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 Suitable top cap grid connection
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 Return to top of page · Post #: 1 · Written at 4:31:40 PM on 20 October 2018.
Jimb's Gravatar
 Location: Kanahooka, NSW
 Member since 18 November 2016
 Member #: 2012
 Postcount: 659

Hi all.
I need to make up a couple of connectors for top cap G1 connections for 6J8 and 6G8 type valves.
I was thinking of cutting up a tinned food can. Making some narrow strips and bending them into shape, or soldering a couple of solder tags together and bending them around. I do not have any original ones.
I am sure some of you would have made some up out of common household stuff.
Regards Jimb


 
 Return to top of page · Post #: 2 · Written at 6:33:32 PM on 20 October 2018.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 882

Hi the originals have a bit of spring in them, a softer type of metal like a can may work loose over time, but, I've used tin cans for valve shields, top cap connectors and all sorts of applications. The best metal would probably be brass sheet but go ahead and snip up a can!
Fred.


 
 Return to top of page · Post #: 3 · Written at 8:09:43 PM on 20 October 2018.
STC830's Gravatar
 Location: NSW
 Member since 10 June 2010
 Member #: 681
 Postcount: 941

The best actually may be beryllium-copper if you can get it, a high strength alloy good for springs. Beryllium is however toxic so take care. But as Fred says tinplate from a can should do if it is reasonably resistant to bending ie will hold its bent shape for a good contact. Beware though that many tin cans are actually tin free steel (chrome plate) and won't solder- usually a grey rather than white metal. Most will be lacquered as well which can be scraped off with a copper coin, or removed with a DC current through a washing soda or bicarb solution.


 
 Return to top of page · Post #: 4 · Written at 9:29:39 PM on 20 October 2018.
Jimb's Gravatar
 Location: Kanahooka, NSW
 Member since 18 November 2016
 Member #: 2012
 Postcount: 659

Thank you Fred and STC830


 
 Return to top of page · Post #: 5 · Written at 8:34:33 AM on 21 October 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4344

I though new were still procurable, I have bought in the past & salvaged from various sources. EVATCO have an encapsulated (insulated) type intended for valves like 6CM5 that have the Top Cap as the Plate.


 
 Return to top of page · Post #: 6 · Written at 11:24:06 AM on 21 October 2018.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6012

I though new were still procurable

Can be found in the USA, e.g. :

https://www.rfparts.com/tubes/tubes-platecaps.html

-- but with the exchange rate and shipping, would need to buy in bulk to make it worthwhile.


 
 Return to top of page · Post #: 7 · Written at 11:33:01 AM on 21 October 2018.
Jimb's Gravatar
 Location: Kanahooka, NSW
 Member since 18 November 2016
 Member #: 2012
 Postcount: 659

Hi Marcc and GTC.
I have seen the insulated types on ebay however from memory the 6CM5 top cap was a larger diameter, and I don't want to wait for stuff to come from overseas.
Regards Jimb


 
 Return to top of page · Post #: 8 · Written at 11:47:55 AM on 21 October 2018.
STC830's Gravatar
 Location: NSW
 Member since 10 June 2010
 Member #: 681
 Postcount: 941

Phosphor bronze would also be a suitable material without the toxicity issue.


 
 Return to top of page · Post #: 9 · Written at 9:15:08 PM on 21 October 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4344

I have 6J8 & 6CM5 from memory it is a standard octal: 6D6 & co have the big Top cap, however, not relevant.

I have two encapsulated EVATCO ones in stock & they fit a 6J8: They have others. The only issue "might" be with a shield. On that basis I can't see any major problem.


 
 Return to top of page · Post #: 10 · Written at 10:39:36 AM on 22 October 2018.
Wa2ise's avatar
 Location: Oradell, US
 Member since 2 April 2010
 Member #: 643
 Postcount: 766

You might be able to use small springs salvaged from VCRs or DVD players. Bend the spring into a loop that could encircle the top cap. If you're lucky, you might find a spring that has a not quite large enough diameter that could grab the top cap. Hopefully the metal will accept soldering to a wire.


 
 Return to top of page · Post #: 11 · Written at 8:20:17 PM on 23 October 2018.
JamieLee's Gravatar
 Location: Clare, SA
 Member since 27 March 2016
 Member #: 1894
 Postcount: 508

I've used an alligator clip on one of mine.


 
 Return to top of page · Post #: 12 · Written at 8:36:23 PM on 23 October 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4344

"I've used an alligator clip on one of mine". Won't that have an effect on the AGC attack?


 
 Return to top of page · Post #: 13 · Written at 8:36:37 PM on 23 October 2018.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 6349

Valve cap clips are available from a seller on Ebay. They are white plastic with the metal part inside. I am not sure if these are available in the size you need though. Worth checking in the valve radio section of Ebay collectables.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 14 · Written at 6:28:31 AM on 24 October 2018.
STC830's Gravatar
 Location: NSW
 Member since 10 June 2010
 Member #: 681
 Postcount: 941

A solderable source thin sheet metal for end caps of various diameters for a one-off job might be flat alkaline cells. The body shell of these is nickel plated sheet steel. The side wall might be a bit thin though as they are drawn and ironed to shape so the side wall could be very thin. An AA or AAA base might be close to the right diameter for a valve cap though. With a bit of work with tin snips would be easy to find out.


 
 Return to top of page · Post #: 15 · Written at 6:33:17 AM on 24 October 2018.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 6349

Any metal that is otherwise suitable can be wire brushed to get any nickel or chrome plate off. Being steel underneath, a higher temperature and some extra flux should get the solder to take.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
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