[ARC5] ARC-5 mini-banana plug replacements

[WA5CAB at cs.com]

Banana pin connectors were made in (that I know of) nominal diameters of 
1/8", 3/16", 1/4". 5/16" and 3/8".  The diameter figure given on the available 
drawings is the minimum hole diameter that the pin can be plugged into, and 
is in each case slightly smaller than the nominal diameter or the actual 
inside diameter of the sockets.  Pomona made Grabit to banana in both the 
mini-banana and standard (3/16") banana sizes.  I have some of both.  They might 
have made any of the larger ones as well.  I never checked.

The mini-banana (1/8" nominal) is, as several have said, the size most used 
by A.R.C (they used larger ones, as well). The ones made by Pomona are sold 
through distributors.  I think I bought my recent stock from Allied.  The 
older stock I have doesn't have anything but Signal Corps information on the 
envelopes (and that pertains to the BC-611) so I don't know who made them.

Speaking only of the mini- males, before buying or salvaging some to make 
ersatz Command Set plugs, check the dimension from the mounting surface to 
the beginning of the leaves (there were several variants of this).  If you are 
using salvaged 6-pin connectors from a junked receiver, this dimension 
needs to match that of the existing pins  Else the new pin won't engage far 
enough or it will fully engage early and keep the other six from fully engaging. 
 And if I recall correctly, the ones on the RF coil rack plugs have a 
longer shank than those on the IF transformer plugs (or it may be the other way 
around - I haven't looked at them in years).

There were/are several mounting methods, too.  The two of interest here 
would probably be hollow rivet (like the originals) and threaded stud.  Before 
ordering, check the dimension range for the thickness of the plate you plan 
to use to mount the pins on.  There were several choices here, too.

McMaster (and probably others) sells the setting tool for the hollow rivet 
type, but they are pricey.  Last time I bought any they were over $40 each.

73
Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480