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I had a Cobra 142GTL a while back that I did some experimenting on, I decided to put in an IRF520N mosfet in place of the 2SC1969 final. When I got done putting in everything into place I was producing 30W PEP output on SSB. However....

... it took out the mode selector switch, more specifically, it burned out the contacts on the LSB side of the mode switch, which was the mode I was using at the time of testing. Too much current draw. That is the caveat, as Nomad and Kopcicle have suggested. Something's gotta give.

I have found that 25W PEP on SSB keeps everything pretty happy after the conversion has been done.

Again, I state that this is an alternate method to keep/get your radio going, not to make a big power upgrade. There's very little to be gained by putting in a mosfet for the sake of trying to squeeze every last watt out of a radio. Unless a person is willing to make several upgrades (power supply, mode switch, AM pass regulator, etc), it's going to cause more problems than what it's worth.

~Cheers~

<blockquote data-quote="ExitThirteen" data-source="post: 690399" data-attributes="member: 6878">I had a Cobra 142GTL a while back that I did some experimenting on, I decided to put in an IRF520N mosfet in place of the 2SC1969 final. When I got done putting in everything into place I was producing 30W PEP output on SSB.&nbsp; However....... it took out the mode selector switch, more specifically, it burned out the contacts on the LSB side of the mode switch, which was the mode I was using at the time of testing. Too much current draw. That is the caveat, as Nomad and Kopcicle have suggested. Something&#039;s gotta give.I have found that 25W PEP on SSB keeps everything pretty happy after the conversion has been done.Again, I state that this is an alternate method to keep/get your radio going, not to make a big power upgrade. There&#039;s very little to be gained by putting in a mosfet for the sake of trying to squeeze every last watt out of a radio. Unless a person is willing to make several upgrades (power supply, mode switch, AM pass regulator, etc), it&#039;s going to cause more problems than what it&#039;s worth.~Cheers~</blockquote>

[QUOTE="ExitThirteen, post: 690399, member: 6878"] I had a Cobra 142GTL a while back that I did some experimenting on, I decided to put in an IRF520N mosfet in place of the 2SC1969 final. When I got done putting in everything into place I was producing 30W PEP output on SSB. However.... ... it took out the mode selector switch, more specifically, it burned out the contacts on the LSB side of the mode switch, which was the mode I was using at the time of testing. Too much current draw. That is the caveat, as Nomad and Kopcicle have suggested. Something's gotta give. I have found that 25W PEP on SSB keeps everything pretty happy after the conversion has been done. Again, I state that this is an alternate method to keep/get your radio going, not to make a big power upgrade. There's very little to be gained by putting in a mosfet for the sake of trying to squeeze every last watt out of a radio. Unless a person is willing to make several upgrades (power supply, mode switch, AM pass regulator, etc), it's going to cause more problems than what it's worth. ~Cheers~ [/QUOTE]

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