Phil Nelson wrote:

Is this something a fumble-fingers like me could attempt? What's involved in
making a movement right resting? I have little to lose at this point . . . .

Assuming you're not serious about "fumble-fingers" - it is likely
"doable" - though it takes a LOT of patience and you will sacrifice some
accuracy (though IIRC the S-meter system in those radios were "relative"
anyway).

First you want to determine what type of meter movement it is -
hair-spring (likely), taut-band, or other (not likely). If it's a hair
spring (spring that spirals in - in a flat plain) and has both a front
and rear adjustment- then it's likely you can successfully "re-zero" it.
The front spring mount usually has a large loop adjuster that is often
engaged by an eccentric pin from the face that allows external zero
adjustments- the rear usually also has an adjustable spring mount - but
far more "dainty" as it's not intended for frequent adjustment - in fact
most are never touched after first calibration when made. It's this back
adjustment that you want to CAREFULLY turn until you zero the meter at
the right. Be very careful to not kink the spring, etc. - most meters
will have enough play to run them fully across using only the back
adjustment - though with some - you may have to use some of the front
adjustment as well. Since the meter will now be "unwinding" the springs
rather than winding it - the meter's linearity will be less than it
should be - but in this application - I doubt anyone would notice. Just
be sure and check for clearance around both springs as they flex as the
needle swings -- as again - the springs will be "un-winding" now rather
than "winding".

Once reversed - you'll have to experiment some to see how it reacts -
whether it appears that the indicated reading is what you would expect -
or if you need to "adjust" the circuitry a bit to better "calibrate" the
system.

HTHs -
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Phil Nelson wrote:
"Crazy George" wrote in message
...

I suspect someone replaced a failed movement in your original
meter with a standard movement.


Hmm, a light bulb flickers dimly in my brain. That would explain why it
looks stock but works backwards. The case of this meter is split to heck all
around and bound together with friction tape, but I figured that was not
that unusual for such old meters. When I opened the smallest electrolytic
can to restuff it, the danged thing split into about five pieces in my
fingers! But I could believe that somebody pried this case apart with a
screwdriver.

The meter enclosures in some variants of the SX-28 were famous for
cracking. Crap probably got inside the original movement after the case
cracked, and that's why it was replaced.

This problem is common enough that someone is actually producing a kit
to fix it. For more info:

http://bama.sbc.edu/Lloyd%20Godsey's%20Blooming%20Meter%20Fixer.htm





If you can engage a meter repair person, that movement can be made
right resting, and the leads reversed inside, and you will be back to
where you want to be.


Is this something a fumble-fingers like me could attempt? What's involved in
making a movement right resting? I have little to lose at this point . . . .

I'm not sure I would attempt it. I had a friend once that did this on a
replacement movement on a radio he was fixing (an SX-24, IIRC). The fix
involved reversing the little spring on the base of the needle AND
reversing the internal wires. Nerves of steel doesn't even begin to
describe the economy of movement required to do this. This guy was an
orthopedic surgeon, so it was something he did everyday. Mere mortals
such as ourselves shouldn't even try it. I would definitely take it to a
pro, or look for a replacement meter on eBay. They do pop up from time
to time there.




Check carefully and see if the leads to the meter are reversed on the
back. If they are, then
the second step above is not necessary, just return the wires to their
correct locations. But the mechanical internal
adjustment is still required.


Living dangerously, I reversed the leads on the back of the meter. Now it
behaves the same, but instead of zeroing at the middle (OK, the 7 marker)
and deflecting to dead left (the 1 marker), it zeros at dead left and
deflects off the scale farther left. So I assume further surgery is
indicated.

Thx again for any advice.

Regards,

Phil Nelson




--
DO NOT REPLY TO THIS MESSAGE AT THE EMAIL ADDRESS ABOVE!
Instead, go to the following web page to get my real email address:
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Need a schematic? check out the Schematic Bank at:
http://techpreservation.dyndns.org/schematics/

Archive of alt.binaries.pictures.radio binary postings:
http://techpreservation.dyndns.org/abpr/

Phil Nelson wrote:
"Crazy George" wrote in message
...

I suspect someone replaced a failed movement in your original
meter with a standard movement.


Hmm, a light bulb flickers dimly in my brain. That would explain why it
looks stock but works backwards. The case of this meter is split to heck all
around and bound together with friction tape, but I figured that was not
that unusual for such old meters. When I opened the smallest electrolytic
can to restuff it, the danged thing split into about five pieces in my
fingers! But I could believe that somebody pried this case apart with a
screwdriver.

The meter enclosures in some variants of the SX-28 were famous for
cracking. Crap probably got inside the original movement after the case
cracked, and that's why it was replaced.

This problem is common enough that someone is actually producing a kit
to fix it. For more info:

http://bama.sbc.edu/Lloyd%20Godsey's%20Blooming%20Meter%20Fixer.htm





If you can engage a meter repair person, that movement can be made
right resting, and the leads reversed inside, and you will be back to
where you want to be.


Is this something a fumble-fingers like me could attempt? What's involved in
making a movement right resting? I have little to lose at this point . . . .

I'm not sure I would attempt it. I had a friend once that did this on a
replacement movement on a radio he was fixing (an SX-24, IIRC). The fix
involved reversing the little spring on the base of the needle AND
reversing the internal wires. Nerves of steel doesn't even begin to
describe the economy of movement required to do this. This guy was an
orthopedic surgeon, so it was something he did everyday. Mere mortals
such as ourselves shouldn't even try it. I would definitely take it to a
pro, or look for a replacement meter on eBay. They do pop up from time
to time there.




Check carefully and see if the leads to the meter are reversed on the
back. If they are, then
the second step above is not necessary, just return the wires to their
correct locations. But the mechanical internal
adjustment is still required.


Living dangerously, I reversed the leads on the back of the meter. Now it
behaves the same, but instead of zeroing at the middle (OK, the 7 marker)
and deflecting to dead left (the 1 marker), it zeros at dead left and
deflects off the scale farther left. So I assume further surgery is
indicated.

Thx again for any advice.

Regards,

Phil Nelson




--
DO NOT REPLY TO THIS MESSAGE AT THE EMAIL ADDRESS ABOVE!
Instead, go to the following web page to get my real email address:
http://member.newsguy.com/~polezi/scottsaddy.htm
(This has been done because I am sick of SPAMMERS making my email unusable)

Need a schematic? check out the Schematic Bank at:
http://techpreservation.dyndns.org/schematics/

Archive of alt.binaries.pictures.radio binary postings:
http://techpreservation.dyndns.org/abpr/

Paul P wrote:


2) The full scale deflection can be calibrated by feeding the FS current
and adjusting the counter weight.

Uhhh - those counter-weights aren't for that purpose - they are there to
balance the movement regardless of position (vertical - laying down, on
it's side, etc.). They are to be adjusted so that the meter needle
doesn't move (i.e. stays on zero) regardless of the meter's physical
orientation. If you try to "calibrate" the movement with those - the
meter will become very "gravity" sensitive - and loose much accuracy -
depending on "how it sits"...

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Paul P wrote:


2) The full scale deflection can be calibrated by feeding the FS current
and adjusting the counter weight.

Uhhh - those counter-weights aren't for that purpose - they are there to
balance the movement regardless of position (vertical - laying down, on
it's side, etc.). They are to be adjusted so that the meter needle
doesn't move (i.e. stays on zero) regardless of the meter's physical
orientation. If you try to "calibrate" the movement with those - the
meter will become very "gravity" sensitive - and loose much accuracy -
depending on "how it sits"...

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

dy or Sherry Guttery" wrote in message
.. .
Paul P wrote:


2) The full scale deflection can be calibrated by feeding the FS current
and adjusting the counter weight.

Uhhh - those counter-weights aren't for that purpose - they are there to
balance the movement regardless of position (vertical - laying down, on
it's side, etc.). They are to be adjusted so that the meter needle
doesn't move (i.e. stays on zero) regardless of the meter's physical
orientation. If you try to "calibrate" the movement with those - the meter
will become very "gravity" sensitive - and loose much accuracy - depending
on "how it sits"...

best regards...
--
randy guttery


I was hoping someone more knowledgeable would speak up! It did occur to me
that the position of the meter would be affected. It is minimal sensitive
to horizontal (in its back) and vertical operation.

What probably happed to my particular case is the cleaning process moved the
weights and I probably resorted their original position.

Is there any documentation about this topic? Some official book? Admittedly
I have not Googled the subject just yet.

Thanks Randy for the clarification,
Paul Pinyot.

dy or Sherry Guttery" wrote in message
.. .
Paul P wrote:


2) The full scale deflection can be calibrated by feeding the FS current
and adjusting the counter weight.

Uhhh - those counter-weights aren't for that purpose - they are there to
balance the movement regardless of position (vertical - laying down, on
it's side, etc.). They are to be adjusted so that the meter needle
doesn't move (i.e. stays on zero) regardless of the meter's physical
orientation. If you try to "calibrate" the movement with those - the meter
will become very "gravity" sensitive - and loose much accuracy - depending
on "how it sits"...

best regards...
--
randy guttery


I was hoping someone more knowledgeable would speak up! It did occur to me
that the position of the meter would be affected. It is minimal sensitive
to horizontal (in its back) and vertical operation.

What probably happed to my particular case is the cleaning process moved the
weights and I probably resorted their original position.

Is there any documentation about this topic? Some official book? Admittedly
I have not Googled the subject just yet.

Thanks Randy for the clarification,
Paul Pinyot.

Paul P wrote:

I was hoping someone more knowledgeable would speak up! It did occur to me
that the position of the meter would be affected. It is minimal sensitive
to horizontal (in its back) and vertical operation.

What probably happed to my particular case is the cleaning process moved the
weights and I probably resorted their original position.

Is there any documentation about this topic? Some official book? Admittedly
I have not Googled the subject just yet.

Yes - my favorite reference is NavShips EIMB TM&Ps - which in civilian
language is: US Navy's Electronics Installation & Maintenance Books;
Test Methods and Practices - my particular copy was published in
January, 1964- and carries NAVSHIPS 900,000.103. Section 5: Care,
Repair and Calibration of Test Equipment, subsection 5-2d(4) covers dial
pointers, zero adjusters, etc.; and section 5-2d(6) covers balance
weight tests; 5-2e(1a-c) balance weight adjustments (various types of
meter construction); 5-2e(2) Zero Adjustment; 5-2e(3) Pivots; 5-2e(3a)
turning, lapping, etc. of pivots; 5-2e(3b) End-Play Adjustments; 5-2e(4)
care and feeding of the hairsprings; and finally: 5-2(f-k) - calibrating
meter movements of various types - including charging/discharging the
movement's magnet.

The EIMB library consists of several volumes:
900,000.1 Communications
900,000.2 Radar
900,000.3 Sonar
900,000.4 Test Equipment
900,000.5 Radiac
900,000.7 Countermeasures
900,000.100 General
900,000.101 Installation Standards
900,000.102 Electronic Circuits
900,000.103 Test Methods and Practices *
900,000.104 Reference Data *
900,000.105 RF Interference Reduction

The two marked with an asterisk I consider two of most valuable books in
my library - they are of great value to anyone with a more than casual
interest in vintage / tube electronics (IMHO).

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Paul P wrote:

I was hoping someone more knowledgeable would speak up! It did occur to me
that the position of the meter would be affected. It is minimal sensitive
to horizontal (in its back) and vertical operation.

What probably happed to my particular case is the cleaning process moved the
weights and I probably resorted their original position.

Is there any documentation about this topic? Some official book? Admittedly
I have not Googled the subject just yet.

Yes - my favorite reference is NavShips EIMB TM&Ps - which in civilian
language is: US Navy's Electronics Installation & Maintenance Books;
Test Methods and Practices - my particular copy was published in
January, 1964- and carries NAVSHIPS 900,000.103. Section 5: Care,
Repair and Calibration of Test Equipment, subsection 5-2d(4) covers dial
pointers, zero adjusters, etc.; and section 5-2d(6) covers balance
weight tests; 5-2e(1a-c) balance weight adjustments (various types of
meter construction); 5-2e(2) Zero Adjustment; 5-2e(3) Pivots; 5-2e(3a)
turning, lapping, etc. of pivots; 5-2e(3b) End-Play Adjustments; 5-2e(4)
care and feeding of the hairsprings; and finally: 5-2(f-k) - calibrating
meter movements of various types - including charging/discharging the
movement's magnet.

The EIMB library consists of several volumes:
900,000.1 Communications
900,000.2 Radar
900,000.3 Sonar
900,000.4 Test Equipment
900,000.5 Radiac
900,000.7 Countermeasures
900,000.100 General
900,000.101 Installation Standards
900,000.102 Electronic Circuits
900,000.103 Test Methods and Practices *
900,000.104 Reference Data *
900,000.105 RF Interference Reduction

The two marked with an asterisk I consider two of most valuable books in
my library - they are of great value to anyone with a more than casual
interest in vintage / tube electronics (IMHO).

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Nerves of steel doesn't even begin to describe the economy of movement
required to do this.

Well, that leaves me out!

I would definitely take it to a pro

Any recommendations?

Regards,

Phil Nelson