[Amps] Could we *all* use the right tube part numbers?

David Kirkby david.kirkby at onetel.net
Wed Feb 16 18:15:44 EST 2005


Steve Thompson wrote:

>On Tuesday 15 February 2005 09:11, David Kirkby wrote:
>  
>
>>Steve Thompson wrote:
>>    
>>
>>>Bill L. Fuqua wrote:
>>>      
>>>
>>>>While you are at it.
>>>>20 meters is not 14 mhz. that should be MHz
>>>>        
>>>>
>>>or even 20 metres :-)
>>>
>>>As for commas and suffix letters in part numbers, I have other things to
>>>worry about. To me it's only a problem if there's ambiguity
>>>      
>>>
>>Well it does as far as search engines are concerned.  Google interprets
>>them differently with or without the commas. Trying to find data on the
>>Eimac 3CX15,000B7  has problems, as Eimac's web page will not be found
>>by Google unless you put the comma in. Yet it will return more hits
>>without the comma, as most people do it wrong.
>>    
>>
>
>Putting it very simplistically, if someone hasn't the wits to find their way 
>round such issues, they shouldn't be messing with things so dangerous. If you 
>want academic precision in all things, this is not the place to be.
>
>Steve
>
Steve,
you failed to address the other (more important) issue I raised. You said.

> I could be very pedantic in specifying that I'd made linearity
> measurements on a 4CX350A, and someone might gain the impression that the
> figures only applied to that variant, when they will apply just the same to
> 4CX350F.


Whilst the 4CX350A and 4CX350F differ only by heater voltage (and so one 
would assume have the same linearity), the 4CX350FJ is different, in 
that it is designed for low intermodulation distorsion - i.e. high 
linearity.

So specifying the exact tube would not be being 'very pedantic' but 
*absoluttely essential* for the numbers to have any sensible meaning. 
Without the suffix, there would be no point in reporting the results.

Would you agree or not?

Likewise would you agree you would need to state the manufacturer of the 
tube too? It's highly likely the linearity might be different from one 
make to the next?

-- 
Dr. David Kirkby, 
G8WRB

Please check out http://www.g8wrb.org/ 
of if you live in Essex http://www.southminster-branch-line.org.uk/





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