A while back I posted about the 'SP-600 from hell'.
After a lot of work, and some great advice, the restoration
is complete. Still a couple of small bugs to work out.

One is bad backlash in the main tuning dial. This
radio uses gears that are mounted on movable plates
that are pre-loaded with an "S" shaped spring. I've made
certain that the plates are able to move freely, and the springs
are OK. Has anyone had, and solved this problem? If
so, I'd sure like to hear from you. At this point I'm stumped.

TIA

Steve
p.s.-still looking for the main tuning and crystal phasing knobs

Steve wrote:
A while back I posted about the 'SP-600 from hell'.

Ahhhh, fond memories from my first "radio" related job. My
boss asked me if I could reassemble a radio for a customer.
It was an SP-600 in several milk crates with all the gears
and hardware in a coffee can.

I'd have to say it's infinitly more "entertaining" to put
the front panel of an SP-600 back toegther having NOT seen
how it came apart.

If I remember correctly, the anti-backlash drive on that was
a two-piece flat gear. (mounted back to back as one) with a
spring to to provide the "anti-backlash".

The two gears are rotated against the spring and then engaged
to the mating gear. The idea being that the spring forces the
gear teeth to mate "perfectly" with the other gear.

You want the two gears to pinch the mating gear. I.e. close
under spring tension. If it is twisted the other way, it tends
to spread the gear, and results in horrible backlash.

Jeff


--
RESTRICTED AREA. Anyone intruding shall immediately become subject to
the jurisdiction of military law. Intruders will be subject to lethal
force, without warning, and on sight. USE OF DEADLY FORCE IS AUTHORIZED
under the Internal Security Act of 1950.

Jeff,
Thats the way any normal radio deals with back lash.
Not the SP-600, at least not mine.

I'll bet putting that SP-600 back together took a while!
The only thing worse would be an R-390 basket case.
E-gad!

Steve

"Jeffrey D Angus" wrote in message
...
Steve wrote:
A while back I posted about the 'SP-600 from hell'.

Ahhhh, fond memories from my first "radio" related job. My
boss asked me if I could reassemble a radio for a customer.
It was an SP-600 in several milk crates with all the gears
and hardware in a coffee can.

I'd have to say it's infinitly more "entertaining" to put
the front panel of an SP-600 back toegther having NOT seen
how it came apart.

If I remember correctly, the anti-backlash drive on that was
a two-piece flat gear. (mounted back to back as one) with a
spring to to provide the "anti-backlash".

The two gears are rotated against the spring and then engaged
to the mating gear. The idea being that the spring forces the
gear teeth to mate "perfectly" with the other gear.

You want the two gears to pinch the mating gear. I.e. close
under spring tension. If it is twisted the other way, it tends
to spread the gear, and results in horrible backlash.

Jeff


--
RESTRICTED AREA. Anyone intruding shall immediately become subject to
the jurisdiction of military law. Intruders will be subject to lethal
force, without warning, and on sight. USE OF DEADLY FORCE IS AUTHORIZED
under the Internal Security Act of 1950.

Steve wrote:
Jeff,
Thats the way any normal radio deals with back lash.
Not the SP-600, at least not mine.

Is it possible to take a couple of pictures of the gear and/or
where it mates?

I'll bet putting that SP-600 back together took a while!
The only thing worse would be an R-390 basket case.

Heh, for a true "Egad!" You should try reassembling a Collins
ART-13 auto-tune radio.

Jeff


--
RESTRICTED AREA. Anyone intruding shall immediately become subject to
the jurisdiction of military law. Intruders will be subject to lethal
force, without warning, and on sight. USE OF DEADLY FORCE IS AUTHORIZED
under the Internal Security Act of 1950.

Jeffrey D Angus wrote:

Steve wrote:
A while back I posted about the 'SP-600 from hell'.

Ahhhh, fond memories from my first "radio" related job. My
boss asked me if I could reassemble a radio for a customer.
It was an SP-600 in several milk crates with all the gears
and hardware in a coffee can.

At our Sony factory service depot we once received a suit box from one
of the dealers. When we opened it we found two big slabs of foam rubber
taped into a sandwich. We opened the sandwich, and there was a camcorder
in a million pieces with a note attached. The note read 'It's all fixed
and ready for you to assemble'!!!!!!!

We frequently had people bring in 'equipment in a bag' and it always
seemed that 'Dad' tried to fix it, or if it was a man bringing it in,
he usually said his son tried to fix it.

Ah, the good old days. I presume the practice still continues.

Irv VE6BP
--
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

Irv Finkleman wrote:
Ah, the good old days. I presume the practice still continues.

It does. Occasionally, I'll get a taxi driver wishing to have his
radio fixed AFTER the dispatcher "repaired" it.

Jeff


--
RESTRICTED AREA. Anyone intruding shall immediately become subject to
the jurisdiction of military law. Intruders will be subject to lethal
force, without warning, and on sight. USE OF DEADLY FORCE IS AUTHORIZED
under the Internal Security Act of 1950.

"Irv Finkleman" wrote in message
...


Jeffrey D Angus wrote:

Steve wrote:
A while back I posted about the 'SP-600 from hell'.

Ahhhh, fond memories from my first "radio" related job. My
boss asked me if I could reassemble a radio for a customer.
It was an SP-600 in several milk crates with all the gears
and hardware in a coffee can.

At our Sony factory service depot we once received a suit box from one
of the dealers. When we opened it we found two big slabs of foam rubber
taped into a sandwich. We opened the sandwich, and there was a camcorder
in a million pieces with a note attached. The note read 'It's all fixed
and ready for you to assemble'!!!!!!!

We frequently had people bring in 'equipment in a bag' and it always
seemed that 'Dad' tried to fix it, or if it was a man bringing it in,
he usually said his son tried to fix it.

Ah, the good old days. I presume the practice still continues.

Irv VE6BP

I understand kids taking things apart. But it just amazes me when a grown
men bring stuff to me to fix because I repair old equip and sometimes I have
to say " Why in Gods name did you take apart that Swiss watch, handycam,
etc..?" Then I have to tell them I can't fix it. I can't beleive the stuff
some guys think they can fix with their handyman tool set. Are they that out
of touch with reality and their own limitations? LOL!!! : )

BH

Jeff,
Useful pics will be difficult. The front panel mechanical
stuff is in layers, and much of it is hidden. If I take the
front panel off (again....), I'll give it a shot.

Steve
"Jeffrey D Angus" wrote in message
news


Steve wrote:
Jeff,
Thats the way any normal radio deals with back lash.
Not the SP-600, at least not mine.

Is it possible to take a couple of pictures of the gear and/or
where it mates?

I'll bet putting that SP-600 back together took a while!
The only thing worse would be an R-390 basket case.

Heh, for a true "Egad!" You should try reassembling a Collins
ART-13 auto-tune radio.

Jeff


--
RESTRICTED AREA. Anyone intruding shall immediately become subject to
the jurisdiction of military law. Intruders will be subject to lethal
force, without warning, and on sight. USE OF DEADLY FORCE IS AUTHORIZED
under the Internal Security Act of 1950.

Steve wrote:

Jeff,
Useful pics will be difficult. The front panel mechanical
stuff is in layers, and much of it is hidden. If I take the
front panel off (again....), I'll give it a shot.

*Big grin* And here we go, back to the original concept of
the front panel being removed and all the parts in a coffee
can.

Although, as an intermediate step, see if you can check the
anti-backlash gear and make sure it it sprung in the correct
direction to pinch, not spread against the mating gears.

Jeff


--
RESTRICTED AREA. Anyone intruding shall immediately become subject to
the jurisdiction of military law. Intruders will be subject to lethal
force, without warning, and on sight. USE OF DEADLY FORCE IS AUTHORIZED
under the Internal Security Act of 1950.

hi Steve,
I'm not sure if you mean backlash, or slippage. The SP-600 doesn't
use the split gears mentioned by someone, as you know.
Are you sure you haven't lost the small ball bearing that is used at
the front of the shaft in front of the main tuning cap, loaded by the
adjustment just outside the steel plate? The tuning capacitor should have
almost no friction, little force is normally needed to turn it, but if
that ball is missing, you'll have lots of friction, and things will
exhibit backlash.
If it's slippage, that more closely fits your description of moving
plate, S-spring, etc. Is it at the brass "wheels" behind the main tuning
knob? If they are bieng held in good contact my the spring, they must
still be absolutely clean. No oil needs to be used on any of the gearing,
it's brass and self lubricating. These 2 "wheels", the small one fits in
a groove on the larger one, work by friction. If there's slippage, clean
them scrupulously with alcohol and a very clean rag. Do not try any
lubricants in that area, or try as some have, to use tape or rubber to
make them sticky.
I have worked on well over a dozen SP-600's in the past few years, and
never have had to do anything other than cleaning to eliminate slippage.
You might try looking at some of the SP-600 refurb/rebuilds that are
well documented on The Hammarlund Historian website,
http://www.hammarlund.info or at some of my own work shown on my own
site, http://www.boatanchors.org
I know I've taken pix of the friction drive mechanism, but not sure
I've gotten them posted on either site.
I hope one of these suggestions helps solve your problem. Let me
know if I can help in any way.
(knobs are rarities, particularly the main tuning/bandchange ones,
they get the skirts broken too easily).
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.boatanchors.org
http://www.hammarlund.info

"Steve" wrote in message
...
A while back I posted about the 'SP-600 from hell'.
After a lot of work, and some great advice, the restoration
is complete. Still a couple of small bugs to work out.

One is bad backlash in the main tuning dial. This
radio uses gears that are mounted on movable plates
that are pre-loaded with an "S" shaped spring. I've made
certain that the plates are able to move freely, and the springs
are OK. Has anyone had, and solved this problem? If
so, I'd sure like to hear from you. At this point I'm stumped.

TIA

Steve
p.s.-still looking for the main tuning and crystal phasing knobs