Gold top 6V6GTs?

[thorpej]

Picked up another Magnavox 8802 for a song with the intent of more heavily modifying it. It included what appear to be the original tubes, but I've never encountered gold-topped tubes before. This seems to be some sort of coating painted on the outside of the glass and pretty much exactly matches where the getter flash is. It *seems* to be original, but it's hard to tell.

Looking up at the getter flash from underneath, it still seems to be in good shape, so it doesn't seem like it was put on there to hide a gassy tube.

Some photos included. Anyone have any insights into these?

Thanks, as always!

 

[knockbill]

Any numbers or markings on the base?

 

[thorpej]

None that I can see, no. Just the Magnavox stamp you see in the second photo above.

 

[gadget73]

yellow print, stop sign logo, Sylvania perhaps? Is there a 312 printed anywhere on there?

 

[thorpej]

Could be. Unfortunately, I left the box of tubes at my office by mistake in a rush to get out of there before the rush-"hour" traffic got too awful, so further inspection is going to have to wait until I get back from vacation. My other 8802 has Magnavox-branded 6V6s that are stamped "Made in Japan", but these have no such markings (or any "Made in" markings at all).

Still curious if the gold coating is original or applied later... The way it appears "flowed", it's almost like the top of the tube was dipped...

 

[knockbill]

I have a pair of original Magnavox Sylvy 6V6s with that yellow print in a 185 amp,,, the other other pair is Hy Tron (Sp),, same yellow print and date code, 1959,,, neither has gold top tho...

 

[primosounds]

It maybe something i have seen in old tubes from a smoker's house. Where the tobacco smoke residue has baked on the top surface forming a uniform goldish brown film. I have over a hundred 6v6 (i used to collect them for my geetar amp) and I am certain i have not seen selected tubes where they painted the whole top of the tube to indicate a specially tested tube. Usually, they would mark such tubes with a colored dot. cheers.