TopBand: Re: [AMPS] 2N5109 preamp

[km1h @ juno.com]

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


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