From:
[email protected]To:
[email protected]Date: Wed, 25 Dec 2013 00:38:59 +0100
Subject: Re: VLF: SAQ
Hi Bob,
I've never been to Grimeton myself yet, so only a
lttle understanding from reading and pictures. Recently there have been articles
on SAQ in two German ham radio magazines (Funkamateur and cq-DL).
Other members of the LF group may have much more knowledge, eg a
couple of interesting tech notes from Dick PA0SE available on the
web:
Perhaps more loosely related, there's also the
unforgettable electro-mechanical VLF receiver from Jim M0BMU
>
Is SAQ transmitter output determined by tuning of antenna. If
over coupled would signal loose it's nice T9 tone and signal
widen?
> The giant alternator essentially behaves like a self excited osc
transmitter? Setting antenna couple just right for max output with stable
chirp free tone?
No, I think the stability and tone quality of an
alternator is solely related to the regulated speed of the motor and the even
tooth pitch in the generator. Antenna coupling will affect the output power, but
the frequency only indirectly due to a slight slowdown of the motor under
load..
> It is essentially dumping keyup into a
large dummy ant like an arc transmitter? Then simplifying tune-up so ant
match and coupling be similar to keyup condition into dummy
ant?
My understanding is that at keyup the antenna is detuned by
a saturating inductor, there is no RF dumping into a dummy load. However
there seems to be an external chirp compensation circuit in the motor drive
which increases torque immediately on key down, preempting the slower
frequency regulator loop.
All the best to you and yours,
73, Markus (DF6NM)
Sent: Tuesday, December 24, 2013 5:59 PM
Subject: RE: VLF: SAQ
Markus;
If you have the time-hasn't got to be right now-first,
Merry Xmas to you and family from us.
Is SAQ transmitter output
determined by tuning of antenna. If over coupled would signal loose it's
nice T9 tone and signal widen?
The giant alternator essentially behaves
like a self excited osc transmitter? Setting antenna couple just right for
max output with stable chirp free tone?
It is essentially dumping
keyup into a large dummy ant like an arc transmitter? Then simplifying
tune-up so ant match and coupling be similar to keyup condition into dummy
ant?
Bob
From:
[email protected]To:
[email protected]Date: Tue, 24
Dec 2013 09:24:13 +0100
Subject: VLF: SAQ
Very nice reception here in Nuernberg as
well:
Merry Christmas to all!
73, Markus (DF6NM)
