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RE: pre-amp



Hello Greg

> Can anyone reccommend a good 440 mast mount pre-amp for FM use that will
> take a 50 watt transmission through it on 2 meters. I want this to boost
> AO27's signal on my Kenwood TM-V7A.

I don't know of a preamp which you can transmit on one band whilst receiving
on another.

There is a dual band 2m + 70cm amplifier PR-2B
http://www.microset.net/products/amplifiers/preamp/preamp.html which I use
on a dual band vertical. For English speakers it is available via
www.wsplc.co.uk who ship worldwide. It will not work full duplex. Whilst it
won't win any prizes for either noise figure or strong signal handling, it
serves its purpose for casual half duplex contacts.

On the other hand a fairly straight forward way to achieve this would be to
use a normal UHF amplifier and a pair of V/UHF duplexers...

[Use a monospace font and turn your word-wrap off for this!]

               +----------------------+    \ | /
               |                      |     \|/
               | V port        V port |      |
+------+     +---+                  +---+    |
|TM-V7A|-----|DUP|                  |DUP|----+
+------+     +---+                  +---+
               | U port        U port |
               |                      |
               |     +----------+     |
               +-----|UHF preamp|-----+
                     +----------+

If you're using separate V and U antennas, of course the second duplexer can
be dispensed with.

I have used duplexers for my satellite system for quite a while (see
http://www.g6lvb.com/G6LVB.htm and
http://www.g6lvb.com/satellite_antenna_system_mkii.htm ) as I am limited by
the amount of coax I can get away with putting up the side of my apartment
block.

Although there are losses associated by placing duplexers in this manner,
I've found that they are not too prohibitive in practice.

73 Howard G6LVB


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