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Re: question about the DEM 13 ULNA 2.4GHz preamp

Hi Mark,

I doubt that you will get very much through the preamp with no power.  i
also don't think it is likely that you did any damage to it you hooking
it up reversed.  As nearly as I can remember I got about 3.1 VDC on the
drain (output lead) of Q1.  there should be about 15 to 20 ma of drain
current and R1 at the drain connection is 15 ohms so you should see about
.25 to .3 volts across it.  You should have a small negative voltage on
the gate (perhaps -.2 volts or so).  If you have an increase in noise
with the preamp in the circuit I would bet it's working OK.  Signals are
very weak from AO-40 now.  I can just hear the beacon with my single
helix.  I haven't put my preamp up yet but the signal is so weak now I
don't think it will do very much good.

Good luck.

73's de Jess - W4MVB
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