New Experimental R820T RTL-SDR Driver that Tunes down to 13 MHz or Lower

Over on the Osmocom mailing list, Oliver Jowett an RTL-SDR experimenter has posted about his new experimental driver for the R820T RTL-SDR which extends the tunable range down to around 13 and up to 1864 MHz (previously 24 – 1766 MHz). Oliver writes

You can get these changes from’ll need to build from source yourself). There should be no application changes needed, just tune as normal. (gqrx needs the “no limits” option turned on) These changes work by limiting the tuner to a range of frequencies that it can reliably tune to, then allowing tuning beyond those bounds by making the 2832’s downconverter do the final bit of tuning. This can add up to 14.4MHz to each end of the range. Also, the tuner is switched to low-side mixing at the top of the range which gives a bit more range there. The practical range is limited by the width of the IF filter and aliasing effects at the extreme edges of the downconverter’s range. I’ve been able to pick up broadcast AM and amateur CW/SSB down to around 15.5MHz without too much trouble. I’d be interested to know how this works for others. Also.. these changes are likely to have broken offset tuning, direct sampling mods, and tuners other than the R820T, as it touches all those areas but I only have an unmodified R820T to test against. If you have different hardware and are willing to spend some time testing then please let me know. I expect that the range of the other tuners can be extended in the same way with not much trouble.

Over on the Reddit RTL-SDR discussion board there has been talk about this patch. Most users are reporting that it works well down to around 15 MHz, but some people are reporting that they have been able to receive signals down to around 4 MHz. Testers also report that this modified driver works much better than the no-hardware direct sampling mod patch released a few months ago. Update: Commenter J.B has been kind enough to upload a ready to go Windows binary for SDR#. Download here Simply copy the files in the zip into the SDR# folder.

Reddit user gat3way was able to take this screenshot showing AM reception at 9.5 MHz
Reddit user gat3way took this screenshot showing AM reception at 9.5 MHz


  1. jean

    Hi all,
    I have try th patch with a noelec metal case sdr bug with rtl chipset can tune down to 1mhz i have tested with my antenna analyser. bud the sensibility become low below 1400 khz.
    I wanna make other test.
    SDr is great

  2. Kenny Murray

    Hello and happy new year to everyone for 2017.

    I had just received my RTLSDR dongle v3 and had ordered it from the rtlblog ebay store. it arrived just after the holidays and i had ordered it just before christmas. a week earlier than i had been expecting.

    Some time ago back about 4 years ago, i had done some expiermentation with some of the sdr dongle and had used a nano 2832 820 dvbt standard dongle.. it did as you would expect.. i had also converted the supplied antenna which had a little mcx connector with a 75/300ohm tv balun by simply using the antenna cable and had also modified the balun so that it had both power passing and power blocking through a cap. worked well for everything. hf preformance was poor but did well for vhf uhf and also scpc satellite using 950-1450mhz and powering up the lnb ect.. needless to say i had tried out a usb dongle as a wide coverage receiver..

    i had moved some time ago and figured after doing some reading. well the new rtlsdr dongles look like they have some improvements. so i decided to pick up one. what i received was the version 3 of the dongle and the little kit that includes the antennas and such. its a pretty good deal. all in one item to play with sdr a little.

    works great for fm vhf uhf and i assume other ranges further up the spectrum… however.. for me and my instance with what is supplied. i was not able to receive intellegable anything below the fm broadcast block. tried several settings. a couple of different pieces of software. a couple of different driver combinations. dll replacements. nothing that could be said for HF reception operation below 30mhz with the supplied telescopic whip.

    to compare something. i do have a icom T90A handheld. with a couple of strong stations that can be received with the stock antenna on HF. the telescopic whip works nice on the handheld radio and does offer improvement over the stock antenna. so we know that there is a fairly strong signal regardless. there was not as much as a beep squiggle or pop on the rtlsdrv3 dongle.. some folks say well try a long piece of wire.. it was not necessary. the stations can be received on a nail so the whip should work as well.. it simply did not within my issue worked as anticipated for what ever reason below 30mhz..

    now having said all of this.. it was absolutely fantastic.. above 30mhz.. fm broadcast block and up.. works well in the avation block. works well on amateur vhf and up further into the public service block. uhf and otherwise..

    i have only had the new dongle about a day. but i have previous expierence with the sdr. i will try some other items. but im fairly sure. its not something im doing incorrectly unless there is a bug in something somewhere.

    it has great reception otherwise. no major complaints of intermod. fm or pager spatter. some slight reception images are present at some frequencies depending what your tuning and where.

    it is understandable that a wire would be necessary for direct reception of hf direct into the chip. but it would have to be a very strong signal. im sure that the signals received should have been strong enough to show something with direct Q and other modified variants. simply nothing..

    having said all of this. out of the package HF reception on a version 3 dongle with what is supplied. it did not work for me. i am a communications operator with about 30+ years. trust me. in my instance. the dongle did not work for reception of HF with a strong signal.

    My advice would be to definately consider an upconverter. i have not tried one. but as for the direct sampling down there on hf with a strong signal with what is supplied. your not going to be happy.. will it work on a long wire. it might or should produce something. i would say its about 30db under of the reception with direct input. basicaly drasticaly attentuiated or non amplified. hence some are saying it will work for hf. it is prehaps a signal over 30db/ which could be achieved with a long piece of wire.. could..

    the dongle is great otherwise. just depends on what your going to use it for and how your going to use it. its properly built. has the right connections and options. if your thinking your going to receive strong shortwave stations on whats supplied such as the included whip. nope. it is not going to happen in that way with direct sampling and Qbranch or drivers or anything else.. a 10$ shortwave radio with a ferrite can do a better job than what is supplied for general BCL and shortwave. on the table no antenna 1200km away with out issue.

    there are a lot of new single chip all in one short wave receivers as hand held or table top radios.. obviously not Sdr and rather inexpensive. yes they preform rather well instead of what your expeecting of a simple dongle with out an upconverter or low noise applifier or band filters. im not trying to slam the dongle. im giving my honest opinion and results with what was supplied from the package and to compare it to two radios. i have had everything under the sun thats been radios over the last 30 years. i have communicated with all regions of the globe.

    the dongle is a great way to introduce radio principles. on its own its not the best product to introduce HF. it can be in one sense with a piece of wire. a little bit of wire. thats all. just a little piece of wire.. really.. it is in one sense.. because then one can or could desire to to add the upconverter and amplifier.. it has a nice waterfall display ect.. a cheap inexpensive single chip battery operated shortwave radio, is something more practical than you would ever imagine. power outages and emergencies the beach and eveything else.

    but we are talking about the dongle right. absolutely. buy one. its a nice package. put up some wire and buy everything else that goes with it. great way to understand spectrum. want a radio. buy a radio. so whats the difference. no computer. bit of a trick to that one.

    what im saying is. if you were to give this to someone as example as a gift or something and expect it to be suitable for instant HF. your also good to give them a battery operated shortwave radio. just remember im saying something important here.. a radio is always a radio.. a computer can be used as a radio..

    try the dongle its nice. try a 10$ single SIS chip am fm shortwave that runs on batteries.

    • Kenny Murray

      after day and night time testing with what was supplied. I was able to receive something on 15.610 // i can confirm that the dongle does infact receive this far down. but does so poorly with what is supplied. yes it would require a long piece of wire. it would work for something. but it would require a very very strong signal. you could also try 18 to 20 turns of wire around a milkcrate. you could also try a bike rim. welding rods. coat hangars. copper pipe and god only knows what else from pizza pans to turkey tins popcans and chickenwire..

      • admin

        Did you enable the Q-branch for direct sampling in the software? With the V3 you shouldn’t use this modified driver, this driver will probably perform very poorly on the V3.

        Just use the original drivers and select the Q-branch.

        • kenny murray

          i tried a couple of different options to just try out everything.

          yes that is correct Qbranch worked best. I had tried both options. what i did to compare was to have a couple of different folder of SDR# with various DLL’s and configurations. i was able to get something to work just not very good preformance. please also understand i have many radios and a lot of expierence with both communications as an amateur for 30 years and also a satcom communications specilaist for Vsat and remote area support.

      • kenny murray

        after trying a end fed wire antenna of about 40 feet from a window on the second floor to the ground with a pop bottle. we all seen this trick done before as example if you ever did a slinky with ah HF rig (-; // anyways the reception of the dongle in this instance was very poor to nil.. nothing is as good as a good antenna, however as we all know even a simple wire antenna should provide some reception and often does to even the most simple of radios. The dongle in direct sampling DOES work.. but its preformance is not really the greatest.. MW BCL nighttime. a little bit of DX.. truth is a 10$ AMFMSW on the table with nothing worked better in preformance with a built in ferrite of 3 inches.. in another example.. was able to receive World harvest radio 5920.. again preformance was quite poor. im assuming that most of the guys that are having most of the luck with direct sampling are those who are hams and prehaps also have decent antennas up in use. random wires do work for SWL. end fed 30 40 feet should be fine in many instances. a radio is nothing with out an antenna. thats true as well. again depends on what your doing and how your doing it and for what purpose. you would require an immense antenna for the dongle to be used with direct sampling or a larger proper constructed one.. depends on what you want to do.. we all know this.. it received a couple of strong MW and SW station.. but also quite a bit poorly.. i can or could do another test with a hundred feet of wire as a simple test. but overall direct sampling did not work all that great.. if your familiar with any aspect of radios. it simply does not preform well in this respect.. having said this.. the same wire.. on a icom T90a everything was overloaded into the front end. same to be said for inexpensive 10$ radio. so its not as much a lack of signal or other items. or also maby too much of everything.. so right off the bat.. its not going to work well as a slinky SWL. i do have other radio for this purpose and was curious of how the dongle would preform. so this i will add. you would either definately want the upconverter or the low noise amplifier or Active antenna. i have to be honest tho.. i have used a lot of different things in a lot of different applications and environments.. its understandable how the dongle works but also understandable how its not a great preformer on a minimal antenna.. radios.. you want folks to have a good expierence or a bad one.. im at this 30+ years.. you can make a radio as a crystal set and or retune some AM radios and add a BFO with a second radio. it would work better than the direct sampling Q line.. dono thats my take on it… everything else tho is absolutely wonderful.. like seriously its a great little wide band receiver. just not on its own with a small antenna. put up a kite and unwind a small transformer winding to tow it up.. how long do you want to make it.. how high do you want to put it.. ever make one and tune it.. trust me.. dongle has bad preformance on HF with direct sampling with a minimal antenna that overloads an icom and at 10$ table top. im sure some folks have fun with it.. im thinking of the little folks here that are buying it and want a good simple way to do Swl. depends on how you want to look at it.. looking at it over all you would definately want the upconverter. the chip works down there but its not preforming to the point that anyone who has a communications background will say its a good way to go and is working absolutely fantastic. upconverting it. yep that could work. it would be more recomended.. you can always put the cart before the horse and make and put up a wicked Endfed L or something 134/150 feet of wire.. then go for the upconverter and say wow. or you can simply use the upconverter and a small antenna and say well that will work for most folks as well.. dongle is great otherwise.

  3. Dave

    Is this meant to work with SDR SPARPER also ? I am unable to select RTL USB, only ExtO_RTL works but FM is awful overloading etc

  4. B. Kenney

    I get “Cannot access RTL device” when I try to run either in I- or Q-Branch of direct sample. What is going on? I tried on SDR# versions 1361 and version 1450 on Windows 7. Normal mode works just fine, but no HF reception. Any help would be greatly appreciated!

      • Bin Kenney

        Oh, really, I didn’t know you were supposed to use it normal mode. Anyway I did try it normal mode using your dongle (V.2) and a generic dongle using the tallest telescopic antenna from you guys. 8im going to find a long wire to throw out the window, or hang it. In normal mode in HF frequencies I just get noise on some SW frequencies. Around 15MHz, I get about 2MHz of high noise. I tried AM mode but about to try LSB and USB. Any other tips?

        • admin

          The 1.5m telescopic antenna probably isn’t going to work on HF (especially with these drivers with poor sensitivity), it’s not big enough. The long wire should work better, and remember that most HF below 14 MHz comes alive only at night, though you might be able to get some broadcast AM in the MW band at all times.

          • Bin Kenney

            I did test this at night though, as I realize the effects of the ionosphere during the night time. Funny, on my handheld portable Shorteave radio the included 20″ telescopic antenna can pick up a few stations at around 7 MHz and WWV at 15 and 20 MHz–all during daytime! Thanks man for the tips!

  5. Puma

    I can get as low as a time station somewhere in the 300khz. I had to add two long wires one going to drain gutter and another wrapping around the backyard about 85ft long. I am goind to try a balum but I get a lot of the AM channels and other stronger signals all the up to 12ghz. At night a lot of signals come in. I am also using a 30db LNA


    Please help me guys !!!

    How to add this modified driver on SkywaveLinux , what are commands line for terminal
    i’m very new on linux, thx

  7. Max

    Absolute trash, at least for me. Image rejection is terrible, there are FM stations everywhere. I heard 89.9MHz at 22 or so MHz…. at least the standard driver just filters out everything below it’s usable frequency. Very surprised that others are getting such good results, got absolutely nothing in the 20m ham band.

  8. Alim

    I want driver for listen HF frequency please help how I get this driver for Hdsdr I have RTL SDR 820T2 dongle

  9. Uncle Undecided

    It kind of works down to ~4MHz, for free I’d say not even bad, but I hope you’re all aware that you can’t get away with installing this modded .DLL and still having the same performance above 30MHz. It’s either HF or V/UHF and you best create a copy of your SDR software and install it there, create a another desktop shortcut (“HDSDR HF”) for the copy and you’re good to go.

    Just saying, because the first thing I saw was the entire 49m-band imaged on 1.09 GHz and strong, fixed (staying put when you tune) AM station images from the FM band upwards. Mine is also getting very noisy above 12MHz. It will never be a DX monster but it”s great as an introduction into HF radio, or for occasional SW BC listening and another episode in the “mind boggling TV sticks” show.

    • Alim

      How I get this driver please helpwant driver for listen HF frequency please help how I get this driver for Hdsdr I have RTL SDR 820T2 dongle


  10. Mike Jensen

    As a HF-centric radio ham I am trying these drivers out. I am using an 80m 1/2 wave dipole, that’s about 20m either side centre-fed.

    I can receive hams on the 80m band (3.5 to 3.9MHz), and the 40m band (7 to 7.4MHz) on single sideband so far.
    I have not been able to receive anything on the 20m band (14 to 14.4MHz) so far for some reason.
    I have not been able to receive CW signals yet but I do hear quite a bit of “ringing” in the audio with this mode.

    I don’t think the receiver sensitivity is that great as the signals are quite low, but I will try and get some data around this.

    • Errol

      I would like to know what or how do I connect it to my FT1000D HF Transmitter witch has a IF Stage output. Can I just take the output from that plug and connect it straight into the HF port of the Tuner? also how do I need to setup the software ???

  11. Kermit

    Just tried the new drivers and it works well with my RTL (820T) dongle, however sensitivity is very poor below 6MHz so an active tunable antenna would be required.
    As for lowest frequency I’ve managed BBC 5 Live at 693 kHz with ease but could not receive other weaker MW stations below this frequency.
    Also could not receive BBC R4 LW 198 kHz despite this being a very strong signal with active antenna so it would appear that only partial coverage of the MW band is possible.
    Frequencies below 13MHz also require specific settings i.e. RF Gain set to 48dB and sample rate 0.900001 MSPS or higher (avoid 0.5 MSPS).
    If you have the newer RTL-SDR / GUSB mixer add-on then set LNA Gain to max but 1 or 2, Mixer Gain to max and adjust VGA Gain accordingly to your requirements.
    Frequencies above 13MHz require occasional adjustments of the gain to avoid noise drowning out the signal.
    Now if only this driver was implemented in HDSDR it would make my day :)

    • Bud

      Made a second folder with these new files. Using a 70 foot wire with a 4:1 UNUN in an Inverted L configuration. I get down to the AM stations and 80 meters LSB very well. No one was on 160 meters at this time. I checked with my FT 450. These new files make a huge difference. Thanks for the advice of resetting the sample rate.

  12. Ronnie

    I was able to receive a NOAA Weather Station on 1650 Khz with my 17 ft 5/8 groundplane antenna. The antenna you have shows how far down the spectrum you can receive, I suppose.

  13. seby

    Attention ! Not working on ASTROMETA DVB-T2 doungle, if u put this o SDRSharp folder, i can’t
    get even FM radios…

  14. Darryl Mann

    Can someone post text install instructions from a Linux Mate 64bit terminal? Do you have to install the driver on the host machine (Linux Mate) I’m running rtl_tcp on a Linux machine and sdr sharp on a Windows 7

  15. Ian

    In my small room in the basement of my house with a little wire strung from one end of my room to the other, I was able to pick up around 5 MHz. I heard Tru News on 5850 kHz and Radio Habana on 6100 kHz. I’m quite surprised to say the least!

  16. Andre

    For me runs super even down to 7 mhz and that with a cheap RTL SDR for 12 euro.
    Only made a copy of SDR# and copy all DLL in to root map of SDR# and start perfect.

    Good Job to the maker now i save 26 euros from the up converter that im not need

  17. lee

    my RTL SDR is all but useless because it is HAMMERED by pager qrm .It just wipes everything out.Same with FM radio qrm.I have tried every possible setting.Even the signals i can rx are very weak with appalling audio.I cannot understand it.I am no dummy when it comes to radio but this is driving me nuts.Don’t know what else to try.

    • joe

      Use the tutorials on this sight to cut a ¼ wave stub for the pager signals and any other strong signals you want to suppress. It is easy and works well.
      \Joe KA9UCN

  18. lee

    this driver did not work for me.dont have a clue why.using windows.put the driver in but everything remained the same…

  19. jskjj

    Binaries worked great on my Windows PC, but can’t get it to work on my Linux server. Compile error after typing MAKE:

    Linking C executable rtl_fm
    /usr/bin/ld: CMakeFiles/rtl_fm.dir/rtl_fm.c.o: undefined reference to
    symbol ‘clock_gettime@@GLIBC_2.4′
    //lib/arm-linux-gnueabihf/ error adding symbols: DSO
    missing from command line
    collect2: ld returned 1 exit status
    src/CMakeFiles/rtl_fm.dir/build.make:88: recipe for target ‘src/rtl_fm’ failed
    make[2]: *** [src/rtl_fm] Error 1
    CMakeFiles/Makefile2:247: recipe for target
    ‘src/CMakeFiles/rtl_fm.dir/all’ failed
    make[1]: *** [src/CMakeFiles/rtl_fm.dir/all] Error 2
    Makefile:113: recipe for target ‘all’ failed
    make: *** [all] Error 2
    [email protected] ~/rtl-sdr/build $

    • jskjj

      This worked for me:

      Open: /src/CMakeLists.txt

      Find: target_link_libraries(rtl_fm m)

      Change to: target_link_libraries(rtl_fm m rt)

      Save file, rerun CMake, Make, etc. (Thanks Oliver!)

  20. mahesh (vu2iia)

    Interesting, with new driver I was able to receive stations above 15Mhz(mostly BC). Antenna I used is a QFH primarily meant for M2. Perhaps a good dipole would definitely improve reception below 15Mhz, even worth trying small hf pre-amp .
    Thanks for new driver.

    • Sean G4UCJ

      With the new R820T ‘V2′, using the driver mentioned above, I can receive CRI, from China, with a great signal on 17490. There are other broadcast sigs around also. Hearing hams on 20m SSB and even some broadcast on the 13MHz band, however there appears to be a large number of spurious signals at these frequencies (even with the gain down) as it is pushing the hardware to do things it was never meant to do. Being able to get the 18 and 21MHz ham bands with the dongle is a rather handy bonus. I know about the limitations of the hardware and, to be honest, I think it is remarkable what has been achieved with these tiny and cheap as chips dongles. For the very cheap price of the hardware, and the enterprising work of very talented software engineers, they have opened up the world of shoestring SDR to the world.

  21. Flavio Tonello Tavares

    Newbie on board.
    Just bought a new one. Took out of the box, and installed the drivers as it is on the site.
    Works as a treat!!!
    But the pacthed one didn´t worked.
    I did´t made any hardware modification on mine.. Should i?
    I manage to scan from 24Mhz to 1GHz. Got the police, radio station, tv sound, talkabouts, ht´s. But nothing in HF.

    • admin

      What’s your antenna? You’ll need a decent HF antenna to receive anything, especially with the poor HF sensitivity with this experimental driver.

  22. Ashok

    Hi all,
    After using almost for 4 months on HF bands, My RTL-SDR showing some problems.
    I use GQRX( git version) on Fedora-20. RTL driver is from
    Problem 1) Suddenly LNA gain between 44.6-48.8 is not working for all the frequency(VHF UHF too).
    Problem 2) Frequency drift on HF band(<30MHz) is quite visible.
    Can any one tell me what exactly is wrong? or my RTL-SDR is nearing end?

    • arp-

      Hello, I’m testing a new experimental driver on Linux (Ubuntu 14.10 x64) / GQRX 2.3.2. The LNC Control has a “short” effect on gain.

  23. Mac

    I tested this new driver yesterday and where able to receive Russian time beacon at 9,996MHz without any problems with MiniWhip connected directly to dongle’s antenna input. At the moment I cannot use LNA4HF as they are in the middle of re-installation to my SDR-RIG, so there are still very interesting things to find out when I can put the new system on again.

  24. Chris

    I can put concerns that this nukes direct sampling to bed, it works fine.

    Now I have DC->13.9M+10M->1.719GHz. Chuffed to bits. :) Yet to test the 10M-24M segment, I will test on my big dipole tonight and magloop when the parts finally arrive.

  25. Robert

    Why are we beating the poor RTL-SDR dongle to death ???????????????
    It’s old technology their is something new in town , the DVB-T2 USB TV Stick HD-901T2 it has three crystals in it . One that run at 16.000 MHz , one at 28.800 MHz , and at 20.500 MHz . The three chips in it are Realtek RTL2832P , Panasonic MN88472 , Rafael Micro R828D . It can pickup from 150 khz to 1.7 Ghz , I believe that is what read . All that is needed is software . I found it at this site .

    • CrysisLTU

      It’s basically the same thing. RTL2832P is the same as 2832U, just has an extra TS interface. Tuner performs about the same, Panasonic chip is a DVB-T demodulator. Tuning range is still the same as RTL2832U dongles.

    • admin

      What CrysisLTU said is right. Also the R8282D is almost the same as the R820T except that it has a wider passband for supporting DVB-T2, which should make no difference for the RTL2832U/P in SDR mode. Not sure where you read 150 kHz? Haven’t heard anything like that, would be interested in the source. Also it’s been reported that the DVB-T2 dongles have more spurs due to the extra crystals and one crystal should be removed to reduce these spurs.

      For reference:
      Reddit Thread about R828D:

      Superkuh on R828D:

      • Robert

        Hi CrysisLTU .
        To start with I would like to thank you for your comments . Their two new sdr dongles that I ran across , one that I talked about and that I did give a frequency from 150 khz to 1.7 Ghz . So you are right the dongle that I talked about doesn’t have any frequency spec given that I know about . Now the other dongle can be found at this web site , and this the frequency is given and it’s from 150 khz to 1.7 Ghz .

      • Robert

        Hi to the admin .
        To start with I would like to thank you for your comments . Their two new sdr dongles that I ran across , one that I talked about and that I did give a frequency from 150 khz to 1.7 Ghz . So you are right the dongle that I talked about doesn’t have any frequency spec given that I know about . Now the other dongle can be found at this web site , and this the frequency is given and it’s from 150 khz to 1.7 Ghz .

        • admin

          Ah the Mirics dongle. It’s been out for a while, but it can be quite hard to find and it’s never anywhere near as cheap as the RTL-SDR. Also it’s reported by the Airspy developer that the R820T/R820T2 is better than the Mirics tuners which seem to overload much easier. I’d argue that if you want a Mirics dongle, it would be best to get the SDRPlay, which uses the Mirics chips. Otherwise for a better upgrade to the RTL-SDR get the Funcube or Airspy.

          • Robert

            Hi to the admin .
            Thank you for the come back . I am going to look into the ideas that you have given me . I am getting very good performance from the R820T dongle ever since I used the mini circuits T16-6T-81 rf transformer , I am getting about 18db higher signal level than the T37-43 toroid with 200 ohm on the secondary . I live in Pensacola Florida and use a MFJ-1020C active antenna , I am able to pick up hams well into Europe and to the west , Hawaii . My antenna is the aluminum flashing on the eves of my house . This gives me a 246 foot horizontal loop antenna . I also have a inverted ( W ) under the roof of my house , they are tided together . It would be nice to know if anybody has found a fr transformer better than I am using .

  26. CrysisLTU

    Wow, this is amazing. With 11m of wire + 9:1 UNUN I’m receiving stations down to ~5 MHz. LNA4HF also helps a big ton. I’ll wait for night time to see if lower frequencies will perform better.
    From 15-16 MHz noise increases, PPM gets unstable, weird… But lower frequencies are fine here!

    Here are some pictures:

  27. Ashok

    The signal in sw band is very feeble. and Only i could receive a chinese station on 17.388Mhz.
    But the image shows nice signals. are you using HF-LNAs?

    Do suggest me.

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