How to connnect FRT-7700 to RSPdx

[kksParticipant]

Hello,

I’m eagerly waiting for my RSPdx to arrive in the next few days. I dug out my old and rusty sub-30MHz dipole antenna from the basement and found also my Yaesu FRT-7700 antenna tuner. Now, i’d like to try out the FRT with the RSPdx.

My question is how do I connect these two?

RSPdx has one BNC and 2 SMA-connectors, whereas FRT-7700 has “just” two wires (well ok, three, but for two different options). I do not understand enough about impedances, losses etc that may occor, if I just crimp the two wires to a BNC or SMA-connector. Of course I could give it a try and see what happens and then compare the result to directly connecting the dipole to RSPdx BNC. But i’m also ok to play around with this a bit more as for some reason I’ve had some extra time at home recently.

For those interested, I attached the FRT-7700 circuit diagram.

73 kks

[kksParticipant]

And a re-try with smaller attachment

Attachments:

1. 

   FRT-7700-Diagram.jpg
   

[kksParticipant]

And then I also found an earlier post, which referred to BNC-to-block adapters to make my life a lot easier. But I’m still interested in the possible electrical issues (impedance mismatch etc) or are they just not relevant under 30MHz?

[Andy2Participant]

I’d just give it a whirl, k. Impedance mismatch loss is relatively small as long as the mismatch is not astronomical, and most receivers (including the RSP’s) have gain to spare anyway. A quick look at at that diagram doesn’t show any danger from DC supplies leaking into your RSP’s front end or anything like that, so I’d say go ahead and see how it goes.
BTW, this forum is now independently-run and has no direct connection with the SDRPlay guys any more, so it is very quiet.
For a *lot* more action try joining the Facebook community, it’s very friendly. There’s a link on the main Play homepage.

Andy.

[kksParticipant]

Tnx Andy,

I’ll give it a try and I will also join the FB-community.

BR,

kks

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