[ARC5] ARC-5 Mods

[Mike Morrow]

Kevin wrote:

>My original BC-455 came from Fair Radio, and was in far from pristine
>condition. ... By 1975 their stock of new units was depleted.

As late as 1977, John Meshna's surplus outlet in Lynn, MA, still had
a stock of R-25/ARC-5 and T-21/ARC-5 units, new in their never-opened-
since-leaving-the-factory packaging.  I bought one R-25, and a couple
of T-21 units.  One of those is still unopened in its 64-year-old
package.  I was stationed at Portsmouth Naval Shipyard in NH, so
Meshna's (north of Boston) was one of my favorite places to browse
around, especially when I got a chance to get into the large warehouse.
But even then they were getting mainly into solid state commercial
surplus.

During the same time period, I would usually stop by Fair Radio when
heading back west on leave.  As you mention, the condition and stock
of Fair's command set items were poor by then.  RCAF AN/ART-13A,
USAF RT-380/AR (AN/ARC-59), and USN RT-594/ARC-38A units seemed to
top the list of the type of aircraft radio gear they were selling
by then.

>I used it for about a year with good results on 40 meters. ...
>I once heard someone describe the receivers as having "no
>perceivable selectivity". That may be true, but they still
>work remarkably well.

The 6 to 9.1 mc units like the BC-455 are especially extremely
broad, with micro-bandspread.  I tried to use a junker R-26 as a
ham rig in the mid-1960s.  I even built an 80m single tube 5763
crystal-controlled CW transmitter on the dynamotor deck.  But
even 40 years ago, the lack of selectivity and bandspread made it
impractical to use on the very crowded 80m Novice band.  (But
the transmitter worked well...gotta' love that 5763!)

I had much better results using a BC-453-A (190 to 560 kc) with
a homebrew two-tube converter for 80m and 40m....selectivity
to spare!  This also had the advantage of bypassing the converter
to copy the very interesting maritime Morse band from 420 to 520
kc at night.  To me, that was the single most interesting band in
the entire radio spectrum, now sadly gone forever. 

>Thank you for your welcome to the reflector. The knowledge I have
>regarding these sets would fit into a thimble, so I may not contribute
>often.

There's a short introductory article covering the "command sets"
at http://en.wikipedia.org/wiki/ARC-5 that may have some value.

I've been interested in this type of equipment since 1964.  In the 
(short) 11 years that I have been a member of this arc5 list (and
the related milsurplus list), I couldn't begin to list how often
the list discussions have lifted me out of much ignorance and
many misperceptions.  Questions presented to the list often
trigger many interesting exchanges.  The list members constitute
the best resource that I've ever come across.

Welcome!

Mike / KK5F