[Boatanchors] OT: Ignorance :)) Yeah, sure

[WA5CAB at cs.com]

To add further confusion, the TCS and all three Command Set manual series 
show the 1625 as a straight tetrode.  No indication on the schematics of the 
beam forming plates.  The ATC, TCZ and AN/ART-13 manuals, however, show the 
1625's as beam tetrodes, with the beam forming plates connected to the 
cathode.

One other thing about the 50's era mod to the tubes is that only certain 
ones could be modified.  I don't remember which manufacturers did it which 
way.  Some brought the beam forming plates lead through the glass base where it 
plus the cathode lead are soldered into the cathode pin.  Others did the 
connection up inside the envelope, where you couldn't get at it.

In a message dated 3/22/2011 2:29:06 PM Central Daylight Time, 
rbethman at comcast.net writes: 
> Somebody is going to have to referee this.
> 
> The 1948 Radio Amateur's Handbook - Twenty-Fifth Edition, pg. 605 gives 
> the specs.  It references base diagram 5AZ also.  It INDEED shows the 
> suppressor grid tied internally to the cathode.
> 
> It would appear that the ARRL has published conflicting information.
> 
> My RCA tube manual from 1957 agrees with the above, and so does my '64 
> GE Electronics, "Essential Characteristics".
> 
> I'm confused!
> 
> Bob - N0DGN
> 
> 
> 
> 
> On 3/22/2011 2:55 PM, mac wrote:
> >The 1625 GG linear mod was to ground the beam forming plates, not the
> >"suppressor" grid..  The 1625 does not have a suppressor grid although
> >the universally referenced base diagram (5AZ)  appears to show one.
> >(Ditto the base diagrams for the 6L6, 6V6, 813 and others.)  The only
> >reference I have that shows these base diagrams correctly is my 1949
> >Radio Handbook (11th edition).
> >
> >Dennis D. W7QHO
> >Glendale, CA
> 

Robert & Susan Downs - Houston
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