Removing Franz pickup issues

[BradHK]

I am starting the work to restore my 1954 M-75. I need to pull the harness. However, I am having issues removing the Franz soap bar style pickups. From the photos I have found it looks like I need to remove the covers then I will have access to four screws holding the pickup to the body. I removed the center screw holding on the covers but it appears that the holes for the pole piece screws have shrunk and shifted slightly over time. The pole piece screws are getting stuck in the holes in the cover and the covers do not want to come off without removing a few of the pole piece screws. This is my first guitar with Franz pickups and I don’t want to break anything or mess up these pickups. Can I remove the pole piece screws that are preventing the cover from being removed and then put them back without issues? Any other tips or suggestions?

Thanks

 

[Default]

The pole piece screws actually hold the pickup together, courtesy of the wire on the top of the bobbin. I would try taking out one (or both) of the outside screws and wiggling the cover off.

 

[BradHK]

thanks and that‘s what I figured based upon the photos. I will leave a few screws in that appear to line up with the holes in the cover and see if I can wiggle the cover around those screws.

 

[GAD]

Also those covers absolutely did (and do) shrink over time, so keep them keyed to the pickups and don't leave them separated for more than a few days.

 

[AcornHouse]

Also those covers absolutely did (and do) shrink over time, so keep them keyed to the pickups and don't leave them separated for more than a few days.

Or, better, as soon as you get the cover off, unscrew the mounting screws and put the cover back on immediately. Those pole pieces are the only thing keeping the holes lined up. Even a few days may be too long before they shrink too far to remount.

 

[BradHK]

Thanks for the tips everybody and I was able to get the covers off without cracking anything and then removed the entire harness. I reinstalled the covers after treating them to a good bath in plastic cleaner and polish. They cleaned up nicely! The pickups both measure just over 7k and a quick check with a multimeter shows everything else working as expected. Does anybody have a wiring diagram for a 1950’s M-75? From what I could tell this is the first time the harness has come out and everything looks original (But desperately In need of a good cleaning). There are some HUGE caps in there (I need to clean them off to get some readings). There are two caps on each tone pot and one at the selector switch. I was not expecting that!

 

[SFIV1967]

That's also the first time for me seeing it this way.
My '56 harness looked a bit different, but one cap had “Micamold Radio Corp.” written on it and MFD .03 and D.C. 200V. So that is a 0.03 micro farad cap, which is 30nF or 30,000pF. It is connected to the neck pickup tone pot. Compared to the cap value on the bridge volume pot this should make the neck pickup a bit warmer sounding compared to the bridge pickup.



The cap on the bridge pickup tone pot in my guitar is a black molded paper-dielectric cap, which was made by TOBE Deutschmann. The value seems to be 0.008 micro farad. (which would be 8nF or 8,000pF). But your guitar uses a clearly different cap there.



The switch in my case had no cap connected, but I assume the previous owner removed it when he exchanged the volume pots, because the second picture shows a switch from a 1959 Aristocrat with a molded paper cap from TOBE Deutschmann. I would take out that cap on the switch.



That's the harness in my '56, the two volume pots were replaced sometime in the 80ies I think to remember:



Also mind that the wiring harness was made in a way that originally the two volume pots where the upper pots (towards the strings) and the two tone pots the lower pots toward the outside of the body.
So on the left side the volume and tone for the neck pickup and on the right side the volume and tone pot for the bridge pickup.

The general wiring is like a Gibson 50's wiring, with the difference that the pickup was connected to the middle lug of the volume pot where the cap is connected as well and the switch is connected to lug 1 on the volume pot.
But in your case a resistor was connected as well in line of the signal.

Ralf

 

[BradHK]

Thanks for posting your harness and details. I just started another thread with some additional details on mine and questions on the use of caps. It looks like my 1954 is definitely different than your 1956

 

[Default]

The cap on the switch was probably added later to get that really wooly Fifties jazz sound. Over the years, we've seen quite a few guitars with caps going straight to ground. Take that cap off and see how it sounds. The factory did that on a MM pup equiped T-100 that I should have kept.

 

[BradHK]

The cap on the switch was probably added later to get that really wooly Fifties jazz sound. Over the years, we've seen quite a few guitars with caps going straight to ground. Take that cap off and see how it sounds. The factory did that on a MM pup equiped T-100 that I should have kept.

My guess is that the cap on the switch is factory to get that “jazz” sound as the cap is exactly the same as the one attached to the neck tone pot and the solder points don’t look like they have been messed with. But, who knows exactly what has happened to the wiring over the last 68 years! I created a wiring diagram that I posted on the other thread I started regarding the capacitors and wiring.