CompuPro floppy controller differences

[Allison]

>
>Subject: Re: CompuPro floppy controller differences
>   From: ard at p850ug1.demon.co.uk (Tony Duell)
>   Date: Thu, 21 Sep 2006 22:28:09 +0100 (BST)
>     To: cctalk at classiccmp.org
>
>> >Oh, I'd be happy to change the pulleys and reset the belt tensions. The 
>> >problem is _getting_ the pulleys. Do you want to be the chap who phones 
>> >Seagate and says 'Hello, I think you used to be Shugart, do you have the 
>> >60Hz conversion kits for the SA801, SA851 and SA4000 in stock'
>> 
>> Pft!  If you brought them here you'd find spares from used drives or even 
>> working domestic versions.  Non of those floppies are exactly rare and even
>> the SA4000 is still around.
>
>Are they really that common in the States? They are not at all common in 
>the UK any more, so don't think of that as being a source for 50Hz pulleys...

If you were her than 50hz pulleys are a non issue. ;)

>And those were the easy drives. I guess RK05s wouldn't be too hard to 
>find 60Hz pulleys for either. What about RX01s/02s? Do RK07s need 
>converting? RL's I know don't. But my ASR33 would. And all my audio tape 
>recorders (some of which may never have had 60Hz varients). 

Lifes rough.  The solution I used once for a 50hz and later a 400hz motor
was a simple transformer output pushpull amp fed with a wein bridge osc,
a very good way to generate variable frequency sinewavs in the <100W class.
so happens I had a 12.6V CT (12A) transformer with the requisite 120V 
primary. Into a lamp load it was under 1% THD and voltage stability was
as good (5%). I ended up using it for all sorts of AC motor control 
solutions. Didn't require special parts or machine shop either.

>Don't worry, I am not going to move to the States. It would be totally 
>impractical for a lot of other reasons.

Whats practicality got to do with anything?  :)


Allison