[Milsurplus] A TCS Transmitter Wiring Mystery

[WA5CAB at cs.com]

Breck,

The roller inductor itself changed (mechanically) around TCS-10.  However, 
I don't see any effective electrical change in any of the manuals from TCS 
through TCS-15.  All schematics show L-108 connected between the hot side of 
the variometer and the capacitor selector switch.

Relocation of the RF Ammeter from the ground side of the variometer to the 
antenna post occurred at Serial Number 9363 of TCS-12 production.  G3VKM has 
reported finding a Change Sheet in his PIB-TCS-13 showing that the change 
occurred from S/N 1387 in that model.  The PIB-TCS-13 and PIB-14 originals 
that I have both show the later RFA wiring on the transmitter schematic, with 
no Change note as found on the transmitter schematic in NAVSHIPS 900,291 
covering TCS-7,9,10,11,12.  However, the schematic in the PIB-TCS-13 is REV A 
and the one in PIB-TCS-14 is REV C.  No document has yet been located that 
shows what S/N the change occurred at in TCS-14.

None of the documents give any explanation for the change.

In a message dated 04/30/2013 16:30:50 PM Central Daylight Time, 
smithab11 at comcast.net writes: 
> A TCS Transmitter  Mystery?
> 
>   Why is the Antenna Loading Coil L108 wired differently on different 
> TCS  series transmitters ?
> On my TCS-9 transmitter L-108 is wired different from my TCS-13. Was 
> this change in wiring only for the TCS-13 or was it introduced in other 
> earlier series of TCS transmitters following the TCS-9?
> What happens to the "Typical  Dial  Setting"  charts with these wiring 
> changes?
> 
> I think I may have a possible answer  to the wiring differences but 
> present several photos and questions at:
> http://k4che.com/TCS%20equipment/Loading%20coil%20Mystery/Loading%20Coil%20
> Wiring.htm
> 
> k4che
> 

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