Topband
[Top] [All Lists]

Topband: Preamp in MFJ1026

To: <topband@contesting.com>
Subject: Topband: Preamp in MFJ1026
From: W8JI@contesting.com (Tom Rauch)
Date: Sun, 7 Nov 1999 07:52:13 -0500
> 1026 jumper set for maximum gain for the auxiliary antenna (Beverage).  It
> makes a significant improvement in the signal level there compared to it
> being switched off. 

While the pre-amp will work in some cases, it is primarily designed 
for low signal-level noise sensing (small whip or loop) antennas. I 
certainly don't recommend buying a 1026 just to get its amplifier, 
especially if you plan on using the 1026 on a large antenna. 

It's best to avoid poor dynamic range, harmonic distortion, and IMD 
performance devices (like low signal level single-ended FET's or 
MMIC devices) in pre-amplifiers. I've found MMIC's especially bad 
for distortion products. They trade off performance for circuit 
simplicity.

The 1025/26 is designed to be a zero-gain device. All amplification 
should be ahead of the 1025/26, and hopefully be pass-band 
filtered and use good CATV-type bipolar transistors.
73, Tom W8JI
w8ji@contesting.com



--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com


<Prev in Thread] Current Thread [Next in Thread>
  • Topband: Preamp in MFJ1026, Tom Rauch <=