Hello everybody

Do you have the transverter designed by DB6NT, version 1.0 4/93 and you
need just a little more output power ? please read on !

After building such a transvertor I could only get 800 mW output power.
For a lineair amplifier I need 1.5 W. A solution could be to buy just
a small AMP. I have found the datasheets from the CLY 5 and CLY 10 on
the internet. Now it was clear to me that it had to be possible to 
obtain more power as the CLY 10 is able of dissipating 4 Watts !
With the original tunning it is only possible to get a minimal drain-
voltage on the CLY 10 of 6.5 Volts. This mean there flows 320 mA.
Following the datasheet the optimum current should be 700 mA. To get more 
current the gate-voltage should be raised. As one can see in the diagram
of the transvertor there are tree resistors connected in series from the
minus 5 Volts to ground. The middle resistor is a potentiometer. With this
pot you can tune the gate-voltage. If you solder a 1 kOhm resistor in
PARALLEL with the one from the pot to ground, you can adjust more current
in the CLY 10. This resultes in a power output of max. 1.3 Watts. You 
should try to get a drain-voltage of 6 volts.

If you want a bit more you can connect a 4,7 Ohm 1,4 Watts resistor in
PARALLEL with the excisting drain-resistor of the CLY 10. Be shure to lower
the current first ! before swithing on !. Now try to get a drain-voltage
of 7.0 - 6.8 Volts. This will bring you the 1.5 Watts.

I have also connected a 22 Ohm resistor PARALLEL to the drain-resistor
of the CLY 5 (that one is also 22 Ohm) and raised the current til I had a
drain-voltage of 6 Volts. I obtain now 1.7 Watts from the transvertor.

This modification is on your own risk !!

The datasheets of the CLY 5 and CLY 10 can be downloaded from SIEMENS at:
www.siemens.de/semiconductor/index/listtyp0.htm

If you have any questions about this mod contact me at:

PE1PFW@PI8WNO
[email protected]

73 Bart :+)