Just discovered that one of the IF cans in my SX-117 has an
open winding. I know that many Halli receivers used the
50.KHz IF, and probably the same coil. The part number
is 050-200735 which is printed on the top of the can.
Thanks!

Steve

Steve wrote:
Just discovered that one of the IF cans in my SX-117 has an
open winding. I know that many Halli receivers used the
50.KHz IF, and probably the same coil. The part number
is 050-200735 which is printed on the top of the can.
Thanks!

Steve


Why don't you fix it? It's big, and the failure is almost always
right where the wire is soldered to the terminal.

-Chuck

Chuck,
Already tried to repair it. The break is in the coil, not
at the terminals, or exposed wires. The coil is encapulated
in a ceramic goop I've never seen before. Removing it
will destroy the windings. As a result it'll be hard to count the
windings (its a center tapped coil with unknown tap)even
if I have to rewind it.

Also tried the high voltage arc technique where you use
a HV supply with a big (12K ohm, 10 watt) resistor
in series hoping to weld the break to another adjacent
winding. This worked briefly...

Groan.

Steve
"Chuck Harris" wrote in message
...
Steve wrote:
Just discovered that one of the IF cans in my SX-117 has an
open winding. I know that many Halli receivers used the
50.KHz IF, and probably the same coil. The part number
is 050-200735 which is printed on the top of the can.
Thanks!

Steve
Why don't you fix it? It's big, and the failure is almost always
right where the wire is soldered to the terminal.

-Chuck

Steve schrieb:

Chuck,
Already tried to repair it. The break is in the coil, not
at the terminals, or exposed wires.

Do any people specialize in rewinding these things? Maybe you could
send it to someone who rewinds transformers.....

steph

Steve wrote:
Chuck,
Already tried to repair it. The break is in the coil, not
at the terminals, or exposed wires.

RATS!

The coil is encapulated
in a ceramic goop I've never seen before. Removing it
will destroy the windings. As a result it'll be hard to count the
windings (its a center tapped coil with unknown tap)even
if I have to rewind it.

I've seen this stuff before. It shatters pretty well on
coils. You might be able to get it off of the coil and
count the turns... but they you are bound to find that
the coil is wound in litz wire.

Also tried the high voltage arc technique where you use
a HV supply with a big (12K ohm, 10 watt) resistor
in series hoping to weld the break to another adjacent
winding. This worked briefly...

I have had good luck doing this with a Sencore Z-Meter capacitor
tester. I keep upping the voltage until I get continuity. Then
I blast it a few more times for good measure.

-Chuck



Groan.

Steve
"Chuck Harris" wrote in message
...
Steve wrote:
Just discovered that one of the IF cans in my SX-117 has an
open winding. I know that many Halli receivers used the
50.KHz IF, and probably the same coil. The part number
is 050-200735 which is printed on the top of the can.
Thanks!

Steve
Why don't you fix it? It's big, and the failure is almost always
right where the wire is soldered to the terminal.

-Chuck

Hello Steve:

I grabbed the SX-100 schematic and see that it uses tapped (but not center
tapped) transformers in the second and third stage. I suspect that these
are the same transformers, with the same taps. Hallicrafters probably used
the same transformers for the SX-96, the SX-100, and the SX-101. The S-76
was one of the first to use the 50 kHz (whoops kc) transformers. I know
there are a lot of parts units floating around so you might check the
manuals of those to see if they are the same.

It is late and bed time, but I have the SX-96, 100, 101, 88, 115 and 117 I
could check (no you cannot have the transformer out of my 88).

Although you could duplicate the coil, it should be fairly easy to find a
replacement. That way, you will not have to determine the tap and duplicate
the coupling.

73, Colin K7FM

Hi Colin,
Thanks for the info. It'll be useful as I'm looking for parts.
Luckily I found what I need and it should be on its way soon.

Steve
"COLIN LAMB" wrote in message
nk.net...
Hello Steve:

I grabbed the SX-100 schematic and see that it uses tapped (but not center
tapped) transformers in the second and third stage. I suspect that these
are the same transformers, with the same taps. Hallicrafters probably
used the same transformers for the SX-96, the SX-100, and the SX-101. The
S-76 was one of the first to use the 50 kHz (whoops kc) transformers. I
know there are a lot of parts units floating around so you might check the
manuals of those to see if they are the same.

It is late and bed time, but I have the SX-96, 100, 101, 88, 115 and 117 I
could check (no you cannot have the transformer out of my 88).

Although you could duplicate the coil, it should be fairly easy to find a
replacement. That way, you will not have to determine the tap and
duplicate the coupling.

73, Colin K7FM