[Hammarlund] Hammarlund Corporate Standard in 1930s

Katsuhiko Hirai mxc04040 at nifty.ne.jp
Sat Nov 28 04:26:52 EST 2009


Dear list member,

  I have found the Interface Design Compatibility between Super-Pro series.

First, I had the curiosity of the unit interface of SP series 
by the posting of Ed W2EMN, 'Message: 4, Hammarlund Digest, Vol 70, Issue 8' 
in the case of SP-200, as follows:

> > Starting from the right terminal on the receiver/power supply
> >  
> > 1.    6.3 V ground
> > 2.    6.3V hot   7A est.
> > 3.     chassis ground
> > 4.    +140V screens  20ma est.
> > 5.    +270V plate volt   60ma est.
> > 6.    +385 output plate volt   50 ma  est.
> > 7.    -50V grid bias 10ma est
> > 8.    AC switch
> > 9.    AC switch
> > 10.   not used
> >  

It's almost same as the SP-10, initial product of the SP-series, 
through URL: http://pub.ne.jp/bluemac/?entry_id=555726

Secondly, I checked the pin assignment of SP-400-X, through the manual.
Those specifications are same between SP-10, SP-200 and SP-400-X.
I assume that the SP-100 would be same as SP-10, though I could not confirm.

I noticed that Hammarlund had already completed the corporate standard 
guideline to design the interface between separated units, in order to 
provide the upward compatibility in the Super-Pro series even around 1930s.

It's really the great concept in engineering.

Best regards,
Katsuhiko Hirai/ JO1GEG
 <mxc04040 at nifty.ne.jp>



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