Using a direct sampling enabled Airspy as a Panadapter for a Yaesu FTDX-5000

Tim Havens is an avid CW operator on the ham bands and primarily uses his Yaesu FTDX-5000 transceiver for this purpose. At the same time he also uses a software defined radio coupled with an upconverter as a panadapter by connecting the SDR to the 9 MHz IF output of the Yaesu.

However a problem Tim encountered was that the frequency drift of any SDR he tried was too large, even with a TCXO based software defined radio (like a modded RTL-SDR or the Airspy), and that it was a constant hassle to recalibrate. Furthermore, he noticed that the upconverters he used introduced their own drift which just added to the overall frequency drift.

To get around this Tim decided to use the Airspy in a special configuration. First he used the external clock input of the Airspy to connect to his Jackson Labs “Fury” GPSDO. This device uses GPS satellites to generate a very accurate 10 MHz clock, with almost zero drift. Secondly, to get around the need for an upconverter with it’s own frequency drift he used the ADC1 direct sampling input ports on the Airspy to connect to the 9MHz IF output of his FTDX-5000 through an extra band pass filter and LNA.

Tim writes that he will soon update his post with more images and a video.

Airspy with external GPS clock and ADC1 output connected.
Airspy with external GPS clock and ADC1 output connected.

3 comments

  1. Jack

    Jackson Labs “Fury” GPSDO?
    ADC1 direct sampling input ports?
    Extra band pass filter and LNA?
    Huh? I go searching for an article or video to assist me in setting up my Airspy HF+ Discovery as a panadapter on my FTdx-5000. I get this. So, now I need to add additional hardware and a more complicated setup in order for the application to be stable and the result to be acceptable?? Thanks for your help. Lol!
    If anyone reading this comment knows where I can get some setup and configuration information that is actually helpful, I would greatly appreciate your comment vis reply. SMH.

  2. Timmy

    I’m not licensed, so I have no idea when it comes to ham gear. I’d read the manual and look for the maximum signal level out of the IF out port and check that it is under the “+10 dBm Maximum RF input” listed in the technical specifications for an Airspy HF+ ( https://airspy.com/airspy-hf-plus/ ) . And if that is not listed in the manual then I’d contact the company the who made the ham radio and see what they advise. Maybe contact them for a schematic and calculate what the maximum signal level could be. And if they don’t know or won’t help then I’d experiment with with a rotary attenuator between the HAM gear and the SDR. Starting with maximum attenuation and dialing it lower and lower. But it could well be that no attenuation is needed is needed. Maybe talk to other hams what they have done.

  3. Alex

    Hi Tim, I just bought an used AIRSPY HF+ to use with my FTDX5000, my idea is to populate my band map during contests in CW. Do you have any tip how can I do that? maybe using the IF out or just using a secondary antenna for that? I’m afraid to burn it out when I tx.

    Any tip would be much appreciated.

    thanks in advance.
    73
    PY2SEX

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