LF: Proposed new LF signal format

Andre' Kesteloot akestelo@bellatlantic.net
Sun, 28 Jan 2001 11:24:38 -0500


Stewart Nelson wrote:

> [...] The WOLF signal is BPSK (at MS100),

> [...]
> Comments and suggestions welcome.
> 73,
> Stewart KK7KA

Stewart is to be commended for developing the very interesting WOLF
concept.

One of the challenges we all face in LF work is the  _reliable_ 
operation of high-power CW transmitters (I have a bunch of fried Power
MosFets
here in the shack that demonstrate that problem).  Generating large
amounts
of RF power with a   _linear_  amplifier is even more difficult, because
of
the problem one faces when one tries to bias several power MosFets in
parallel. (I am assuming here that most radioamateurs will try to use
cheap Mosfets, not expensive RF types).

Ideally, for such applications as WOLF, one would need a linear
amplifier, yet what cheap power MosFets seem to like best is on/off
operation :-)

One approach to that problem was offered by Timothy Hulick Ph.D. W9QQ,
in two papers he presented at the AMRAD Technical Symposium  that was
held
here in Virginia on 17 June 2000. 

These papers: 
 
"The Digital Amplitude Modulator" and 
"The Digital Linear Amplifier" 

were reprinted in the Symposium's proceedings.

73
Andre' N4ICK