[BC] Te st Your Wits on This

[Jerry Mathis]

On Mon, Feb 27, 2012 at 5:46 PM, Dave Dunsmoor <mrfixit at min.midco.net> wrote:
>> I have no absolutely idea why I tried reorienting the tube in the socket,
>but when I did, the RF neutralization value dropped to under 10 watts.
>>
>> By then making small adjustments in the tube's orientation, I got the
>value down to practically nothing, and got the rig on back the air shortly
>after 5 AM.
>>
>> Richard Rudman

>   Ok, someone, ANYone, explain this to me? I'm lost....

>   Are we talking about a tube such as a 3CX15000 or the like? Has to be, a
>pin-type would not do well... :-)

>Dave Dunsmoor

It's a 20KW transmitter, so the final will be something like a 4CX15,000 or a 8990 or 4CX20,000.

I'm frankly suspicious that there's still something wrong in the tube socket, probably inside where it can't be seen. A short between something where there shouldn't be. Six screws through the ceramic, I'm thinking there's a carbon trace somewhere. Moving the screws around when they rotated the socket broke the connection with the carbon trace.

That's my theory anyway, and I'm sticking to it!  :)  They may never know unless the problem recurs and they have to change out the tube socket. I'm like you, I just don't see how rotating the tube in the socket would fix the problem.

Having said that, I'm also a believer in the philosophy of, "if it works, leave it alone!".

--
Jerry Mathis