PS: Watch the duty cycle of the output signal. I don't know how
accurate it has to be for that PA. Maybe you'll need another amp stage
in front of the 4426 and anti-serial Z-diodes. Or an op amp stage...
There are several methods as i said :-)
73
Am 04.12.2015 21:39, schrieb DK7FC:
R Mal,
Then i would try the TC4426, if you have them at home. And a ferrite
transformer to rise the voltage level a bit and to decouple TX from PA.
https://129.206.22.210:8001/f/80bc50b01d/
for example.
I also prefer Schmitt-trigger based drivers and rectangular input
signals.
Just use a scope and watch the output signal of the 4426. Maybe you
will need a higher transformation ratio. Or use the ICL7667 if you have
one. It can be driven from a 3.3V signal on the input and gives an
output sqare wave of abt the supply voltage (I use it as a driver
between Raspi and my main MF PA).
73, Stefan
Am 04.12.2015 19:17, schrieb mal hamilton:
Guten Tag Stefan
Main amp is a single Decca 5501 module and has a smit trigeer
so
can take sine or square wave. I use square wave input for Opera and
QRSS because of the divide down from 5 Mhz main VFO. The input to main
amp needs around 7 – 10 volts. At present I use VFO 472 – 479 Khz
/4001(SQUARER)/4017 DIVIDE BY 10/tc4426 driver to main 5501 amp input
73 de mal/g3kev
Sent: Friday, December 04, 2015 5:07 PM
Subject: Re: LF: WSPR OBSERVATIONS
Am 04.12.2015 17:53, schrieb mal hamilton:
[...]
When I get time I will QRO but need to build an intermediate
RF amp between TCVR and main MF amp
Which input signal does your main MF amp need? Rectangular? Sine? Which
input-Z? Which amplitude?
73, Stefan
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