A short while ago, AA1K I think passed along some info about Beverage
preamps and said he had an article on constructing one with a very low parts
count. I think that was in June 73 Magazine p. 55. There are several other
articles if anyone is interested; among them:
QST April, 77; QST Dec. 77; QST Aug. 88
I have built a few of the preamps from this last QST article by W1FB, and
they work great. The parts count is much greater, but the gain is
adjustable and they are a 2 band affair. I like this preamp, and have two
operating now. If you don't want to breadboard, there is a board available
from FAR circuits.
I use a relay to switch remotely the band (80 and 160). On 80, this preamp
is a real tiger with my NE 880 ft Beverage; on 160 it does a very good job,
but the results are not as startling as on 80 where the long wire provides
greater starting gain.
The only problem I have encountered is overload, but if you keep the RF gain
turned back this can be overcome nicely while still providing good gain.
I have enjoyed the comments by all about whether to preamp or not to preamp.
As far as I am concerned, a preamp is a necessity in my situation, where my
receive antennas (both Beverages and ewes) is perhaps not the best (ground
too moist for really good Beverage operation, not enough room in some
directions), but I realize that preamps are not necessary in every situation.
>From what I have seen, noise is not a problem with any of these preamps. I
built one of the single FET jobs a few years ago as a broadband affair, and
even with that one noise was not a problem.
73,
Bill, VE3CSK
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