[HBR] Progess report and 50:1 drive idea

[n2ey at aol.com]

-----Original Message-----
From: windy10605 at juno.com
To: hbr at mailman.qth.net
Sent: Tue, 25 Apr 2006 08:42:15 -0500
Subject: Fw: [HBR] Progess report and 50:1 drive idea


>One of the best no backlash high ratio drives is still the tuning
>mechanism out of a BC221 Frequency Meter which always show up at
>swapmeets.
 
For my money, they are *the* best. There are at least two different styles, one used in the LM series and
one used in the BC-221 series. Slight differences but the same quality. I've built receivers, VFOs and
transceivers with them.

>The Command Set anti-backlash gear sets are also great but the gear ratio
>is higher and you have to get mechanically creative to use it.

The ARC-5 transmitter caps have the same ratio as the BC-221 - 100 to 1. Fifty turns to make the 
capacitor turn a half revolution. They are second only to the BC-221/LM caps. The ARC-5 receiver
caps are good too but not the same.
Still another option is the tuning gang from the TCS series. But they're "only" 50:1.
The trick to using any of these is to use the whole unit - capacitor, drive, and dial/drum. Simplifies
things greatly. ARC-5s and BC-221/LMs with usable caps but that are beyond restoration are neither rare
nor expensive. 
73 de Jim, N2EY