Macgregor Codamac
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Macgregor Codamac
I'm putting a Macgregor Codamac back into working order, and I'm having trouble identifying a capacitor. Here's a pic - you can see why it's a candidate for replacing. It's the blue one next to the pot at the top right.
Having got it out, one of the end wires fell off, so it was obviously open circuit and couldn't be tested. Looking at the markings, I see the following:
4/
10V
The 4/ does indeed look like a slash, and not a poor 7. There are no other markings. Has anyone any idea what it might be?
Having got it out, one of the end wires fell off, so it was obviously open circuit and couldn't be tested. Looking at the markings, I see the following:
4/
10V
The 4/ does indeed look like a slash, and not a poor 7. There are no other markings. Has anyone any idea what it might be?
- F2B
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- Joined: 16 Feb 2018, 11:23
- Location: 20 m NE of Amsterdam
Re: Macgregor Codamac
Yes, that is an electrolytic capacitor, 4.7 or 47 µF/ 10 Volts
Looking at the sheer size of the thing I'd say 4,7 ....
Should be available still...
Looking at the sheer size of the thing I'd say 4,7 ....
Should be available still...
F2B or not to be....
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Re: Macgregor Codamac
I hear the 4, but I can't see the 7. It looks much more like a 4/
I enclose a pic of the offending cap, and a pic of the markings on the only other similar cap on the board. They seem to have an odd way of marking value...
The 4/ is the lower pic you can see why I don't think it says 4.7...
I enclose a pic of the offending cap, and a pic of the markings on the only other similar cap on the board. They seem to have an odd way of marking value...
The 4/ is the lower pic you can see why I don't think it says 4.7...
- F2B
- Posts: 200
- Joined: 16 Feb 2018, 11:23
- Location: 20 m NE of Amsterdam
Re: Macgregor Codamac
0.64 seems an odd value to me as well.
640nF... The usual steps are 560 > 680
There should be someone with the diagram around this place.
Let's wait and see...
640nF... The usual steps are 560 > 680
There should be someone with the diagram around this place.
Let's wait and see...
F2B or not to be....
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- Joined: 17 Jun 2018, 09:54
Re: Macgregor Codamac
...and perhaps it's a 0.47uf. How would I tell?
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- Posts: 68
- Joined: 17 Jun 2018, 09:54
Re: Macgregor Codamac
Remember this is from a 1960 tranny. I suspect that it's some old form of cap marking. if no one knows, the only thing to do might be to reverse-engineer the circuit and work it out that way
Unless anyone has a circuit diagram for a Codamac?
Unless anyone has a circuit diagram for a Codamac?
- F2B
- Posts: 200
- Joined: 16 Feb 2018, 11:23
- Location: 20 m NE of Amsterdam
Re: Macgregor Codamac
I'd second Phil's suggestion without a blink.
Phil has designed a wonderful encoder that makes a codamac go like it was supposed to.
Phil has designed a wonderful encoder that makes a codamac go like it was supposed to.
F2B or not to be....
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Re: Macgregor Codamac
All interesting comments - but does that mean that no one knows what a marking of 4/ means on a cap?
- Phil_G
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Re: Macgregor Codamac
Codamacs were an abomination, put it out of its misery and gigerise it Dodgy!
I cringe when I see those wipers. Why????? what was Wee MacGregor thinking???
That cap isnt critical, its only the keying rate in conjunction with the preset, codamacs
were so inaccurate and drifty that I suspect they were SOT anyway. I can understand
everyone saying its a 7 as 4.7 etc is a standard E6 (and upwards) value, but its not unusual
to see non-standard values in timing specific stuff like the coder in the codamac.
i would try a 4.7μF tant and check the keying speed, if it cant be adjusted to suit the actuator
then up-it or down-it to suit. Check the quick-blip too, though thats less critical.
Honestly Dodgy I wouldnt worry. It looks as though its only the quick-blip pulser speed, just try a few near-values and test. I'm not aware of a circuit diagram in circulation, it would be nice to have
I cringe when I see those wipers. Why????? what was Wee MacGregor thinking???
That cap isnt critical, its only the keying rate in conjunction with the preset, codamacs
were so inaccurate and drifty that I suspect they were SOT anyway. I can understand
everyone saying its a 7 as 4.7 etc is a standard E6 (and upwards) value, but its not unusual
to see non-standard values in timing specific stuff like the coder in the codamac.
i would try a 4.7μF tant and check the keying speed, if it cant be adjusted to suit the actuator
then up-it or down-it to suit. Check the quick-blip too, though thats less critical.
Honestly Dodgy I wouldnt worry. It looks as though its only the quick-blip pulser speed, just try a few near-values and test. I'm not aware of a circuit diagram in circulation, it would be nice to have
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Re: Macgregor Codamac
Well, Phil, how could I ever doubt you! 4,7uf works a treat.
Now for the difficult bit - trying to make it work with a Kinematic.....
Now for the difficult bit - trying to make it work with a Kinematic.....