Where to source 3" tall 9-pin preamp tube shields (for 6BM8)?

[dchang0]

Hi, everyone--

Anyone have any idea where to order single-unit 3" tall 9-pin preamp tube shields (Fender-style)? Do they even make tube shields that tall?

Thanks in advance!

[Steve Conner]

I've never seen one. Power tubes that run hot are usually just held in place with a spring clip, AFAIK.

[Enzo]

I agree, I have never seen a power tube shield.

[dchang0]

Turns out they do make them. I found a Russian supplier of military 9-pin sockets with fully-enclosed 70mm shields. Obviously, shipping is very high, and they have a minimum order... Hopefully, there's a US source...

And, as you guys indicated, there are indeed spring clips. As I understand it, the EL84 clips will work, provided the base is 3/4" and not 7/8" as is sometimes used for some makes of EL84s.

[roughcut studios]

Check out the IERC tube shields with the internal fins. The fins transfer heat away from the glass envelope. Supposedly the tube would run 10% cooler with these in place. Used by the military, and by Hewlett Packard in their old signal generators. I have some that are 2 3/4" tall that fit 6bm8 or el84.
....Jon

[dchang0]

Woooooooo, those sound great--thanks for the suggestion and confirming that the 2 3/4" fit the 6BM8! I actually saw a 2.5" one on ebay but wasn't sure what to make of them. Do they hook onto the bayonet lugs on typical Fender-style shield bases?

Also, if you happen to have the model number, that would be a huge help. The 2.5" one has part number TR5-6025. Can't seem to find the part number for the one that is 2 3/4" tall.


Update: P/N is 6027B, "extra tall." At $12 each, they are PRICEY, even used, but it beats breaking 6BM8 tubes at $15 to $20 a pop.

[roughcut studios]

Here are some photos of some that I have. They are all marked 6027B. They snap onto standard tube shield bases. One photo shows the liner removed. ...Jon

[dchang0]

AWESOME! Thanks, Jon--I found a source for them and ordered one. To anyone else interested, Fair Radio Sales Company Inc. carries them in three different types under the same MILSPEC number. As of this writing, $15 for the model with the highest heat dispersion rating, $12 for the medium one, and $10 for a competitor's knock-off that meets the same standard.