[Collins] 75S-1

[David Harmon]

Cory.....

Most likely, the rx is an early model with vertical ribs molded in the
front of the meter case.
These meters were not mechanically damped like the later models were, so
yes this is normal.
I have an old S-1 Line that has the undamped meters and it is slightly
aggravating to use but I soon got used to it. The transmitter has one
too.
You could damp the meter by connecting a large capacity electrolytic
across the meter movement....don't forget to discharge the cap first!

The non linearity in the PTO is easy....just follow the manual procedure
to adjust it.

I prefer the sound of the early S1-Line over the later models.....it
just sounds warmer or something but I can notice a more pleasing tone.

Regards

Dave Harmon
NSRCA 586
K6XYZ[at]comcast[dot]net
Torrance, Ca.

-----Original Message-----
From: collins-bounces at mailman.qth.net
[mailto:collins-bounces at mailman.qth.net] On Behalf Of
kiyoinc at attglobal.net
Sent: Thursday, June 03, 2004 3:58 AM
To: collins at mailman.qth.net
Subject: [Collins] 75S-1

I've acquired, make it, adopted a Collins 75S-1 with 500 Hz
filter, 312B-3, and the manual.  

The fellow who sold it to me indicated that the CW filter and
the speaker, together, were worth more than the receiver.

I checked on eBay and that seems to be true.  

I've been turning round 40, 80, and 75 with the 75S-1,
comparing it to my *very hot* SB-303.  I prefer the sound of
the 75S-1 to the SB-303.  

The SB-303 has dual 2.1 kHz crystal filters in it and drives a
modified (no tweeter) Radio Shack Minimum-7 speaker.

I've noticed two things about the Collins, the S-meter is
jiggly, seems to have little damping. Is this normal?  Is it
the AGC time constant capacitor?  

The PTO is not as linear as it could be.  It is on spec but
just barely. If I set the hairline to the calibrator at 100,
then 200 and 0 are about 1 kHz off.  

Other than that, it seems to work perfectly.

Almost no signs of wear on the radio, a few minor scratches
and some knob-wear but otherwise it looks like it just came
from Collins. 

de ah6gi/4 mostly heathkits here but now building a Collins
collection.




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