Microwave WebSDR User Guide
Contents
1. FfEfE 81 135 8 255 20140816 07 35 145534 0 G4ADE G England 2FfEfE B1 135 86 255 20140816 07 51 145608 0 GB3SR G England G4TVP 20140816 07 57 145532 0 MOCPG G England G4TVE 20140817 19 20 145558 8 gTwih loud and clear G England modkt 20140817 19 23 145558 8 2e0ltr weak G England modkt 16 The display showing multiple frequency bands is a useful way of seeing what other users are using the SDR for and where any interesting activity is occurring Good examples of this include balloon and satellite tracking when it is possible to See many users on just one or two specific frequencies This WebSDR is currently being used by 6 user s simultaneously compact view wepe Deenen Deenen peen peren Deenen Deen Deenen Deenen peen porters Deenen Deenen Deenen eeen Deenen Deenen Deenen Deenen peen 1 44100 206 4300 144400 144500 44600 44700 44500 44900 145000 145100 145200 45300 45400 145500 45600 5 700 145800 1300 17 The Chatbox facility is a quick way of exchanging messages with other users especially if a special event or rare station is being heard If you wish to use the Chatbox please make sure you have entered your name or callsign at the top of the WEB SDR page so that everyone else knows who they are talking to It s also good just to say hello from time to time especially if new users are logged in 18 Chatbox text entry area Just type your message in here and press enter But please don t leave offensive or insulting2. We still have to calibrate the frequency but may not be able to get it spot on as we are only using a 5 dongle 2021z G8JNJ Dongle has 60 dB dynamic range we have optimised for weak signals so don t beam at us 2023z G8JNJ Now waiting for ISS pass at 20 30 GMT 2039z G8JNJ Excellent visible pass in Southern UK really bright at 20 33 GMT a 2040z m0aeu Just got some photos of the pass I think 2059z m0aeu Photos of the ISS passing over https 18 Aug 0744z G8JNJ ISS Passes UK today at 14 51 16 26 18 03 19 40 21 16 amp 22 55 GMT 0744z G8JNJ Russian spacewalk is planned for today and hand launch of Cubesat 0748z G8JNJ ISS pass at 21 16 from West to SSE with peak at 17 degree elevation in the SW should be visible 0749z G8JNJ More info about Chasqui 1 cubesat at http amsat uk ora 0750z G8JNJ More info about the ISS and amateur radio operation at http chatbox submit 1 8 Statistics Past 10 seconds CPUload 50 0 7 00 users audio 325 5 kb s waterfall 253 7 kb s http 8 0 kb s 19 WebSDR HTMLS5 sound Copyright 2007 2014 P T de Boer pa3fwm websdr org 20 1 User name or Callsign entry When using the WEB SDR please type your name or Callsign in to this box It will identify you on the frequency plan and in the Chat facility if you post a comment 2 Select the waterfall view you require Displaying multiple waterfall views is useful if you want to watch the general activity level on all the ba
3. 70 dE dE dB en Pa po oe 5 O 90 15 The logbook section allows you to make a note of any special or unusual signals you may have heard The logbook can be recalled whenever you next use the WEB SDR along with any other entries that others may have made WebSDR logbook note that entries can be made by anyone so correctness is not guaranteed date UTC freq call comments dacce country heard by 20140727 09 53 145525 0 GBIPF G England PATRG 20140731 17 04 433350 2 m3otr scott ffFfEF 108 254 218 41 20140731 17 19 433078 1 M3OTE IG England aj sug 20140731 17 58 433692 5 B 64 Fantastic achievement GEAFC 20140731 18 35 144800 0 CE3TE CE Chile 2ECCE 163 247 46 197 20140807 14 38 145738 0 mopog Great signal G England FfEff 213 180 200 96 20140807 14 33 145738 0 g4zcu Great signal G England FfFfFE 213 190 200 56 20140807 18 40 144800 0 LUEMAI HOLA LU Argentina lutemal 20140813 11 28 433376 0 ian receiving on 4 frequencies mema 7 20140813 11 30 433376 0 g8 kaw multiple frequencies at once G England moma 20140813 20 17 433378 0 g3olzx same sig 5 frequencies G England mema 7 20140815 16 09 144407 8 gb3vhf b displayed frequency is off by al G England GEHGH 20140815 16 13 144438 0 gb3vhf b should be 144 428 5 for j665b G England GEHGN 20140815 17 51 10368800 0 GE3SEE G Englad 2ECfEE 86 30 216 185 20140815 20 02 144439 0 GB3VHF G England FfFffF 82 68 5 70 20140816 07 35 145534 0 MOVED Some kind of local net G England
4. i 1 i f i I 145955 14296 CW Morse Transmission USB Single Side Band SSB Transmission For CW on off Morse and data transmissions the signal should be placed inside the yellow outlined box For USB voice transmissions the signal will look fairly wide and this should also be positioned within the yellow outlined box You may find that you need to make very small adjustments to the received frequency in order to get the correct pitch of voice before you can understand what is being said When receiving beacon and data signals from orbiting satellites using USB you may need to keep on retuning as the Doppler shift present on received signals can quickly move outside the bandwidth of the receiver 5 Decoding telemetry and other data Some transmissions only carry data signals which may require additional equipment or software to decode Fortunately many of the more common types of data transmission can be decoded by using your PC soundcard and some free software Before you can do this you first need to find a way of getting signals received from the WEB SDR into your soundcard There are three common ways to do this 1 Make a three way audio splitter lead so that the sound card loudspeaker output can be connected to your external loudspeaker and the soundcard line input at the same time 2 Use the mixer option that can be found on some soundcards to feed the soundcard audio output back into the line input 3 Use some virt
5. messages The purpose of this SDR is to encourage casual users and people interested in radio and associated technologies to participate so don t do anything to discourage them 18062 G8JNJ A ISS packet now up on 145834 44 FM 1811z G8JNJ A Very short duration pass that time so that s it for today 18122 G8JNJ A ISS Passes tomorrow 30th August are at 09 11 10 46 18132 GEJNJ A 12 22 13 59 15 36 amp 17 13 GMI UIC Z BST 1 Hour 18142 G8JNJ A Check out the times and status at the ISS Fan club site http www issfanclub com 18152 G8JNJ A Hi to any Balloon Trackers attending EMF this weekend https twitter com emftcam 2322z neaam Good signals were just heard from EO 80 on 145 88MHZ with a beacom 31 Aug 08112 m6maj g8jnj thanks for info re 145 650 20042 ffff 82 1713 217 181 hoi dit is pd5jvd 0062 ffff 82 74 187 0 Hello Jan pdSjvd this is Pa2NB 21392 F6HIJ good reception of AOTS sat 145 935 bpsk telemetry f6htj 22112 KFSOEX Dimitri was here Hi Dimitri chatbox submit 19 The statistics box shows how many people are currently using the SDR and how much CPU and network bandwidth is being consumed in the process 20 This box shows the software version number and author s contact details WebSDR HTMLS sound Copyright 2007 2014 P T de Boer pastwmiiwebsdr ong 3 Frequency bands The hardware we are using for the WEB SDR to receive signals limits the range of frequencies in each band to a ma
6. results This subject will be covered in more detail later in this quide 10 The Waterfall view controls allow you to define the best type of display for the type of use you are making of the WEB SDR The Zoom out Zoom in Max out and Max in buttons allow you to quickly change the range of frequencies you can see in the waterfall display Clicking on Max out will show you the whole of a frequency band and Max in will zoom into frequencies just around the one you are tuned to This is useful if you want to identify very weak signals or wish to set the receiver bandwidth to match that of the transmitted signal The speed size and type of waterfall can also be modified to help spot wanted signals simply by selecting one of the options in the drop down entry boxes Selecting Spectrum in the view box changes the waterfall so that it looks more like a conventional spectrum analyser display with the amplitude of signals being plotted on the vertical axis against frequency on the horizontal axis This can be useful if you wish to compare the relative strength of received signals 144700 1lggboo 144900 145000 145100 145200 145300 145400 The Hide labels tick box simply clears the orange marker tags from the frequency display if they are not required or are cluttering the overall display 11 Signal strength meter This provides a bargraph display of the received signal strength A digital representation of the received signal str
7. 30m AGL 434MHz Helix Dipole at 30m AGL 144Mhz Helix Dipole at 30m AGL More details relating to the helical antennas can be found at http g8jnj webs com currentprojects htm 7 References Useful Web links WEBSDR DC 30MHz http websdr ewi utwente nl 8901 Amateur bandplans http thersgb org services bandplans html rsgb_band_plan_jan_2014 1 htm List of uWave beacons http www microwavers org indexb htm UK repeaters http www ukrepeater net index html AMSAT UK http amsat uk org Amateur sat freqs http www dk3wn info p page_id 29535 On line sat tracker http www n2yo com Funcube Website http funcube org uk ISS Fan Club http www issfanclub com Balloon tracker http spacenear us tracker UK High Altitude Soc http ukhas org uk start UKHAS Google forum https groups google com forum forum ukhas UKHAS IRC Chat http webchat freenode net channels highaltitude Software mostly free Orbitron stat tracker http www stoff pl Fl digi balloon telemetry http ukhas org uk projects dl fldigi SSTV decoder http namsoft ca pages mmsstv php Soundcard Packet Modem https nome comcast net wb20sz site APRS client for windows http aprsisce wikidot com RTL Dongle Install http www rtlsdr org softwarewindows SDR Sharp http sdrsharp com SDR Sharp plugins http sdrsharp com plugins 7 00 RTL820 SDR dongle https www cosycave co uk
8. 33 2m wider CW wide LSB USB AM FM me rn Or tune by clicking dragging scrollwheel on the frequency scale narrower CW narrow LSB nrw USB nrw AM nrw Or use scroll wheel snd dragging on waterfall Memories Or drag the passband edges on the frequency scale Speed slow v store new 8 Size medium v View waterfall v Hide labels Logbook Call of station that you hear 1 5 Comments if any submit Note time frequency your name call and DXCC information are added automatically View the last 20 lines of the logbook or the entire logbook ctrl click for new tab window 90 5 dB peak 89 6 dB mute L squelch BANANA 2 Volume Audio recording start 1 3 Signal strength plot none v 14 Chatbox This chatbox is intended to discuss the operation of the WebSDR 1 7 The operators of this site disclaim any responsibility for text appearing in this chatbox 14502 ITIT YZ 3 YU IBY SOrry NOT registered with the Site yer de GEV 1957z ffff 92 3 90 189 Have noticed that if I beam in the direction of the WebSDR on 2m it de senses by 16dB 400W amp 9 ele horizontal yagi 2003z G4DCV Did a frequency calibration check yesterday using GB3VHF which is GPS locked and runs JT65B 2005z G4DCV If you tune to 144 4285 JT65B should indicate DF 0 I made the WebSDR 9 76kHz out I realsie it has been noted it is about 10kHz out 2009z G4DCV Sorry that s in USB mode I had to tune the WebSDR to 144 438 to get GB3VHF DF 11Hz 2020z G8JNJ
9. SUWS Microwave WebSDR User Guide Index 1 Overview 2 WEB SDR user interface 3 Frequency bands 4 The different types of signals you may hear 5 Decoding telemetry and other received data 6 Technical Data 7 References SUWS Microwave WebSDR User Guide V1 1 M Ehrenfried G8JNJ 08 09 2014 1 Overview The WebSDR is operated by the Southampton University Wireless Society in collaboration with Phil MODNY Martin G8JNJ and Noel G8GTZ The web based receiver covers multiple VHF and UHF amateur radio bands and can be used by anyone anywhere in the world The WEB SDR can be viewed with most popular Web Browsers The earlier versions of software used JAVA which limited the ability to use anything other than a browser with JAVA plugin The most recent version of WEB SDR software also runs HTML5 which means that the SDR can now be used on a variety of additional mobile devices and tablet PC s The receiver site is located near the town of Farnham in the South Eastern part of the United Kingdom at Latitude 51 23 Longitude 0 82 2 WEB SDR user interface The main WEB SDR page is divided into a number of functional areas Your name or callsign G8JNJ 1 view all bands others slow one band blind Allow keyboard 3 4 Waterfall Java HTML5 Sound Java HTML5 Frequency 144800 00 kHz 7 Bandwidth 9 Waterfall view 4 0 Pana TS T T 16 09 kHz 6dB 16 55 kHz 60dB maa baka Band 3cm 437 435 4
10. ength is also shown in dB values just below the bar graph These figures are useful if you wish to make accurate comparisons of received signal strength between different stations or when using different antennas 9 0 dB peak 9 0 db 12 The three buttons below the signal strength display allow users to temporarily Mute turn off the receive audio apply Squelch to mute the audio when no signal is being received or to select Auto notch to remove unwanted whistling carriers or Morse signals when using USB or LSB for reception The overall volume control can be found at the bottom of this section 13 Pressing the Audio Recording Start button will initiate a recording of the signals you are hearing This can be ended by pressing the Stop button and you will then be given the option to download the recording to your own PC The title of the recording indicates the date time mode and frequency that was present when the recording was started This is very useful if you want to record a satellite pass so that you can decode the received data some time later 14 The Signal Strength Plot function is also useful if you wish to see the variation in strength of received signals over a period of time It is possible to select long or short duration plots which can be useful when observing the variation of signals from satellites or propagation beacons Signal strength plot fast vr dB dE p 30 40 dE dE
11. ernational Space Station if it is in range of the UK CUBESAT cf TEE 2 ISS gen gn 145820 145830 145840 145850 145860 Slow Scan Television is also occasionally transmitted from the ISS on 145 800MHz FM It can be decoded with software such as MMSTV http hamsoft ca pages mmsstv php 6 Technical Software Supplied by Pieter Tjerk de Boer PASFWM the author of the WebSDR 3cm RF 10GHZz Slotted Waveguide Antenna Horizontal Omni at 30m AGL Masthead Octagon LNB down converting to 618MHz G8JNJ modified RTL 820T DVB T Dongle on 618 620 MHz 10 368 10 370 GHz Extra Screening 23cm RF 1296MHz ADM Slot Antenna Horizontal Omni at 30m AGL SPF Masthead Pre Amp G8JNJ modified RTL 820T DVB T Dongle on 1295 6 1297 6 MHz Extra Screening and TCXO 70cm RF 434MHz Helix Dipole at 30m AGL HABamp with 20dB LNA and 430 437MHz SAW Filter Notch filter for GB3FN Amateur repeater at 433 375MHz 3 x G8JNJ modified RTL 820T DVB T Dongles on 432 434 434 436 436 438 MHz Extra Screening and TCXO 2m RF 144Mhz Helix Dipole at 30m AGL HABamp with 20dB LNA and 144 146MHz SAW Filter G8JNJ modified RTL 820T DVB T Dongle on 144 146 MHz Extra Screening and TCXO All the dongles mounted inside a screened metal box which provides additional physical protection screening and thermal stability Antennas 10GHz Slotted Waveguide Antenna Horizontal Omni at 30m AGL 1296MHz ADM Slot Antenna Horizontal Omni at
12. es and High Altitude Balloon HAB telemetry which makes use of short range licence free radio devices which also share these frequencies and can be seen operating between 434 0 and 434 8MHz e 433 o 432 MHz 434 MHz Part of the Amateur 70cm Band Amateur radio narrow band modes FM repeaters amp simplex activity and short range licence free radio devices which also share these frequencies and can be seen operating between 433 7 and 434 0MHz Note that the GB3FN Amateur repeater station is based less than a mile away and is a very strong signal when it is transmitting We have added an additional notch filter to reduce the severity of this problem but it still causes occasional interference under certain conditions 70cm SSB CW amp Propagation beacons 432 000 433 000 70cm FM repeater outputs 433 000 433 400 70cm FM Simplex 433 400 434 800 Short range radio devices common frequency Licence free 434 900 High Altitude Balloon tracking telemetry RTTY and SRD s 434 000 434 800 FO 29 JAS 2 linear transponder downlink 435 900 435 800 CubeSat beacons 40 operational 436 800 437 700 DATV 437 000 e 2m o 144 MHz 146 MHz Part of the Amateur 2m Band Amateur radio narrow band modes FM repeaters amp simplex activity Satellites and the International Space Station Note that when the SDR first starts up you will be listening to bursts of Packet Data using the FM reception mode on the default frequency of 144 800MHz 2m SSB am
13. ncy display under the waterfall shows the range of frequencies being received and the yellow marker under the frequency scale shows the current frequency that is being monitored Left clicking and dragging the mouse left or right just below the frequency scale will retune the SDR 144715 drag to tune Left clicking and dragging the mouse left or right on the edges of the yellow tuning marker will change the bandwidth of the receiver RX Bandwidth drag to change filter 7 Band and frequency selection this allows specific bands and frequencies to be chosen for the reception of signals Values can be entered numerically or by clicking on the various arrow head keys buttons The band buttons allow a quick selection of the required frequency range without having to type in frequency values Frequency 144810 03 kHz nl bnn lai bia bn makta Band 3cm 43 0435 O433 2m Or tune by clicking dragging scollwheel on the frequency scale 8 The memory buttons allow you to Recall Erase and Store your own specific frequencies which can be used again the next time you log into the SDR providing that you have entered a name or Callsign in the text entry box at the top of the page 9 Receiver Mode and Bandwidth The WEB SDR is capable of receiving many different types of transmissions which may use various modulation schemes Choosing the correct type of modulation and a suitable reception bandwidth is key to obtaining the best
14. nds but this may slow down the display and limit the number of simultaneous viewers who are able to use the SDR at any time If you intend to monitor just one frequency for a long period of time please consider selecting the Blind option which disables the scrolling waterfall display and maximises the performance of audio streaming 3 Ticking the Allow Keyboard option permits you to use single keystroke commands such as those shown below This may be preferable if you don t wish to use a mouse or touch screen to navigate through the most common command sequences jk gt freq down up shift ctrl alt faster ulcaf USB LSB CW AM FM Zz Z centre zoom waterfall g enter frequency 4 Clicking on the appropriate Radio Button allows the manual selection of JAVA or HTML5 operation of the waterfall display and steamed audio Normally the most suitable selection will be made automatically by your browser but when an Apple tablet is detected a further option for iOS Audio will appear Waterfall O Java HIML5 Sound O Java HIML5 5 The waterfall display shows the reception of active radio signals as a series of scrolling vertical lines It is possible to move the centre of the waterfall without retuning by left clicking and dragging the mouse left or right on the waterfall display Center Waterfall You can zoom into a specific portion of the waterfall by clicking and using the scroll wheel 6 The freque
15. p CW 144 000 144 400 GB3VHF 2m Propagation beacon 144 430 ATV Talkback 144 750 APRS Packet European common frequency 144 800 2m FM simplex calling channel 145 500 2m repeater outputs 145 600 145 7875 International Space Station FM Voice and SSTV 145 800 International Space Station Packet Digipeater 145 825 FunCube 2 linear transponder downlink 145 930 145 950 AO 73 FUNCube 1 linear transponder downlink 145 950 145 970 AO 7 Phase 2B linear transponder downlink 145 975 145 925 3cm Narrowband modes 10368 000 10368 750 3cm Propagation beacons 10368 750 10369 000 GB3SEE visible at all times 10368 850 Further detailed information regarding the Amateur radio allocations in each of the frequency bands can be found at http www thersgb org services bandplans 19 http www thersgb org services bandplans 20 http www thersgb org services bandplans 21 http www thersgb org services bandplans 25 Or alternatively select the appropriate band on this web page http thersgb org services bandplans html rsgb band plan jan 2014 1 htm 4 The different types of signals you may hear There are many different types of signals you will see and hear whilst using the WEB SDR It may take some time before you can identify each type and be able to understand how to extract information from the signal you are receiving But hopefully these notes will help you along the way The best starting point may be to look at any signal you are
16. p to 30 KHz high with temperature which is not bad considering it is unmodified and mounted on the mast You can obtain an accurate frequency calibration from the GB3SEE Amateur radio propagation beacon which is visible at all times on 10368 850 and the GB3CCX and GB3LEX beacons which are audible from time to time especially during periods of Rain Scatter and Tropospheric ducting Signals that are scattered by raindrops have a particularly raspy sound to them and it is often quite difficult to understand or decode signals that are being received in this way 3cm Narrowband modes 10368 000 10368 750 3cm Propagation beacons 10368 750 10369 000 GB3SEE Visible at all times 10368 850 e 23cm o 1296 1297MHz Part of the Amateur 23cm Band Amateur radio propagation beacons and narrow band modes such as SSB amp CW Morse The GB3FN Amateur propagation beacon is very loud at all times and GB3MHL GB3DUN are audible with any improvement in conditions such as aircraft scatter Heathrow lies directly on the path to MHL 23cm Narrowband modes amp beacons 1296 000 1297 000 23cm FM repeaters amp simplex 1297 000 1298 000 e 437 o 436 MHz 438 MHz Part of the Amateur 70cm Band Amateur radio satellites and Digital Television Downlinks from orbiting Amateur radio satellites can be heard throughout this band but they are usually centered on 437 5MHz e 435 o 434 MHz 436 MHz Part of the Amateur 70cm Band Amateur radio satellit
17. receiving in the waterfall display The type of signal can usually be identified by zooming in on the vertical trace so that you can more clearly see the way in which the signal is being modulated in order to convey information If the signal is fairly constant thin line which varies in width with a slightly irregular pattern the chances are it will be a voice transmission using either AM or FM ae a ed I ee Pa a F pi a fi To Lt NR H a 145640 B If you choose either of these modes you will see a yellow outlined shape with sloping edges and a vertical centre line just underneath the frequency display The vertical centre line should be dragged to the centre of the signal you are attempting to receive and each of the sloping edges of the yellow outline should be dragged so that the whole of the received signal is just contained within the area defined by the yellow outline For the best results try to place both sloping edges of the yellow outline to be symmetrical about the vertical centre line By doing this you will have ensured that you are tuned to exactly the centre frequency and have matched the bandwidth to that of the transmitted signal in order to obtain the best possible reception Use the volume control to set the audio level to suit your listening conditions If the audio sounds distorted try selecting a different mode or slightly retune the receiver centre frequency or bandwidth settings Mo
18. st of the time you are likely to hear speech but some frequencies only carry bursts of data which may need a special decoder to recover information from the transmission If the signal looks like a very thin line which breaks up as the signal varies in strength then you may be monitoring a CW Morse Single Sideband Voice USB or LSB or data transmission Many of these signals do not transmit a constant reference carrier signal or in the case of Morse the carrier may be switched on and off to send the message In order to make sense of these signals we have to inject our own reference signal in order to be able to recover any meaningful information This can be done by selecting the Upper USB or Lower LSB Sideband modes on the SDR Most signals in on the VHF and UHF bands require USB but there are very occasional exceptions In order to receive signals using USB you have to set the receive frequency very carefully If you look at the yellow outlined shape with sloping edges and a vertical centre line just underneath the frequency display you will notice that when USB or LSB is selected it has an asymmetrical shape to it The vertical line shows the frequency at which the locally generated reference signal Local Oscillator has been injected and the outlined area to the left for LSB and to the right for USB shows where the received signal has to be positioned in order to be able to recover the information being conveyed by the transmission
19. ual audio software to create new virtual audio ports that you can cross connect and select various sound sources and devices to each other without using external patch leads Examples of such software include Virtual Audio Cable http www tomsguide com us download Virtual Audio Cable 0305 31100 html and Jack Audio connection kit http jackaudio org Once you have managed to get audio from the SDR fed back into your PC you can use free software such as the following to decode the signals you can hear dl fldigi http ukhas org uk projects dl fldigi Can be used to decode telemetry signals from high altitude balloons Morse beacons slow scan television and much more UK High Altitude Balloons 1 a a Ux0 Ux1 Ux2 Balyolo Ux5 1 d i ae YA RE Ba aaa PAA AA AA I 434259 434399 434450 434500 434550 12th March 2014 Note that if you are uploading data from the balloons you are tracking please make sure you set your Latitude to 51 23 and Longitude to 0 82 which is the location of the WEB SDR receiver site For the International Space Station ISS Dire Wolf https home comcast net wb2osz site Is a soundcard AX25 packet modem which can be used in conjunction with APRSISCE 32 http aprsisce wikidot com to decode Amateur AX25 packet data and APRS position reporting information that can be heard on 144 800MHz FM or occasionally on 145 825MHz FM when being broadcast from Amateurs on board the Int
20. ximum tuning range of 2MHZz For this reason we have had to limit or split the frequency coverage of individual bands in order to provide the best coverage of specific frequency ranges or popular allocations Because the SDR receive site is very close to 7 other transmitter masts in the immediate vicinity it occasionally experiences problems with interference from very strong transmissions on frequencies outside of the bands covered by the SDR Although we have made reasonable attempts to minimise this as much as possible it is not possible to completely eradicate unwanted signals Also note that some sections of the Amateur frequency bands covered by this SDR particularly on 70cm are shared with the primary Government users who may be occasionally heard operating on odd spot frequencies The bands we have chosen to receive with the WEB SDR include the following e 3cm 10 368 GHz 10 370 GHz Part of the Amateur 3cm Band Amateur radio propagation beacons and narrow band modes such as SSB amp CW Morse Signals on this band can normally only be heard over distances of a few 10 s of Km However when it is raining or there are other enhancements in radio propagation due to changes in weather conditions it may be possible to hear signals from much further away The receiver uses an Octagon PLL LNB satellite down convertor and has the correct frequency labels on the scale rather than the RTL dongle tuning range The Octagon does drift u
Download Pdf Manuals
Related Search