[ARC5] ARC-2 Significance and Quality

[David Stinson]

----- Original Message ----- 
From: "Ray Fantini" <RAFANTINI at salisbury.edu>


Just had the opportunity to look at the schematic and now see 
just what's going on inside the ARC-2 and have to say although I 
never knew it that radio is way significant, don't know if the 
Collins collectors know this or not but the design of the radio 
using a variable IF over a fixed IF may be the first example of 
this in a Collins design, something almost everything they did 
for the next twenty years incorporated......
----------------------

>From a 1975 CQ column by Gordon White:

"The receiver section uses three radio-frequency stages,
a single mixer and four intermediate-frequency stages
at an I.F. which varies from 1 to 1.5083 MHz,
using the now-familiar Collins variable i.f. design,
slug-tuned, through a movable rack and
cam arrangement.  This scheme was followed in
the 51J4 and the R-390A, to mention two
very successful later Collins designs..."

The AN/ARC-2 is very impressive.
Built with the finest quality parts, sturdy and very robust.
I found three bad caps: two familiar "flower pot"
electrolytics made my A.R.C. and an oil-filled cap
 from G.E. that "healed" itself during testing.
Given proper lube, oil, cleaning and care,
I expect this radio to be working 100 years from now.
It is built that well; easily the best construction I have
seen in a WWII radio of anything like this complexity.

One thing, though:  the shielded cable used throughout.
The insulation on the center conductor of this cable
melts easily.  Just get a soldering iron near it...
I mean, if you look at this cable with a sexy thought
in the back of your head, it starts melting!
So if you do any soldering in the set, be extra careful.
You gotta have some small tools, good eyes,
lots of light and a steady hand to work on it.
It's crowded in there.

73 Dave S.