[Milsurplus] More TCS

[WA5CAB@cs.com]

Dave & Group,

In a message dated 11/20/2003 12:07:15 PM Central Standard Time, 
arc5@ix.netcom.com writes: 
> >Upping the high B+ to 450-500 will work fine.  I have a complete TCS-14 
> that
> >normally I operate from a PP-380/U.  Years ago (>15) I made one mod to the
> >PP-380 by removing the spare fuse holder clips and installing the GK-9-32SL
> >Remote connector (for some strange reason excused with some double-talk in 
> the
> >manual, the stock PP-380 doesn't let you use the Remote/Speaker unit)....
> 
> It's reported that there is a Navy-issued mod to put that remote
> connector
> in the PP-380, Robert.  Although I don't have a copy of the change
> order, it makes perfect sense.  So in my book this is a "legit" mod.
> 

Whew!!!  Saved by the F.C.  :-)  If anyone ever comes across it, I'd be 
interested in how the "official" one was done.  Putting it where I did makes the 
end of the PP-380 look just like the matching end of the 21881 dynamotor supply 
sitting next to it.  I wired it the same as in one of the larger shipboard 
supplies, except that although I have the relays, I did not go to the trouble to 
install the remote Start/Stop relay for the transmitter side of the supply.  I 
have long arms and if I stretch just a little, I can touch the transmitter 
ON/OFF switches on both the transmitter and the remote.  

> >You can in fact keep both 1625 finals running in AM by tacking an easily
> >removable jumper across the appropriate terminals on the Voice/CW switch.
> >However, as others have mentioned, there isn't enough audio available to 
> make it
> >really worthwhile...
> 
> Ya'll do what you want, but you won't catch me doing that.
> Ain't worth the risk.
> 

I forgot to mention that mine had the jumper installed when I bought it some 
quarter-century ago but after playing with it a bit, I took it out.

BTW, I've been reminded recently that some (one for sure) TCS transmitters 
had a mod installed to allow operation off of a 230-250 VDC supply.  This 
consisted of jumpers installed across the screen dropping resistors for the 1625's.  
And at least in the case of one, the clip-in 20K resistor R119 was missing.  
If you come across one like this DO NOT fire the thing up with a standard 400 
V supply until you remove the jumpers.  You'll fry the tubes.  This is 
actually shown on some of the transmitter schematics but as I had never seen a 
transmitter with the jumpers, I had forgotten it was there.  This may have been a 
carry-over from the Collins 56Q which was just the transmitter with either a 400 
V (and 230 V) or a 230 V (only) power supply.  Do not remove the jumper from 
the 1625 output tubes' grid leak resistors to ground, however.  This is a 
service jumper which when removed allows monitoring the final grid current with an 
external meter.

73
Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
<wa5cab@cs.com> (Primary email)
<wa5cab@houston.rr.com> (Backup email)


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