Topband: Review of Rig Expert AA-55 antenna analyzer on 160 meters with BCB QRM

[Richard (Rick) Karlquist]

The Rig Expert AA-55 was recently reviewed in QST; you can read
all about it there.  The QST review shows that its drive level
is something like +12 or +13 dBm, so I hoped that this would
enable it to work on 160m at my QTH.  My QTH is located 6 miles
from a 50 kW AM BCB station on 1140 kHz, over high conductivity
ground .  On my 90 foot top loaded vertical, it produces
around +10 dBm.  There are also a dozen or so other
stations 20 dB below this one, including one at 1700 kHz.
Previous attempts with various network analyzers, even using
a very exotic BCB reject filter, were unsuccessful.

I went ahead and purchased the AA-55 anyway, because it would
be very useful for a lot of other stuff.  After using it for various
measurements on bands other than 160 meters, I would rate
its general utility as "perfect", just what I need for HF
antennas, and the whole thing is self contained (no laptop
to drag around, although you can attach one to download
measurements.)  So I totally got my money's worth before even
trying it on 160 meters.

One thing that impressed me was ease of use.  Many hobby
type analyzers I have used have a terrible user interface.
The AA-55 was intuitive.  I never read the manual.  I
just got to work with it.

Anyway, after I completed my recent maintenance project on the 160
meter vertical, I simply hooked the AA-55 directly to the vertical
at the base.  To my amazement, this thing just WORKED!
No BCB interference, and I wasn't even protecting it with a
filter.  "Finally", as they say.  I was very pleased to find
out that my base resistance was 24 ohms, which is the same
as what EZNEC says it should be over perfect ground.  So
the ground screen gets a clean bill of health.

I can highly recommend this product.

Rick N6RK