[Jake Blake]

Is the Loktal tube design unique to Philco only?  

[Radioroslyn]

No they were designed by Sylvania primarily for the auto radios and two way radios. Since they lock in they don't wiggle out as a vehicle bounces down the road. Sylvania was the main supplier of tubes for Philco.

[morzh]

All early transoceanic radios by Zenith are loctals.

[Jake Blake]

Thanks Terry.

[Jake Blake]

Thanks Mike.
Ron indicated earlier that Philcos came with (glass) Sylvanias, as opposed to the metal tubes RCA  and others used.  I think  Zeniths  were included,
and they must have continued on with the Loktal versions when the came out.

[Tucker]

I’ve got a Zenith 10s464 console that uses a loctal tube. I belive Bendix may have also used them.

[Jake Blake]

"  . . . that uses a loctal tube"

Only one?

[amptramp]

I have a Crosley 1528 radio that uses a 7F8 twin triode for AM and FM oscillators.

[Tucker]

Yep, it only has the one #1232 tube. All the other tubes are octal.  I also have a Zenith 12h670 that I haven’t restored yet. That one has 7 loctals and 5 octals.

[mikethedruid]

I remember working on a Silvertone three band radio back when I was a kid. It used loctal tubes for all its tubes.

[EdHolland]

Our 1947 Zenith 12H090 uses a mixture of Octal, Loctal and miniature 7 pin valves. It is quite the electronic cocktail.

[Jake Blake]

". . . quite the electronic cocktail."    

If it's all original, it's a good cocktail!

[Tim Tress]

Zenith and Colonial (Silvertone) both used Loktal tubes heavily. Both companies, along with Philco, had Sylvania as a tube supplier. There was a lot of anti-RCA sentiment when they came out with their metal tubes, and when Sylvania introduced the Loktal tubes a few years later, they were eagerly accepted.

[amptramp]

Midwest also used loktal tubes.  Lots of them.  Many of their sets were high tube count.