[Amps] QEX Innovative Tube Linear?

[Tom W8JI]

> Only for the 8950 and M-2057 (or Y-2057) as they were the 
> only ones that GE said were for RF amplifier service. The 
> M-2057 was a custom tube that was manufactured by GE. They 
> took an 8908's guts and placed them in a 12 pin compactron 
> base which was what a GE engineer told me. The only specs 
> I have on the 8908 is in a GE tube applications book. I 
> have the GE application sheets on the 8950 and M-2057. All 
> the other sweep tubes were based around TV horizontal 
> output service, however the maximum DC anode voltages 
> still apply.

Will,

I'm a little puzzled, and this may be confusing other people 
also.

As I recall you stated quite emphatically everyone should 
follow the letter of a spec sheet regardless of what factory 
engineers might OK and even if actual operation proved the 
change perfectly acceptable. That was for a momentary tuning 
condition!

If I think along the very same lines, it also seems totally 
unacceptable to run a tube in linear service when linear 
operation is NOT specified, and it also seems unacceptable 
to use data sheets for pulsed horizontal sweep service in 
linear service applications. Pulse and linear service are 
worlds apart in every rating except filament voltage.

We were all told that not following the exact letter of data 
sheets would or could get engineering licenses revoked, it 
could also run a business into bankruptcy from lawsuits. If 
factory engineers aren't allowed to tell people it is OK to 
operate tubes outside of the exact letter of data sheets for 
few moments of tuning, and if tube engineers are not allowed 
to make exceptions for a few moments of tuning, wouldn't 
that apply even more here since this is continuous operation 
outside of the data sheets?

For example, my RCA data sheets for the 6LQ6 only have 
constant current charts that go to 450 volts dc. Why is it 
now OK to specify 900 volts when it is off the charts, when 
other people (even with manufacturer's permission) aren't 
allowed to do that? Since the tubes isn't spec'ed for linear 
service, doesn't that violate good engineering practices?

Perhaps I'm missing something?

73 Tom