and precise overall feel as did its predecessors The sheet steel case
15. and measured MDS The test is run with preamp off The higher the value the better Test Conditions SSB mode 2 4 kHz filter preamp off ATT off NR off NB off negative offset Reciprocal mixing in dB input power MDS both in dBm Table 5 Reciprocal Mixing Noise Offset kHz 3 6 MHz LSB 14 1 MHz USB 50 1 MHz USB 15 16 3 1516 3 15 6 3 Roof Fitr 3 IF filter shape factor 6 60 dB This is the ratio of the 60 dB bandwidth to the 6 dB bandwidth which is a figure of merit for the filter s adjacent channel s rejection The lower the shape factor the tighter the filter In this test an approximate method is used An RF test signal is applied at a power level approx 60 dB above the level where the S meter just drops from S1 to SO The bandwidths at 6 and 60 dB relative to the input power are determined by tuning the signal generator across the passband and observing the S meter Reciprocal mixing noise limits the level range to 60 dB or less Test Conditions 10 000 MHz SSB CW modes preamp off AGC MID ATT off NR off NB off Table 6 IF Filter Shape Factors 2 4kHz SSB 1 42 1 57 500 Hz CW 1 40 1 59 250 Hz CW 1 46 2 25 4 AGC threshold amp SSB filter roll off An RF test signal is applied at a level 6 dB below AGC threshold with AGC off The signal is offset 1 kHz from the receive frequency to produce a test tone While tuning the s
16. assband curves for various filter configurations 10 Fig 1 2 4 kHz SSB filter Sharp Fig 2 2 4 kHz SSB filter Soft Figure 3 500 Hz CW filter Sharp BPF 11 Fig 4 500 Hz CW filter Sharp non BPF Figure 5 500 Hz CW filter Soft Fig 6 250 Hz CW filter Sharp 5 NR noise reduction measured as SINAD This test is intended to measure noise reduction on SSB signals close to the noise level The test signal is offset 1 kHz from the receive frequency to produce a test tone and RF input power is adjusted for a 6 dB SINAD reading 120 dBm NR is then turned on and SINAD read at 30 50 and 60 max NR settings Test Conditions 10 000 MHz LSB 2 4 kHz Sharp AGC MID preamp off ATT off NR off NB off Twin PBT neutral Table 9 NR SINAD SINAD dB 0 6 25 8 40 11 50 13 99 16 60 15 This shows S N improvement of 10 dB with NR at maximum for an SSB signal roughly 5 dB above noise level This is an approximate measurement as the amount of noise reduction is dependent on the original signal to noise ratio Figures 7 and 8 are spectrograms of a single tone RF signal at 120 dBm with NR off and at maximum respectively Figure 7 SSB 2 4 kHz 120 dBm RF signal NR off 1 5 2 1 EN poj il e
17. band amplitude at 14099 kHz Result Carrier and opposite sideband both lt 80 dBc 40 23b SSB transmit audio frequency response via USB port In this test a white noise baseband is applied to the USB port from a tone generator program running on a laptop computer The spectrum analyzer is connected to the IC 7410 RF output via a 60 dB high power attenuator The 10 dBm reference level equates to 100W Test Conditions 14100 kHz USB DATA OFF MOD USB USB Level 50 default Test signal white noise WIDE MID and NAR TBW are at default values On computer adjust USB Audio Codec device volume for 45 ALC reading Using Marker on spectrum analyzer measure frequency and relative amplitude at lower passband edge Move marker down 6 dB and record frequency Move marker down a further 14 dB and record frequency again Repeat procedure for upper passband edge The test data are shown in Table 20a Table 20a Measured SSB TX lower and upper cutoff frequencies via USB input TBW 2 2 6 dB 20 dB 6 dB 20 dB NAR 380 300 1980 2133 MID 227 133 2426 2587 WIDE 107 93 2860 2954 23c SSB transmit audio frequency response via MIC socket To address a user enquiry concerning MIC socket frequency response a swept measurement was performed manually with DATA OFF MOD MIC TBW WIDE and a 3 mV rms test tone level Fig 24 shows that the MIC input is essentiall
18. below depict the Manual Notch Filter stopband for Wide Mid and Narrow settings Due to the limited dynamic range of the measurement method the accuracy of the amplitude scale is limited 14 Fig 9 Manual Notch Filter WIDE Fig 10 Manual Notch Filter MID 15 Fig 11 Manual Notch Filter NAR 1 J Tm 130 E EE SO E Lee em cm E pem eue ueram Ee Le pn pt 60 0 8 5 1 8 1 5 2 8 2 5 3 8 3 5 7 AGC impulse response The purpose of this test is to determine the IC 7410 s AGC response in the presence of fast rising impulsive RF events Pulse trains with short rise times are applied to the receiver input Test Conditions 10 000 MHz LSB 2 4 kHz SSB filter Sharp NR off NB off on Preamp off 2 AGC Fast with decay time set to 0 1 sec Test with pulse trains Here the pulse generator is coupled to the IC 7410 RF input via the pick off port of a line sampler The sampler s main port is terminated in 500 The IC 7410 is tuned to 10 MHz as the RF spectral distribution of the test pulse train has a strong peak in that band AGC Fast 0 1 sec and Preamp 2 are selected The pulse rise time to 70 of peak amplitude is 10 nS Three pulse durations are used 30 50 and 100 nS In all cases pulse period is 600 mS Pulse amplitude is 16V e m f The AGC recovers completely there is no evidence of clamp
19. d diagrammatic bandwidth displays and a BPF Indicator icon facilitate use of this feature Examples of BPF and non BPF filter passbands are illustrated in Figs 3 amp 4 Pages 11 12 8 Notch Filters The tunable manual notch filter MN is inside the AGC loop and is extremely effective The MN has 3 width settings WIDE MID and NAR its stopband attenuation is at least 70 dB The manual notch suppresses an interfering carrier before it can stimulate AGC action it thus prevents swamping The auto notch filter AN is post AGC It suppresses single and multiple tones but strong undesired signals can still cause AGC action and swamp the receiver MN and AN are mutually exclusive and ANF is inoperative in CW mode The NOTCH key toggles OFF AN MN When MN is selected a pop up field is displayed at the bottom of the screen allowing selection of WIDE MID or NAR narrow notch by pressing and holding the key Operation of the NOTCH key is identical to that in the IC 7700 or IC 7600 10 NR noise reduction The DSP NR functionality is comparable to that of the IC 7700 and works very well In SSB mode the maximum noise reduction occurs at an NR control setting of 60 As NR level is increased there is a slight loss of highs in the received audio this is as expected The measured SINAD increase in SSB mode was about 10 dB 11 NB noise blanker The IF level DSP based noise blanker is arguably one of the IC 7410
20. d to the IC 7410 RF output via a 60 dB high power attenuator The 10 dBm reference level equates to 100W Test Conditions DC supply 13 8V measured at DC power socket 14100 kHz USB DATA OFF MOD USB USB Level 50 default Test tones 700 and 1700 Hz at equal amplitudes On computer adjust USB Audio Codec device volume for 100W PEP each tone at 6 dBc Figs 16 17 and 18 show the two test tones and the associated IMD products Fig 16 Spectral display of 2 tone IMD at 3 6 MHz 100W PEP ATTEN MKR 16 33dBm RL 18 16dB 3 59838MHz pM a db PU i CENTER 3 5983 MHzZ SPAN 16 66kHz 166Hz UBH 16G6Hz SHP 862ns 25 Fig 17 Spectral display of 2 tone IMD at 14 1 MHz 100W PEP ATTEN MKR 16 17dBm RL 18 14 16676MHz Lat PL Lo 7 ee ee CENTER 14 1667 6MHz SPAN 16 6 6kHz RBW 166Hz 16G6Hz SHP 882ms 26 Fig 18 Spectral display of 2 tone IMD at 50 1 MHz 100W PEP ATTEN MKR 16 67 dBn RL 18 358 16676MHz _ _ _ ee JJ GE LaL TTL Ny _ dP CENTER 50 1007 0MHz SPAN 16 66kHz RBW 166Hz 16G6Hz SHP 882ms IMD Products Rel Level dBc 0 dBc IMD3 3 order _ IMD5 5 IMD7 7 order IMD9 9 21 Fig
21. equencies are configured as shown in Figs 19b 20b and 21b Fig 19a IC 7410 402001066 Harmonics 1888 3 6 MHz 17 87 2818 HARMONIC MEASUREMENT RESULTS FUNDAMENTAL SIGNAL 3 666 MHz 18 8 dBm HARMONIC LEUEL dBc FREQUENCY 2 83 3 7 286 MHz 3 73 7 18 86 MHz 4 87 5 14 46 MHz 5 97 3 18 88 MHz 6 93 8 21 68 MHz 7 86 7 25 28 MHz 8 183 3 28 88 MHz MEASURED LEUEL MAY BE NOISE OR LOST SIGNAL TOTAL HARMONIC DISTORTION e lt OF HARMONICS MEASURED 29 Fig 19b ATTEN 18 111122 WO pd dk 11110101 START 16GkHz STOP 56 16MHz RBW 3 8kHz 1 8kHz SHP 42 0sec 30 Fig 20a IC 7416 02001066 Harmonics 1 14 1 MHz 17 67 2616 HARMONIC MEASUREMENT FUNDAMENTAL SIGNAL HARMONIC LEUEL 73 3 66 7 85 2 88 5 96 8 98 0 105 8 NOU h O NM MEASURED NOISE OR TOTAL HARMONIC DISTORTION dBc LEUEL LOST lt OF HARMONICS MEASURED RESULTS 1418 MHz 10 0 dBm FREQUENCY 28 20 MHz 42 38 MHz 56 48 MHz 78 58 MHz 84 68 MHz 38 78 MHz 112 8 MHz MAY BE SIGNAL 31 Fig 20b ATTEN RL 18 __ ___ ll it fh mmimmmmmmmm WY 2 2 222 2 2 START 1 0MHz STOP 161 6MHz xRBH 2 1 6kHz SHP 8 4 sec Fig 21a
22. g by 1 kHz Measured audio output voltage 3 9V rms Thus audio power output 3 9 8 1 9W in 8Q Spec is 2W 21 B Transmitter Tests 16 CW Power Output In this test the RF power output into a 50Q load is measured at 3 6 14 1 and 50 1 MHz in CW or RTTY mode at a primary DC supply voltage of 13 8V Table 16 CW Power Output RF Power P Meter Power Output W 3 6 Freq MHz 3 6 14 1 50 1 16a Autotuner ATU insertion loss In this test the transmitter is set for 100W 50 dBm output P on various bands On each band the ATU is activated and tuned and the output P2 measured and noted ATU insertion loss P1 Test Conditions RTTY mode 3 6 14 1 and 50 1 MHz successively P 50 dBm power meter and 50Q resistive load connected to ANTI Table 17 ATU Insertion Loss Freq MHz P ATU in dBm P2 ATU out dBm ATU insertion loss dB 3 6 50 0 49 3 0 7 14 1 50 0 49 3 0 7 50 1 50 0 49 4 0 6 16b Autotuner hunting check In this test the ATU is activated and tuned at 100W output on each band in turn On each band a brief SSB transmission is made during which the tester checks aurally for ATU sounds and visually for random SWR flutter above 1 1 Test Conditions 1 RTTY mode midband frequency on each band in turn P 100W RF power meter and 50Q resistive load connected to ANTI 2 Brief
23. high frequency hiss is heard on AM when receiving a weak signal lt 100 dBm The hiss is especially noticeable at less than 30 modulation NR and or a narrower IF filter reduces or eliminates the hiss If the modulation percentage is increased to 80 and or if signal power is 85 dBm or higher the receiver quiets fully See Test 1a AM Sensitivity in Receiver Test section 4 Close in reciprocal mixing noise is a few dB worse than on the IC 7600 This will affect the reception of weak SSB CW signals in the presence of strong adjacent out of band signals See Test 2 Reciprocal Mixing in Receiver Test section 20 Conclusion After several days worth of cockpit time on the IC 7410 I am very favorably impressed by its solid refined construction clear and informative display easy familiarization experience smooth operating feel impressive array of features and excellent on air performance taking into account the concerns listed above This radio offers much of the functionality and performance of the IC 7600 in a 746Pro sized package and in a price class between the IC 7200 and the IC 7600 Icom are once again right on the mark with the straightforward USB computer interface 21 Acknowledgements I would like to thank Ray Novak N9JA at Icom America and Paul Veel VE7PVL and Jim Backeland VE7JMB at Icom Canada for making an IC 7410 and an IC 9100 available to me for testing and evaluation Adam Farson 7
24. ignal generator across the IF passband the frequency and audio level are noted at several points on the filter flank Test Conditions 10 000 MHz LSB 2 4 kHz filter 15 kHz roofing filter preamp off AGC M then off ATT off NR off NB off Input signal level 104 dBm 6 dB below measured 98 dBm AGC threshold 4a AGC threshold With AGC M increase RF input power until baseband level increases lt 1 dB for a 1 dB increase in input level Measured value 98 dBm 4b Roll off With AGC off reduce RF input power to 6 dB below AGC threshold 104 dBm Test data in Table 7 roll off in dB Table 7 IF Filter Roll off Offset Hz Sharp Soft 27 250 4 300 0 3 5 5 400 0 3 4 500 0 3 750 0 1 1 2000 2 1 5 2500 2 5 5 2700 3 7 2800 13 14 4c Typical IF filter passband curves examples illustrated below depict typical filter passbands Due to the limited dynamic range of the measurement method the accuracy of the amplitude scale is limited In this test a flat noise spectrum band limited to 30 MHz from an RF noise source is applied to the antenna input and the filter passband curve is captured by a baseband spectrum analysis program running in a PC connected to the IC 9100 via the USB port Test Conditions Noise loading PSD 142 dBm Hz IC 9100 tuned to 14 100 MHz AGC slow NR NB preamp ATT off Twin PBT neutral Figs 1 6 are the measured p
25. ing Table 11 AGC impulse response Pulse duration ns AGC recovery ms S Pre off S Pre 2 30 100 no clamping S2 S7 50 100 no clamping 2 5 S8 100 100 no clamping S1 S8 16 8 Noise blanker NB impulse response As the IC 7410 s noise blanker is a DSP process upstream of the AGC derivation point the NB should be very effective in suppressing impulsive RF events before they can stimulate the AGC To verify this the NB is turned on during Test 7b above NB Level is adjusted for best suppression of the test pulses At 30 nS pulse duration the S meter deflection is completely suppressed with Preamp off 1 and 2 showing that the impulsive events never reach the AGC derivation point At NB Level 25 Depth 8 Width 85 occasional faint ticks are heard At Width 100 the pulse ticks are almost inaudible with Preamp off with Preamp 2 a very faint chuff sound is heard for each pulse Signals and or band noise would mask these artifacts completely Next NR is activated With NR at 60 and NB on the ticks are completely inaudible As in other Icom IF DSP radios the NB mitigates AGC response to fast rising RF events default value 9 S meter tracking amp AGC threshold This is a quick check of S meter signal level tracking Test Conditions 2 4 kHz USB Preamp off ATT off AGC MID A 14 100 MHz test signal at MDS is applied to the RF input The signal power
26. is increased and the level corresponding to each S meter reading is noted S9 readings are taken with Preamp off Preamp 1 and Preamp 2 in turn Table 12 S Meter Tracking 52 53 54 55 56 57 S8 59 59 10 59 20 59 30 59 40 S9 50 S9 60 50 51 96 94 91 88 86 83 80 11 75 72 62 52 43 34 23 Preamp 1 on 59 79 dBm 2 59 88 dBm Measured AGC threshold preamp OFF 98 dBm from Test 4 9a Attenuator tracking This is a quick verification of attenuator accuracy Table 13 ATT Value ATT Value dB OFF 0 ON 18 17 10 In Band IMD test The purpose of the In Band IMD Test is to measure the intermodulation IMD products present in the audio output of the receiver when two closely spaced signals both falling within the IF passband are applied to the RF input In this test two signals f and f of equal amplitude and separated by 200 Hz offset injected into the receiver input f 10000 0 and f 10000 2 kHz The 3 order IMD products are at 9999 8 and 10000 4 kHz respectively The two test signals are combined in a passive hybrid combiner and applied to the receiver input via a step attenuator A baseband spectrum analyzer here a PC running a FFT spectral analysis program is connected to the IC 7410 s rear panel USB port
27. is finished in an attractive black crinkle coating and fitted with a handle on the left side The case retaining screws are located in recesses in the case covers The front panel is sculpted somewhat like the IC 7700 front panel and has a smooth matte surface The IC 7410 is quite heavy 10 kg 22 Ib It uses the same die cast compartmented chassis as the IC 9100 except that the rear panel holes for the 2m 70 cm and 23 cm antenna sockets are covered by blanking plates The radio is fitted with the new 4 pin DC power socket A USB B socket is provided on the rear panel allowing direct CI V and baseband connectivity to a PC via a standard USB cable Both the case and the rear panel are well ventilated The front case feet are solid and extensible allowing the front of the IC 7410 to be angled upwards 2 Control knob key functions and menus Apart from some differences in placement the IC 7410 s control knobs will be very familiar to users of the IC 7600 and IC 746Pro The menus are somewhat akin to those in the IC 7600 as the IC 7410 s feature set is very similar to that of the 7600 but minus Dual Watch The menu presentation resembles that of the IC 746Pro but the larger number of configurable settings is accommodated by item numbers selected via up down softkeys e g the RTTY KEYER in CW mode and TCON tone controls menus I found the set up process fairly intuitive after consulting the relevant user manual sections in cases of
28. k AM signal lt 100 dBm with the 9 kHz IF filter selected The hiss is especially noticeable at less than 30 modulation or when the received carrier is unmodulated NR and or the 6 or 3 kHz IF filter reduces or eliminates the hiss If the modulation percentage is increased to 80 and or if signal power is 85 dBm or higher the receiver quiets fully 1b 12 dB SINAD FM sensitivity In this test a distortion meter is connected to the external speaker jack and an FM signal modulated by a 1 kHz tone with 3 kHz peak deviation is applied to the RF input The input signal power for 12 dB SINAD is recorded Table 4 Table 4 FM SINAD Sensitivity Preamp 29 5 MHz 52 525 MHz 52 525 MHz Squelch Sens off 118 109 116 1 120 118 126 2 122 120 129 2 Reciprocal Mixing Noise occurs in a superheterodyne receiver when the noise sidebands of the local oscillator LO mix with strong signals close in frequency to the wanted signal producing unwanted noise products at the IF and degrading the receiver sensitivity Reciprocal mixing noise is a measure of LO spectral purity In this test a strong undesired signal is injected into the receiver s RF input at a fixed offset from the operating frequency The RF input power is increased until the receiver noise floor increases by 3 dB as measured at the audio output Reciprocal mixing noise expressed as a figure of merit is the difference between this RF input power
29. low The NR did not distort the recovered audio even at its maximum setting 60 Above 60 the NR control had no further effect Note that the AM bass and treble EQ settings were both 0 dB with HPF off AN was effective in suppressing interfering tones and heterodynes but MN caused some distortion when tuned across the signal The reason for this is that MN suppresses the carrier in a manner similar to selective fading d RTTY I did not operate RTTY during the on air test period but monitored some 20m RTTY signals I found that I was able to tune accurately using the center tuning indicator the RTTY decoder in the lower field of the screen displayed the received text accurately The squelch can be set to mute the audio in the absence of a received signal this is convenient when using the Twin Peak Filter TPF Recsive 17 Test for EMC and Baseband Levels No EMC issues of any sort Lori were observed when using a headset plugged into the IC 7410 s PHONES jack or an external speaker connected to the radio s EXT SP jack Tests were conducted at 1 kW on 40 20 17 15 12 and 10m and at 500W on 6m 2 I measured the RX baseband output levels at the USB port using OROM CBR DM780 and at ACC Pin 12 AF with a true RMS DVM With a 10 000 MHz S9 10 dB test signal offset 1 kHz to yield a 1 kHz test tone DM780 read 61 of full scale and the level at ACC Pin 12 was 219 mV RMS well within the 100 300 mV spec 18 Inte
30. mit a continuous string of dits and increase KEY SPEED until the received tone can no longer be heard in the spaces between dits In the test run performed on July 14 2011 the received tone could just be heard at 12 wpm but was no longer audible above this speed 23 ACC Pin 11 MOD analog baseband input level for 100W output A kHz test tone is injected into ACC Pin 11 and the input voltage required for 100W RF output is noted Test Conditions 14100 kHz USB DATA OFF MOD ACC DATA 1 MOD TBW WIDE default test tone 1 kHz Adjust test tone level for 100W output in USB and USB D1 modes The required input levels were 35 mV rms for USB and 35 mV rms for USB D1 A quick frequency response check was also performed using the spectrum analyzer The test data are shown in Table 20 Table 20 Measured SSB TX lower and upper cutoff frequencies via ACC Pin 11 MOD input TBW Lower Hz Upper Hz 6 dB 28 dB 6 dB 20 dB WIDE 73 60 2956 3100 23a Carrier and opposite sideband suppression A 1 kHz test tone is applied to ACC Pin 1 or via the USB port Carrier and opposite sideband suppression are checked on the spectrum analyzer at 100W RF output Test Conditions 14100 kHz USB DATA OFF MOD ACC DATA 1 MOD ACC TBW WIDE default test tone 1 kHz Adjust test tone level for 100W output in USB mode Read carrier amplitude at 14100 kHz and opposite side
31. n there are selectable Sharp and Soft shape factors for SSB and CW The IC 7410 comes fitted with a 15 kHz MCF roofing filter at the 64 455 MHz 1 IF Easily installable plug in 6 and 3 kHz roofing filter modules are available as optional accessories The filter menu allows association of any one of the 3 roofing filters with each of the 3 IF filter selections The Twin PBT controls and PBT CLR key operate in exactly the same manner as on the IC 756Pro series as does the BPF filter configuration feature for filter bandwidths of 500 Hz or less The TPF menu item in the RTTY menu selects the Twin Peak Filter TPF in RTTY mode No CW APF Audio Peak Filter is provided However the CW RX LPF and HPF are a reasonable alternative to the missing APF their ranges are 100 2000 and 500 2400 Hz respectively The HPF and LPF can be set to bracket the received CW tone in a tight 100 Hz audio bandwidth The F 3 softkey restores these filters to default off 7 BPF vs non BPF filters As in other Icom IF DSP radios the IC 7410 allows the user to select two additional shapes for 500 Hz or narrower filters in addition to SHARP and SOFT These are BPF steeper skirts and non BPF softer skirts To configure a BPF filter select a 500 Hz or narrower CW RTTY or SSB D filter with Twin PBT neutral To set up a non BPF filter select a filter with BW gt 500 Hz and narrow the filter to 500 Hz or less by rotating the Twin PBT controls Numerical an
32. ncy in the lower field of the screen It mutes the receiver during its acquisition cycle Scope span is configurable in the range 0 5 to 25 kHz The Notch MN and FILTER keys and the Twin PBT controls open pop ups in the lower field of the screen These can be used to select notch width and filter PBT bandwidth respectively The CFL display backlight in the test unit was slow starting 15 sec delay when powering up the radio cold after it had been off for a few days at lt 15 C ambient 5 USB interfaces The IC 7410 is equipped with a a rear panel USB B port The radio can be directly connected via the B port to a laptop or other PC via a standard USB A B cable This is without doubt one of the IC 7410 s strongest features The USB port transports not only CI V data but also TX and RX PCM baseband between the IC 7410 and the computer As a result the USB cable is the only radio PC connection required Gone forever is the mess of cables level converters and interface boxes I believe that this feature will be standard on all future Icom HF radios An Icom driver is required in the PC this is downloadable from the Icom Japan World website 6 Filter selections and Twin PBT As do the other Icom DSP transceivers the IC 7410 offers fully configurable RX IF selectivity filters for all modes Three default filter selections are available for each mode with continuously variable bandwidth via the FILTER menu In additio
33. rfacing with Ham Radio Deluxe HRD I installed the Ver 1 1 Icom USB drivers downloadable from the Icom Japan world wide support site and HRD Ver 5 Beta on my laptop and connected the computer to the IC 7410 with a standard USB cable The IC 7410 showed up in the computer as USB Audio Codec Once I had set the levels correctly HRD started working and was displaying PSK31 and RTTY traffic and waterfalls DM780 is a component of HRD 19 Concerns The following issues were observed in the course of lab testing 1 An ALC overshoot of up to 6 dB occurs on SSB but not on any other mode when a white noise baseband is applied to the USB port with USB MOD level at 50 This overshoot can be reduced to 1 5 dB by careful adjustment of baseband level and Compression This adjustment requires observation of the RF envelope with an oscilloscope and is quite critical The overshoot can damage amplifiers driven by the IC 7410 Note This phenomenon was not observed at all on my IC 7700 This issue has been reported on the IC 7410 Yahoo Group See Test 17a ALC Overshoot in Appendix 1B Transmitter Tests 2 CW QSK full break in does not work well when using the internal keyer at speeds gt 12 wpm If a string of dits is transmitted at speeds gt 12 wpm the receiver does not recover between dits This issue has been reported on the IC 7410 Yahoo Group See Test 22b QSK Recovery in Appendix 1B Transmitter Tests 3 A disturbing
34. s increased sufficiently to raise the noise floor by 3 dB Test Conditions fo 15 MHz CW 500 Hz IF filter 15 kHz roofing filter ATT off NR off NB off Preamp off Set main tuning to 15 000 MHz Test signal freq 2 64 455 15 143 91 MHz Measured MDS 135 dBm Test signal power for 3 dB noise floor increase 20 dBm Thus image rejection 20 135 115 dB 14a rejection In this test the IC 7410 is tuned to a mid band frequency fy and a test signal is applied to the antenna port at the 64 455 MHz 1 IF The test signal power is increased sufficiently to raise the noise floor by 3 dB Test Conditions fo 15 MHz CW 500 Hz IF filter 15 kHz roofing filter AGC M ATT off NR off NB off Preamp off Set main tuning to 15 000 MHz Test signal freq 64 455 MHz Measured MDS 135 dBm Test signal power for 3 dB noise floor increase 26 dBm Thus 1 IF rejection 26 135 102 dB 15 Audio THD In this test an audio distortion analyzer is connected to the external speaker output An 8Q resistive load is connected across the analyzer input An S7 to S9 RF test signal is applied to the antenna input and the main tuning is offset by 1 kHz to produce a test tone The audio voltage corresponding to 10 THD is then measured and the audio output power calculated Test Conditions 10 MHz USB 3 kHz IF filter 15 kHz roofing filter AGC F ATT off NR off NB off Preamp off Offset tunin
35. s strongest features I found it to be extremely effective in suppressing fast rising impulsive RF events before they can stimulate AGC action within the DSP algorithm The NB completely blanks noise impulses which would otherwise cause AGC clamping I found its performance comparable to that of the IC 7700 s NB The NB menu threshold depth and width is accessed by pressing and holding the NB key The NB works very effectively in conjunction with NR 12 AGC system The IC 7410 has dual AGC loops The primary loop samples the digitized 36 kHz IF at the ADC output This loop limits the IF signal power applied to the ADC input thereby preventing ADC over ranging even in the presence of extremely strong signals The digital AGC detector for the secondary loop is within the DSP algorithm Level indications from both detectors are processed in the DSP for AGC management This architecture prevents strong adjacent signals from swamping the AGC and allows full exploitation of the ADC s dynamic range The AGC menu is similar to that of the IC 7600 The Slow Mid and Fast AGC settings are customizable via menu for each mode and AGC can be turned OFF via menu 13 Receive and transmit audio menus The IC 7410 TCON Tone Control menu offers the same generous selection of audio configuration parameters as that of the IC 7600 and IC 7700 TBW low and high cutoff frequencies RX and TX Bass Treble EQ RX HPF and LPF transmit compression etc All audio
36. settings are grouped under the M2 TCON softkey F 4 in menu M2 14 Metering As in the IC 746Pro on screen bar graphs replace the traditional moving coil meter Pressing and holding the ANT METER key toggles between ALC and COMP The S meter P and ALC scales are displayed at all times 15 VFO Memory management The IC 7410 offers the same VFO and memory management features as other current Icom HF transceivers VFO memory toggle and transfer memory write clear memo pad Split VFO A B swap and equalize etc 16 Brief on air report Prior to starting the test suite I installed the IC 7410 in my shack and connected it to my solid state I kW amplifier and multi band vertical antenna The interface was straightforward RF drive PTT ALC and carrier request for amplifier auto tuning Once I had set up the ALC for 1 kW output I was 100 QRV a SSB I made several 20m and 17m SSB QSO s with friends who are familiar with my voice and the sound of my signal Distant stations reported that the audio quality of my transmissions was excellent clean and natural when using the Heil PR 781 desk mic plugged into the radio s MIC socket Two stations I worked on 20m SSB assisted me in optimizing transmit audio settings for the PR 781 and HM 36 It was observed that higher COMP settings caused slight distortion on voice peaks when using the HM 36 The radio showed no signs of excessive heating even after a few hours rag chew SSB
37. ter frequency for a 1 S unit 3 dB drop S meter reading and the frequency offsets Af and Af recorded The 3 dB bandwidth 247 This procedure is useful for checking the 6 and 3 kHz roofing filters but not the 15 kHz filter This restriction is imposed by the 10 kHz maximum DSP IF filter bandwidth Test Conditions 10 MHz AM mode 10 kHz IF filter AGC M ATT off NR off NB off Preamp off Table 15 Roofing Filter BW in kHz _Nominal BW Meas 3 dB BW 6 10 3 7 2 10 kHz is the limiting case due to the DSP IF filter bandwidth of 10 kHz It is possible that the actual bandwidth of the 6 kHz roofing filter exceeds 10 kHz 13 AGC action due to signal within roofing filter passband but outside the DSP IF channel The purpose of this test is to determine the input power level at which an unwanted signal falling within the roofing filter window but outside the DSP IF passband starts stimulating the AGC Test Conditions 10 MHz CW 250 Hz IF filter 3 kHz roofing filter AGC M ATT off NR off NB off Preamp off Offset tuning by 500 Hz AGC action S meter indication starts at 25 dBm test signal power due to effect of reciprocal mixing noise When offset is increased to 1 kHz S meter indication starts at 24 dBm 20 14 1 IF image rejection In this test the IC 7410 is tuned to a mid band frequency fo and a test signal is applied at twice the 1 IF The test signal power i
38. voice transmission in SSB mode No audible or visible evidence of ATU hunting was observed on any band 16c SWR scale accuracy The SWR scale is read with 50Q and 100Q resistive loads connected in turn to ANTI To minimize the effect of line lengths on measurement accuracy this test is run at 1 8 MHz The RF POWER setting remains unchanged when switching loads Test Conditions 1 81 MHz RTTY P 10W into 500 load Table 18 SWR Scale Accuracy Nominal Load DC Resistance SWR Reading 500 50 19 1 1 1000 100 90 2 1 Note that with the 100Q load the SWR reading is somewhat dependent on 22 17 SSB Peak Envelope Power PEP Here an oscilloscope is terminated in 50Q and connected to the IC 7410 RF output via a 50 dB high power attenuator At 100W CW the scope vertical gain is adjusted for a peak to peak vertical deflection of 6 divisions Test Conditions USB mode HM 36 mic connected Mic Gain 45 COMP OFF ON TBW MID COMP set at 30 6 dB compression on voice peaks SSB TX Bass Treble set at 0 dB default supply voltage 13 8V Speak loudly into the microphone for full scale ALC reading Figs 13 amp 14 show the envelope for 100W PEP without and with compression respectively Fig 13 100W PEP speech envelope no compression Fig 14 100W PEP speech envelope 6 dB compression 23 17a SSB ALC overshoot Reports of ALC overshoot in the IC 7410 Yahoo Group led
39. y flat in the range 300 Hz 3 kHz Fig 24 IC 7410 MIC Input Response Attenuation dB Frequency Hz Copyright 2011 A Farson VA7OJ AB4OJ All rights reserved August 17 2011 41
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