From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
To: rsgb_lf_group@blacksheep.org
Date: Thu, 22 Mar 2001 13:49:17 -0000
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Subject: LF: WOLF - transmit
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Thanks, Jim, for the useful description of your transmit system for WOLF.

Being a very lazy constructor, I am trying to find a simpler solution.

Am I right in saying that my Decca Tx does not cause you a problem when I 
key it with normal CW? If that is the case - I certainly don't get any clicks 
from you - and bearing in mind that I key the 'VFO' output, why not simply cut 
the drive during the critical transition period?

Alternatively, why go to the trouble of only reducing the PSU volts only when 
there is a transition? Why not reduce it every time there =could= be a 
transition, ie once every second (I think I am right in saying the bit rate is one 
bps?). This would mean that the whole thing could be driven by an oscillator. 
Of course it would need to be synched to the keyer, but isn't that easier than 
what you are using?

And what about using a linear amplifier, eg BK Electronics, and simply putting 
an LPF on the output of the XOR gate modulator used by the Lowfers? This 
would be a really easy answer, at least up to a few hundred watts, wouldn't it?

I mean no criticism of your circuitry - it's just that I don't fancy building 
something that complex. Have I missed something terribly important?

I remain fascinated but still rather baffled, and would appreciate your 
thoughts, and those of anyone else.

Mike, G3XDV (IO91VT)
http://www.lf.thersgb.net