THIS ARC-5 THING CAN GET OUT OF CONTR0L!



See:  PA3ESY

POWERING UP COMMAND SETS

AS STAND-ALONE RECEIVERS

There are some good reasons for operating just one receiver. 

E,g, R-24/ARC-5 with an AC power supply and a simple loop antenna makes an excellent broadcast-band DX receiver.

The receivers as originally shiupped included the dynamotor to provide high voltage for the tubes.  It was intended to be plugged into a radio system.  Tuning was done by a flexible shaft from a control box that also controlled the RF Gain, turned the BFO on and off, and provided the audio jack for the headset.


So in this state it's pretty useless for stand-alone operation.
BASIC LOCAL OPERATION OF ARC-5 RECEIVERS

View from outside rear of set



  • Connect +24 VDC to pin6
  • Connect -24 VDC t pin 1
  • Audio output is from pin 2
  • Audio return is pin 1




VIEW FROM FRONT OF SET



Remote Control Adapter MX-21 / ARC-5
a.k.a.
Switch panel Adapter  CBY-49107 (ARA)
FT-230-A (SCR-274)

Remote Control Adapter MX-21 / ARC-5 is normally
supplied with all communication receivers.  It is plugged into the front of the set via J-1.   Its sole function is to complete the low-voltage circuit and to cover up the opening that otherwise would exist in the front of the receiceiver.  In this case all control functions are made from remote control boxes via J-3 on the back of the set.
Local Control

This is the answer if you can find one.

C-24/ARC-5
a.k.a.
FT-260-A (SCR-274)



AS SEEN FROM BACK OF ADAPTOR
(IT'S UNSIDE DOWN)
Or modifiy an MX-21/ARC-5
Tuning Knob

Also, some of the later ARC-5 units have a slide-on knob inside the lid.
 Improvised
1/4" brass or aluminum tubing


Suggested by Ken W7EKB
 

Non-Invasive AC Power Supply for ARC-5 Reveivers

A simple AC supply built on a dynamoter base will power any 24-volt ARC-5 Receiver.  No internal modifications are needed.

HV APPROXIMATELY 250 VDC
LV 24-28 VOLTS AC OR DC



  • Back-feeds B+ and heater power (AC) via the dynamotor connector.

  • Picks up output audio from J-3 (rear of set) via miniature banana plug, and feeds it to a 1/4" phone jack through a 10K pot.  (Now you have a separated audio gain control in addition to the existing RF gain control.)

  • Also provides a pilot lamp and convenient ground terminal.

  • You'll nned a local control unit plugged into the front of the set, and an appropriate tuning knob.

RTFS!


Just for greater understanding.

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