Page 1 of 4

Diamond Disc 250 horn alignment question

Posted: Sun Jul 12, 2015 9:28 pm
by mikejk
A question about the position of the gunmetal reproducer elbow and it's position on the black japanned horn throat on a C-19.
The horn is hitting the inside of the grille when long recordings are finishing causing a slight problem.
Also, the position of the reproducer over the record doesn't seem right. The reproducer seems to be positioned too far to the right. The gunmetal elbow seems to be rotated too far to the right allowing the horn to travel too far letting the left edge of horn hit the inside of the grille.
On all my other DD machines, the horn finishes travel a little past facing straight forward, but on the C-19 it travels all the way to the inside of the grille.
So, my question is, how is the joint between the gunmetal reproducer elbow, and the black japanned horn throat secured ? Soldered, or pressed together. Can it be loosened and adjusted or is it as it should be ? If the gunmetal elbow were rotated to the left, it seems that would take care of the problem.
Thanks,
Mike

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 2:14 pm
by larryh
I can't tell you the exact fix but I recall the edison repair mans manual telling how to align the horn and tracking cog. It might be as simple as a screw setting on the lift rod being set in the wrong place but that sounds perhaps to simple. Someone here should be able to tell you where to look to get it back in balance. I don't recall if this group has that manual in the help sections or not but the Edison Online Discussion group does if its not here.

Larry

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 3:20 pm
by Valecnik
There is a manual posted here somewhere. If that does not help, post some pictures and perhaps someone can help you.

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 5:03 pm
by mikejk
Ok guys.
Thanks for the replies. I will get a few photos on and look for the manual.
Mike

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 6:14 pm
by fran604g
Hiya Mike,

The reproducer should be aligned in a perfect straight line from the horn throat as the red line in this image shows. I believe that the knurled locking ring is soldered onto the tapered horn throat.

Hope this helps you out.

Best,
Fran

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 8:26 pm
by mikejk
Fran,
Thanks for the post, that helps. I may be imagining a problem where none exists, but have a look at these pictures.
The reproducer is already at an angle at the start of a record, so by the time it is finished the angle seems too great. In the illustration you posted the reproducer is straight at the beginning of the record.
The pic of Martha Overture shows that before it is finished, the horn is hitting the inside of the grille.
The connection between the elbow with the knurled collar, and the black japanned horn is the connection that needs to be rotated to bring the reproducer in a straight line, no ? Am I making too much of this, just doesn't seem right. What do you think ?
Thanks,
Mike

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 9:05 pm
by fran604g
Hiya Mike,

I don't think you have anything wrong with the overall travel, it appears to be the same as my C250 is. If the reproducer continues to travel too far at the end of a record - it shouldn't come in contact with the label, for instance - then you need to adjust the safety stop.

The safety stop is actuated when the "finger" under the operating handle contacts the "stop" lever. Under the turntable is a small set screw that can be loosened, adjusted, and retightened to adjust the hinged part of the stop lever, so that the finger contacts the lever sooner, if the reproducer travels too far.

The "Edison Diamond DIsc Phonograph" owner's manual outlines the procedure as follows:

First, let machine wind down completely, or turn speed control to extreme clockwise position so as to stop turntable from rotating.

Then:

2) Remove reproducer from horn
3) Remove turntable (lift off)

Perform either of the next two steps, depending on the travel desired.

4) Should the motor stop too soon, loosen the set screw and move lever so the finger contacts it later, and retighten set screw. (Be careful to not overtighten this screw, as the head can be easily broken off).

5) Should the motor stop too late, loosen the set screw and move the lever so the finger contacts it sooner, and retighten the set screw. (Be careful to not overtighten this screw, as the head can be easily broken off).

6) Replace the turntable and reproducer, and note where the reproducer stops, and continue steps 4 and 5 until the diamond stylus plays to the end of a record, and can not contact the label.

NOTE: Some selections have less material between the label and the end of the record, so it's advisable to choose a record with the most playing time to make this adjustment.

Best,
Fran

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 9:50 pm
by mikejk
Fran,
Thank you for the post, this is just me over thinking things.
This problem must be a situation caused by this particular record, Martha Overture, which is recorded very close to the label. The horn hits the grille before the music has ended, allowing the feed rack to grind and jam. I had actually adjusted the stop finger to this record because it is the longest playing record I have, and at that point the grille was out of the machine; upon playing it for the first time discovered the problem. But still however, the starting angle of the reproducer on this C 19 is greater than on all the other DD machines in the house which start out with the reproducer straight.
Thanks again,
Mike

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 9:59 pm
by fran604g
So you've played the same record on another Phonograph? I did notice the short space that is visible between the final groove and the label.

I wonder if there were quality control issues with this particular record, or perhaps even the C19. It is a relatively late machine, IIRC. Can you put a straight edge on top of the horn throat, extend it across the top of the reproducer and take a picture looking straight down upon them. I'd love to see if the two are out of alignment. Just for curiosity's sake.

Fran

Re: Diamond Disc 250 horn alignment question

Posted: Mon Jul 13, 2015 10:55 pm
by phonogfp
I must say that in the photo showing the reproducer positioned in the first rotation of the groove, the neck of the horn looks too far to the left. I suspect that the top piece of the horn (the mostly horizontal section where the reproducer attaches) was separated from the lower section and replaced at an improper angle.

The top piece should be rotated clockwise on the lower section until the neck of the horn sits directly behind the reproducer when it's at the start of the record.

George P.