The AM Forum

The 813 has a metal "bayonet" base, but the only sockets I've ever seen are the standard flat Johnson type ceramic jobs and their Chinese variants. Is there, or was there, an 813 socket with a bayonet shroud for the 813?

I've seen bayonet sockets for that base.

That was years ago, and I don't remember what gear those sockets were in.

They didn't have the usual "push and twist" slots, rather a simple straight ones so you don't have to see into the socket to insert it correctly.

73DG

IIRC the 813 has 6 pins with one oversized pin as a key. The only ones I have known that are bayonet are the 810's. 805's, 838's and others that have a 4 pin base, (I think there are some rectifiers in there also).

The 813 has a "giant" 7 pin bayonet metal base; the two larger diameter pins are the filament pins. I've never been inside an ART-13, but looking at some pictures it appears that the 813 in that application was in a bayonet socket. Maybe only military rigs put the 813 in that sort of socket?

   This all got started because building an 813 rig is on my retirement (one month to go!) bucket list, and I was in my shop looking through my tube sockets; not finding any of the 813 sockets that I thought I had. But, looking at a couple of 810 sockets, I got to thinking about how cool it would be to have my 813's in sockets like that.
   Well, regular ceramic sockets are plentiful, so no problem. Sussex is coming up!

Found this on eBay. Looks right.

1 X UX7 GIANT TUBE 7 PIN CERAMIC SOCKET. RCZOC19

(the URL is ridiculously huge)

That looks like the one I remember, but it wasn't in Spain LOL.

The 803 pentode also had a true bayonet socket, made by Johnson.  It looks like that for the 4-pin jumbos like 211, 805, 872, eTc, but with 5 pins.  Same pin arrangement as the 4-400, but a smaller ring.

73DG