Those Magnificent Television Tubes

[Kay Pirinha]

As suggested by wg_ski, you can derive almost any parameter from the curves. Note that a PL504 is a 6GB5 with increased plate dissipation ratings and another heater. Everything else is the same. Also note the triode curves .

Best regards!

 

[wrenchone]

I picked up a few "Magnoval" sockets, which appear to be Novar sockets which will accept Magnoval pins if they are jammed in forcibly. It looks like they are really Novar sockets - I tried plugging in a 6LR8 and it works, though the fit is tight.

 

[SCD]

Hello Wrenchone:
I too have used those asian sockets for Novar tubes. I suggest you take the pin sockets out of the ceramic base and crimp them to fit a novar tube. Not a big deal, the hardest thing is to find the right set of pliers to do the crimping. I used a dead tube as the centre base for crimping the sockets. Worked very well for me. It is a bit fussy but quite doable.

I hope this helps

 

[wrenchone]

The pins already fit a Novar tube without modification of any sort.

 

[SCD]

that is excellent.
Could you pm me the source

 

[wrenchone]

An Ebay search... Search term is "Magnoval PC socket".

 

[SCD]

thanks

 

[wg_ski]

Ones that vacummtubesinc.com are selling are Novar (magnoval dont fit at all, but 6LR8 do, better than the NOS Svetlana ones that are supposed to take either). I ran across them when looking for 12-pin. I’ve tended to stay away from magnoval in general, and kept my Novar inventory light due to socket availability. If I can keep getting Novar sockets, I’ll keep digging up Novar tubes. When I get a reliable source of good magnoval sockets, those tubes will be on the menu.

 

[wrenchone]

Magnovals do fit, but they need a fair bit of force to seat the tube. They fit my 18GB5s and a sample of 6P44S. I'm looking right now at an 18GB5 plugged into one of those sockets.

 

[smoking-amp]

Novar sockets from Magnovals and Compactron pins:
https://www.diyaudio.com/community/threads/real-novar-sockets-inside.397358/

 

[kodabmx]

FYI I make Novar sockets for chassis mount:
https://www.diyaudio.com/community/...-usa-large-9-pin-tubes-with-1-mm-pins.378427/

 

[wrenchone]

I have Novar sockets for chassis mount - I don't need to make them. I also have both chassis mount and PC mount duodecar sockets.

 

[wrenchone]

I just got a bunch of 21HB5A sweep tubes - these are probably what I will use instead of the 18GB5s in my amp design using feedback-based triode emulation. Not needing a top cap contact is a big plus for these tubes, as well as good data sheet transconductance. I will need to check and see if I've ever bothered to generate a footprint for a PC mount duodecar socket. I know I have PC mount novar footprints.

 

[wrenchone]

Not having a top cap is an extra double plus, as the top caps on the 18GB5s are those teensy ones that are a PITA to deal with. To get something that doesn't look totally dorky (and that would stay on) would probably require me rolling my own top contacts using 5mm fuse clips and silicone tubing.

 

[wg_ski]

Vacuumtubesinc.com has the micro size anode caps, and they fit. As well as PC mount compactron sockets - buy sone and use calipers to measure for the hole pattern. Hopefully their source for compacton and Novar doesn’t dry up.

They still had some 26LW6’s last time I got stuff there too. I had all I need so I didn’t clean ‘em out.

 

[wrenchone]

I have 60 PC mount 12 pin sockets on hand - that's plenty for the war chest. Given a choice between no plate cap and one of those micro PITA plate caps, I'll choose no plate cap any day of the week, even if it means I have to come up with a footprint for a 12 pin PC mount socket - not such a horrible deal once I figure out the rotation angle for placing the holes.

 

[wg_ski]

How much did you give for the HB5’s? They normally go for about 12 bucks, which is higher than versions of the same with a top cap. When going for the $12 class, no top cap tube, I went straight to the top. Getting the last of vacuumtubes.net’s (the other FL supplier) 6HJ5’s. I bought a dozen, decided I liked them, got another dozen. Then I asked “got any more left?” last fall. He said he finally ran out of that big batch of Raytheon brand, and all he had was a box of misc. mixed brands. Bought all 17. No two boxes were the same, but inside they were all the Raytheon type, and all had useable emission.

 

[wrenchone]

I paid about half that from the source I used, though the tubes I got were clearly used/tested. Vendor was Radio Electric Supply in Florida.

 

[wg_ski]

Vacuumtubes.net = RES. Yeah, they have the 21HB5’s for $6. The 6 volt version is $18. It’s the opposite for the HJ5 - the 6V version is (was) $12 and the 21V version $15. And the other supplier is out of 6HJ5 now too (not my doing).

I got a batch of the 6GY5’s (HB5 with micro top cap) from RES for $3 a pop. Then top caps for 2, so $5 tubes. Since I found the top caps I went on the warpath for $3 tubes of all kinds that had those micro caps. All I’d ever found before were the ones that fit the bigger tubes.

 

[wrenchone]

I don't like the plate caps for the small top caps - they ride high on the top cap due to the shoulder and look dorky, plus there's exposed HV metal. I can make a top contact using 5mm fuse clips and silicone tubing that will fit reasonably tight and not leave any exposed HV metal. My preference is no top cap if I can swing it.