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#Polyphase network with USB/LSB relay #polyphase

Martin Wilens
 

Hi all,
I was wundering how many build the #Receiver (https://www.qrp-labs.com/receiver.html) with #Polyphase network module.

Before I used little 2-way header socket jumpers.

Here is a photo of the  Polyphase network with a relay instead of jumpers to inspire other builders.
See document Controlling additional relays (https://www.qrp-labs.com/images/appnotes/AN003_A4.pdf)
Instead of the american 2n3904 I used the european bc547
The connector with 6 holes came from a usb-cable inside an old computer
One changeover switch straigt on the connector and one crossed


Keep on builing.
73 PE1RIX

Bill Oelker
 

Hi Martin, thanks for sharing a great Idea. I have built 2 receivers with the polyphase networks. I use one 24/7 for spotting wspr on 40M. It works great. I yet have not needed to listen on LSB but will keep this in mind. Might be fun to listen to ssb on 40M or 80M. Maybe a upgrade, I wonder how a solid state relay on a chip, would work, or maybe a gate type chip??

Bill
KN8DMK

Steinar Fremme - LB8FH <steinar@...>
 

Hello!

Yes I have build a receiver with the polyphase module, and seems to receive well.

Really good sensitivity - and frequency accuracy after changing the xtall on the Si5351A to a TCXO 0.1ppm crystal oscillator.

Have some issues to have the software to run on my mac, but that is another matter :-)

73 de LB8FH 

Daniel Ekman SA2KNG
 

I just successfully built the receiver and polyphase and this is definitely something I will consider adding to that build.
I'm trying to make a complete multiband shortwave receiver with everything controlled with hamlib/rigcat, to be used with remote listeners/skimmers for anything from WSPR to SSB. More to come on this when it nears completion, code and schematics will be released.

KEN G4APB
 

Hi Martin,
I have done a similar mod to two U3 receivers I have. I connected the relay drive to the spare switch on the front panel so now I have a USB/LSB select,  which I use for listening to voice SSB on 40m. I have also tried to add the potentiometer tune mod but that is not working properly yet.
73 Ken g4apb