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THE AM BULLETIN BOARD => Technical Forum => Topic started by: ve6pg on March 08, 2009, 09:42:58 AM



Title: APACHE BLOWIN FUSES....
Post by: ve6pg on March 08, 2009, 09:42:58 AM
...after quite a spell sitting idle, i put an apache on the bench...re-toobed it, turned it on, and let it run in the filaments fer most of the day...
...all seemed ok...it blew a few fuses after a short period on the air...plate current was good, etc...so this morning, i replaced a fuse, and with the power turned off, i plugged it in, and it is now blowing fuses, with out even being turned on....i see there are 2 caps in the ac line...have not checked them yet, but has me thinking...anyway, any ideas on this one?...as i said, blowing fuses as soon as it is plugged in, without the main power turned on...

..tnx...tim...

..sk..


Title: Re: APACHE BLOWIN FUSES....
Post by: W3SLK on March 08, 2009, 09:49:51 AM
Boy Tim, that could be anything. Your best bet would be to start at the AC power input and disconnect/reconnect until you find a branch that causes the fuse to blow. I have a Ranger that did that and it traced it down to the spaghetti decomposing and the wire shorting out at the accessory jack. GUD luck.


Title: Re: APACHE BLOWIN FUSES....
Post by: w3jn on March 08, 2009, 10:58:38 AM
Most likely you need to replace the AC line filter caps.   They are there to prevent RF from exiting the transmitter via the AC line.  Be sure and use X1/Y2 rated caps.

There are other possibilties - shorted AC line wire to the chassis, power transformer winding shorted to the chassis, etc., but the line capacitors would be my first suspect.  Should be very easy to find with a VOM.

This guy is in Canada and sells 'em  http://www.justradios.com/X1Y2capacitors.html
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