Hi Folks: On the MMT tx, check all the tx transistors for proper bias voltage
(.4 ~ .7 typical on base ), if zero or 12~14 volts that device is likely toast
(or no B+ getting to collector). I have seen the final output tuning cap that
shunts to ground fail in a high vswr condition. That puts the collector to
ground and takes out the in-line fuse once the cap failure is a DC short
condition. With the 404 and 432 MHz energy close to each other you can be led
astray with a broadband RF power meter when attempting to detect low level
signals. A high Q 432 Mhz filter can help as can a MMIC stage or two after the
filter to the RF meter to get some sign of a 432Mhz signal coming through the
system if no access to a spectrum analyzer is possible. (Likewise for the
404Mhz, sometimes those old gold twin cavity military filters are quite useful
on the test bench). Mike wa3tts
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