[HBR] Progess report and 50:1 drive idea

[keith ford]

So Don,  do you have that article online?  Or better
yet your T.J. Lindsey incognito?

Seriously that would be interesting to read.

 Keith.

--- Don <dkelly42 at cox.net> wrote:

> Walt,
> 
> "Does anyone have experience with string drives at
> ~50:1?   What about a
> 5:1 
> ball drive and a 10:1 string drive?"
> 
> Walt I tried what you mentioned above not long ago.
> Good idea.
> 
> I used a 2" drum and 1/4" shaft. This gave me 8:1. I
> also mounted a
> drive from Dan's Small Parts. See EPICYCLIC CORD
> DRIVE NO. 4413. It
> inclused a 5:1 panel mount drive. I panel mounted
> the drive shaft
> coupled to the tuning shaft. That gave me 40:1. My
> tuning range was 400
> Khz and the tuning was pretty nice but had to be
> aligned perfect.
> 
> http://www.danssmallpartsandkits.net/
> 
> 
> I rebuilt the VFO and reduced the tuning range to 70
> Khz for CW and did
> not need or use the drive again. This particular
> drive has only 8oz
> torque. I don't think it is 1st class quality and
> would not have trusted
> using it long term unless I did some better
> mechanical construction. The
> small drum is not made well as the coupling is not
> dead center. 
> 
> However, Jackson Brothers has a similar 5870 drive
> with a similar output
> torque but I expect much better construction. The
> trick is in the
> alignment. 
> 
>
http://www.mainlinegroup.co.uk/jacksonbrothers/index.htm
> 
> 
> Maybe a source of ideas or parts for future
> projects. I want to try the
> 5670 drive sometime.
> 
> I like the homemade string drives. They don't wear
> out and you can
> always find a replacement. But can be a difficult
> mechanical problem to
> install.
> 
> BTW, I wrote an article 20 years ago about a string
> mechanisms using a
> jar lid for the drum if anyone would be interested.
> 
> K5UOS
> 
> 
> 
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