Topbanders;
The 2N5109 is an ultralinear CATV device and circuits have been around
for several (over 10) years. This is the same device I have used for
years in many, many preamp and QRP projects. Cost is a whopping $1.75
each or so.
One of the best circuits is the lossless feedback design that was
patented by Anzac maybe 20 + years ago. It was copied in the HRM VHF
colums back in 1986 or so. A 2N5109 will have 1.5dB NF and 10dB of gain
with a IP3 of +11dB AND cover 1.5-150MHz in that circuit.
Tom's suggestions are something many should try.....I have not used the
2N5109 in a PP amp but experiments with a pair of U-310's in a 2 turn
loop have been most gratifying. As he said..it is fairly bullet proof as
compared to a monolithic device.
The bottom line is to experiment...not blindly follow some ad in some
magazine or whatever.
Anyone wanting a schematic of the Anzac circuit give me your address.
73 Carl KM1H
-
---
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
|