Hi All,
I got this very odd tuning eye tube. When I first got it I thought it was just a 1629. It isn't a 1629.

It has an octal plug and all 8 pins are populated. The filament is on 2 and 7 and is 6.3 volts, 270 milliamperes.
Of the 8 pins only four have connections. The two plates are connected together in the base of the tube by a 1 meg resistor.
Its internal structure is identical in appearance to an Airline 6U5 that I have. It is marked Z1358A, which I have not been able to cross to anything. It has the Ken-Rad label.
Oddly is says on the base to replace with a 6AL7, however the pinout of the 6AL7 is quite different.
The green target is bright, indicating little use.

Any idea what it is?

Best Regards,

Bill Grimm

Hi Bill

Must be a special made by Ken Rad. X or Z in front of a number usually indicates this. Can't see how it would be interchangeable with a 6AL7? A 6AL7 has 3 input pins and a line display.

There are Russian octal eye tubes out there but wouldn't have Ken Rad on the base.

You are lucky it has a bright display.

Norm

:Hi All,
: I got this very odd tuning eye tube. When I first got it I thought it was just a 1629. It isn't a 1629.
:
: It has an octal plug and all 8 pins are populated. The filament is on 2 and 7 and is 6.3 volts, 270 milliamperes.
: Of the 8 pins only four have connections. The two plates are connected together in the base of the tube by a 1 meg resistor.
: Its internal structure is identical in appearance to an Airline 6U5 that I have. It is marked Z1358A, which I have not been able to cross to anything. It has the Ken-Rad label.
: Oddly is says on the base to replace with a 6AL7, however the pinout of the 6AL7 is quite different.
: The green target is bright, indicating little use.
:
: Any idea what it is?
:
:Best Regards,
:
:Bill Grimm

Hi Norm,
Thank you for the reply. It seems that you think this was made as a special lot for a cutomer that wanted tubes similar to a 6E5 or 6U5, but with an octal socket. I didn't know that was done.

Is there some way of telling by looking if it is more similar to a 6U5 or 6E5?
A simple converter plug will adjust the pin out for a 6 pin socket.
The step after that will be to find a radio with a bad eye tube. That shouldn't be hard.

Best Regards,

Bill Grimm

Bill G.,

FYI - I believe RCA in around 1960 considered producing a modernized 6U5. The developmental numbers were CA73 and CA74 I think. The CA73 was an octal based modernized 6U5 and the CA74 was a shortened version of the CA73.

Radiodoc
****************

:Hi Norm,
: Thank you for the reply. It seems that you think this was made as a special lot for a cutomer that wanted tubes similar to a 6E5 or 6U5, but with an octal socket. I didn't know that was done.
:
: Is there some way of telling by looking if it is more similar to a 6U5 or 6E5?
: A simple converter plug will adjust the pin out for a 6 pin socket.
: The step after that will be to find a radio with a bad eye tube. That shouldn't be hard.
:
:Best Regards,
:
:Bill Grimm

Hi Radiodoc,
Thank you for the information. If I come across anything like that I will know what it is.

Best regards,

Bill Grimm