Topband: Preamp for 160m (and 80m)

Brad Rehm brehm at ptitest.com
Wed Feb 2 11:08:58 EST 2005


" I'm not sure that a preamp is needed with this antenna. "

I agree, but Oliver didn't his reason for asking for comments about preamps.


" Have any of you compared the Mini-circuits preamps to the common ham-type
preamps? They don't have much in ready built coaxial amps that go down to
1.8 MHz. They do have many monolithic amps such as the ERA-5. It is spec'ed
at 20 dB gain, 4 dB NF and 33 dB IP3. And being a bipolar amp it is quiet at
1.8 MHz. This part is $4 and is easy to get working.

Dave WX7G"

The preamp in the W8ZR multicontroller is an ERA-x monolithic amp, and
although I haven't tested it in our lab, it seems to do quite well under
crowded band conditions.  No problems last weekend, for example.

I have tested one of the Mini-circuits ready-built preamps.  The data aren't
here at the office, but I remember that the IP-3 and noise figure were quite
good.  I've used it side-by side with several of the "ham" preamps and it
worked well.

Brad


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