Hello Alex,
it would be really nice to be able to see if your signal coul make it over
to Europe, the distance between you and my QTH is 'only' about 4038 km ;-)
My VFO is not very good because it was builded for normal CW operation.
OK. I will be lookin for XTAL for this frequency. There is some oportunity
to get such a XTAL.
... you could also look into some other solutions that should work pretty
well. For example, there is a way to use two xtals that are 137.7 kHz
apart. The frequencies of thos x-tals are mixed. If the two xtals have
approximately the same temperature behaviour, the resulting frequency is
very stabile. You find a possible sulution on the homepage of Peter, DF3LP
at
http://www.qsl.net/df3lp/137khz/LF-transmitter.html
Another way would be to use to HF transceiver or a good HF vfo and divide
it's frequency by a certain factor, or use the transceiver in combination
with an xtal converting the frequency to 137.700 kHz.
I prefer to use PIC16F84 microcontroller as QRSS TX keyer, not PC. To
build such a keyer I should know:
1. What dot duration accurancy should be?
2. What is standard dotlenth and should it be very stable? May be I can
use RC generator in the controller...
3. Should I do any synchronization of each dot/dash start to global time?
If not it's better...
... typical dotlength for QRSS operation is 3 seconds for "normal" QRSS
QSOs (very much used within Europe, when the signal strength is just not
sufficient to work with normal CW, and 60 or 90 seconds for
intercontinental beacon operation, stations from VE have been successfully
copied in Europe, and European stations have been copied in VE and W by
using 60 or 90 second dot length. So far only a few attempts were made
using "synchronized" dots, but the majority of the succesful tests were
made with non-synchronized signals. The accuracy of the dot length is not
very important.
There is an excellent software written by Rik, ON7YD available at
http://members.aol.com/lwcanews/qrs311dl.htm
it works under Windows 95/98 and, as far as I know, also under Windows
3.11. The interface to the TX is done by using the serial port using a
transistor.
Best 73
Geri, DK8KW (W1KW)
LF-homepage http://www.qru.de
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