The Dressler VHF/UHF active antennas are far from impressive, especially
for the price. I borrowed two of the active VHF/UHF Dresslers from the
local rep (forget the model but went to 2GHz and was not the high IP3
version) and tested them on a antenna range against a Radio Shack
Discone. The source antenna was a commercial 50MHz to 1GHz log periodic.
I don’t have the results handy but above the mid VHF range the Dressler
did a little better than the Discone but not by much, the best
performance was about 5 or 6dB at 1ghz if I remember correctly, which
was my upper test limit at the time. Oddly, the Discone worked about the
same on VHF high band and much better in the VHF air band. What was more
surprising was the Discone was better from 50MHz to 100MHz than the
Dressler even though the Discone was below it’s natural cut off freq of
around 100MHz. I thought something was wrong with the Dressler but both
units gave the same results and the Dressler gain control was all the
way up in both cases. The rep confirmed they were both working properly
when returned also. Without opening the Dressler, we could only conclude
the “antenna” element inside was a poor design and the internal pre-amp
can only do so much with what its fed. Much better performance could be
had starting with a Discone and feeding it with a Dressler or similar
pre-amp, which the local rep uses himself. If you hear of a good report
from a Dressler owner, it’s probably because they have to justify the
high price they paid for the thing.
The reason I went to all the trouble of setting this test up was to find
a replacement for an active antenna I had that died after a lightning
strike. It had a very complicated trapped “fat dipole” that presented
its internal pre amp with a good match from 50MHz to around 2GHz and
outperformed anything I have ever use for monitoring purposes. It
performed as good as many of the large high gain commercial antennas I
have and also had enough gain to feed several receivers. Never
encountered any intermod problems in the RF dense LA CA area either, it
was the best of everything. Unfortunately, it was a prototype and I
cannot locate the designer who mad a small test production run of these
things.
Mike



Brian wrote:

GET A DRESSLER ACTIVE ANTENNA
IT WILL OUT PREFORM BOTH OF THE OTHER ANTENNAS 25- 1200MHZ