KLV350

[Crusher]

I have a klv350 that a friend gave me. You can turn it on and let it sit and it is fine. As soon as you key amp though, it blows the main 10A fuse. The inside looks fine, I was wondering though is it possible that one of the two tubes is shorted? Any ideas or suggestions would be great.

Thanks in advance,
Crusher

 

[paws264]

I have a klv350 that a friend gave me. You can turn it on and let it sit and it is fine. As soon as you key amp though, it blows the main 10A fuse. The inside looks fine, I was wondering though is it possible that one of the two tubes is shorted? Any ideas or suggestions would be great.

Thanks in advance,
Crusher

Either you have a bad tube or the diodes in your B+ powersupply are shorted.

 

[Crusher]

I pulled both tubes and keyed it up. The fuse did not blow. Someone else had also told me it is not uncommon for the tubes in that amp to short out. Now I just need to find who has new tubes. A local electronics store has them(Copper Electronics), but they want $50 each. I was told they normally go for about $25 each. Hmmmm someone trying to make a little extra money. I have to look at Westgate or RF parts.

 

[lords]

I pulled both tubes and keyed it up. The fuse did not blow. Someone else had also told me it is not uncommon for the tubes in that amp to short out. Now I just need to find who has new tubes. A local electronics store has them(****** Electronics), but they want $50 each. I was told they normally go for about $25 each. Hmmmm someone trying to make a little extra money. I have to look at Westgate or RF parts.

If you look at the KLV350 Schematics you will see the diodes before the tubes that you should check...just because you pull the tubes and it don't blow, doesn't meant the tubes are bad...pull the legs of the diodes to check them before you go and spend bucks for 2 new tubes...and yes that board is a bit harsh when a solder gun touches it...I use a cold solder gun on them boards

do you have a friend that has a tube checker..that checks the the tube for shorts?

 

[Crusher]

I think it's the tubes. I checked both diodes to see if they were bad, they check good. Only conduction 1 way. There is also a bleeder resisiter and that too looks and checks fine. Thank you for pointing me in that direction. I know VERY little about tubes and probably would not have figured that out for awhile. Heck I didn't even know that the connector on top was for biasing. LOL
Thank You,
Crusher

 

[lords]

I see 4 diodes to check going to parts of the tubes