Kelly Johnson wrote:
> Is an Inverted Vee inherently more susceptible to QRN than a dipole or
> yagi?
>
> My noise levels on 80m are much, much higher than my noise levels on
> 40m. I mean on the order of 6 or 7 S units higher. I'm looking for
> an explanation. I have a 2 element yagi on 40m, but an inverted vee
> on 80m. Is it explainable by the vertical polarization of the
> inverted vee? Is it just 80m vs 40m? Is it the location of my
> inverted vee (ie.closer to the overhead power lines)?
Make sure you have a good current balun on the inverted vee so
the feedline doesn't act as a vertical ( =noisy ) antenna. The
only acceptable balun IMHO is about 15 turns of RG58 coax wound
around a 2.4 inch toroid of Fair-Rite 43 or 73 material. AFAIK all
baluns you can buy are junk. My inverted vee is very quiet, often
being as good as a beverage. Guess what I use for a balun.
Hint: I didn't buy it at HRO.
>
> While I'm at it, how about an explanation of why the noise level on CW
> (with a 250Hz or 500Hz filter in line) is lower than SSB (with a
> 2.4KHz filter in line) on 40m, but not on 80m. It seems as if my S
> meter reads about S1 on a good day on 40CW and about S5 on 40SSB, but
> reads about S7 on 80CW and S8 on 75SSB. I would expect noise levels
> on the S meter to drop when I kick in the 500Hz filter, but it doesn't
> seem to do so on 80 meters. Could this just be a wacky S meter? BTW,
> I'm using an FT-1000MP
>
This could be a result of impulsive noise that pumps the AGC.
Narrow filters destroy impulses. Have you tried your noise blanker?
Rick N6RK
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