Bottlehead Forum

General Category => General Discussion => Topic started by: glennn111 on September 12, 2011, 09:33:10 AM

Title: Tube base replacement.
Post by: glennn111 on September 12, 2011, 09:33:10 AM

I have seen on various sites, replacement bases for both octal and 4 pin tubes. I have a pretty good idea of how to do the replacement having made a octal power cable before. But what type of cement is used for a tube? Any other tricks or advice would always be appreciated as well.

Title: Re: Tube base replacement.
Post by: 2wo on September 12, 2011, 06:32:12 PM

RTV works pretty well...John

Title: Re: Tube base replacement.
Post by: glennn111 on September 13, 2011, 08:02:19 AM

Thanks John. That's a pretty straight forward answer. I was somehow expecting some exotic potion, but RTV seems pretty obvious.
Thanks again.
Glenn

Title: Re: Tube base replacement.
Post by: Jim R. on September 13, 2011, 03:56:11 PM

Also, I think tube monger, Antique Electronics Supply, and thetubestore.com sell base cement, though the  RTV should be fine too.

-- Jim

Title: Re: Tube base replacement.
Post by: Grainger49 on September 14, 2011, 12:09:45 AM

There are many versions of RTV out there now.  You will want one that withstands heat.  In the beginning all were high temp, but not today.

Title: Re: Tube base replacement.
Post by: coca on September 14, 2011, 06:49:22 AM

The Rtv that is sold at automotive supply stores is meant for high temp. application.

Bernie.

Title: Re: Tube base replacement.
Post by: glennn111 on September 14, 2011, 01:25:15 PM

Thanks to all for your input. I think I will go with the RTV (high temp). Availability being the main factor, but also I think it should work quit well.
Thanks again.

Title: Re: Tube base replacement.
Post by: John Roman on September 18, 2011, 03:27:07 AM

Perhaps a dumb question here, but can you actually replace the base without compromising the vacuum?

Title: Re: Tube base replacement.
Post by: Jim R. on September 18, 2011, 07:34:16 AM

John,

Yes, in octal tubes and others with bases, the connections to the internal structures are done via flexible leads that have the glass sealed around them, and then the base is attached with the leads pulled through the pins in the base, soldered in place to the pins, and then the base glued to the glass.

HTH,

Jim