[Lowfer] G3AQC on 72 kHz

[Bill Ashlock]

John A,

>Something's overloading if you're hearing chickens being plucked that >far 
>away from 100 kHz. There will be Loran lines (plenty), but the >racket 
>shouldn't be all that audible.

Yes, that's what is most likely the problem. It's so bad that I'm seeing 
chicken feathers all over the screen! <G> When I tune to 100k, with the 
Preamp 1 engaged, the S-meter covers the full travel for maximum strength. 
Is that 40db over S9? (I'm at work and can't look at the R75). So it's 
likely a tuned circuit is needed ahead of the R75. I could even be 
saturating the antenna matching transformer and be introducing some IM at 
that point. Darn! I hate the thought of having to go back to a tuned loop as 
the only way to eliminate Loran C, with all the light dimmer noise I'll be 
facing in the 5:00pm to 12:00pm time frame when 73k signals are prime.

What I should do is build a separate tree antenna for 73k with a tuned 
matching transformer. Darn things are so simple build and install.

>try keeping the noise blanker off.

Didn't think of this. Could have been on.

>Of course, don't forget that I'm using a tuned loop which has some 
> >rejection of Nantucket Loran when aimed at the U.K.

Yes. The Loran signal I'm hearing could actually be some 73k spattering and 
there's nothing to be done except use a loop and put the splatter in a 40db 
null off to the side. Therefore, I'll run an experiment today where I'll set 
up my tuned loop to 73k and see if the chickens go away -both in the 
direction of Nantucket and the UK.

>Regarding the freq calibration, despite all the pulsing and wide BW, >you 
>will see a line right on 100 kHz when using Argo and with the >receiver in 
>CW mode. Probably best to look with an Argo 30 or 60 >second screen so 
>there aren't too many competing lines.

I wouldn't doubt my problem in seeing this was the extreme overload. I'll 
attach the scope to the coax lead-in and see what the amplitude is like.

Thanks a lot for the help! Just ain't fair that you see a near-perfect ARGO 
copy and I see zilch! (and closer to the UK to boot) <GGGG>

Bill



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