maco 75 orange face amp

[Macoman105c]

just bought the amp..the guy said it needed a new tube,,, found a nos 8950 put it in when I key down it does not unkey...have to put in stand by to unkey.. whats wrong with it?

[Deleted User 30222]

That's kind of weird. And it does key and unkey with no amp? By chance did you install a new mic also?

[MDYoungblood]

There is a miss match somewhere causing the amp oscillate, possible is just a stinky relay, or just too much input. It is hard to say by the little bit of info you gave us. What radio are you using? What is the DK of the radio? Have you checked the jumpers? SWR?

3's

Greg

[Bluerunner]

Sounds like it is oscillating. Check the tuning.

[Macoman105c]

It is a Galaxy 2517 with a 2 watt dead key swinging to about 15 or 20 watts.. try to ad just tuner on the front did nothing...it does have a screw inside of the box or some kind of adjustments should I try tuning that?? I put in a new 8950 tube is only putting out around a hundred Watts I know that's not right should be more than that

[MDYoungblood]

I looked at the schematic of one and don't see anything tunable inside but then again the schematics I see aren't complete.

3's

Greg

[Macoman105c]

its where you can put a screwdriver in it to adjust I guess?