Oops, thanks Gary. Try again. I did a minor change in the schematic and
updated the file, i thought with the same name.
Now a new link and test:
http://dl.dropbox.com/u/19882028/LF/schematics/TX%20IQ%20converter.png
Should work now.
73, Stefan
Am 21.03.2012 13:37, schrieb Gary G4WGT:
Stefan,
The link did not work for me.
73, Gary - G4WGT.
----- Original Message ----- From: "Stefan Schäfer"
<[email protected]>
To: <[email protected]>
Sent: Tuesday, March 20, 2012 10:04 PM
Subject: LF: 137 kHz transmit IQ converter schematic
LF,
I took the time to draw the circuit of my transmit IQ converter in
the new program i have.
This is the circuit i use to generate my transmit signal to drive the
exciter of my PA. The 137 kHz signal is directly generated in this
circuit. It is mixed with 125 kHz internally.
The basic idea is taken from Andy/G4JNT, tnx agn. The circuit is
however modified for an input frequency of 10.7...12.8 kHz which can
be generated by the soundcard. The 125 kHz generator can be locked to
a reference signal, into a PLL which isn't shown here (separate
circuit). Anyway the circuit is a stand alone device. The input
signal level may be 0 (=100%) down to -30 dB full scale of the
soundcard without a change of the output signal (including a safety
factor of > 10 dB).
http://dl.dropbox.com/u/19882028/LF/schematics/TX%20IQ%20converter.png
Comments welcome.
73, Stefan/DK7FC
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