[Elecraft] [K3] Birdies

[Geoffrey Mackenzie-Kennedy]

Hello John,

Thank you for your reply, and my apology for not being able to return 
sooner.

I am inclined to think that the source of these "birdies" is external to 
your K3, and getting into the receiver via some connecting cable(s).

The reason why the birdies are less noticeable on the sub-receiver is 
probably because it is in a shielded module, whereas the main receiver is 
"open plan".  However if there any coax cables or wires entering  the sub- 
receiver's enclosure through holes in the shield, then whatever is causing 
the birdies will get into the sub- receiver.  The dimensions of the 
sub-receiver's shielded enclosure might also affect the strength of the 
sub-receiver's birdies on different bands, especially the higher frequency 
bands (the "Waveguide effect").

Will look again at your screen capture, because I think that there is 
evidence that the birdies have discrete sidebands, which might help to 
identify their source.

73,

Geoff
LX2AO



On May 22, 2012 at 7:53 PM, John Bekema wrote:


> Hello Geoff!
>
> I am using a linear power supply. On the lower end of the 10m band,
> the birdies are a bit less.
>
> On six meters, the birdies are stronger, for example on 50.09374 is an
> S8 birdy. But the funny thing is, when listening
> to the subreceiver to the same freq, with the same settings, the birdy
> is much less noticable. It barely moves the meter.
>
> Also when listening with one ear to the main rx and the other ear to
> the sub rx while slowly tuning, I can hear on the main
> receiver 'whooop whoop whooop' while nothing is heard on the
> subreceiver. (receivers linked)
>
> Ideas?
>
> John