[R-390] R-390A On 160 Meters

[Roy Morgan]

On Feb 23, 2009, at 11:16 PM, 2002tii wrote:...
> Don't discount the effect the multicouplers may be having on the
> results.  The output-to-output isolation is only on the order of 20
> dB ...the ones I've
> measured have been significantly worse -- around 10-12 dB ...   
> Distortion in
> the multicoupler amp can spread the junk all over the bands, ...

Don,

Thanks for the real world numbers on the multicouplers.  I have a  
military one sold by the surplus folks in Canada before they  
disappeared.  It's an RCA CU-5069/FRD-10A - apparently a lot of them  
were made by TMC for RCA in Canada, or the other way around. This unit  
is a pretty early solid state unit, and I'd expect it's performance to  
be poorer than the ones you report on.  For info, see:
http://skirrow.org/Boatanchors/TechTalk6.pdf

I also have an older military unit that uses 12AT7's for the amplifiers.

An interesting experiment would be to do an IN-OUT comparison with  
some weak signal, or with a busy band to see how a multicoupler was  
degrading the signals.

Sooo many projects, sooo little time.
Roy

Roy Morgan
k1lky at earthlink.net
529 Cobb St.
Groton NY, 13073