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One time I was called out to one of our AM broadcast sites as the Gates BC-1 transmitter had gone off the air. It kept blowing the 600 volt power supply that provided power to the RF drivers and audio amp section prior to the modulators. It would blow a fuse as fast as I could install them yet static resistance checks said things were fine. Getting fed up I decided to replace the fuse (3 amp IIRC) with a higher rated one to see if it would hold or if I could see anything happening before it blew. I was getting low on fuses and installed a 7 amp slo-blow and watched carefully as I hit the switch. BINGO!! I saw a tiny purplish-green flash in one hard to get at corner of the audio driver board just before the fuse blew. It ended up being a shorted ceramic disc bypass capacitor that would appear OK with an ohmmeter but when the 600 volts was applied it would flash over and short to ground. The slo-blow fuse allowed it to heat up enough before blowing that I was finally able to see where the fault was. Sometimes desperate times calls for desperate measures. If you're lucky they work. If not you have to explain to the boss how all the extra damage happened. LOL

<blockquote data-quote="Captain Kilowatt" data-source="post: 632661" data-attributes="member: 39"><p>One time I was called out to one of our AM broadcast sites as the Gates BC-1 transmitter had gone off the air. It kept blowing the 600 volt power supply that provided power to the RF drivers and audio amp section prior to the modulators. It would blow a fuse as fast as I could install them yet static resistance checks said things were fine. Getting fed up I decided to replace the fuse (3 amp IIRC) with a higher rated one to see if it would hold or if I could see anything happening before it blew. I was getting low on fuses and installed a 7 amp slo-blow and watched carefully as I hit the switch. BINGO!! I saw a tiny purplish-green flash in one hard to get at corner of the audio driver board just before the fuse blew. It ended up being a shorted ceramic disc bypass capacitor that would appear OK with an ohmmeter but when the 600 volts was applied it would flash over and short to ground. The slo-blow fuse allowed it to heat up enough before blowing that I was finally able to see where the fault was. Sometimes desperate times calls for desperate measures. If you&#039;re lucky they work. If not you have to explain to the boss how all the extra damage happened. LOL</p></blockquote><p></p>

[QUOTE="Captain Kilowatt, post: 632661, member: 39"] One time I was called out to one of our AM broadcast sites as the Gates BC-1 transmitter had gone off the air. It kept blowing the 600 volt power supply that provided power to the RF drivers and audio amp section prior to the modulators. It would blow a fuse as fast as I could install them yet static resistance checks said things were fine. Getting fed up I decided to replace the fuse (3 amp IIRC) with a higher rated one to see if it would hold or if I could see anything happening before it blew. I was getting low on fuses and installed a 7 amp slo-blow and watched carefully as I hit the switch. BINGO!! I saw a tiny purplish-green flash in one hard to get at corner of the audio driver board just before the fuse blew. It ended up being a shorted ceramic disc bypass capacitor that would appear OK with an ohmmeter but when the 600 volts was applied it would flash over and short to ground. The slo-blow fuse allowed it to heat up enough before blowing that I was finally able to see where the fault was. Sometimes desperate times calls for desperate measures. If you're lucky they work. If not you have to explain to the boss how all the extra damage happened. LOL [/QUOTE]

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