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eHam Forums => Amplifiers => Topic started by: KG6IDR on February 08, 2013, 08:52:31 AM



Title: Ameritron AL 572
Post by: KG6IDR on February 08, 2013, 08:52:31 AM
Hi, my Ameritron AL 572 had a hot smell to it a couple of weeks ago, then the other day htere was a noise in my receiver and the plate was up to 300 ma with no transmit. I shut it off and turned it back on and it was ok. The taylor tubes are only putting out 600 watts on 40m so I put in new Pinta Labs 572b's . I turned the amp on and let it set for around half an hour tuned it on 40m was getting 1000w high voaltage was 2600v @120v the grid and plate both went up ,grid 150 plate 600ma at the same time,there was a POP. I took cover off and cannot see any thing bad, burnt except a little oil? on the inside of  cover by one of the tubes. tested all eight tubes tha new Penta test good and the old Taylord test good but down some. Any one have any ideas?  Les  KG6IDR


Title: RE: Ameritron AL 572
Post by: AD4U on February 08, 2013, 10:12:53 AM
Oil?  Not familiar with this amp, but since there is "oil" inside, you may have blown a filter cap.  By changing out the tubes and still having the problem, you can eliminate an internal tube short.  That is unless both sets of tubes are bad.

Dick  AD4U


Title: RE: Ameritron AL 572
Post by: KG6IDR on February 08, 2013, 10:46:47 AM
The small amount of oil is where the tube base would be also it is showing neg.  grid current.


Title: RE: Ameritron AL 572
Post by: W8JX on February 08, 2013, 03:51:25 PM
Oil can only come from one thing here, a blown CAP (unless you have had oil can out in it for some reason)


Title: RE: Ameritron AL 572
Post by: KG6IDR on February 08, 2013, 04:11:45 PM
It would be one of the caps under tube socket and they look good.


Title: RE: Ameritron AL 572
Post by: W8JX on February 08, 2013, 09:21:31 PM
It would be one of the caps under tube socket and they look good.

First thing to check is main filter caps. You have a electrolytic to popped somewhere.