[Collins] Would like to find

[Dr. Gerald N. Johnson]

On Sun, 2006-10-01 at 20:37 -0700, telegrapher at att.net wrote:
> My new (to me anyway) 75S-1 showed up without a manual.  This one is a 
> real keeper.  Clean as a pin and works great.  I think there was some 
> talk about a mod done to them, like adding another IF stage back when 
> they were just past new.  Is that correct?  Might think about adding 
> that in if it's worthwhile.  Otherwise, I'll just listen to it a lot. 
> Been using it almost continuously since it showed up the other day. 
> Even AM sounds respectable and there's nothing like the Collins sound. 
> Tuning is smooth as are all the control movements.

There was mod to some S-line receivers to move an IF transformer from
the AM "filter" permanently to the IF strip for a bit more attenuation
of filter bleed through. SB-2 for the S3B/C. It might be applied to the
S-1, though I've not checked closely and I've not made the mod to my
75S-3B.
> 
> Now for a really nice manual. Think this one has a SN around 11K.  Might 
> be 19K.  It's a little smudged off so can't get a good read on it.

Sometime during S-1 production, Art demanded the serial numbers be
issued in random order because he was annoyed how 75A4 receivers were
valued by serial number. Just because the radios came from the factory
with different circuit mods that made the later serial number radios
work better. So instead in the S-line model numbers and badges changed
to show the rough vintage.

The manual and service bulletins can be downloaded from the Collins
collectors association web page, www.collinsradio.org
> 
> Any help with a manual?
> 
> Didn't see anything listed on the auction house.
> 
> Larry
> W0OGH
> 

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer