[Boatanchors] WTB: MAR 6 monolithic RF preamp chip - need a couple

[Carl]

Greg, the specs "look" good on paper but those devices cant handle a 
band full of loud signals without severe IMD. Might be OK on a loop or 
other negative gain antenna.

Instead take a look at the lossless feedback circuit. With a 2N5109 it 
will deliver a 1.5 dB NF, 10-11 dB gain, 50 Ohms in/out, and an 
intercept point to be proud of. A tiny tuner can be added if desired to 
those older radios that have poor image rejection. MFJ makes a nice SWL 
one.

Ive been using that circuit on rice boxes, boatanchors as well as a few 
30's console radios since the mid 80's.

A Google should turn up a circuit but if not I can scan mine and send 
it.

Carl
KM1H




----- Original Message ----- 
From: "Greg Mijal" <bluebirdtele at embarqmail.com>
To: <boatanchors at mailman.qth.net>
Cc: "glowbugs List" <glowbugs at piobaire.mines.uidaho.edu>
Sent: Tuesday, March 10, 2009 10:03 PM
Subject: [Boatanchors] WTB: MAR 6 monolithic RF preamp chip - need a 
couple


> Anyone got a couple of Minicircuit labs MAR 6 RF pre-amp chips they 
> want to get rid of.
> I need to build a couple of pre-amps for some  tube receivers.
> If you havn't tried one of these puppies yet they are very good 
> preamps all the way to 2 ghz. Very easy to build up, needing only a 
> couple of parts and a small board to mount it on.  A pot in series 
> with a 9 v battery can be used to control the gain and noise. If you 
> Google it you will find a kit for around $17 on the internet.
> Thanks
> Greg
> WA7LYO
> Kinston NC
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