Topband: question about RX splitter

Peter pc2a at pi4cc.nl
Thu Oct 20 08:30:00 PDT 2011


Gilles

As you tried to build your own with the info found here?
http://www.bavarian-contest-club.de/projects/misc_projects/splitter.pdf 
<imap://pc2a@imap.xs4all.nl:993/fetch%3EUID%3E/Drafts%3E1254?part=1.2&filename=Welcome%20to%20CoPilot%20Live%20navigation%20DACH.txt>

We use them to allow an SDR/K3 combo to share the same antenna.
A few pictures the way we make them can be found here:
http://www.pi4cc.nl/tech-info/rx-splitter/


Peter
PC2A
www.pi4cc.nl


VE2TZT schreef:
> Thanks guys for your direct or via reflector pieces of advise.
>
> Just a remark : the 25 ohms is correct in the input/serial configuration 
> suggested by Bryant&Bower in the article I have mentioned previously while 
> the 100 ohms is the right one in the most common output/parallel 
> configuration of a splitter.
>
> On the basis of all that, I am in the process to make some cut and try tests 
> with different cores and turn numbers using my VNA 2180 .
> I am planning to test the two configurations (common and Bryant&Bower ) and 
> will advise you of my final results.
>
> More info about the need : I cannot use a commercial splitter because I am 
> intending to use two of them in a to be constructed switching box (as small 
> and light as possible) which will dispatch two 75 ohms beverage inputs (JA 
> and NA/EU directions) to two radios. One radio being for example the 80m 
> radio and the other the 160m radio. The outputs to the radios must be 50 
> ohms because those outputs are going to the radios via W3NQN RX band filters 
> and we want have the filters at they best in a multitransmitter environment. 
> In the same spirit, the switching system manages to put a 50 ohms resistor 
> at the unused output of the splitters. To finish, each operator will have a 
> remote switch next to his radio to choose its directions. The common mode 
> rejection at the inputs is just a precaution for expedition places where the 
> quality of station ground is far from optimal.
>
> 73, Gilles VE2TZT
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>   



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