[Milsurplus] Black paint/white paint

[Glen Zook]

There were approximately 1500 of the Eldico S-119 systems made.  These consist of the T-102 transmitter (similar performance to the Collins 32S-2), the R-104 receiver (similar performance to the Collins 75S-2), the M-135 control unit (nowhere close to the Collins 312B-4), and the P-109 power supply (similar to the Collins 516F-2).  The transmitters and receivers both used Collins mechanical filters but that is where the real similarity stopped!  The VFOs are completely different except that both use permability tuning.  The Collins PTO uses a 6AU6 and the Eldico VFO uses a 6U8.  There is no buffer in the Collins PTO but the Eldico VFO uses the triode section of the 6U8 as a buffer.

Eldico uses tubes in the transmitter balanced modulator and Collins used germanium diodes (2 in the early versions and then 4 in the later versions).

The Eldico can use the same heterodyne oscillator crystals as the Collins.  However, the 200 kHz frequency segment differs by 100 kHz.

Art Collins actually approved the Eldico units as a required "second source" to the Collins equipment.  However, there was an agreement in place which prohibited Eldico from marketing the equipment to amateur radio operators.  When Eldico made some inquires about selling the equipment to amateur radio operators, Collins Radio "stepped in" and quashed that idea.

I do have a complete S-119 system and occasionally do use it.  The VFO tuning is no where near as smooth as the Collins and the dial is somewhat smaller in diameter which, in turn, is not quite as accurate as the Collins PTO.  However, the calibration is still pretty good and the VFOs do "track" very well.

Back in the mid-1970s I had a T-102, R-104, and P-109 (that without the cabinet).  I traded it off after a year, or so.  I got my present S-119 a little over a year ago.

The Eldico equipment is pictured in photos 2 and 3 at

http://k9sth.com/uploads/K9STH_Shack_Photos.pdf


I do have a copy of the complete technical manuals for the equipment.
 
Glen, K9STH


Website:  http://k9sth.com


________________________________
From: Jim Haynes <jhhaynes at earthlink.net>
To: J. Forster <jfor at quikus.com>
Cc: milsurplus at mailman.qth.net
Sent: Thursday, September 15, 2011 8:02 PM
Subject: Re: [Milsurplus] Black paint/white paint

In the same vein, there was the Air Force purchase of copies of the
Collins S-line amateur radio equipment made by Eldico for updating the
base MARS stations, circa 1960.

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