Mitchell High Fidelity 3-D record reproducer

[classiccaprice]

I was over at my uncle's house today where he showed me an item that I'm supposed to take when I have the space for it.  A 195? Mitchell High Fidelity 3-D record reproducer.  I couldn't find much online about Mitchell, but I thought someone on here would be able to shed some light.  I realize that this is something for audiokarma, but I don't have a non-free email account that I can use to set up an account so I can't ask there.

 

When my uncle's parents built their home back in 1956 an old man lived across the street on a ~5 acres of land.  When he died they bought the property and this was in the house... it stayed in the house until my uncle tore it down to build his current home and my uncle had the forethought to save it and it's base.  It's in rough shape, but I've only found one other online.  I also found it's photofact... 

 

My uncle estimates that it hasn't been used in 40 years...

 

 

http://www.flickr.com/photos/poopfilter/sets/72157600033958118/

 

[classiccaprice]

shot 2

 

[classiccaprice]

shot 3

 

[classiccaprice]

shot 4

 

[cfz2882]

cool-on the tube closest to the two capacitors a date code is visable:5x-17,can't quite read the the 2nd number-that will give the date the tube was made and if other tubes and the two capacitors are similar dated that will give year of manufacture(sure looks early to mid '50s era).If you power it up,should use a series bulb or variac to bring the voltage up gradually so long disused caps can "reform" before full voltage is applied(this assuming the phono was in working order when last used)

 

[classiccaprice]

My uncle apparently turned it on several years back and it does spin... I know that wasn't the smartest move in his part, but he didn't know. I'm sure there will be a few blown caps, at least.

 

[cfz2882]

possible gassy tube in linked phono

in the phono seen operating in the link,the center tube has major blue nitrogen glow-"gassy" it's one of the 6w6s.GE tubes,late-50s and later seem to have this condition more often than other brands.

 

[whirlcool]

This was made by the Mitchell Manufacturing Co, 2525 N. Clybourne Av, Chicago, IL. They made radios and phonographs from about 1949-1964 or so. They also made or imported those tiny little 8 transistor radios from Japan and resold them under the Mitchell name 1961-63 or so.

From Google maps it looks like the original building was torn down and is now a parking lot for some newish apartment buildings.

Other than that it looks like they were around for 10-15 years and then faded into obscurity.

Mitchell Mfg. Co., ; Chicago, IL manufacturer in USA, Model | Radiomuseum.org

Mitchell Mfg. Co., ; Chicago, IL manufacturer in USA, Model types from United States of America , 60 radios, 158 pictures, 271 schematics, tubes

www.radiomuseum.org

 

[classiccaprice]

Most of the tubes are from the late 50s... 1957, 1958, but some are as late as 1965.  

 

Thanks for the info, everyone.... especially Allen.    It's an intriguing design.  I'm especially intrigued with the base.  The top section is screened to allow air to get to the tubes which are exposed under the turntable (I didn't remove any panel when I took that picture).  The bottom section has record storage and a second speaker.  I don't think it's a stereo unit, but maybe I'm wrong.  When it becomes mine I'll post more pictures.  

 

[cfz2882]

amp

looks like it has a decently powerful push-pull mono amp of ~10w-will be cool to get it working and see how nice it sounds!

 

[whirlcool]

Here are some more photos of a 3D model:

http://www.flickr.com/photos/poopfilter/sets/72157600033958118/

 

[coldspot]

This ad from 1955 might be a clue on the year it came out

St. Petersburg Times - Google News Archive Search

 

[twintubdexter]

I find all this interest in radios, phonographs and console stereos just great! Allen, is that tube tester in your photo a good one? I'm looking for one on ebay but I know little about them. Do they usually need to be recondtioned? I'll bet a lot of other experts on here are "tube tester savvy." Any info would be greatly appreciated.

40 tubes in the Magnavox CG alone, right now I just assume if they're hot they're happy...

 

[whirlcool]

Yes, Sencore tube testers are usually good ones. Try to find the best one you can find (exterior condition). A shoddy looking exterior could meant that it spent years rattling around in the rear of a service truck or stored inside in a climate controlled area.

Personally I like B&K, EICO and Hickok brands. Usually all that is needed to overhaul these units is to recap them and they are usually fine. It's always best to buy the most recently made models possible. And when buying a tube tester make sure it comes with the settings book so you know how to set the controls for each style of tube. There are literally thousands of different settings.

 

[firedome]

tube testers

vary greatly in quality, and test tubes by different methods... you don't necessarily need an expensive (generally $400+) Hickok mutual conductance type of tester for basic tube testing, some of the less elaborate Sencore, Eico, Heathkit etc emmisions testers are fine for simple good/bad testing so unless you plan to test a lot of tubes and sell on eBay they are fine. We've had 7-8 testers over the years and the ones we liked best were the several TV series military testers made by Hickok and others under contract, but they are quite pricey and overkill for 90% of folks.

 

[cfz2882]

tube tester

my tube tester is a B&K #707 made in '66 this one doesn't have sockets to test the early 4 and 6 pin tubes though.I had a small,simple knight tester(made in japan in '69)that could test the early ones.

 

[kb0nes]

I have an old Heathkit Tube Tester I cleaned up and recapped years ago. I find I don't use it much though. Almost all my tube work is done on relatively straightforward audio amplifiers and its just easier to try the tube in circuit and see what it does. If I did more radio or TV repair I'd use the tube tester more.

I also noticed that purplish glow on the power tube in the link, but I wouldn't assume its from gas. That looks more like florescence which often happens in perfectly good power tubes where some stray electrons impact the glass envelope. I have a bunch of good hard EL34's that all exhibit the pretty photogenic purple glow! A gassy tube will indeed glow in use, but that glow tends to be more internalized.

 

[cfz2882]

EL34 glow

interesting about the blue glow from florescense-i'll have to look at the two EL34s in my 1957 built knight kn 530 amp and see how it looks in the dark-amp is not in DD use,so will be sure to hook a speaker to it before powering up.

 

[tolivac]

The glow appears to be glass flourescence-harmless.See this all of the time-seen this in some of the transmitter tubes out here-the older Continental electronics transmitters tubes in the final power stages will glow on the glass.Now if the glow is inside tube elements or not on the glass-greenish-purple glow-then its gas.For us transmitter will kick off.For tube testers I like Hickock.Just about all of the radio stations I have worked with had them-that unmistakable red or black case!And we have a few Navy surplus ones here-Hickock ones made for the Navy.Gov't sites usually get the military gear surplus.Hickock testers now can be found at reasonable prices from various places.
Don't let any guitarists see that PP 6V6 phono amp-they will want it for a "G" fiddle amp!Those smaller TT amps are loved by guitarists as G amps.
For our transmitter tubes-if there is slight gas-cook them on a Hi Pot tester or connect the getter element on the tube to the filament connector-some transmitter tubes have an active getter than can be used-a small filament made of a metal that absorbs gas as the tube operates.Of course small receiving tubes don't have active getters.