[UK-CONTEST] RX Dynamic Range - AFS SSB

[Ken Eastty]

> I am thinking that they are using rigs with relatively poor usable close in Dynamic Range 
> on 80m and many of the signals were very strong. I am on the other hand 
> using a K3 with its excellent close in Dynamic range especially with 
> pre-amp off and 10dB attenuator in. The strongest non-local signals were 
> up to about -20dBm at times. A level which causes IMD and signal 
> compression in many receivers even with the preamp off and the 
> attenuator on (assuming the rig has an attenuator).
>
> David G3YYD
>
>
>
>   
Some operators probably don't realize that under the S9++ signal levels 
experienced during SSB
AFS that noise blankers in many RX's generate IMD & should be switched off.

There's little doubt that anyone who didn't 'bag' a frequency before the 
start of the contest would have
had great difficulty finding a spot  to call CQ almost impossible, no 
'warming' a frequency before the contest?
A good idea but I can imagine that instead of people calling test there 
might instead be a lot of idle S9+ carriers.

It was possible in the latter stages of SSB AFS to get caught out by 
Eu's operating just above 3750
as you worked up through the band if you weren't taking careful note of 
the frequency they were using.

73....

Ken

G3LVP