[Hallicrafters] S-107 Alignment and Mark 1/2 Differences

[Glen Zook]

I had a early model S-107 when I was first licensed as
a Novice Class in May of 1959.  It did NOT have a tone
switch and had a phone jack on the front panel.

I have a 2 Mark 2 versions right now but have a Mark 1
book.  There are several discrepencies in the Mark 1
book.  First of all both the schematic and the photo
of the front panel do show a switch.  But, the
schematic also shows switches to control the phone
jack (which shows to be of the old 2-pin type) and for
the phono input (so that you could use the old 45 rpm
RCA record players with it).  But, no where on the
photographs do either the pin jacks or switches for
the headphones or the input to the amplifier appear.

All that the tone switch did was to place a 1000 ohm
resistor across the primary of the audio output
transformer.

The alignment instructions do reference the tone
switch.  However, I tend to believe that by the time
the S-107 got into general production that the tone
switch was eliminated (haven't looked to see if the
1000 ohm resistor is across the audio output in either
of my S-107 transformers or not), that the switch /
pin jack was replaced with a "standard" 1/4" headphone
jack, and the audio input was wired in directly and in
now called "audio output to external amplifier" (which
allows the receiver to be used as a "tuner" for the
old bype hifi systems).

All of the changes made for less work on the
production line and eliminated 3 switches thus also
reducing the cost.

Also, all 3 of the S-107 models that I own/owned had
the internal speaker with the perforations on the top
of the cabinet

Glen, K9STH



--- Julian Bunn <Julian.Bunn at caltech.edu> wrote:

am slightly confused by a reference in the Alignment
Instructions for the Mark 2 to setting the Tone
control to High.
 
There is no Tone control on my Mark 2.

The S-107 picture in Chuck Dachis' book shows a Tone
switch in the position where the Phones jack is on my
Mark 2. Perhaps that picture is of a Mark 1? (Also,
curiously, his S-107 picture shows no evidence of the
speaker grille holes on the top of the receiver: where
was the speaker mounted?)


Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco


		
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