I have a Force 12 C3 and I originally fed it with RG 213 direct connected to
the driven element and it worked well until I got a lightning strike and then
the swr went to 3 to 1 at resonance. So I replaced the coax thinking it might
be damaged since there is no visible damage to the antenna and it has no traps
so I see no way the antenna could be bad. I thought of investing in a high
power 1 to 1 balun to feed the antenna and invested in a 8kw rated Alpha Delta
balun to use on this antenna. Only problem is how to mount the balun on the
antenna. I mounted the balun on top of the boom right over the driven element
which is on the bottom of the boom. I used aluminum strips to connect the
balun to the driven element but in order to clear the boom the strips had to be
about 6" long each and the result it that resonance is too low to be used at
all. SWr drops to 1.8 to 1 at the bottom of each band and it over 3 to 1 at
the middle of the phone band. the tuner will bring the
swr down to flat but I suspect the balun might really get hot with that
mismatch. Question is can I attach the balun on the bottom side with the
terminals next to the driven element using 2" jumpers and fabricate a sort of
rear brace for the balun and attach it at the Pl259 end up to the boom. The
balun would not touch the parasitic driven elements but it would be only 1"
below them. Could this work or does anyone have any other suggestions like
maybe doing away with the balun and just going back to a coax choke like I
originally had? Is there anything to be gained by using the 1 to 1 balun
instead of just a coax choke? I don't want to burn anything up if I
accidentally get past 1500 for a moment while tuning the amp or running too
much carrier on AM?
WB5OXQ
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|