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Old 08-22-2018, 12:51 AM
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Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,762
Quote:
Originally Posted by EdKozk2 View Post
Hi Tom,
There was a magnetic cutting head produced that could be substituted for your crystal one. The the current 7000 ohm primary/ 70,000 ohm secondary impedance transformer can be switched to a standard 7000 ohm / 4 ohm transformer. The magnetic cutting head was Astatic M-41-3. The replacement transformer for the change over was Stancor A-3854 or A-3859.
My wife and picked up one of these Recordio's in January. I just recapped mine last month. I had to change the phono cartridge. The crystal cutter and transformer were both shot. The secondary of the transformer was open. I installed a standard speaker transformer for a 6V6 load (5000 ohm) to 4 ohm speaker. My Recordio uses the 6SN7 to drive the cutter. I ended up building a DIY magnetic cutter. It works well enough to at least record on plastic disks. The frequency response is limited, very weak on the high frequency end.
Ed
Thanks for that excellent information Ed.
Today I spent some time taking stock of the record cutters I have and remembered I have more hiding. The Recordio's head is still unknown condition but I'm fairly confident it is equipped with a crystal cart. I had a spare cutter cart (that I pulled from a spare mech that I sold) that is the same size/shape...I opened the spare up to discover rotted crystal. I'm going to have figure out some form of signal source to test the Recordio's cart.

My memory of the Recordio working may have been wrong...At the time of that memory I owned a second no-name record player/cutter/amp that I still have that unit has a magnetic cutter cart that has continuity...That may have been what I was remembering. Neither unit is in great cosmetic condition...The No-name had much of the tweed eaten off its case when stored in the garage in Florida (damn cockroaches!) and the Recordio needs woodwork, grille cloth, and correct knobs, but has the factory stand (that makes it into a legged mini-console), and the original instruction book (and some accessories) going for it. Not sure if I'll fix one or both right now.

I have been toying with the idea of growing new Rochelle Salt crystal piezo elements to try in pick up carts. Lots of videos on making the crystals on youtube, but none trying to use them for the application or make them the right size... If I can make such a thing work for a pick up then maybe I could scale it up to a cutter cart. Supposedly the originals were all Rochelle Salt carts back then. I figure new Rochelle Salt elements must be the way that the places that rebuild 40's playback and cutter carts do it so if I can figure out the process I could do my own professional rebuilds. I may shelve the Recordio, for now, all is recapped and working but the cutter mode and I have other cutters.

Just a moment ago I remembered there is a cutter on my Philco BOL console too...Can't test it now but the head feels like the magnetic one in my no-name unit...Fingers crossed on that.
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Tom C.

Zenith: The quality stays in EVEN after the name falls off!
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