When I bought my SB-101 back at the beginning of this year, I found that the drive arrangement for the main tuning dial was damaged in transit due to an exceptionally bad packing job done by a FedEx shipping store. In hindsight, if I’d known what a problem this would turn out to be I’d have filed a damage claim. None of the parts, of course, have been made for many years, and finding replacements is difficult to impossible without buying another radio and parting it out.
The dial drive consists of two special phosphor bronze disks with a tiny spacer between them. These pinch an aluminum drive ring attached to the plastic dial. One of the disks was cracked when I got the radio, no doubt from the same impact that bent the tuning knob. I tried a number of fixes for the slipping drive. First was an O-ring, which worked wonderfully… for a few days, then it started slipping as well. After a few attempts to get the solution to work reliably, the crack in the broken disk eventually grew to the point where the disk came apart completely. I replaced it with a disk made from cork and rubber gasket material for a friction drive. That worked, albeit with a little slippage once in a while, until I started using the rig in earnest. The combination of time and use eventually made the slipping problem intolerable.
I’d been scouting eBay and the ham for sale forums for a solution. I was hoping for an SB series radio – any of them at all – that had an intact and working dial mechanism, but the rest of the rig in bad shape. I’d love to find one at a bargain price at a hamfest, but so far that hasn’t happened. Finally I found an auction for an SB-101 bezel with the tuning knob and attached dial drive parts. Beat up, scuffed, a little corroded, and probably missing a part or two – but it had what I needed, and wasn’t terribly expensive. I bought it.
As I suspected, it was missing parts. Both of the drive disks were there, though the two spacers were gone. When the gasket material finally failed completely, I pulled the bezel off and replaced it so the rig now has a properly assembled, complete drive mechanism.
The difference was immediately obvious and is amazing. Tuning is now perfectly smooth, with absolutely no slip or backlash. Tuning SSB stations is a breeze (at last).