[Hallicrafters] SX-17 Recap, Redux and Other Issues.

[Bill Gerhold]

A short while ago I posted about recapping my SX-17 and was dismayed at the
tightness of the parts layout and what seemed to be a very difficult if not
impossible task.  Well, I took a fresh look at it and decided (as others
have suggested), to replace the caps I can get at specifically targeting
ones that if shorted could cause massive of expensive damage or ones located
in the AVC circuit.  So I am proceeding in this direction.  Incidentally,
the 2 caps I have removed so far have a definite high value resistance that
new caps do not.  So, these caps even with the meg ohm readings are probably
causing performance problems with the receiver.  So this is a good thing to
do.

However, I ran into a strange problem (?) as I looked deeper into the
circuit.  First off, the SX-17 was not fused.  According to the schematic
one side of the AC power is fed to the on/off switch and then on to the
primary winding of the power transformer.  Apparently, the 2-wire line cord
was replaced with a 3-wire line cord again with no fuse by a previous owner.


I removed this line cord and noticed the chassis entrance hole for this
3-wire line cord was the exact size for a fuse holder.  So I grabbed a fuse
holder from the junk box and mounted it in this hole.  So far, so good,
right?  Upon removal of the 3-wire line cord, I noticed the following.  The
ground wire was connected to the chassis as it should be and the other 2
wires were soldered directly to the transformer winding!  My eyes opened
wide upon seeing this because the on/off switch on the front AC switch does
turn the radio on/off, filaments and panel lights.  At least it gives one
the impression it is since the heaters and panel lights come on.

I then also noticed, what seems to be a strip heater mounted on the rear
apron (internal).  However, there is no heater in the schematic or parts
list that I have nor is there any indication of the (2) pilot lights on the
schematic.  The construction; technique, neat-laced harness and parts
placement all look original.  Therefore, I am thinking, either I have a
modified receiver or I have a different version from you run of the mill
SX-17.

Questions.  Does anyone know if there were different versions of the SX-17
besides the FCC special SX-17F.  Does anyone know if a strip heater was ever
employed in the SX-17 to keep it warm similar to the SX-111?

K2WH