[Elecraft] Re: Noise level on 160m

Mon Nov 25 07:06:16 2002

On 25 Nov 2002 at 4:01, LA3ZA wrote

> I notice that the band is very noisy, but my K2 behaves in a strange way as
> I have to work it with the Attenuator on and RF gain in the 10 or 11 o'clock
> position to get rid of a kind of noise that makes it almost impossible to
> copy anything. The Noise Blanker makes it a little bit easier, otherwise the
> RF gain has to be turned down even more. The noise seems to come as the RF
> gain crosses a threshold and then it will distort the received CW also. To
> me it seems like some sort of overload or oscillation in the RF/IF part of
> the receiver. I have also noticed this kind of behavior on 80 m from time to
> time.

I also suffer from very similar noise on top band and to a lesser 
extent on 80m. I had originally thought it was local noise to me (and 
was certainly not there some years ago when I was more active on the 
band). It is certainly not generated internally in the K2 and was 
completely absent when we used my K2 in the RSGB Field Day in June. 
It is also usually absent during daytime and the early morning hours. 
I rather suspect it is from the increasing use of computer and TV 
devices (ADSL springs to mind as well).

I have two antennas for 160m - a 30ft vertical (modified Butternut) 
and my 60ft longwire. The noise is usually (but not always) much 
worse on the long wire. Saturday top band was relatively quiet, but 
the noise was certainly much worse Sunday evening and 80 was also 
very noisy.

Now that we know the same noise is being heard in Norway it seems it 
is far wider spread than just a local noise level here. I suspect the 
cause is common, but from different sources.

73s Dave G3YMC

[email protected]
[email protected]
http://www.dsergeant.btinternet.co.uk