On 26-5-2012 0:48, Stefan Schäfer wrote:
I've been thinking about using the 2nd D Flipflop of the 4013 and
build a divide by 4 circuit. With this exciter one could easily use a
HF TRX like the IC-706 and drive the exciter by transmitting QRP in
the 160m band. 1900 kHz will then result in 475 kHz and the frequency
accuracy should be fine. In Split-mode one could transmit on 160m and
receive directly on MF. Using 3x 150 Ohm / 2W in parallel and another
1 kOhm resistor in series with 2 antiserial Z-diodes should be OK for
driving the input of the 4013 and getting a perfect SWR for the TRX...
Maybe this is how i will do it.
A similar set-up is running for some time here.
I started with de QTX 100W design with a 2MHz x-tal driven. (I'm also
one of those lurkers of this group)
Frustrated by the single channel I realized thet the TS-440 has an "all
band" option.
Simply replaced the the X-tal with a "dummy"-driven single transitor in
saturation, which fed de CD4024 by 4 divider.
From the dummy there is an attentuation by 4. Drive from the TS440 is
full CCW, almost zero.
It produces100W from 400-600kHz. Off course only non-lineair modes can
be used (CW, Opera, Slowhell ect)
There is small interface which plugs into the transverteroutlet which
drive the fast reed antenna relais.
Also experimented with a mixer from 2MHz to 500kHz which works fine,
only it requires some caution in relation to the drive.
Otherwise a wide noiseskirt is included. The PA is not lineair and whole
circuit has a certain "treshold".
NL 600m license is restricted to CW only, we consider Opera when
prefixed with a morse ID a such, the rest which follows is just test and
tune signals :-)
The divider route is therefore best suitable in my case.
Jan/pa3abk
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pa3abk<-> dordrecht jo21it
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