[ARC5] What's Dis?

[Robert Eleazer]

A friend of mine picked up a box of tubes at a flea market this past weekend.  It has what appear to be NIB 1625's and so forth; I'll be making an inventory.  But it also has two "somethings" that I have never seen before.

They are glass tubes about  4 inches long with a finned copper heatsink in the middle.  They have two wires coming off the base  and a screw cap on the other end.  On the copper heatsink it says "R.E.L. #1 MFD BY N.E.CO."  and they have a serial number also.

Anyone know what these are?

Wayne