• Re: Vintage Radio Dial Cord Replacement

    From Bob F@21:1/5 to Bob F on Mon Jan 16 16:10:26 2023
    On 1/16/2023 3:57 PM, Bob F wrote:
    On 1/16/2023 3:34 PM, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been
    f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and
    affords no grip to the cord whatsoever, so the thing just slips around
    such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.

     Does it need a couple/few turns around the pulley?


    I suppose a little bees wax rubbed on the cord could help.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bob F@21:1/5 to Cursitor Doom on Mon Jan 16 15:57:20 2023
    On 1/16/2023 3:34 PM, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and affords no grip to the cord whatsoever, so the thing just slips around
    such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.

    Does it need a couple/few turns around the pulley?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to All on Mon Jan 16 23:34:39 2023
    Anyone successfully done this? If so, what's the secret? I've been
    f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and
    affords no grip to the cord whatsoever, so the thing just slips around
    such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeff Layman@21:1/5 to Cursitor Doom on Tue Jan 17 09:46:51 2023
    On 16/01/2023 23:34, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and affords no grip to the cord whatsoever, so the thing just slips around
    such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.

    Have you got all the old bits from the dial cord? Is there a spring
    missing which might have tensioned the cord?

    Other than that, can you get a rubber band which fits tightly round the
    pulley so the cord can grip that rather than the metal? Not sure how
    long it would last, though, before it perished.

    --

    Jeff

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to All on Tue Jan 17 03:57:52 2023
    There are several steps in the process, starting with using the correct material. Over time, I have found that braided *DACRON* fishing line of the correct gauge is best. It comes in many gauges and you want the cheap untreated stuff - no PTFE coating,
    just the basics. Then, obtain a some liquid resin - such as may be found at any music store that sells violin strings and so forth. I have also found over time that suture needles (arc-shaped) make knot tying much easier. Also, thin, high-quality super-
    glue (Zap brand is ideal) and a wooden toothpick. Lastly, 'hand' makes a difference - so make sure that you are winding around the pully in the correct direction, or the string will bind.

    Useful tools - either long-nose hemostats, best with a curved nose, or some hooked dental picks

    What might also help: A few small springs, and a few brass eyelets.

    https://www.etsy.com/listing/827996181/15mm-inner-diameter-super-tiny-eyelet-in?click_key=a73c1d6da8f650f841c5d8239e7bd0a47902822a%3A827996181&click_sum=f09bd185&external=1&rec_type=ss&ref=pla_similar_listing_top-1&sts=1

    https://www.amazon.com/uxcell-0-7mm-Stainless-Tension-Spring/dp/B01MRUSUK6/ref=sr_1_11?crid=1AKCE236ABGS5&keywords=small+tension+springs+with+hooks&qid=1673955666&sprefix=small+tension+springs%2Caps%2C76&sr=8-11

    http://www.segalandassociates.com/Documents/Radios-Televisions/Sams_Dial_Stringing_Diagrams.pdf

    a) The correct string of the correct gauge - cut to the right length + about 2" (5 cm).
    b) Pre-stretch the string - put a weight on it (perhaps a pound/500 grams or so) overnight.
    c) In a perfect world, you will put an eyelet at one end - wind the string around the eyelet and compress it to hold the string. A touch of SG applied with a toothpick will reduce fraying and make the knot stronger.
    d) Start at the hook, tab or other attachment point on the pulley that DOES NOT have the spring on it (OK, some have two springs, and Trust the Germans for that as they never use one part when three-or-more will do) and guide the new string through the
    path, maintaining just enough tension that it does not slip off. Use the hemostats/dental picks to get it around tight corners.
    e) When you get to the actual dial shaft - the one from the knob you turn - wrap it twice around the shaft in the correct 'hand' - you will get a sense of that from the stringing diagrams attached.
    f) When you get back to the main pulley, and have the extra material left over, insert the spring, and apply tension until the spring stretches about 30% from its resting state.
    g) Mark that length on the string, and then cut it with perhaps 5mm left over (1/4") This will be to wrap the eyelet or make the knot.
    h) Make the knot or eyelet, and attach it to the spring - it should still be stretched approximately 30% from its resting state when finished.
    i) Using a soft paint-brush or Q-Tip, run a light coating of resin over the string. This will add considerable friction, but no harmful residue.

    Takes longer to describe than to do.

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to All on Tue Jan 17 07:06:47 2023
    See those little pulley's that handle the string? They absorb all the string's efforts if they're dragging (and get worse with string tension on them). If you can remove them, clean and polish the shafts and apply some graphite.

    NEVER. EVER. GRAPHITE!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ohger1s@gmail.com@21:1/5 to Cursitor Doom on Tue Jan 17 06:56:39 2023
    On Monday, January 16, 2023 at 6:34:48 PM UTC-5, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and affords no grip to the cord whatsoever, so the thing just slips around
    such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.

    Friction, friction, friction... not at the drive pulley where the dial cord grabs but everywhere else.

    You must eliminate all possible friction from everywhere in the tuning system. Make sure the tuner's bearings are free of hardened gunk and lubed. When disconnected, the tuner should only require a very light touch to rotate.

    See those little pulley's that handle the string? They absorb all the string's efforts if they're dragging (and get worse with string tension on them). If you can remove them, clean and polish the shafts and apply some graphite. If you can't remove
    them (some are staked on), then run some non aggressive solvent into the shaft and spin by hand until the move with no effort. With a small jeweler's screwdriver, add some graphite to the hub and tap so the graphite gets inside the pulley. Don't "poof"
    the graphite in as it will probably get on the pulley's surface and transfer it to the string where it might make it back to the drive pulley shaft.

    A lot of guys miss the dial indicator.. they're usually just folded metal that slide along the metal dial scale. Those things drag like you won't believe. Sometimes the dial might have a piece of folded fish paper inside as a bearing, but many don't.
    In any case, clean and polish the edge of the dial with an abrasive if need be to form a highly polished bearing surface. Rub some graphite into the area right where the dial slides along. Careful not to get graphite on the dial itself (unsightly).

    Before restringing, get a Q-Tip/ISO and clean the drive pulley shaft and all secondary pulleys of lube or wayward graphite. If you excise all possible friction, you'll find it will tune with no dragging, jerking, or stopping even with less turns around
    the drive pulley than the diagram calls for (resist the temptation of adding more turns than it calls for - it only causes windup binding).

    I've had people pooh-pooh this advice and end up giving me the radio to restring because they don't believe that tiny amount of friction will prevent the dial cord from grabbing.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to bobenge...@gmail.com on Tue Jan 17 09:30:27 2023
    On Tuesday, January 17, 2023 at 12:21:43 PM UTC-5, bobenge...@gmail.com wrote:
    On 1/17/2023 6:57 AM, Peter W. wrote:
    [...] Then, obtain a some liquid resin - such as may be found at any music store that sells violin strings and so forth. [...]
    Isn't it rosin that they use on bow strings?

    Yeah, yeah!!

    My bad!

    https://www.amazon.com/Old-Master-Liquid-Spray-Rosin/dp/B07VS4WBT6

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bob Engelhardt@21:1/5 to Peter W. on Tue Jan 17 12:21:37 2023
    On 1/17/2023 6:57 AM, Peter W. wrote:
    [...] Then, obtain a some liquid resin - such as may be found at any music store that sells violin strings and so forth. [...]
    Isn't it rosin that they use on bow strings?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From tschw10117@aol.com@21:1/5 to All on Wed Jan 18 15:56:09 2023
    Peter, do you mean liquid "rosin" as used on violin bow strings?

    It actually is sold as a solid but I believe it is soluble in alcohol. Scrape some rosin shavings into iso-propyl and apply to the string. The alcohol will evaporate and leave the rosin in place.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to tschw...@aol.com on Thu Jan 19 03:41:01 2023
    On Wednesday, January 18, 2023 at 6:56:11 PM UTC-5, tschw...@aol.com wrote:
    Peter, do you mean liquid "rosin" as used on violin bow strings?

    It actually is sold as a solid but I believe it is soluble in alcohol. Scrape some rosin shavings into iso-propyl and apply to the string. The alcohol will evaporate and leave the rosin in place.
    Terry:

    I linked a liquid version - it has the virtue of being of the correct concentration for the need.

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ohger1s@gmail.com@21:1/5 to tschw...@aol.com on Thu Jan 19 07:01:21 2023
    On Wednesday, January 18, 2023 at 6:56:11 PM UTC-5, tschw...@aol.com wrote:
    Peter, do you mean liquid "rosin" as used on violin bow strings?

    It actually is sold as a solid but I believe it is soluble in alcohol. Scrape some rosin shavings into iso-propyl and apply to the string. The alcohol will evaporate and leave the rosin in place.


    Rosin is a band-aid and isn't required if it's strung properly and friction is mitigated. You can use virtually any non-stretching string of a similar diameter and it won't slip.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Carlos E.R.@21:1/5 to ohg...@gmail.com on Thu Jan 19 18:11:16 2023
    On 2023-01-19 16:01, ohg...@gmail.com wrote:
    On Wednesday, January 18, 2023 at 6:56:11 PM UTC-5, tschw...@aol.com wrote:
    Peter, do you mean liquid "rosin" as used on violin bow strings?

    It actually is sold as a solid but I believe it is soluble in alcohol. Scrape some rosin shavings into iso-propyl and apply to the string. The alcohol will evaporate and leave the rosin in place.


    Rosin is a band-aid and isn't required if it's strung properly and friction is mitigated. You can use virtually any non-stretching string of a similar diameter and it won't slip.

    On some radios, the string passes metal rods that are not pulleys, and
    there having friction would be bad.

    --
    Cheers, Carlos.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to All on Thu Jan 19 09:46:07 2023
    Rosin is a band-aid and isn't required if it's strung properly and friction is mitigated. You can use virtually any non-stretching string of a similar diameter and it won't slip.

    I will give a poor analogy to the reason for the Rosin - poor, because technology has changed over the last 20 years, or so. But for us Luddites:

    Those of us, who, back in the day, drove air-cooled VWs which we serviced ourselves for the most part, always used a wee bit of anti-seize on the spark-plugs to avoid head damage, and we adjusted torque accordingly. Most especially those of us who were *
    really cheap* and used un-plated plugs. Today, plugs are, for the most part, plated from the factory and anti-seize is not recommended by manufacturers any longer. Similarly back in the day VW also used lug bolts, and there was a 'whole thing' on anti-
    seize on the threads (not the bearing face) of the bolt. Again, not so much today due to improved technologies and plating processes.

    Getting back to Rosin - the OP is starting with a vintage German radio - and as I have noted on occasion, the Germans never use one part where three-or-more will do better. So, restringing such a beast is one of more troublesome tasks in the vintage
    radio hobby. Even getting the chassis out of the case/cabinet is a massive PITA. So, the idea is to do it once and get another 50-75 years out of the effort. The things that mess up dial mechanisms:
    a) Age: The pulleys wear, the springs (if any) wear, and the bearings wear such that the pulleys wobble.
    b) Dust and airborne crud contaminate the system causing additional friction, or slippage.
    c) And many hobbyists rely on their memory rather than looking for a diagram when re-stringing.

    There are few absolute cures for a) - I have found that going to the next higher (or two) string gauges can help for two reasons: A greater bearing surface, so less tension is required, and therefore less wobble. And the string centerline is further
    from the edge of the pulley - again, less wobble. Replace the springs, of course.

    Dust and crud can be cleaned - in fact a radio from a smoker environment will not see the display in our house until absolutely thoroughly cleaned. Most will be rejected prior to purchase in any case.

    And, there are sources for stringing diagrams, even for many/most Euro radios. Further, the generic diagrams are useful to find similar configurations. I need to repeat HAND MATTERS! And may German radios tune from Right-to-Left - matters even more!

    What the rosin does best is reduce the amount of tension required on the string, and together with the slightly larger diameter increase the friction without increasing wear. And if simple Dacron is used, that first application is well-and-truly life-
    time. The analogy that comes to mind is the fiber core of elevator ropes - as a reservoir for lubricants - the Dacron acts as a reservoir for the rosin and does not spread it all over the place as a sticky mess - a little goes a long way.

    Yes, I keep high-tack PTFE-impregnated synthetic oil for bearings and such - it is emphatically non-conductive, and stays where-put, does not oxidize and does not turn to varnish even in warm environments. NEVER graphite as it is a conductor, and can '
    track' even if by accident. Horrible stuff in an electronic environment, especially with tubes involved.

    It is a process - and if done carefully, those next 50 years are a near certainty.

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Allodoxaphobia@21:1/5 to ohg...@gmail.com on Thu Jan 19 18:20:02 2023
    On Thu, 19 Jan 2023 07:01:21 -0800 (PST), ohg...@gmail.com wrote:
    On Wednesday, January 18, 2023 at 6:56:11 PM UTC-5, tschw...@aol.com wrote:
    Peter, do you mean liquid "rosin" as used on violin bow strings?

    It actually is sold as a solid but I believe it is soluble in
    alcohol. Scrape some rosin shavings into iso-propyl and apply to the
    string. The alcohol will evaporate and leave the rosin in place.

    Rosin is a band-aid and isn't required if it's strung properly and
    friction is mitigated. You can use virtually any non-stretching
    string of a similar diameter and it won't slip.

    I've often thought waxed dental floss might be a solution
    for dial cord. But I never had a opportunity to employ it.

    Jonesy
    --
    Marvin L Jones | Marvin | W3DHJ.net | linux
    38.238N 104.547W | @ jonz.net | Jonesy | FreeBSD
    * Killfiling google & XXXXbanter.com: jonz.net/ng.htm

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to All on Thu Jan 19 11:33:54 2023
    I've often thought waxed dental floss might be a solution
    for dial cord. But I never had a opportunity to employ it.

    Not quite as bad as graphite, but approaching that state.

    Once-upon-a-time dental floss was made from silk, and could be doubled or tripled to make a reasonable, stretch-resistant cord. Silk, like nacre feels smooth, to the touch, but creates considerable friction when tight - while not being overly abrasive.
    Today the crap is made, primarily, from PTFE, and is flat, not round. It is also highly abrasive and will cut through soft aluminum pulleys and sheaves if made tight enough not to slip. Since it has a very low surface area, and PTFE is a naturally
    slippery material, and because the surface is textured to catch tartar but still slip easily, it is altogether nasty in that application. Not to mention that as landfill, it can last hundreds of years. Worse, if burnt, the POC are deadly to felines and
    Avian species.

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Guy Patterson@21:1/5 to ohg...@gmail.com on Tue Jan 24 07:36:33 2023
    On Tuesday, January 17, 2023 at 9:56:42 AM UTC-5, ohg...@gmail.com wrote:
    On Monday, January 16, 2023 at 6:34:48 PM UTC-5, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and affords no grip to the cord whatsoever, so the thing just slips around such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.
    Friction, friction, friction... not at the drive pulley where the dial cord grabs but everywhere else.

    You must eliminate all possible friction from everywhere in the tuning system. Make sure the tuner's bearings are free of hardened gunk and lubed. When disconnected, the tuner should only require a very light touch to rotate.

    See those little pulley's that handle the string? They absorb all the string's efforts if they're dragging (and get worse with string tension on them). If you can remove them, clean and polish the shafts and apply some graphite. If you can't remove
    them (some are staked on), then run some non aggressive solvent into the shaft and spin by hand until the move with no effort. With a small jeweler's screwdriver, add some graphite to the hub and tap so the graphite gets inside the pulley. Don't "poof"
    the graphite in as it will probably get on the pulley's surface and transfer it to the string where it might make it back to the drive pulley shaft.

    A lot of guys miss the dial indicator.. they're usually just folded metal that slide along the metal dial scale. Those things drag like you won't believe. Sometimes the dial might have a piece of folded fish paper inside as a bearing, but many don't.
    In any case, clean and polish the edge of the dial with an abrasive if need be to form a highly polished bearing surface. Rub some graphite into the area right where the dial slides along. Careful not to get graphite on the dial itself (unsightly).

    Before restringing, get a Q-Tip/ISO and clean the drive pulley shaft and all secondary pulleys of lube or wayward graphite. If you excise all possible friction, you'll find it will tune with no dragging, jerking, or stopping even with less turns around
    the drive pulley than the diagram calls for (resist the temptation of adding more turns than it calls for - it only causes windup binding).

    I've had people pooh-pooh this advice and end up giving me the radio to restring because they don't believe that tiny amount of friction will prevent the dial cord from grabbing.


    Thank you!! After reading this, a light bullb went off and I decided to pull out a troublesome Philco that has always slipped. I had some guys at Kutztown restring it about 5 years ago and it worked for a few days and started slipping again, so I
    stopped using it. Nothing more frustrating than trying to change the station or even tweaking the tuning as it drifts after an hour of use. They put on some liquid which was probably rosin and it worked great at the table. Too bad it didn't last. You
    were right about the pulleys. With the dial string removed they spun freely but putting either a little side pressure or up pressure on them where they might butt up against the peened top made them stiffen right up. That is probably why the heavier
    the spring I tried the worse it got. I used the wide end of a flat toothpick to tap in a bit of graphite moly powder i had kicking around from Pinewood derby between the pulleys and the shafts, and now the pulleys spin easily even when I side load them.
    I also found the top rail of the dial binding when I pushed down on it just like you said. I used a small needle file and dressed the top edge and then sanded it smooth and rubbed in some graphite with a qtip so I wouldn't get any on the dial face and
    now the dial indicator pushes smooth even when I put pressure on it. The tuner itself seemed free but I added a couple of drops of light synthetic oil to the bearings anyway. My Philco now tunes like butter and I can even put my thumb on the big tuner
    pulley and it still pulls the tuner through. I can now tune and fine tune this radio for the first time ever. Thanks so much. I will do this with every radio I have from now on.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Allodoxaphobia@21:1/5 to Guy Patterson on Tue Jan 24 18:35:33 2023
    On Tue, 24 Jan 2023 07:36:33 -0800 (PST), Guy Patterson wrote:
    On Tuesday, January 17, 2023 at 9:56:42 AM UTC-5, ohg...@gmail.com wrote:
    On Monday, January 16, 2023 at 6:34:48 PM UTC-5, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been
    f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and
    affords no grip to the cord whatsoever, so the thing just slips around
    such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.
    Friction, friction, friction... not at the drive pulley where the dial cord grabs but everywhere else.

    You must eliminate all possible friction from everywhere in the tuning system. Make sure the tuner's bearings are free of hardened gunk and lubed. When disconnected, the tuner should only require a very light touch to rotate.

    See those little pulley's that handle the string? They absorb all the string's efforts if they're dragging (and get worse with string tension on them). If you can remove them, clean and polish the shafts and apply some graphite. If you can't remove
    them (some are staked on), then run some non aggressive solvent into the shaft and spin by hand until the move with no effort. With a small jeweler's screwdriver, add some graphite to the hub and tap so the graphite gets inside the pulley. Don't "poof"
    the graphite in as it will probably get on the pulley's surface and transfer it to the string where it might make it back to the drive pulley shaft.

    A lot of guys miss the dial indicator.. they're usually just folded metal that slide along the metal dial scale. Those things drag like you won't believe. Sometimes the dial might have a piece of folded fish paper inside as a bearing, but many don't.
    In any case, clean and polish the edge of the dial with an abrasive if need be to form a highly polished bearing surface. Rub some graphite into the area right where the dial slides along. Careful not to get graphite on the dial itself (unsightly).

    Before restringing, get a Q-Tip/ISO and clean the drive pulley shaft and all secondary pulleys of lube or wayward graphite. If you excise all possible friction, you'll find it will tune with no dragging, jerking, or stopping even with less turns
    around the drive pulley than the diagram calls for (resist the temptation of adding more turns than it calls for - it only causes windup binding).

    I've had people pooh-pooh this advice and end up giving me the radio to restring because they don't believe that tiny amount of friction will prevent the dial cord from grabbing.


    Thank you!! After reading this, a light bullb went off and I decided
    to pull out a troublesome Philco that has always slipped. I had some
    guys at Kutztown restring it about 5 years ago and it worked for a few
    days and started slipping again, so I stopped using it. Nothing more frustrating than trying to change the station or even tweaking the
    tuning as it drifts after an hour of use. They put on some liquid
    which was probably rosin and it worked great at the table. Too bad it
    didn't last. You were right about the pulleys. With the dial string
    removed they spun freely but putting either a little side pressure or
    up pressure on them where they might butt up against the peened top
    made them stiffen right up. That is probably why the heavier the
    spring I tried the worse it got. I used the wide end of a flat
    toothpick to tap in a bit of graphite moly powder i had kicking around
    from Pinewood derby between the pulleys and the shafts, and now the
    pulleys spin easily even when I side load them. I also found the top
    rail of the dial binding when I pushed down on it just like you said.
    I used a small needle file and dressed the top edge and then sanded it
    smooth and rubbed in some graphite with a qtip so I wouldn't get any
    on the dial face and now the dial indicator pushes smooth even when I
    put pressure on it. The tuner itself seemed free but I added a couple
    of drops of light synthetic oil to the bearings anyway. My Philco now
    tunes like butter and I can even put my thumb on the big tuner pulley
    and it still pulls the tuner through. I can now tune and fine tune
    this radio for the first time ever. Thanks so much. I will do this
    with every radio I have from now on.

    GREAT followup!! GOOD onfo! Very few do that. Thanks!

    Jonesy
    --
    Marvin L Jones | Marvin | W3DHJ.net | linux
    38.238N 104.547W | @ jonz.net | Jonesy | FreeBSD
    * Killfiling google & XXXXbanter.com: jonz.net/ng.htm

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From ohger1s@gmail.com@21:1/5 to Guy Patterson on Fri Jan 27 07:50:27 2023
    On Tuesday, January 24, 2023 at 10:36:36 AM UTC-5, Guy Patterson wrote:
    On Tuesday, January 17, 2023 at 9:56:42 AM UTC-5, ohg...@gmail.com wrote:
    On Monday, January 16, 2023 at 6:34:48 PM UTC-5, Cursitor Doom wrote:
    Anyone successfully done this? If so, what's the secret? I've been f***-arsing around for 4 hours today trying to do one on a 1972
    Grundig portable FM/AM radio and got nowhere. The design is most of
    the problem. For some reason, the drive pully is completely smooth and affords no grip to the cord whatsoever, so the thing just slips around such that the pointer only moves when it can get a bit of traction.
    What a f***ing joke.
    Friction, friction, friction... not at the drive pulley where the dial cord grabs but everywhere else.

    You must eliminate all possible friction from everywhere in the tuning system. Make sure the tuner's bearings are free of hardened gunk and lubed. When disconnected, the tuner should only require a very light touch to rotate.

    See those little pulley's that handle the string? They absorb all the string's efforts if they're dragging (and get worse with string tension on them). If you can remove them, clean and polish the shafts and apply some graphite. If you can't remove
    them (some are staked on), then run some non aggressive solvent into the shaft and spin by hand until the move with no effort. With a small jeweler's screwdriver, add some graphite to the hub and tap so the graphite gets inside the pulley. Don't "poof"
    the graphite in as it will probably get on the pulley's surface and transfer it to the string where it might make it back to the drive pulley shaft.

    A lot of guys miss the dial indicator.. they're usually just folded metal that slide along the metal dial scale. Those things drag like you won't believe. Sometimes the dial might have a piece of folded fish paper inside as a bearing, but many don't.
    In any case, clean and polish the edge of the dial with an abrasive if need be to form a highly polished bearing surface. Rub some graphite into the area right where the dial slides along. Careful not to get graphite on the dial itself (unsightly).

    Before restringing, get a Q-Tip/ISO and clean the drive pulley shaft and all secondary pulleys of lube or wayward graphite. If you excise all possible friction, you'll find it will tune with no dragging, jerking, or stopping even with less turns
    around the drive pulley than the diagram calls for (resist the temptation of adding more turns than it calls for - it only causes windup binding).

    I've had people pooh-pooh this advice and end up giving me the radio to restring because they don't believe that tiny amount of friction will prevent the dial cord from grabbing.


    After reading this, a light bullb went off and I decided to pull out a troublesome Philco that has always slipped. ...... I also found the top rail of the dial binding when I pushed down on it just like you said. I used a small needle file and dressed
    the top edge and then sanded it smooth and rubbed in some graphite with a qtip so I wouldn't get any on the dial face and now the dial indicator pushes smooth even when I put pressure on it.....Thanks so much. I will do this with every radio I have from
    now on.<

    You're certainly welcome - glad you got it fixed.

    Yep, I've seen rough edges and even outright burrs where the dial indicator rides on the dial background. I suppose those dial backs are simple stampings, and they could have a sharp edge on them. Filing down the burr with a file and smoothing it with
    sandpaper was a great idea. It almost makes it a bearing surface if done properly.

    I can't tell you how many times I've seen cranky dial indicators cause dial cord slippage because of friction between the dial and the dial background . They announce themselves when they kind of "arch up" or move in jerks when the tuning shaft is moved
    - they shouldn't. Once cleaned, deburred and lubed they just glide.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)