Miniature tube retainers?

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sepulchre
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Miniature tube retainers?

Post by sepulchre »

My current build uses a 6X4 rectifier. It's a 7 pin miniature tube. I've been looking but can't seem to find a retainer for it. I've got them for the 12AX7 and two EL84 size tubes in the build but nothing for this little rectifier.

Am I just missing them somewhere? Will I have to customize a 12AX7 retainer? I know the tube will probably be fine without it, but I don't like "probably be fine" situations. I did see a 7 pin socket that comes with an aluminum sleeve. I wonder how hot this guy is going to run and if such a sleeve is not a good idea. 'Probably be fine', right?
Stevem
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Re: Miniature tube retainers?

Post by Stevem »

Univox amps of which there are many that use the 6x4 recto have a spring type fold over clip.
I had to make one once and I took some mild steel, bent it to what I needed and then heated it up red hot and instantly dropped it in water which turns the mild steel into a low grade spring steel and works good enough!
If you look at some hobby shops and or model railroad shops some times they stock phosfer bronze wire and that already has a springy nature to it.
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Kagliostro
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Re: Miniature tube retainers?

Post by Kagliostro »

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sepulchre
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Re: Miniature tube retainers?

Post by sepulchre »

Kagliostro: Thanks but that one is for a short (38mm) tube. The 6X4 that I need this for is 53mm.

Stevem: Actually, it's a Univox style amp that I'm building. The U45b schematic was my base plan but I've changed it somewhat. My original intent was to clone it because that was the first amp I ever owned way back in the day when they were new. It sounded pretty good but I wanted a little more gain available so I added some boost (on a switch) and upped the supply filter caps a little. When Edcor gets me the transformers we shall see if I have done it justice.

I appreciate the tips for making a retainer. I bought a few regular preamp tube retainers and maybe one can be modified to fit the bill. If not I'll try making one from scratch as you proposed.

Thanks guys! Here's the logo for it and a shot of the unfinished cab.
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Kagliostro
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Re: Miniature tube retainers?

Post by Kagliostro »

that one is for a short (38mm) tube. The 6X4 that I need this for is 53mm.
I think you must do a merge between that and a 9 pin one

K
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Kagliostro
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Re: Miniature tube retainers?

Post by Kagliostro »

May be you can solve the problem in this simply way

[img:1024:768]http://i804.photobucket.com/albums/yy32 ... 302e53.jpg[/img]

K
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sepulchre
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Re: Miniature tube retainers?

Post by sepulchre »

That's pretty clever, Kagliostro. If my modified preamp things don't work I'll keep this in mind.
davent
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Re: Miniature tube retainers?

Post by davent »

I modified a 12a_7 retainer to use with a 6aq5 as i have lots of 7pin sockets already and the only way i could find the proper sized retainer was to buy them with the sockets.

Used two Keystone terminal lugs, bent at right angles, one end held by the socket mounting screws and the retainer hooked into the other end of the terminal lug. (Part #7325 i believe)

Edit: Make that a #7331
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sepulchre
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Re: Miniature tube retainers?

Post by sepulchre »

Yeah, a 6aq5 is an audio tube. They are shorter than the rectifier, by 15 or 20 mm. But you're onto the right idea IMO. I'm playing with 12A_7 retainers with modification in mind.
davent
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Re: Miniature tube retainers?

Post by davent »

sepulchre wrote:Yeah, a 6aq5 is an audio tube. They are shorter than the rectifier, by 15 or 20 mm. But you're onto the right idea IMO. I'm playing with 12A_7 retainers with modification in mind.
6AQ5's a beam-power pentode, 7 pin mini 6v6.
Datasheets have both of the 7pins at 2 3/8" max..

http://www.r-type.org/pdfs/6x4-1.pdf
http://www.r-type.org/pdfs/6aq5-2.pdf
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sepulchre
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Re: Miniature tube retainers?

Post by sepulchre »

Oh I see. You're right. There are a group of shorter audio tubes. I mistook the 6aq5 for one. Sorry.
davent
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Re: Miniature tube retainers?

Post by davent »

No problem!
I've got the tube mounted horizontal and the setup seems a good fit, now i just need to finish the amp. Was the only idea i could come up with and the price was right.
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sepulchre
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Re: Miniature tube retainers?

Post by sepulchre »

What I am doing uses a 6BM8 which is a power pentode coupled with a triode. I'll use two for a push/pull PA. One of the triodes will be a cathodyne PI and there will be third tube, a 12AX7 for a preamp and driver.

I figure I'll make some hooks out of copper attached to the mounting screws to hold the retainer.
davent
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Re: Miniature tube retainers?

Post by davent »

Sounds like fun and great looking cab!

Shouldn't be too difficult to come up with an extension for the retainer you have. Long ago i came across an article on bending your own but could never track it down again when the time came that i was going to need to do something similar, so it goes.
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sepulchre
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Re: Miniature tube retainers?

Post by sepulchre »

If I cannot modify a preamp retainer I think Stevem's suggestion of using some mild steel may be of use.
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