[Hallicrafters] Dial Cord -- Slip No More Forever

[k6uuz at juno.com]

K5MVR et al;

Thanks for sharing your experience. Here are some comments from someone
who has restrung MANY dial cords. (I made my living for 55 years
repairing radios). I don't recall a single instance of a slipping dial
cord that couldn't be fixed without resorting to your method. (don't get
me wrong. If it works for you, that is fine).

The largest cause of slippage is too much load. I always lube the
bearings on both ends of the variable capacitor. If the grease has dried
and is hard, remove it and put in some new. Lubraplate is great. Also
squirt some contact cleaner on the ground wiper. Not only does this
reduce friction, but is protection against intermittent operation. I do
recall one SX-100 and a couple of another brand also starting with H,
that use rubber drive belts (O-rings), that WILL stretch. After a
thorough cleaning and lubing, they still slipped. Turning the capacitor
by hand revealed excessive friction. Apparently the frame of the
capacitor was too tight against the bearings. I had to spring (bend) the
frames outward just a little. For small capacitors, I took a pair of gas
pliers and ground a notch on the outside of both jaws. By inserting the
pliers into the capacitor (plates closed of course) pull the handles
apart. Just a little at a time, until the capacitor feels free but does
not have any play in the bearings. For larger capacitors, I remove the
capacitor from the radio and secure it in a vise, and slightly bend the
frame with a Crescent wrench. That fixed all three. I also lub the
pulleys, as a lot of little frictions add up. I also recall a Gonset
GSB-100 transmitter with a slipping cord for the dial drum. Again turning
it by hand revealed too much friction. After several attempts at bending
the sheet metal mounts, I could spin it with little effort.

Another factor is the composition of the dial cord. You mentioned Nylon,
which is a slippery material. It is frequently used for bearings. I use
only cotton covered cord. I get mine from a sporting goods store. It is
sold for fly-fishing as it floats on the water.

Another factor is the size of the cord. It used to be available in
several diameters. I have some NOS, made by GC Electronics, that is about
twice as thick as fishing line. The larger diameter has more surface area
to grip the shaft. I don't know if it is still available.

Ed Richards

On Fri, 22 Feb 2002 13:57:26 -0600 Ron Evans <cosmos41 at ix.netcom.com>
writes:
> Greetings, Halli-gang
> 
> Well, the restringing of the bandspread capacitor on my S-85 is 
> accomplished, and I just have to share a technique I blundered onto 
> that 
> may come in handy for you sometime.  Many of you will have your own 
> particular technique, and I'm hoping you will share it with the 
> list.

> So, what tips or techniques can you share?