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[aprssig] Building a new digi

Stephen H. Smith wa8lmf2 at aol.com
Thu Apr 2 01:08:48 UTC 2009


Keith VE7GDH wrote:
> I did one test some weeks ago with a
> T2-135 side-by-side with a KPC-3+ and the T2-135 didn't perform too
> badly, but the Kantronics TNC did seem to decode more packets. The
> antennas had different characteristics, so I swapped them around and
> the Kantronics TNC still came out ahead. 

Could you disable transmit and then feed both radios from a single 
antenna?   

I have a modified Channel Master 1-to-2 coax splitter originally used to 
feed two TVs from one antenna. I replaced the F connectors with BNC 
connectors so I could use various RG-58 coax cable jumpers with BNC 
connectors with adapters to connect two radios at once for comparative 
tests.

 Although the device is claimed to be  75-ohms in and two 75-ohms out, 
actually it just reflects the input impedance to two like outputs, and 
works just as well 50 in / 50 out.   The device is rated for 50-950 MHz 
(i.e. all of the classic VHF and UHF TV freqs and everything in between. 


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Stephen H. Smith    wa8lmf (at) aol.com
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