Tube substitution question

1/25/2009 12:57:23 AMPeter G. Balazsy

I wonder why the 2a6 is a sub for the 55
and the 75 seems to be the same as an 85 yet the tube substitution guides don't say so.

What am I missing?

1/25/2009 5:52:19 AMYou are missing....

YOU ASKED "WHAT YOU ARE MISSING?" YOU ARE MISSING YOUR BRAIN AND SOME HEMP ROPE FOR YOUR SPEAKER...Plus is it not time for you to post another one of your so called restorations on this site.. soo we can all go oooohh ahhh and then tell you to shut up...LOL LOL

:I wonder why the 2a6 is a sub for the 55
:and the 75 seems to be the same as an 85 yet the tube substitution guides don't say so.
:
:What am I missing?
:

1/25/2009 11:03:25 AMLewis L

:YOU ASKED "WHAT YOU ARE MISSING?" YOU ARE MISSING YOUR BRAIN AND SOME HEMP ROPE FOR YOUR SPEAKER...Plus is it not time for you to post another one of your so called restorations on this site.. soo we can all go oooohh ahhh and then tell you to shut up...LOL LOL
:

Somebody leave the door to the nursery open again?
Lewis

1/26/2009 2:41:08 AMPeter G. Balazsy

is that you Marv?

1/25/2009 8:07:24 AMTonyJ

I have an RCA 85T that came with an 85 where a 75 should have been installed and the set worked fine with it. I ultimately put the correct tube in it and didn't really notice much of a difference. I believe the 85 is basically the same but with lower gain. Not sure why they aren't listed as subs, unless the manuals focused on more widespread use numbers?

:I wonder why the 2a6 is a sub for the 55
:and the 75 seems to be the same as an 85 yet the tube substitution guides don't say so.
:
:What am I missing?
:

1/25/2009 9:41:13 AMbob

:I wonder why the 2a6 is a sub for the 55
:and the 75 seems to be the same as an 85 yet the tube substitution guides don't say so.
:
:What am I missing?
:-------------------------------------------------------------------------------------------------------------------------------------------------------------------: According to the tube substitution guide I have the 85 can be subtituted for the 75 but only on a temporary basis until the proper tube can be acquired.

1/25/2009 9:58:23 AMbob

::I wonder why the 2a6 is a sub for the 55
::and the 75 seems to be the same as an 85 yet the tube substitution guides don't say so.
::
::What am I missing?
::-------------------------------------------------------------------------------------------------------------------------------------------------------------------: According to the tube substitution guide I have the 85 can be subtituted for the 75 but only on a temporary basis until the proper tube can be acquired.------------------------------------------------Also the 55 can be substituted for the 2A6 but only in parallel connected circuits.

1/26/2009 2:39:22 AMPeter G. Balazsy

Also the 55 can be substituted for the 2A6 but only in parallel connected circuits.

Not sure what "Parallel connected circuits" refers to exactly in this case.

This Gilfillan radio uses a 2A6 just as the print calls for.. but the socket actually says 55 printed on it... and as I said either works.

From what I have found out from others now... the 55 and 2A6 ARE swappable but the 2A6 has higher gain.
.. and the same goes for the 75/85 situation.... the 75 has higher gain.

1/26/2009 9:58:29 AMbob

:Also the 55 can be substituted for the 2A6 but only in parallel connected circuits.
:
:Not sure what "Parallel connected circuits" refers to exactly in this case.
:
:This Gilfillan radio uses a 2A6 just as the print calls for.. but the socket actually says 55 printed on it... and as I said either works.
:
:From what I have found out from others now... the 55 and 2A6 ARE swappable but the 2A6 has higher gain.
:.. and the same goes for the 75/85 situation.... the 75 has higher gain.
:I assume (parallel circuits) means the tubes are wired in parallel as opposed to in series.

1/26/2009 1:24:42 PMmaybe?

::Also the 55 can be substituted for the 2A6 but only in parallel connected circuits.
::
::Not sure what "Parallel connected circuits" refers to exactly in this case.
::
::This Gilfillan radio uses a 2A6 just as the print calls for.. but the socket actually says 55 printed on it... and as I said either works.
::
::From what I have found out from others now... the 55 and 2A6 ARE swappable but the 2A6 has higher gain.
::.. and the same goes for the 75/85 situation.... the 75 has higher gain.
::I assume (parallel circuits) means the tubes are wired in parallel as opposed to in series.

The 55 is rated at 1 amp for the heater whilst the 2A6 is 0.8 amps. For series connected heaters the extra 200mA might cause problems with other tubes?