Cushcraft AP8A Problems

[Michael D. Harmon]

I bought a Cushcraft AP8A about a year and a half ago. After I put it
up, the VSWR was extremely high on 40 and 75, so I resigned myself
(duh!) to the fact that the AP8A just wasn't going to work like my old
14AVQ (160 countries - no radials).

I got an MFJ 259B for Christmas this year and set out to "diagnose" my
AP8A. I decided to see how far off resonance I really was. The antenna
was resonating just fine down around 28.4, but when I checked the
antenna on the 12M band, the resonance point was 25.4 MHz! Since the
10M and 12M traps are a single unit, I played around with the length of
the bottom mast (base insulator to bottom of 10M trap) and discovered
that I ran out of mast before I got the antenna to resonate down as low
as 24.94 MHz.

I emailed Cushcraft and received a somewhat curt reply that they no
longer supported the AP8A antenna, and suggested that I look to the
instruction manual for assistance (gee thanks, guys!).

I realize that my VSWR problem on 40 and 75 is due to my lack of
radials, but is it reasonable to assume that my 12M problem could be
related to my lack of radials as well? I am planning to put my radials
down in the spring thaw so I can kinda walk them into the mud so I won't
get into them with the lawn mower.

Does anyone out there have any ideas which might be of help? I'm not
averse to doing aluminum surgery, if that's what it takes to get it to
work on 12M, but I want to be sure I know what I'm doing before I break
out the hacksaw.

Thanks es 73,
Mike Harmon
WB0LDJ
mha...@tranquility.net

[Cortland Richmond]

Michael,

I'm not familiar with this antenna, so this is a guess but... why not see if
the 10 meter/12 meter trap is installed right way up? Some traps have two
coils, one in each end of the trap. If the ten meter coil is at the top, and
your twelve meter coil at the bottom, it will resonate the antenna too high
on 12 meters ( and maybe a bit low on 10).

Good luck!

Cortland
ka...@saber.net

[hollozzz]

I cut and I cut it and it's still too short.....Don't let this happen to
you!!! Yes the lack of radials can detune the antenna on 12m. Get as
many and as long possible down as you can. Wrap a nail 2 times with wire
and drive in the ground every 5 feet or so(this should work in frozen
ground so maybe you can do this now).
73 Cliff N0HC

[fiberoptic]

Mike,
I have a AP8 (not using it now ) but when I do use it HAS
TO HAVE RADIALS or I have poor match on all bands. If you can get
yours to work on some bands without radials you are doing better than
me. I have a manual I can copy if you need one.

73's de KM6QJ travis

n Mon, 27 Dec 1999 21:30:23 -0600, "Michael D. Harmon"