more on am than ssb

[1iwilly]

so i pick up another cobra 2000 from a scale of 1 to 10 about an 8 the issue I'm having is after an upgrade of tr41 and some cold solder joints
when tunning the radio if i tune for max on am then SSB falls off instead of like 12 watts it shows about 8 talking and when i tune to bring ssb up to specs am dropped from 28 pep to 18 pep I'm a am talker i never had an interest on ssb but been OCD i want the radio to be even like it should be
i usually tune l-47-l48-l46-l-45 then the l-38 using a 1000hz tone for am and a two-tone for ssb

 

[Shadetree Mechanic]

Have you checked the bias on the output transistors?

 

[nomadradio]

am dropped from 28 pep

A Cobra 2000? With the internal power supply?

Makes it sound as if the power supply regulator has run away, putting more than 13.5 Volts on the radio. The hottest Cobra 2000 on the planet should never show more than about 20 Watts PEP on AM or SSB.

Setting bias current on the final is absolutely the next step, before you toast the final. If the final-bias trimpot is set too high, the final transistor overheats on sideband and power falls off until it cools down.

Or until the radio cooks the final. Have a look at the color of the exposed metal surface on the mounting tab of the final transistor. If it's fuzzy and dark gray or black, it's been running really hot.

73

 

[1iwilly]

the bias is set at 30 and 60 voltage reg was changed with tip-42c the upgrade from stock