On 2/13/2011 1:25 PM, Gary Slagel wrote:
> I recently built 2 verticals for 80 and 160 by shuntfeeding my tower. They
> both seem to load nicely and are broadbanded, partly because of an
> insufficient radial system.
>
> When I transmit on either 160 or 80 the meter on my rotator controller
> deflects.... this makes sense since I'm running rf right through the rotator.
> Till now I've run only 100 watts thru the antennas but I'd like to see if
> the antennas will handle a KW ok. I'm wondering if there's any chance of
> damage to the rotator (Ham IV) if I do this. I'd guess not but it makes me
> a little nervous.
It could be coming in on either or both the coax or rotator cable.
As you are showing a good match, I assume the match is at the tower and
you are not using a line tuner at the shack.
When operating 75 at roughly 800 to a 1000 watts the LEDs on my
6-pack and remote antenna switches would light. At the legal limit they
were bright enough I was worried about damage. I tried chokes on the
cables, but nothing changed. Then I added a current balun where the feed
line between the 75 sloper and the remote antenna switch reached the
tower. No more interferrence.
The chokes/baluns I used were 5, 2.4" 31 Mix toroids with 5 turns of
LMR-400.
I'd try one in the rotator cable near the control box to see what happens.
Read Jim Brown's (K9YC) RFI tutorial
http://www.audiosystemsgroup.com/RFI-Ham.pdf about toroids, RFI, baluns,
and audio interfacing. It's well worth the time.
73
Roger (K8RI)
>
> Currently 10 watts deflects the meter about 10%. 100 watts deflects it about
> 25%.
>
> Anyone have a thought on this?
>
> Thanks,
>
> Gary Slagel
> Hot Springs, SD
> N0SXX
> http://marina.fortunecity.com/sanpedro/351
>
>
>
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