[Milsurplus] Need Info On TAV-4

[WA5CAB at cs.com]

Well, duh!  I looked at that twice last night and guess because I had been 
looking the the TAV-4 system nameplate filtered it out.  CN made TAV and 
TAV-1.  CAY made TAV-2, -3 and -4.  With the rated output power bumped from 15 
W to 20 W.  TAV-a contractor is shown as CN/RW (RW is Washington Navy Yard, 
who must have done the modification).

I guess I'll have to retract half of my statement of last night about the 
5-digit Navy Type Number system and Contractor Codes.  The Contractor Code 
system used at least into the 50's did begin before 1918.  But the 5-digit 
system must date from the early 30's (Mike, the radio proper of TAV-2 could 
have been 43001).

Nick, the lower case letter ("a" in this case) following the System 
Nomenclature means a modification of some sort.  In one example that I know of, the 
modified set is not interchangable or compatible with the unmodified one.  
If I recall correctly (it's hot in the attic this afternoon) RBA-5a, RBB-2a 
and RBC-2a were modified for operation from 25 CPS mains (not shown in SHIPS 
242A because it was done in 1950).  In the case of some of the RU sets, it 
means fewer or different than standard coil sets were supplied.   The GF 
transmitter was used with RU-2 receiver.  RU-2a was supplied with a beacon band 
coil set and operated standalone.  Therefore it would have had to be 
modified.  Whether they changed the front panel connector as in RU-5, 11, 12, 18, 
19 I don't know.  I'm trying to recall whether I ever saw a "b" or not but I 
don't think so.  The GP-6 to GP-6a modification was done backwards.  The 
modified sets continued to be GP-6 (substantially the same as GP-7).  The 
GP-6a was originally built and issued as GP-6 and when during production, the 
remote connector was changed from 4-pin to 6-pin, the Fleet was instructed to 
stamp all 4-pin sets with an "a".  In this case the two models were not 
interchangable.

By contrast, when an individual component was modified but not enough to 
get a new Type Number, it got an upper case letter suffix.  Sometimes 
separated fron the five digit number by a hyphen, sometimes not.  I've even seen it 
one way on the nameplate and the other way in the manual.  But in most cases 
the modified set was at least backwards compatible.

In a message dated 4/20/2011 2:30:19 PM Central Daylight Time, 
navy.radio at gmail.com writes: 
> All very interesting and congrats on bringing to light a really neat 
> unit, Don.
> 
> FWIW, Howeth says "During 1930...49 models TAV and TAV-1 medium-frequency 
> portable field transmitters were issued to major units of the fleet; "
> 
> TAV and TAV-1 might possibly be a design by National Electric Supply 
> (manuf code CN) - they made some WWI era Navy gear at least.
> CN-238 rcvr, CN-239 rcvr, CN-240 rcvr, CN-1105 airborne xmtr
> Maybe Westinghouse (CAY) was a follow-on contractor for TAV-4?
> 
> Aside - Say, Robert, what's the story on an equipment number like TAV-a 
> instead of TAV-1?
> 

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480