Comments on "The ARRL-Recommended 12-V Power Connector".
by Avery Davis, WB4RTP

On page 22.6 of the 1995 ARRL Handbook is a recommendation for a 12-
Volt power connector to promote "compatibility and interchangeability
among VHF/UHF equipment at disaster and public event sites".  I first
heard about using the Radio Shack part #274-222 connector for this at
the February 1994 meeting of Atlanta C.A.R.E.S. during an excellent
presentation on what should go in to an emergency communicator's "jump
kit" by David Rice, KD4SHH.  The 1995 ARRL Handbook article is very good, 
but I do have a few additional suggestions.

Alternate sources:  first, the price that Radio Shack sells the #274-
222 is very competitive with alternate sources, such as Mouser, Newark
or Digi-Key.  All of them offer discounts for large quantities, such
as 100.  Here are some speicifications and part numbers:

Radio Shack Cat. No. 274-222, "2-Conductor Male/Female Molded Nylon
Connector Pair With 0.093" crimp terminals', contains two connector
housings, one plug and one receptacle, plus four terminals, crimp
type, two male and two female. All this costs about $1. I was able to
match this connector in my Molex databook and in the Digi-Key catalog.
Here are the Molex and Digi-Key numbers:

Plug Housing: 03-09-2021, Digi-Key WM13505-ND
Receptacle Housing: 03-09-1027, Digi-Key WM1304-ND
Male Terminal: 02-09-2103, Digi-Key WM1100-ND
Female Terminal: 02-09-1104, Digi-Key WM1101-ND

Assembly Instructions:
The male terminals are used in the plug housing, and the female
terminals are used in the receptacle housing. The receptacle is always
used for the source of power, and the plug is always used for the load
(just like with electrical appliances and house wiring. For polarity,
pin 1 is positive and pin 2 is negative. The connector is keyed with a
bevel on the pin 1 end.  #18AWG wire size is recommended.

For use, just attach these connectors to everything that you might
want to use in a communications emergency: radios, batteries,
chargers, accessories, power supplies, etc.

First Hint&Kink:  Whenever you attach a plug on the end of a cord for
a load device, also attach a receptacle on a short pigtail from the
plug.  This allows "daisy-chaining" multiple devices on a single power
source without having to prepare special "Y" or "Octopus" adapters.

Second Hint&Kink:  The tolerance of the fit of the terminals in the
housing is less than perfect for these connectors, so sometimes
"plugging-in" can be difficult.  One way of improving the fit of the
terminal is to hold them in place with hot-melt glue.  First, assemble
the connector normally, then plug it in to a mating connector, being
careful to get the terminals aligned correctly.  Now, take a hot melt
glue gun and fill the cavity where the wire goes into the housing.  Be
careful not to get any glue in the front part of the connector where
the mating terminals make contact.  Another advantage of using hot-
melt glue is that you can leave some excess glue between the wires and
the back of the housing to act as a strain relief.