[amsat-bb] Radios with built in duplexers How best to use?

[Michael Tondee]

It looks like I'm going to be able to afford to buy a dual band FM rig  
which will get me a little more back into the sats but the ones in my 
price range have built in duplexers.  I guess the only way I can use two 
antennas is to use another duplexer up at the antennas and split the 
coax there but it seems like I'm going to get signal loss doing that. 
The other thing I've thought about is going with a dualband antenna  
where I would have one cable without all the extra connections but I'm 
wondering if a problem might arise with using a 70 cm preamp in that 
configuration. Would the 70cm preamp RF bypass relay work when  2meter  
RF was transmitted? Assuming it would, would it pass the 2 meter TX and 
RX signals through otherwise?  I know I should know this but I'm kind of 
stumped.  Any information or suggestions would be greatly appreciated.
Tnx and 73,
Michael, W4HIJ
AMSAT # 36017