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Posted: Fri Mar 30, 2007 2:30 pm
by rickcrazy
P.S. two: can you guess what those bobbins were fashioned from?...

Posted: Fri Mar 30, 2007 2:46 pm
by loverickbass
Looks like from The Byrds "Mr. Tambourine Man" vinyl LP. I see a few grooves near the pole pieces. I need to stick a needle to it and make sure! He He...Image

Posted: Fri Mar 30, 2007 11:31 pm
by rickcrazy
Well, bingo! Not from a Byrds long-player though.

Posted: Sat Mar 31, 2007 3:10 am
by loverickbass
I'm just messin' with you Sergio. You already told me earlier what you made them from.

BTW, how hot did you wind them? I'm guessing less than 7.4K.

Posted: Sat Mar 31, 2007 1:38 pm
by rickcrazy
That's right. Around 6.8 K.

Posted: Sat Mar 31, 2007 1:40 pm
by loverickbass
Thank You Sergio.

Posted: Tue Apr 10, 2007 9:05 pm
by heinpete
Here is a close up of a 1970 high gain from Elys' 4001:
Image

Posted: Wed Apr 11, 2007 2:19 am
by loverickbass
Cool! Looks like it's bobbin is cardboard or fiberboard. Reminds me of the bottoms of vintage fisher price toys.

Posted: Wed Apr 11, 2007 3:20 am
by elysrand
Wow, Pete, that's a gorgeous photo you took! You have both a very good camera, and a true artist's eye for composition Image

Rickenbacker 21-fretter courtesy of John Hall and Electro...

Posted: Wed Apr 11, 2007 3:22 am
by elysrand
Sérgio, is that the late-sixties "phenolic" material in the hi-gain bobbin? It does not look like "record vinyl" in this photo.

Posted: Wed Apr 11, 2007 4:49 am
by johnhall
That's G-10 mil spec glass filled epoxy printed circuit board material- just about indestructible.

G10 Spec Sheet

Posted: Wed Apr 11, 2007 10:51 am
by rickcrazy
Hey, thanks, John. "Just about indestructible". I'll say!
Elys, the treble pickup originally on my November '70 21 fretter looked exactly like that. Currently it's safely tucked away in my "Rick parts drawer".

Posted: Wed Apr 11, 2007 12:39 pm
by elysrand
We used this single-layer glass-filled epoxy for RF circuit boards in VHF radios for years. Only a two-sided circuit board, so you could do plated-through bridges front-to-back easily on the wave-soldering machine. John is right, this stuff takes a lot of soldering iron abuse, much stronger than plain old brown phenolic perf board.