[ARC5] Brass-tubing tuning-adapter.

[hwhall at compuserve.com]

The article I have may be the same one. It has a 40m scale illustrated and it used three circlular arcs to cover 7.0 to 7.3 MHz in three knob turns. Each circle was marked with a 100kc scale. The illustration looked very neat but probably was for looks only as the scale marks had to be found experimentally. The pointer was a bent wire held by one of the case screws.

The guy made the scale circles sort of align by marking the first 100kc on one circle, then dropping to the next circle to begin the next 100kc, as so on. Looks like it takes a bit of getting used to.

 

 Wayne

 

-----Original Message-----
From: Bill Cromwell <wrcromwell at gmail.com>
To: hwhall <hwhall at compuserve.com>; arc5 <arc5 at mailman.qth.net>
Sent: Wed, Aug 27, 2014 6:25 pm
Subject: Re: [ARC5] Brass-tubing tuning-adapter.


Hi Wayne,

I saw that method described - complete with pictures. I don't recall now 
if I saw it on a web page or downloaded one of those conversion books 
and saw it there. The one I saw was for the 40 meter band on a 6 to 9 Mc 
receiver. The trouble is that it has a separate scale for each turn of 
the knob and they do NOT align. A Vernier scale made to align with the 
existing dial scale will do the job with just *one* scale. If the tuning 
mechanism had a one to ten turn ratio then the scale on the knob would 
work wonderfully well. But one turn of the knob does not do 10 or 100kc. 
It still might be of interest to some of our friends here. I'll see if I 
can find it.

73,

Bill  KU8H

On 08/27/2014 07:33 PM, hwhall at compuserve.com wrote:
> In my 1970 edition of Tom Kneitel's "Surplus Conversion Handbook" 
> there is a one page article, "Bandspreading ARC-5 Receivers", that 
> describes a band spread scale that attaches to the knob that drives 
> the spline shaft.
>
> Wayne Hall
> WB4OGM
>
>