Hello Barry,
I have no experience with them at medium wave, howver my experience with
them on VHF/UHF keep them out of consideration for my low band receive
antennae. In addition, they do not have the features that one would want on
the low bands.
For my Pennant and rotatable loop antenna I have purchased and modified
a current manufacture Ameco PT-3. This is not a perfect answer (is there
one) either.
First off, for a dedicated receive only antenna (I used a GAP DX-Voyager or
slopers on transmit) the PT-3 must be modified for transmit vs. rreceive
antenna switching by punching out rear panel pre-punched (not very well
punched) holes. A relay, SO-239 connector and toggle switch must then
be installed. Ameco does sell the parts, however they do NOT sell the unit
so configured. The modification is no big deal unless the punched holes are
almost unpunched, in which case (as in my case) you must remove the
rear panel and pucnh them out. The toggle switch allows operation of either
antenna for receive.
Once modified the unit works very well. The isolation between the two antennae
in receive could be a bit better, they do NOT ground the transmit antenna
on receive, this you must do if it is a problem in the BCI area. Half of
the DPDT switch that must be installed can be used for this purpose.
The PT-3 only supports 300w rating for RF switching, it that, so it must be
inserted in the transmission line between the transmitter and an amplifier. It
is RF switched as it arrives and adjustable for delay. However it is simple
enough to mod for PTT.
In operation the frequency range of preamplication and gain is user adjustable
on the front panel of the unit. I have found that the PT-3 in combination
with my antennae to be a big advantage in DXing on and 75/80 meters this
season. So far I have not do so well on 160m, mostly due to my operating
schedule and propagation coincidance.
Steve, N2CKH
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