AMI Continental 2 Pin Bank

[juke46]

My Continental 2 is getting tired or is that lazy (like me). It works great but is beginning to develop a problem pushing the pins in the pin bank when a selection is made. Pins are dry and clean and move with out excess effort (by hand).  I know this is a common problem with these as the pulse to push the pins outward grows weaker and/or shorter.    I have not done anything to the power supply such as rectifier-capacitor replacement.  I found "on the internet" a recommendation for upping that 1,000 MFD Cap to a 2400 MFD Cap.  Seems kind of BIG?  The DC motors run well and strong but I probably should replace the selenium rectifier with a full wave bridge anyway.  Am I on the right track for putting the "push" back in the anemic pin pusher?  Thanks As Always!  David, (Geritol Ghetto)


Glad to see the New Web Site Grow!  Happy It Is Here!  Thanks for Getting It Going!!

[robnyc]

Hello David,

this is a common problem on old pin-based memory schemes. In the case of AMI I suggest:

-Replace the selenium rect with a modern bridge or individual diodes.
-Replace the main filer in the supply with a 2200 mfd.
-Replace the cap in the search unit that controls the length of the write-in pulse. This may be your main problem. I forget the actual value there. IRRC, it is somewhere around 100-150 mfd. I did increase it by about 30%. If you do increase the timing cap make sure you have the correct fuse in the low-DC supply.

In general, if a problem gets worse as the item warms up -it is electronic (leaky caps, or in an amp gassy tube).

If the problem gets better with operation it is mechanical and due to old, dirty or broken down oil. Pitted relay contacts can cause erratic operation that changes with use. AMI's though were pretty good in this aspect.

Rob-NYC

[Ron Rich]

Hi David,
Two things come to mind- can't tell you why, nor can I guar-un-tee that they are even close, to correct--
1. Sprague relay contacts burned
2. Something in the pusher mechanical portion--such as a dirty coil plunger ?
Ron Rich

[juke46]

Thank You Ron and Rich! Your knowledge is a real treasure! I'll get on that in a few days. I changed all the old 2 conductor wires a few weeks ago. That stuff was really ready for replacement! I sure am liking the new website! Thank You!

[juke46]

I have a start on getting the AMI Continental 2 pin bank working. I now have a 2200uF capacitor in the power supply but I am experiencing a blown 1 amp fuse after making 2-3 selections. I suppose I should lower the capacitor to a lesser value? Would capacitor polarity be a concern? In my "excitement" (goof up) I did not notice which end actually went where. It does push the pins in. I did try a 1.25 amp fuse but after a few selections it took that one out too. Someone has already put a 150uF cap in the search unit. I might replace it anyway.

I am thinking of replacing those other "old" caps in the search unit since I have the cover off. Good idea?

Along the way I discovered a green wire not attached to anything lurking near the power supply box. It has a spade lug on it. The other end attaches to somewhere on the mechanism top under the cover. I thought it might be a ground wire but no continuity between the mechanism and the spade lug. I'll probably need to remove the mechanism cover to see where it really goes. UGH! Got to remove the tone arm bias spring as part of removing the mech cover. I always hate putting that little dude back in.

I have a nice original manual but the only large schematic in it is for the amplifier. I doubt AMI would issue a manual without a complete schematic?

Thanks Everyone!

[Ron Rich]

Hi David,
Not sure, if Conties had it, but a fairly large schematic may be stapled to the rear door--earlier models had this "feature" ? Ron Rich

[robnyc]

David, I'm not certain as to why you are getting blown fuses in the low-Dc supply. I increased the main filter to 2200 in all the AMI machines of that era.

take a look at the actual pulse that punches the pin. It should be only a brief fraction of a second. It must not "hold" for any length of time. It it seems like a half-second or longer it is probably a good idea to lower the value of the 150mfd in the search unit.

Also, the Low-Dc fuse should be a -slow blow- type. The idea in this circuit is to use a fuse that is marginally too small for the current through it. A time delay fuse (slow) will handle that if the duration is not too long.

There is a remote possibility that either the scan coil or, hopefully not, the punch coil have shorted turns. I don't have any idea as to the impedance of either coil.

If you want to plow through my Photobucket there are a lot of AMI schematics from that late fifties and 1960's K model which would be similar, if not exactly the same as the Cont:

s1192.photobucket.com/user/Rob-NYC/media/AMI-%20I%20200/changer-2.jpg.html?sort=3&o=1 K-schematic

s1192.photobucket.com/user/Rob-NYC/library/AMI-%20I%20200?sort=3&page=1 AMI "I" model.

s1192.photobucket.com/user/Rob-NYC/library/?sort=3&page=2 Page 2 with AMI diagrams....Look at following pages as well. These pages were uploaded based of queries from people and not in any order.

Rob

[juke46]

Rob,
Thank You! I did not try a slo-blo fuse but I sure will. Watching the pins get punched it is an extremely fast operation so I am probably OK there. Thanks for the schematics on Photobucket! I'll dig through them and see what I find! I greatly appreciate your assistance!! David

[juke46]

Rob and Ron,

Thanks Again! We have played about 20 selections and the pins are getting pushed in very nicely. The 1 amp slo-blo fuses are holding without a sign of trouble. My wife is very happy, a good thing, because she was getting meaner than an acre of rattlesnakes (her favorite songs are on the Continental). I did notice in the manual the power supply/junction box listed the 3 external fuses as one 8 AMP cartridge fuse and two 1 amp Fusetrons. I believe some used to call the time delays Fusetrons although it is a company that makes fuses, I believe. I don't really know! Anyway now I'll clean it up, oil it in all the places it says to and get that mech cover back on and play the heck out of it.

I think I have found the purpose of the green wire with the spade lug on it. I traced it to entering the title board assembly and it has continuity to the title board frame. I suppose the purpose was to make certain the title board was grounded to the rest of the machine. I think I shall attach the spade lug to the power supply/junction box.

Thank You! David

[Ron Rich]

Hi David,
Glad it's running !!
The 8 Amp is NOT a "slo-blo". The two 1 amps ( or on earlier models, they used 8/10 amp, fuses there), are "slo-blo" !
The word "Fusetron" is the trade-marked name Bussman mfg. company used for "slo-blo" fuses. Other companies call them "time delay" fuses. Buss (now a "division" of another corp.) designates "slo-blo's in several ways. Jukeboxes generally use the MDL symbol for them. The other major maker (Littlefuse-also now a "division" of--) designates them as "313". Fastblows used in jukes are usually designated as "AGC's" by Buss, and #312's" by LF. Ron Rich

[juke46]

Ron,
Thanks! I got the fuse info! Thank You! I will copy and print that valuable fuse info because I'll never remember! It perfectly explains what all of those different fuse labels are for. I left the AC 8 AMP as a "Fast-Blo" fuse.

This is a valuable web site and we should tell all of our jukebox friends about it.

David