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Author Topic: Tunning Troubles  (Read 2774 times)
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N8ETQ
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Mort


« on: March 07, 2012, 07:00:23 AM »

Good Morning,

Should I do anything with this before I put
it back in? It will be a PITA to get out again.

One thing after another with this Amp.
HT-33B tunning cap.

Thanks

/Dan


* HT-33B_Repairs 027.jpg (335.99 KB, 1824x1368 - viewed 398 times.)
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The Slab Bacon
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« Reply #1 on: March 07, 2012, 09:40:57 AM »

Good Morning,
Should I do anything with this before I put
it back in? It will be a PITA to get out again.
One thing after another with this Amp.
HT-33B tunning cap.
Thanks
/Dan


REPLACE IT! ! ! ! ! !  all of those zots and zorches on the plates will cause it to arc over again, kinda like the electrodes in a sparkplug.

or.....................

Take it completely apart and file the plates flat and smooth again, then buff the file marks off. (make them look like they originally did pre-zorch)

or..................

Replace it with a similar valued vacuuuuuuuum cap (best choice!!)
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"No is not an answer and failure is not an option!"
N8ETQ
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Mort


« Reply #2 on: March 07, 2012, 10:22:48 PM »


Yeah, Thanks, I guess I knew that.  I'll try option 2 and prolly
drop the screen voltage on this thing to keep the power down a little.
PITA

73

/Dan


"Take it completely apart and file the plates flat and smooth again, then buff the file marks off. (make them look like they originally did pre-zorch)"
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ke7trp
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« Reply #3 on: March 10, 2012, 11:09:13 PM »

Yeah. What Frank said.  I have better luck replacing them if at all possible.  Once they get arced out like that its almost always going to do this again. I wonder what caused this to start.   

On air caps like that its best to have the plates good and meshed.  If the amp always tunes with the ends poking into the other plates thats a NO GO.  You wont have much area there to couple.  if you can add a fixed door knob in so the plates are meshed more, then you prob wont arc it out again.  At least thats my experience here and that was my fix.

I would not take that apart.  I have cleaned them up many times with a simple Dremel tool and some good thin stone bits. Then sandpaper  to finish.
C
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Jeff W9GY
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« Reply #4 on: March 11, 2012, 11:54:19 AM »

Parasitic causing this???
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Jeff  W9GY Calumet, Michigan
(Copper Country)
N8ETQ
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Mort


« Reply #5 on: March 11, 2012, 12:54:49 PM »


Hey Jeff,

   I don't know for sure as I can't bring it up yet. P.sup issues.
It's well made and the grid circuit is swamped with R's so I
suspect more "Pilot Error" or antenna issues. We will see when
My caps come in.  I'll update this thread with results.

Thanks es 73

/Dan

Parasitic causing this???


* HT-33_Grid.gif (17.67 KB, 701x393 - viewed 322 times.)
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