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Is my tube soft..... very funny .... the AMP tube....

lonestarbandit said:
a constant warm yellow/white glow with no dimming.
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Then you are good to go in that department.

Leads me to wonder if a prior owner put hard miles on the tubes before you acquired the amplifier?

Not every 120-Volt outlet is toxic, but if a previous owner ran it on a 'soft' outlet, the damage could have been done before you got the amplifier. History can be a big deal.

73
 
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He is a ham. I wouldnt have thought he beat it to death but no telling. It's certainly functional just maybe not at peak power that it could be. Guess I have to decide if that's worth 300 bucks to find out...
 
linearone said:
"The dip" usually occurs at the same point as max power out. Try tuning up by simply adjusting the controls for maximum pep while speaking. If you cant generate a tone, say "claudio", and adjust all knobs.
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Yes Sir, I have done that. That's what generated my original numbers.
 
Have one of these due tomorrow night.
We will see what it's meter thinks for fun.
 

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Well that went badly wrong.
That brand new MFJ 986 was bleeding RF talkback everywhere, would tune down then shoot up to sky high SWR and a something electronic ozone smell is coming from it with a whole 500 (supposedly can take 1.5k max) max watts in.
This thing is going back immidately.
I did not open it but I'd bet it was arcing.
This happened inmidiately after hookup.
I have nothing bad to say about the sellers (as long as they refund me) but the manufacturers....much to say there.
I don't want a replacement. This experience has soured me on MFJ for a while. Thank God the old 3-500z just shrugged it off.
 
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lonestarbandit said:
Well that went badly wrong.
That brand new MFJ 986 was bleeding RF talkback everywhere, would tune down then shoot up to sky high SWR and a something electronic ozone smell is coming from it with a whole 500 (supposedly can take 1.5k max) max watts in.
This thing is going back immidately.
I did not open it but I'd bet it was arcing.
This happened inmidiately after hookup.
I have nothing bad to say about the sellers (as long as they refund me) but the manufacturers....much to say there.
I don't want a replacement. This experience has soured me on MFJ for a while. Thank God the old 3-500z just shrugged it off.
Click to expand...
Are you using it on the ham bands or just cb?
 
It was intended for ham bands once I get my license but that tuner didn't last 2 minutes. Fortunantly my antennas are around 1.5 and 1.2 for CB presently straight through so I didn't "need" the tuner I was just trying to future proof the station and have one unit for meter/coax switch/tuner but this one was janky. I'll probably look into a Palstar later on.
 
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lonestarbandit said:
I'll probably look into a Palstar
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Much, much safer move.

I detest rotary inductors. They were the "hamsexy" feature of the nineties, but they are damaged too easily. If a previous owner failed to remove the oxide layer periodically, the coil's surface can get burned and pitted. Bad juju.

I'm reminded of the "I do cars" guy on YouTube. Tears down motors that never got the oil changed. He points out the results as he tears a motor down. Cleaning the black silver oxide from your rotary inductor isn't that different from regular oil changes. The longer you blow it off, the more damage you'll see.

The temptation to turn the inductor knob with too much drive power proves irresistible to many prior owners. Same result. Spots on the coil that are pitted and burned.

Are you dead certain that none of your coax jumpers has a high resistance on the ground side from one end to the other? I associate that fault with freaky hard-to-explain problems.

73
 
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Yes Sir. I'm fine without that tuner inline.
It was brand new and defective out of the box. I was just working at future proofing for the ham bands ahead of time but it didn't work out. Seller sent me a return label so all is well other than my disappointment with MFJ. I WILL now however test all my jumpers purely because you've now put that in my head even though I'm back functioning as normal without that tuner.
 
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Yes Sir all correct. I did not move it under power. Just like those variable TX stars, big no no but people do it.
It was just defective out of the box.
Smelled some serious "10 ohm" smell out of is as well immidately after keing up with it inline so something or many somethings were not well with that tuner.
As it was brand new, I wasnt about to assume liability by tearing into it. Just boxed it up, sent it back and learned my lesson about MFJ and glad I had the old AL80A battle wagon between that thing and the rather sensitive Yaesu FT710. THAT would have been a heart break if that junk tuner took out my radio.
 
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New penta tube installed... making the whiskeys with a LOT less drive.
Also have new (old) tuner from a silent key estate sale and unlike the brand new one I bought and had to return, it works great.
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