[CQ-Contest] SO2R and broadband noise

[David Hachadorian]

----- Original Message ----- 
From: "Pete Smith" <n4zr at contesting.com>
To: <cq-contest at contesting.com>
Sent: Friday, January 06, 2006 7:13 PM
Subject: [CQ-Contest] SO2R and broadband noise


>I have been doing some tests with my new single-tower SO2R setup, 
>transmitting on a TS-930S and listening on a Mark 5.
> Results so far are very gratifying.  I have noticed, though, that 
> regardless of band, when I have the TS-930 in transmit, but not 
> key-down, I can hear a slight increase in the noise floor on the 
> Mark 5.  The amount of increase is subjectively the same, whatever 
> band I'm listening on, and does *not* change between key up and key 
> down.
>
> I'd characterize this as a nuisance, and probably not an operational 
> problem under extreme weak-signal conditions, but I'm curious what 
> could be causing it.  Any thoughts?

Almost all (if not all) synthesized radios transmit broadband noise. 
That's why a bandpass filter is required on the transmitting radio, as 
well as on the receiving radio. If you don't have the filters, and the 
broadband noise is your only so2r interference problem, a stub on the 
transmitting radio should be adequate to solve the broadband noise 
problem.


Dave Hachadorian, K6LL
Yuma, AZ