Example 5r4WGB WGA etc ARe they just more improved versions . I Working on a Heathkit DX-100 and Looking at the HV section.

Letters of A, B etc are improvements. Sometimes more current of some controlled parameter like heater warm up time. W meets a military specification.

If the original tube was 5R4G you can use a GA or GB. W is also acceptable in most cases. I have come across one problem with a W. 6SN7WGT has a low loss base and less inter electrode capacity. I have seen these tubes out of range as horizontal oscillator in old TV's.

Norm

:Example 5r4WGB WGA etc ARe they just more improved versions . I Working on a Heathkit DX-100 and Looking at the HV section.
:

:Letters of A, B etc are improvements. Sometimes more current of some controlled parameter like heater warm up time. W meets a military specification.
:
:If the original tube was 5R4G you can use a GA or GB. W is also acceptable in most cases. I have come across one problem with a W. 6SN7WGT has a low loss base and less inter electrode capacity. I have seen these tubes out of range as horizontal oscillator in old TV's.
:
:Norm
:Thank you, I've heard some of the 5r4 's develop internal shorts. tube tester time!
Andy

::Example 5r4WGB WGA etc ARe they just more improved versions . I Working on a Heathkit DX-100 and Looking at the HV section.
::
:
:

::Letters of A, B etc are improvements. Sometimes more current of some controlled parameter like heater warm up time. W meets a military specification.
::
::If the original tube was 5R4G you can use a GA or GB. W is also acceptable in most cases. I have come across one problem with a W. 6SN7WGT has a low loss base and less inter electrode capacity. I have seen these tubes out of range as horizontal oscillator in old TV's.
::
::Norm
::Thank you, I've heard some of the 5r4 's develop internal shorts. tube tester time!
: Andy
:
:
:
:::Example 5r4WGB WGA etc ARe they just more improved versions . I Working on a Heathkit DX-100 and Looking at the HV section.
:::
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::
:
If you run across an "AL" suffix, it stands for "airline" and is the top of the line in tubes, even better than MIL/
Lewis
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