Remaking The Horseshoe Bass Bobbin

[Wiker]

Koji, if I was to make a pickup myself I would make it like yours. I would much rather have adjustable pole pieces like that, as it seems magnetic horseshoe pickups are very sensitive distance between string and poles.

Problem there is if you adjust them ( like any of the pre 73 pups) you take the pole away from direct contact with the shoe ( or Magnet), which in turn will affect the transfer of magnetic power away from the pole.

I also thought that would be no good, but I have a bobbin with adjustable poles from Lollar. All the pole screws are of equal length so one can screw them all down flat if needed. Doesn’t make much difference, not that I can hear, when the poles are not in touch with the shoes, but ...

Not to mention on those 69-73 versions where you turn the E or G pole and cut the coil .

Sometimes the best way to learn is to do something stupid.

[heinpete]

Yes Geir, you are pretty close. Resistance is a function of the length of the wire and the diameter. For the same length, a smaller wire will have more resistance. And of course, longer length will be more resistance. The size of the core will determine the length of wire per turn (you must remember that as the wire builds on the core, it will take more wire for each turn, and thinner wire will not build up as fast).

If you don't want to read a bunch of Techno-Geek speak, quit reading NOW...

You have been warned!

For a given core material/size/shape and magnetic field, more windings will generate more output. More windings will also increase inductance, but inductance is very dependent on the core material too. A big chunk of iron as a core will have more inductance than an air core for the same coil of wire.

Now, as for the "loss of clarity", I'm not exactly sure what that means as it's not really a term used in electronics. But I'm sure it is related to the frequency response and resonance of the coil. All factors of the coil will affect this, the resistance, the inductance, and the inter-winding capacitance. The capacitance happens because you have a lot of wire close together and it acts like a capacitor.

The resistance has the least affect because resistance is constant over frequency. Inductance and capacitance act like frequency dependent resistors. For inductors, the higher the frequency, the higher the "impedance" (a fancy word that means frequency dependent resistance). For capacitors, the higher the frequency, the lower the impedance.

Now, since the signal travels through the coil, it will look like the resistance of the coil gets higher as the frequency increases because of the inductance. More inductance will mean less high frequency can get through the coil and out to the amp.

The same thing happens with the interwinding capacitance even though its impedance gets lower with rising frequency. This is because the capacitance is between the windings and is essentially shorting out the windings at higher frequencies, causing them to produce a lower output voltage.

OK, you're safe now, the Techno-Geek portion is finished...

...nice to read! But can we get a bit more information about the impact of the several neck PUs, HS and HG (from 1968 onwards) in reality. I can't put the puzzle pieces together . Does somebody have an overview about the correlation between winding, capacity, frequency, output and resistance? A simple table starting with the 1968 HS going to the 1973 slotted pole pieces HG, the 1978 HG, than the 1993 RIHS and the later the 1997 adjustable pole pieces HG. I'm thinking of only one expert in Portugal who might actually be the only person capable of such task...Sergio, help!!!

[Moonie Man]

I would much rather have adjustable pole pieces like that, as it seems magnetic horseshoe pickups are very sensitive distance between string and poles.

Geir, I agree. I understood well about the point of your indication in my experiment of the Lap Steel bobbin direct replacement.

In the Horseshoe Pickup, the "Adjustable Bobbin type" thinks that it originally makes sense from an "Adjustable Polepiece type."
Supposing it may break down original nature of the Horseshoe pickup, I will think how it is a system [ like the following figure ] whose I am - "Tune-O-Bobbin Matic" Horseshoe.



However, I am not going to try this system at this time.

[Seans]

Nice idea Koji.

I suppose the whole question is whether or not you can get the magnetic strength up to it's original point, which is doubtful, so closing the gap slightly should help, but not getting to point where the output starts to honk.
Just listening to CS his HS is probably as new as, he really is attacking the strings here, almost sounds in places the strings are to close to the poles, but woh does sound good though,

[Wiker]

I would much rather have adjustable pole pieces like that, as it seems magnetic horseshoe pickups are very sensitive distance between string and poles.

Geir, I agree. I understood well about the point of your indication in my experiment of the Lap Steel bobbin direct replacement.

In the Horseshoe Pickup, the "Adjustable Bobbin type" thinks that it originally makes sense from an "Adjustable Polepiece type."
Supposing it may break down original nature of the Horseshoe pickup, I will think how it is a system [ like the following figure ] whose I am - "Tune-O-Bobbin Matic" Horseshoe.

When I said "adjustable pole pieces" I was simply referring to how your pickup is constructed , with the pole screws going through a core in the bobbin without touching the wire. Then you can screw each pole up and down individually without the screws cutting the coil wire.

The bobbin I have on my magnetic shoes work like that. The screws will be in contact with the magnetic shoes only when screwed all the way down. Because the magnetic horseshoe pickup seems so sensitive to string height, it's quite useful to be able to adjust pole height for each string individually. Of course when a pole is raised it won't be in physical contact with the shoes anymore, but doesn't seem to make much difference.
I don't know anything about magnetism, but it does extend out in space, affecting objects at a distance without physical contact, so...

[Wiker]

:
Just listening to CS his HS is probably as new as, he really is attacking the strings here, almost sounds in places the strings are to close to the poles, but woh does sound good though,

Yes, that is what I like about the horseshoe. It is much more sensitive to how hard you play.

[Moonie Man]

Many thanks, Geir.

[Moonie Man]

There should be structure of the bobbin of Horseshoe how -- it is -- although it seems that it is alike, it attaches and there is enough room for an argument, I would like to leave it to the others about it.

This purpose of mine is to remake the bobbin for the Bass in the faithful [ as possible ] more good state, and to make use possible by making my Horseshoe into my own Bass.
About a bobbin, I am satisfied with the result of Version-2 I have made. I would like to make that into a completed type for a while.
I am going to the theme to the next step - Coil Winding.

[weemac]

Koji, your work is probably of much higher standard than it probably needs to be! It will work really well.
For the record the coil on my 64 RM1999 (which looks to have the original winding) has a DC ohms of 7.4 Kohms which on a good day works well with the toaster (7.5 kohms) on the same bass. As the shoes degauss (which some do a lot) the toaster takes over more.

Emac.

[Moonie Man]

Emac, Thank you for your information!

[ram]

Koji, great step by step.... can hardly wait for the winding pictures!!!

[leftybass]

This is a great thread, enjoying it as well..!

[teeder]

This is a great thread, enjoying it as well..!

Agree! I vote that this thread be saved somewhere special.

[johnallg]

It should be a sticky, maybe in the Winding forum. Great info here.

[ricosound]

There should be structure of the bobbin of Horseshoe how -- it is -- although it seems that it is alike, it attaches and there is enough room for an argument, I would like to leave it to the others about it.

This purpose of mine is to remake the bobbin for the Bass in the faithful [ as possible ] more good state, and to make use possible by making my Horseshoe into my own Bass.
About a bobbin, I am satisfied with the result of Version-2 I have made. I would like to make that into a completed type for a while.
I am going to the theme to the next step - Coil Winding.

The duct tape was the Ah Ha moment for me