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MG TD TF 1500 - TD Clock

While finishing up making a front end alignment jig on a rainy sunday, I decided to rewire the clock in hopes that it once more would function. Pressing the button and finding no movement I gave up again. Today I noticed it had advanced 15 min. Hopes were high, so moving the car indoors tonight, I again pressed the button, put my ear through the steering wheel, and heard the movement. It had a purring motion which sounded fine, but then a little clunking and then no more. Pressed again and it starts purring, then, kopakta kopakata and then nothing. Kept this up for half an hour, until I was afraid someone would catch me at this. Why this little detail is so important to me I'm not sure, just never had a clock in any of my TD's ever function.
The alignment jig I dreamed up at 2 am worked perfectly though, so I got that going for me! Any input on clock maintence/ rebuild would be appreciated. Bob, Newtown, Ct.
R.AF. Robert Finucane

Bob, I have the same problem and decided nothing coule be done abouot it. I'll be most interested in the comments coming but please describe what button you pushing to get 15 minutes.
Warmly,
Dick Thomas
TD13583
Dick Thomas

Somewhere (the the NEMGTR's TSO?)there was a great article about clock service. What usually happens is the tiny carbon brush on a spring sparks every time it hits a pin on the balance wheel, and eventually burns the pin off. Or they can just be gunked up. Hal Kramer used to rebuild them- he did mine some years ago, and did a modification to reduce the spark/burning. Dick, I think he is talking about pushing the set button in an popping it out to start the mechanism. George
George Butz

Mine worked for one hour on a trip back from Watkins Glen 4 years ago...now it is only correct twice a day!
gblawson (gordon)- TD#27667

I had Hal Kramer transistorize mine about 10 years ago and it's been running fine ever since. As far as I know he still provides the service.
Bud Krueger

Hal Kramer can get any of the clocks to working on a permanent basis. He did mine about 10 years ago and it is still going strong. Contact him at: halandjoan@aol.com
Cheers - Dave
David DuBois

Bob,

Try your clock removed from the car, connect it to a battery charger on the bench to see if you get it to run loner. I had the same problem on mine and it turned out to be a bad ground.

If you still have a problem try cleaning the end of the contact wire with the point of a needle file.

John
John Scragg

I am certain that Bud Krueger has found the only way to get that damn clock working for more than just a while. It already helps if you connect a diode across the coil in such a way that it has no effect when the contacts close but short-circuits the coil when it opens, that removes the spark. That gives about 4 years of life.

I have built a "synthesizer" of square waves that allows simulation of the clock operation by having a "up" part of the pulse and a "down" part, with a precision control of their width of one out 2 to the 16, i.e. 1 over 65,536 - or say about 2 then thousandth of a second. So you can get the clock to work WITH NO CONTACTa, but after a day or so you have to readjust the timing because the clock mechanics changes - I guess, wear. An error which is automatically taken into account by the contact mechanism. So forget it, no digital synthesis for that clock! A lot of time spent in vain.

Denis
Denis L Baggi

Okay, I'll own up to the fact that mine did tend to fail a few years after being transistorized. It began to lose time periodically. I opened it up and discovered that, he who is virtually perfect in many things, i.e., Hal Kramer, had created a cold solder joint on one of the transistor leads. I resoldered it and it's been fine ever since. Must also admit that I do periodically disconnect the power for brief periods, seldom as long as a day. Resetting the clock never fails to jump start it. Then there's the biennial daylight saving time change ...... Bud
Bud Krueger

Dennis/Bud,

Since you both seem to know about these things can you tell me where to connect the diode referred to. I've tried to find out from other sources but with no luck.

Thanks, John.
J.C Mitchell

J.C., this is how you connect the diode, whether your car has positive or negative ground. You find the coil leads and remove a bit of the insulation. Then, with a voltmeter, identify the lead which is positive in respect to the other while the clock ticks. This is the lead to which you connect the diode lead with a band or mark, which is the cathode.

This means that the diode is connected in such a way that when the coil is energized, it is like an open circuit and plays no role; however, when the contacts open and an inverse voltage is created by the coil, the diode is like a short and kills the spark.

Buy a few diodes, small ones, no matter what, either black plastic or glass with red marks, they cost a few cents each. In the worst case, if you err, the diode burns and you replace it. You can even try with LEDs, light emitting diodes, and then you can actually see the reverse voltage being eliminated - transform your clock to a Christmas tree!
Denis L. Baggi

John, I'd refer you to the June, 1991 issue of TSO for Hal's article, "The Clock That Can Show The Correct Time". If you'd email me off-forum I'd be happy to send you some details. The diode does help, but the transistor is the big key to longevity. In keeping with Denis' math lesson I'll quote a bit from Hal's article referring to the contact switching "...This adds up to 430,000 closures per day or 157,680,000 closures per year."
Bud Krueger

There was another article in the TSO, in which a solid state watch was carefully grafted into the opening of the clock, and (obviously) ran on a battery.

As I recall, the appearance was indistinguishable from the original.. and it kept accurate time!
I would guess that article was included with the famous TSO CD and so someone can look it up.

Gord Clark
Rockburn, Qué.

Gordon A. Clark

Dennis and Bud,

Thanks to you both for your helpful responses.

Dennis, I've heard mention of a 47uF condenser being suitable - is this the same as a diode? We have a national chain called 'Tandy' who supply electronic bits - as a novice in this field what do I ask for?

Bud, thank you for the offer of off-forum advice - I'll be in touch.

Gordon, I'd be tempted with the 'conversion', but I don't think its possible on a TF with the long 'drive' to the remote clock face?

Cheers, John.
J.C Mitchell

John --- Tandy is the parent company of a chain called Radio Shack in the States. What you ask for is an 'Electrolytic Capacitor' 47 uF (microfarads) and a voltage suitable for a 12 volt system. I would get a 25 volt capacitor. Be vary careful when you install it, they are polarity sensitive and go bang if you put them in with the wrong polarity.

I have no idea if the capacitor will help the clock get rid of the sparking. My clocks have been converted to transistor to reduce the sparking to close to zero.

Cheers,

Bob
R. K. (Bob) Jeffers

Gordon C.
"As I recall, the appearance was indistinguishable from the original.. and it kept accurate time! " Isn't that a bit of a contradiction? :) Dave
David DuBois

If you truly want a Smiths clock that works perfectly vist http://www.jaguarclock.com/ Mike Eck has developed an electronic micro circuit that will make you clock run reliably and accurately. He reworked the clock in my XKE several years ago and it is still working perfectly. Highly recommended. Read the testimonials.

Frank
51 MG TD
Frank

And, he has a sense of humour: "None of the original clock parts are removed, so the installation is totally reversible, in case you ever want a non-functional clock again!"
gblawson (gordon)- TD#27667

J.C. Mitchell, a capacitor may help kill the spark but it is not the same idea. I have not tried it. I would think that the diode is a better solution, because: it is essentially a switch that has no effect when the coil is energized, but it short-circuits the coil when starts "misbehaving".

This said, I agree that the transistor in between is an even better solution, and it the same as transistorized ignition. Instead of having the current flowing through the contacts, only that much current to switch the transistor is needed. Hence the transistor acts as a current amplifier, and practically no current passes through the contacts.

-------------------------------
Now let's see:
Gordon A. Clark, Rockburn, Qué., gordclark@securenet.net

There was another article in the TSO, in which a solid state watch was carefully grafted into the opening of the clock, and (obviously) ran on a battery.

As I recall, the appearance was indistinguishable from the original.. and it kept accurate time!
I would guess that article was included with the famous TSO CD and so someone can look it up.
------------------------------

I have that CD but never saw that article. Personally I would not care if behind the dashboard there were some bulky item as long as the damn clock worked. Thanks Gordon.

Denis
Denis L. Baggi

Whew! 'clock' appears in 146 documents with 516 instances. It looks as if the article about the quartz watch is in the August '97 TSO on page 15. The title is "Clock Solution" by Richard Concklin.
Bud Krueger

Denis,

Let me see if I can locate that article.

Gord Clark
Rockburn, Qué.

Gordon A. Clark

...oops Bud found it.

gac
Gordon A. Clark

Thanks Bud and Gordon, I will look it up.

Denis
Denis L. Baggi

Hi,

Thanks to all who responded - I now have a clearer idea of what I need to do,

Cheers, John.
J.C Mitchell

This thread was discussed between 06/05/2008 and 14/05/2008

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