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[Amps] Amp Conversion Update

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Subject: [Amps] Amp Conversion Update
From: "Paul Christensen" <>
Date: Fri, 29 Aug 2014 18:33:28 -0400
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I'm making slow progress on my amp conversion. Some of you may recall that an Alpha 77Dx "beater" is being converted into a custom amp. At this time, the microcontroller code is nearly finished, the new front panel is complete with a quad set of 250-degree analog meters, a new front panel switch-bank PCB was designed, and much of the hardware mods have been made. I'll have a few pics in about a week.

The loading cap pair are jettisoned and I'm using one 7-1000 pF vacuum cap. But here's a problem I'm up against. To add the vacuum cap, I need the same turns-counter hardware that Alpha used. Images in the links below. Alpha used a pair of keyed disks on the 1/4" shaft ends to engage a Nylon spacer. The opposite side of that spacer then engages the vacuum cap. The hardware is press-fit such that the panel can be removed without the need for shaft couplers. Due to space considerations, there's just no way to access coupler set screws between the front panel and inner panel. That's why Alpha chose this method.

Apart from making my own, does anyone know where I can find this hardware? If there are no leads, I’ll check with RF Concepts and Dick Byrd, N4UQ after the holiday weekend. Tnx!

Paul, W9AC

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