[ARC5] Help! Looking for info to build a home-brew T-R control box.

[J Mcvey]

First of all, get a complete SCR274 manual here:scr274


The arc5  modulators and transmitters are different in a few ways (even though they look similar).The ARC5 manual is useless for the transmitters.The receivers are interchangeable in the racks but they too are a little different electrically..
The scr274 manual has all the racks, boxes and interconnects you need.
The only interconnect between the rx/tx system is the antenna relay and the modulator provides a side tone for the receiver rack . ( The relay in the rack switches the audio output between the receiver and the sidetone when keyed.). You don't have to use it though, because there is enough leakage to hear the tx in the receiver.
All you really need is to wire up a 3-5 amp relay as shown in the BC442. schematic. This is connected to the TX .rack and runs off of the keying line from the modulator.
I'm not clear on how "original" your setup might be. How you key the tx makes a big difference on how things will get wired.The original system keyed the B+ and it works very well!
Don't know how you can avoid soldering stuff though...





 

    On Thursday, March 16, 2017 10:03 PM, Leslie Smith <vk2bcu at operamail.com> wrote:
 

 

G'day all,

I wish to set up a T-R control system for a single ARA (or SCR-274-N)
receiver and transmitter.  (I have racks for these.)  I have most of the
components - although only the transmitter & receiver are from BC-nnn. 
My PSU, modulator and T-R logic are home-brew.

 I have the (easily found) manual AN 16-30 ARC5-2 (in pdf form).
 In that manual section VIII contains drawing of individual components,
 and  interconnection.
 For example, Fig 8-5 shows the transmitter schematic and external
 wiring (incl the connection to the modulator component).

 In the same manual Fig 8-70 shows how to connect a single transmitter &
  receiver to the ARC-5 test rig.

 On page 153/54 I see a drawing showing wiring for rack MT-65, and I
 suspect this is CLOSE to the wiring for the FT-266-A (but only the
 MT-65 shows triple receivers, not one!)  

AND SO ON.  THAT's WHAT I HAVE.

  However, these drawing apply to the ARC-5 components, NOT the
  SCR-274-N/ATA/ARA  components.

 I have wiring diagrams for the BC-234-A single tx rack.  I have a rack.
 I figured the orientation of the 12 way connector and the function of
 each pin in that connector.  As I write, I do NOT 
have a connector, but I am certain I can buy 4mm brass tube and drill a
2.50 hole up the center and (with care) can 
make a connector to fit the pins on the rack.    (Yes, I understand
there is +600V on these pins!)

 I have found I can buy SOME connectors on eBay, but probably not the
 larger  12 way connector I mention above. 


Anyway, I'm certain others (many others) have sketched a home-brew tx-rx
control system for a working "command" rig.  I WISH TO AVOID SOLDERING
WIRES TO PINS ON RACKS ETC.  

                  o-o-o NOW TO MY REQUEST  o-o-o

Can anyone here EITHER

  (1) Point me to a sketch of a working control system for a command
  tx-rx pair.
      Remember I have NO cables, only racks.

                            OR

  (2) Advise the difference between the ATA/ARA/SCR sets and the ARC-5
  manual.

ALSO
  I have a card I built (PC card) with T-R logic that switches power and
  aerial between a receiver (any receiver) and a transmitter (any
  transmitter), but  for low voltage only.  With a little extra work
  (and a few relays) I could  adapt this (quite useful) card to work
  with the command components I  already have.

FINALLY:
  If this info does NOT EXIST in any single place it's time it did.  
  I would like to  collate and post this info in some public place. 
  I suggest this info should go into "files" at the YAHOO ARC5-Radio
  group.

Thank you for your interest.

Les Smith
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html


   
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20170317/22d398e9/attachment-0001.html>