The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Hi all!

Today I received a RM KLV350 with a possible short circuit problem from a very dissapointed owner and good friend. I've tried some plausible solutions but none worked. The thing is that when the amp is switched on and on stand-by, transmitting/receiving is no problem and the valves light up normally. When the amp is switched to power and a TX is applied the fuse blows with a bright flash. The first time this occurred while transmitting.

In my opinion some part must have given way which causes leakage to ground

I consulted rmitaly.com to obtain the partslist, layout and schematic info and at first i thought D7 had blown which could cause a major leakage to ground so the fuse blows up.

Could anybody have an idea where to look for?

Any help will be enormously appreciated!!

Cheers!

Breaklight

19WAC495

... meanwhile I checked all the capacitors and diodes... all fine. I checked the relay switch as well and it works properly. Only thing left seem to be the valves..? What I found out is that when the amp is hooked up between the transceiver and the antenna it gives a bad SWR whereas my own amp doesn't do anything to the SWR...

So what's next?

Check you don't have a valve that is shorted from the top cap to the pins at the bottom, there should be no connection between then.
You will have to remove the valves to do the test.
Dave.

Hi Dave,

Sounds plausibel to me. At this point an order has been placed to obtain two new valves as nothing else seems to give any troubles. I didn't get the chance to test the amp without the valves fitted so I'll do this a soon as possible... it probably (hopefully) figures

Thanks for the help!

John.

John,
Did you find the problem with the Amp ?.
I just had one in today with the same fault and it had one shorted valve.
Dave.

Having same problem. Has anyone figured out what is causing this? I seem to think it's shorted Tube.

Thanks,

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