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Re: Restoring/replacing crystal cartidges for electric picku

Posted: Thu Nov 14, 2019 5:53 pm
by ChuckA
marcapra wrote:I think my entry above was not clear. I wasn't talking about replacing my horseshoe cartridge on my Edison C-2. I was talking about replacing pickups with crystal cartridges with ceramic carts.
Marc,

As I said in an earlier post the main issue is the lower output voltage of ceramic vs crystal. Many of the early amplifiers were designed around the 1 to 2V output of the crystal pickups, most amps will not be able to deliver anywhere near their rated output with a ceramic pickup. There is also an issue with frequency response of the crystal vs the ceramic units.

Chuck

Re: Restoring/replacing crystal cartidges for electric picku

Posted: Thu Nov 14, 2019 6:01 pm
by Hyperion
ChuckA wrote:
Hyperion wrote:
ChuckA wrote:
Just received a batch back from Germany and they all seem to work as expected, voltages are well over 1V.

Chuck
Cartridges or just crystals? Did Schmidt do them?

Cartridges and yes they were from Herbert Schmidt.

Chuck
Chuck, I would advise using extreme caution with those cartridges. I know two people who sent crystal cartridges to Schmidt, and both had bad experiences. Guy #1 sent him a few and thought something was off when he got them back, so he opened them up (he says Schmidt had cemented them shut, so it was really difficult), and that while the actual crystals were fine, he was horrified to see that Schmidt had seriously cut corners when he set and installed them. Guy #1 said he ended up having to re-set them all himself, or else none of them would have lasted long. Guy #2 told me he sent Schmidt one cartridge, and when he finally got it back (both guys say it takes Schmidt 3-6 months to turn stuff around), it worked for less than two weeks until the needle hit a hairline crack on a record and output suddenly dropped WAY off, to the point where it was barely audible. Guy #2 suspected the crystal had cracked and wrote Schmidt, who told him to send it right back and he would fix it for him. So he does, and when Schmidt gets it he tells him yes, his crystal had cracked. Then Guy #2 waits another 4 months for Schmidt fix it (I guess Schmidt put him back at the end of the queue), and when he finally does, Schmidt sends Guy #2 a second bill! And it was for the same amount as the first one! Guy #2 told me he paid that bill, against his better judgment, but will never send Schmidt anything again, and strongly advised me not to, either. Both guys also warned me that Schmidt won't let you send anything to him insured because he claims that he would have to pay import duties on it if you did, so if your cartridge gets lost en route, you're SOL. That alone, coupled with no tracking and a 3-6 month turnaround, is bad enough, but if this Schmidt does shoddy work and then doesn't even stand behind it when something inevitably goes wrong, there's no way I'm going to send him anything. And like I said, Westech doesn't do it, unless you want your crustal retrofitted with a ceramic cartridge, instead.

So again: Isn't there ANYONE in the U.S. who repairs/restores old crystal cartridges? What did people do before Schmidt, just not restore old phonographs with crystal pickups?

Re: Restoring/replacing crystal cartidges for electric picku

Posted: Thu Nov 14, 2019 9:05 pm
by ChuckA
I guess the answer to your main question is nobody. At least no one I have run across.
A big problem is that there is no source for replacement crystals.

There was a guy in New England and another in Canada years ago but both stopped a long time ago and they both used ceramic elements from donor cartridges which would get it working but still had the low output problem.

Ceramic elements with low output need a very high input impedance(2-3Meg ohm)preamp stage with 6-10dB gain to raise the voltage to the required 1 to 2V level needed for the existing amp.

I have one of his rebuilt cartridges in a customer's Capehart that has been working perfectly for over 2 years.

I'll let you know if I have problems with the cartridges received, he did a dozen various models.

Chuck

Re: Restoring/replacing crystal cartidges for electric picku

Posted: Fri Nov 15, 2019 11:54 am
by tesch1932
Hi, I also am trying to get around to rebuilding a crystal cartridge for a 1948 RCA phono.

These cartridges need upwards of 3v to work correctly.

Check out the following topics on "Antique Radio Forum" I have found these helpful:

https://www.antiqueradios.com/forums/vi ... 9&t=306336

https://antiqueradios.com/forums/viewto ... 9&t=365720

My ambition is to experiment with growing my own crystals, but am almost certain that I would not be able to recreate the factory conditions in which they were originally grown. Also, from what I understand, they have to be "cut" a certain way.

OldRestorer discusses growing rochelle salt crystals, as well as what modern cartridges can be used as "donors" for an older cartridge. He would be the one to ask, I believe.