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

[rrkrr]

Bill,
The "strip heater" is a high wattage resistor - it's mounted on the 
chassis for a heat sink. As I recall, it's the screen voltage dropping 
resistor for the audio output tube.  My SX-17 did not have a fuse 
either.  I installed one.  I also believe the wiring for the power 
switch, which is on tone control, gets interconnected with the power 
cord on the same connector strip on the power transformer where the 
transformer windings are attached.  So it may look like the power cord 
is connected directly to the transformer windings, but it really isn't.

Bob
WB4TGG

Bill Gerhold wrote:

>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
>
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