I can vouch for these cranks, they work better than the originals!

Scott W7SVJ

 

From: [email protected] <[email protected]> On Behalf Of n3lll --
Sent: Wednesday, April 26, 2023 13:00
To: ARC-5 <[email protected]>
Subject: [ARC5] ARC -5 6743 Crank Replacements - I have a solution

 

As long as I have been messing around with ARC-5 radio's the achilles heel has always been the tuning knob crank.  Most of the 6743's, when you can find them, are pretty well beat.  I wonder if they were good when new?  I am 74 and have never seen a new one.

 

I set about using modern tools and materials to recreate the spline connection and improve upon the design of the original,  with the same general form factor as the 6743.  

 

Once I reproduced the spline, I needed a way to assure that the shaft was aligned with the spline without any horizontal or vertical movement.  I accomplished this by press fitting the shaft and its shroud  into a small  flanged 10mm ball bearing.  The result was a frictionless knob with smooth operation and excellent mechanical stability.  

 

If you want to see one in person, I will be bringing some with me to the Dayton Hamfest, we will be in location 8332 in the infield.  Very easy to find, it is the first stall to your left as you enter the infield from the west end entrance.

 

Here is a very short YouTube of its operation ... tom, N3LLL

 

https://youtu.be/hTXW8KWkFsA

 

Info on the knobs is at http://www.kitparts.com/ARC5  or email me!