[Milsurplus] TCS Parts Needed

[WA5CAB at cs.com]

OK.  First, identification.  Neither the receiver nor the transmitter are 
TCS-5 or earlier because they each have three handles on the front panel 
instead of four corner posts.  And they each have the power connectors attached 
to a sheet metal bracket which attaches to the front panel from the rear 
with two screws.  So originally, you could remove the front panel without 
having to disconnect any wiring except for removing the nuts from the antenna 
posts to release the leads behind the panel.  There are other differences, but 
those are sufficient.

Most of the TCS's up through TCS-12 were built by Collins (except that some 
TCS-12 receivers were sub-contracted to Magnavox).  And the ID plates, 
decals or stenciling on top of the audio output and modulation transformers say 
"COLLINS".  TCS-6 was built by Hazeltine (CHZ) and TCS-8 was built by 
Stewart-Warner (CWS).  TCS-13 was built by Hamilton (CIH) and TCS-14 and TCS-15 
were built by Air King (CKP).  Collins always used Phillips head screws 
externally and mostly internally.  Except for CWS, all of the other contractors 
used slotted head screwss

Besides the change at TCS-6 mentioned above, the only other significant 
change to the receivers was the change from air core to iron core IF and BFO 
transformers at TCS-8.  The air core transformers were capacitor tuned (as are 
yours) with the capacitors (only one for the BFO) accessible from the top.  
The iron core transformers were slug tuned, one accessible from the top and 
the other from the bottom.  So that makes your receiver either a TCS-6 or 
-7 and the slotted head screws make it a TCS-6.

The fact that the receiver nameplate is missing isn't unfortunately 
unusual.  The Noise Limiter kit must have been an early design dating from TCS 
through TCS-3, which had no nameplates on the front panel.  As you can see, the 
escutcheon for the kit covers two of the nameplate mounting holes.  And 
unfortunately, if you cut the escutcheon off  enough to clear the nameplate, you 
cut of a good bit of writing.  The optimum solution is to move over and 
drill and tap 4 new screw holes for the nameplate.  Aside from mine, I've only 
ever seen one more receiver where that was done.  Most just discarded the 
nameplate.  One or two put the nameplate under the escutcheon.  Some cut off 
the escutcheon.

On the transmitter, if you have the cabinets there should be a two-hole 
pattern in the top for the Acceptance plate and a four-hole pattern for the 
Radio Set nameplate.  The top of the receiver cabinet has no such holes.  As 
you didn't mention the cabinets and neither are shown in any of your photos, I 
assume that you don't have them.

The transmitter has Phillips head screws so it isn't either a TCS-6, 8, 13, 
14 or 15.  Besides the corner post to handles change, almost the only other 
change made to the transmitters was that at TCS-12 Serial Number 9363, the 
RF Ammeter was moved electrically from between chassis and the bottom of the 
variomenter to between the antenna relay and the antenna post.  So if the 
RFA has the original wires going to the relay and to the right hand SO-239, 
it's probably a TCS-12.  If it doesn't, then it could be TCS-7, 9, 10, 11 or 
12.  There was also a variation in how the rotary loading coil was mounted.  
But I don't have that pinned down yet.

Besides removing L-107, the PO also added in its place a loading capacitor. 
 My guess is that the rotary inductor is now the plate tank coil.  There is 
also an added RF choke visible in your top view photo.  That will be the DC 
feed to the finals.  And S-102 should be visible just over the rotary coil 
but isn't.  S-103 would also have been rewired.  C-125 and C-126 both have 
to pass AC (audio) and electrolytics won't work.

Besides for some unknown reason just removing the crystal sockets from the 
receiver, he also removed them from the transmitter and replaced them with 
four different ones that look like they might fit FT-171-B, DC-34 & 35 or 
CR-1*/AR holders.

You need to look at the 1st IF transformer in the left rear corner of the 
receiver.  The two trimmer capacitors should be visible, and they aren't.  So 
something was done there.

I have (somewhere) some NOS crystal sockets for TCS.  I have enough parts 
units that I'm sure I could supply the other missing parts.  And I sell a 
reprint of NAVSHIPS 900,291 that covers TCS-7 through TCS-12.  The only thing 
that you could do about making the front panels look original (besides fixing 
the receiver nameplate) is to replace the SO-239's with Type N connectors 
and mount them behind the panel.  The Navy modified a small number of TCS's 
that way for use in submarines, probably just before or during the Korean 
War.


In a message dated 11/11/2017 09:12:01 AM Central Standard Time, 
mark.k3msb at gmail.com writes: 
> I’ve always wanted a TCS setup but the prices have prevented me from 
> owning one.
> 
>  Last summer I answered an ad on QTH.com for a TCS RX and TX in the local 
> area; as it turned out, the owner lives on a fishing boat on the Chesapeake 
> Bay.   The TCS units were stored in a closet on the boat and he needed 
> space, so they were for sale – at a price that made me offer several prayers 
> that I would be first in line.    Well, the Good Lord heard those prayers 
> and I drove down the following Saturday to get them.
>  
>  http://www.k3msb.com/tcs/main.html
>  
>  I’ve no idea as to what flavor of TCS this is, but I’ve included photos 
> with date stamps to help ID it.
> 
>  They look to be in nice condition but there are a few “concerns”….. and I
> ’d like to get stock replacement parts as indicated below.
> 
>  Transmitter:
> 
>  L-107 (a variomoeter?)  is missing and has been replaced by an “ad hoc” 
> matching network.   Is there any chance of obtaining L-107 and associate 
> parts?
> 
>  C125 and C126 are gone; I’d like to get replacements.   This is not a big 
> concern since a pair of electrolytic and diodes will work in their place.
> 
>  Name plate for the transmitter is missing.
>  
> 
> Receiver:  
> 
>  The crystal socket base assembly in the receiver is missing.
> 
>   
> 
>  One the negative side, L-107 is gone.   On the positive side, it looks 
> like this unit was in fact used on the air so that gives me hope they will 
> work.   Also, the RX does have the noise limiter installed.
> 
>   
> 
>  73 Mark K3MSB
> 
>  
> 

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