Shadow tuning tube for Heathkit cap ckr

4/28/2009 2:43:20 PMBob barker

I have restored a Heathkit C3 capacitor checker. However the green glow of shadow tuning tube can only be seen in total darkness. Disconnecting the 47k resistor increased the voltage on pin 4. That helped but only very little. All voltages appear normal.

The tube is a 1626, as specified in the manual. I cannot find any ref to this tube. Can a 6E5 or 6U5 be directly substituted? Was 1626 Heath's own number to promote tube sales or is the tube really unique?

4/28/2009 3:54:43 PMRadiodoc

Bob,

You sure that eye tube is not a 1629.

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

:I have restored a Heathkit C3 capacitor checker. However the green glow of shadow tuning tube can only be seen in total darkness. Disconnecting the 47k resistor increased the voltage on pin 4. That helped but only very little. All voltages appear normal.
:
:The tube is a 1626, as specified in the manual. I cannot find any ref to this tube. Can a 6E5 or 6U5 be directly substituted? Was 1626 Heath's own number to promote tube sales or is the tube really unique?

4/28/2009 4:44:21 PMCarl T

The eye tube is 1629. Schematic can be found here:

http://www.nostalgickitscentral.com/heath/schematics/heathkit_schema_c3.gif

:Bob,
:
:You sure that eye tube is not a 1629.
:
:Radiodoc
:****************
:
:
::I have restored a Heathkit C3 capacitor checker. However the green glow of shadow tuning tube can only be seen in total darkness. Disconnecting the 47k resistor increased the voltage on pin 4. That helped but only very little. All voltages appear normal.
::
::The tube is a 1626, as specified in the manual. I cannot find any ref to this tube. Can a 6E5 or 6U5 be directly substituted? Was 1626 Heath's own number to promote tube sales or is the tube really unique?

4/28/2009 4:47:28 PMNorm Leal

Bob

Radiodoc is right 1626 is a triode. 1629 is the eye tube. It was used in test and military equipment. They are available from AES, Radio Daze and others. A 1629 has an octal base while 6E5/6U5 have 6 pin bases so are not interchangeable.

Norm

:Bob,
:
:You sure that eye tube is not a 1629.
:
:Radiodoc
:****************
:
:
::I have restored a Heathkit C3 capacitor checker. However the green glow of shadow tuning tube can only be seen in total darkness. Disconnecting the 47k resistor increased the voltage on pin 4. That helped but only very little. All voltages appear normal.
::
::The tube is a 1626, as specified in the manual. I cannot find any ref to this tube. Can a 6E5 or 6U5 be directly substituted? Was 1626 Heath's own number to promote tube sales or is the tube really unique?

4/28/2009 4:52:07 PMWarren

Here is a link to that eye tube

http://www.nj7p.org/Tube4.php?tube=1629

Maybe could addapt a 6U5 if your not able to get the 1629

4/28/2009 10:58:44 PMRadiodoc

Probably be easer and cheaper to find a 1629 than a 6U5 eye tube. The 1629 has a 12 volt filament and the 6U5 has a 6 volt filament.

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

:Here is a link to that eye tube
:
:http://www.nj7p.org/Tube4.php?tube=1629
:
:Maybe could addapt a 6U5 if your not able to get the 1629

4/29/2009 9:30:54 PMBob Barker

:Probably be easer and cheaper to find a 1629 than a 6U5 eye tube. The 1629 has a 12 volt filament and the 6U5 has a 6 volt filament.
:
:Radiodoc
:*****************
:
:
::Here is a link to that eye tube
::
::http://www.nj7p.org/Tube4.php?tube=1629
::
::Maybe could addapt a 6U5 if your not able to get the 1629

4/29/2009 9:34:44 PMBob

Thanks for all the help. I am travelling and cannot cfm the 1626/1629 mix up but you all must be right.

This was my first use of the forum. I am impressed.