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Diodes are possibly bad, blown shorted from some kind of failure.

When MOSFET, they need to be ZENER types, 5.1 to 5.6V 1 watt rated.

you also install them where the BAND is towards the Gate (to the left) - in Bipolar days, the Band was towards the Ground - Emitter side (to the right)

Better check those Bias pots, They may have opened, forcing full 8V TX voltage - causing "Zener" effect - you should be able to adjust from a low as 0.7V to as high as 4,5V nothing more. That is adjust...not just check for them...if the diodes blew, they'd blow open usually from the Zener-ing they perform (crowbar latch on) until reset or they pop like a fuse...

Check traces, see the post I sent earlier - make the work as clean as possible and check the Bias section. Else what did happen will keep happening until it's fixed.

<blockquote data-quote="Handy Andy" data-source="post: 762387" data-attributes="member: 52309">Diodes are possibly bad, blown shorted from some kind of failure.When MOSFET, they need to be ZENER types, 5.1 to 5.6V 1 watt rated.you also install them where the BAND is towards the Gate (to the left) - in Bipolar days, the Band was towards the Ground - Emitter side (to the right)Better check those Bias pots, They may have opened, forcing full 8V TX voltage - causing &quot;Zener&quot; effect -&nbsp; you should be able to adjust from a low as 0.7V to as high as 4,5V nothing more. That is adjust...not just check for them...if the diodes blew, they&#039;d blow open usually from the Zener-ing they perform (crowbar latch on) until reset or they pop like a fuse...Check traces, see the post I sent earlier - make the work as clean as possible and check the Bias section. Else what did happen will keep happening until it&#039;s fixed.</blockquote>

[QUOTE="Handy Andy, post: 762387, member: 52309"] Diodes are possibly bad, blown shorted from some kind of failure. When MOSFET, they need to be ZENER types, 5.1 to 5.6V 1 watt rated. you also install them where the BAND is towards the Gate (to the left) - in Bipolar days, the Band was towards the Ground - Emitter side (to the right) Better check those Bias pots, They may have opened, forcing full 8V TX voltage - causing "Zener" effect - you should be able to adjust from a low as 0.7V to as high as 4,5V nothing more. That is adjust...not just check for them...if the diodes blew, they'd blow open usually from the Zener-ing they perform (crowbar latch on) until reset or they pop like a fuse... Check traces, see the post I sent earlier - make the work as clean as possible and check the Bias section. Else what did happen will keep happening until it's fixed. [/QUOTE]

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