Topband: Preamp?

Bob Marshall-Read
Mon, 19 Jun 2000 09:16:47 +0100


I use two on my pennants and loops.

1. I have switchable east and west pennants (6 metres vertical and about
13 metres long, both fed through a DPDT relay at the nose).  On this
arrangement I use the C and S 160m preamp, which uses the 3SK88 as the
active device and it does a great job. About 25 dB gain, and the noise
isn't a factor on 160 with this preamp.

2. On the south pennant (north is right into the aurora and not really
beneficial) about the same size I use the ICE 160m preamp and it also
gives useful gain of about 25 dB.  Again, noise is quite low with the
preamp switched in.

Without the preamps, the signal levels are way down (about 28 dB), and for
long haul, not really audible in most cases.

I use the Sherwood modified Drake R4C on all of the receive antennas
(including two co-ax tuned loops phased through an MFJ-1026) and all are
switched through one of the two preamps.

As  I am space disadvantaged (the lot is 30 by 145 metres) and this season
the nearby field can not be used for the west beverage, this compromise
receive combination appears to be working well.  VK6 is now workable in the
summer months and deep Asian stations are now Q5 whereas last season, it
was touch and go.

Hope this helps.

73 and CU on the band!

Bob   G4VGO  EI7IU  KY0C

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