July 27th 09, 08:33 AM
posted to rec.radio.shortwave
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First recorded activity by RadioBanter: Jul 2009
Posts: 16
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Balanced amplifier?
On Jul 26, 3:52*am, Bushcraftgregg wrote:
On Jul 25, 9:23*pm, Ross Archer wrote:
I'd like to try building an *untuned* loop amplifier covering HF and
wonder if anyone has seen links on this.
The thinking so far is using a pair of 2n2219a bipolar transistors
running a few hundred milliamps, with their collectors driving
opposite ends of an RF output transformer, and a reasonably large loop
(say 1 meter square or more).
I'd like the output to be "hot" enough to compensate for a losses from
a nice long run of cheap cable-TV type coax cable (through which power
will be fed up to the amp). *But not so "hot" as to create distortion..
Anyone here have experience with this sort of project? *If so, is the
2n2219a a stupid choice? *Would I be better with JFETs, and would a
single-ended amplifier work almost as well as a balanced amp? *(My
thinking is the balanced amp would potentially be quieter.)
It would be fun to try this, and my junk box is overflowing with
parts, so why not? 
-- ross
Huh, haven't seen you around here in ages
Ross.
Life is funny that way.
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