Stryker 955 v2 help

[El Mafioso]

Hello need some help with a Stryker 955 i have 50 watt deadkey no audio on am ssb seems fine fm have audio but still same high deadkey added new mosfets new voltage regulator and still no luck any input would be apreciated thanks!

 

[johnecashflo]

Check the potentiometers on the main chassis I have recently fixed a few 955 and 655 with the same issues and it was potentiometers with no adjustment (no resistance) or the complete opposite (too much resistance) had a few that were reading in the millions of ohms. You should be able to check them for voltage change while adjusting. If you have no change or very irratic voltage swings then it could be the problem. You can also check for resistance values by using the ohms settings.

 

[loosecannon]

this is a V2 chassis so there will be no potentiometers on the board.

check that large SMD transistor mounted to the PC board that is just to the right of the big green electrolytic cap.

be aware that if this part is shorted, it could take out other good components, so be sure to check all the mosfet output transistors and the AM reg before powering up the radio.
LC

 

[El Mafioso]

this is a V2 chassis so there will be no potentiometers on the board.

check that large SMD transistor mounted to the PC board that is just to the right of the big green electrolytic cap.

be aware that if this part is shorted, it could take out other good components, so be sure to check all the mosfet output transistors and the AM reg before powering up the radio.
LC

Thanks i did change it and no luck this radio is going to be a lot of fun i can hear audio inside the radio but no rf output also changed voltage regulator twice just incase but still nothing

 

[loosecannon]

depending on the order you replaced things, and whether or not you tried to TX during those replacements, you could have taken out one or more of your new parts.

this can lead to chasing your tail looking for a problem that you've actually already fixed but still have one or more bad parts.

best thing you can do is unsolder all the legs from the driver, the finals, and the AM Regulator (the one mounted to the side of the chassis), and remove that transistor mounted to the PC board next to that cap.

then test each part with a transistor checker. If they all test good, then you can hang your head in sorrow since you're going to have to start checking those tiny components along the AM TX path.

the problem you are describing is a textbook example of "bad AM reg and associated transistor".
LC

 

[El Mafioso]

depending on the order you replaced things, and whether or not you tried to TX during those replacements, you could have taken out one or more of your new parts.

this can lead to chasing your tail looking for a problem that you've actually already fixed but still have one or more bad parts.

best thing you can do is unsolder all the legs from the driver, the finals, and the AM Regulator (the one mounted to the side of the chassis), and remove that transistor mounted to the PC board next to that cap.

then test each part with a transistor checker. If they all test good, then you can hang your head in sorrow since you're going to have to start checking those tiny components along the AM TX path.

the problem you are describing is a textbook example of "bad AM reg and associated transistor".
LC

Thanks for your input will mess around with it again in a few days waiting on some parts to come in hopefully i can get to work again

 

[El Mafioso]

Update.. still no luck if i short the voltage regulator i get 50watt+ deadkey no modulation these means the tx section is good will continue testing out all the smaller components