Looking for curves for obscure tube

[coldcathode]

Been real busy working around the house until recently. I was sorting some of my collection and started with globe and st shaped tubes. I came across what appear to be NOS Tung-Sol 485' (4 of them). The only data I can find is make plate voltage of 180 and Mu of 12.5 or so. I am wondering if anyone has in their collection of data some curves? It appears this was a very little used tube. I am always up for a challenge and I was thinking a nice line stage using these might be nice.

Anyone got any further info on these?

 

[Tom Bavis]

It's a Sparton number, don't know if anybody else used 'em. You could probably use the curves for 56, 76, 6P5 or 27 and be close enough.

 

[Tubelab_com]

I can't find any info on the 485, but I can offer this. I found an old Sparton radio chassis in the dirt at a flea market. I got it for $10. It had a bunch of globe tubes in it and I don't remember all of the numbers. The output tubes were marked National Union NX-483. They had a guarantee sticker from 1929! The NX483 turns out to be the same as a 183 which is an output triode that works like a 45 with a 5 volt filament. They sound really nice in a Tubelab SE.

It is possible that the 485 could be an NX-485 or could be similar to a 185. A quick Google search didn't turn up anything, but maybe some of the old radio sites may have some info.

 

[coldcathode]

Thanks guys! I guess what I will do is try a simple gain stage and cathode follower and listen??

I come across a lot of interesting tubes using the "flea market" method. I have also found that showing interest as "something I know nothing about but would like to play with" gets the price much lower than giving away that I know about tubes. LOL

Quick question that I know both of you can answer,

What load resistance should I use if I know the Plate resistance from the little data I have?