Tube substitution

6/28/2007 1:21:13 PMTex

I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

6/28/2007 1:55:13 PMBill G.

:I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

Hi Tex,
You are in luck, no rewiring needed. Just order a 6Q7 and you should be in business.

In the 1950's and 1960's 6Q7 tubes were getting hard to find. Radio repairmen sometimes built adapters like this so that common tubes could be used as replacements.

Today 6Q7 tubes are relatively easy to find.

Best Regards,

Bill Grimm

6/28/2007 1:58:16 PMNorm Leal

Tex

A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.

If the 6AT6 tests weak it will likely still work in a radio.

Norm

6/28/2007 3:41:04 PMBill G.

:Tex
:
: A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.
:
: If the 6AT6 tests weak it will likely still work in a radio.
:
:Norm
:
::I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

Hi Norm,
I was going to tell him much the same as you did, but then noticed he had a photo attached. The photo was of a 6AT6 in an octal converter with a grid cap wire hanging out.
The photo is http://i195.photobucket.com/albums/z31/TexRadios/Tube.jpg. It didn't come out well on the screen.

Best Regards,

Bill Grimm

6/28/2007 3:49:34 PMTex

::Tex
::
:: A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.
::
:: If the 6AT6 tests weak it will likely still work in a radio.
::
I tried to post the photo, it didn't work. I'll try again.

::Norm
::
:::I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

:
:Hi Norm,
: I was going to tell him much the same as you did, but then noticed he had a photo attached. The photo was of a 6AT6 in an octal converter with a grid cap wire hanging out.
: The photo is http://i195.photobucket.com/albums/z31/TexRadios/Tube.jpg. It didn't come out well on the screen.
:
:Best Regards,
:
:Bill Grimm

6/28/2007 3:59:00 PMTex

:::Tex
:::
::: A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.
:::
::: If the 6AT6 tests weak it will likely still work in a radio.
:::
:I tried to post the photo, it didn't work. I'll try again.
:
:::Norm
:::
::::I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?
::
::Hi Norm,
:: I was going to tell him much the same as you did, but then noticed he had a photo attached. The photo was of a 6AT6 in an octal converter with a grid cap wire hanging out.
:: The photo is http://i195.photobucket.com/albums/z31/TexRadios/Tube.jpg. It didn't come out well on the screen.
::
::Best Regards,
::
::Bill Grimm

6/28/2007 5:32:57 PMBill G.

:
::::Tex
::::
:::: A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.
::::
:::: If the 6AT6 tests weak it will likely still work in a radio.
::::
::I tried to post the photo, it didn't work. I'll try again.
::

::::Norm
::::
:::::I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

:::
:::Hi Norm,
::: I was going to tell him much the same as you did, but then noticed he had a photo attached. The photo was of a 6AT6 in an octal converter with a grid cap wire hanging out.
::: The photo is http://i195.photobucket.com/albums/z31/TexRadios/Tube.jpg. It didn't come out well on the screen.
:::
:::Best Regards,
:::
:::Bill Grimm

Hi Tex,
I could see it strait away this time, and now I know how to do it myself, too.
Let me know how the replacement 6Q7 does.

Best Regards,

Bill Grimm

6/29/2007 12:07:57 PMTex

::
:::::Tex
:::::
::::: A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.
:::::
::::: If the 6AT6 tests weak it will likely still work in a radio.
:::::
:::I tried to post the photo, it didn't work. I'll try again.
:::

:::::Norm
:::::
::::::I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

::::
::::Hi Norm,
:::: I was going to tell him much the same as you did, but then noticed he had a photo attached. The photo was of a 6AT6 in an octal converter with a grid cap wire hanging out.
:::: The photo is http://i195.photobucket.com/albums/z31/TexRadios/Tube.jpg. It didn't come out well on the screen.
::::
::::Best Regards,
::::
::::Bill Grimm
:
:Hi Tex,
: I could see it strait away this time, and now I know how to do it myself, too.
: Let me know how the replacement 6Q7 does.
:
:Best Regards,
:
:Bill Grimm
I originally tested the tube out of the adapter, as a 6AT6, it tested bad. I tested it in the adapter, as a 6Q7, it tested good.

6/29/2007 1:42:10 PMBill G.

:::

:::
::::::Tex
::::::
:::::: A 6Q7 is an octal tube. 6AT6 is 7 pin miniature. These are not interchamgeable due to socket type but are electrically similar. You can use a 6AV6 in place of 6AT6.
::::::
:::::: If the 6AT6 tests weak it will likely still work in a radio.
::::::
::::I tried to post the photo, it didn't work. I'll try again.
::::

::::::Norm
::::::
:::::::I have a Sparton 987, the schematic calls for a 6Q7 tube but there is a 6AT6 in its place, the tube database doesn't list 6AT6 as a replacement for 6Q7. The 6AT6 test bad. If I use a 6Q7 to make it original would I have to do any rewiring?

:::::
:::::Hi Norm,
::::: I was going to tell him much the same as you did, but then noticed he had a photo attached. The photo was of a 6AT6 in an octal converter with a grid cap wire hanging out.
::::: The photo is http://i195.photobucket.com/albums/z31/TexRadios/Tube.jpg. It didn't come out well on the screen.
:::::
:::::Best Regards,
:::::
:::::Bill Grimm
::
::Hi Tex,
:: I could see it strait away this time, and now I know how to do it myself, too.
:: Let me know how the replacement 6Q7 does.
::
::Best Regards,
::
::Bill Grimm
:I originally tested the tube out of the adapter, as a 6AT6, it tested bad. I tested it in the adapter, as a 6Q7, it tested good.

Hi Tex,
You have just tested your tube tester.

Sockets on tube tester tend to get worn. Sockets for 7 and 9 pin miniatures tend to go first. I have this problem on my tube tester, also.

Best Regards,

Bill Grimm