Philco Mystery Control: Theory and Operation
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- Опубликовано: 27 ноя 2022
- Since I had access to a functional Philco radio with the Mystery control, I decided to do my best to document the operation of the remote control and receiver. You can skip towards the last few minutes to see the system in operation if you don't care about my blathering.
I only had one camera, so the operation shots were loosely synchronized from multiple takes running the remote, and not everything worked out exactly the same. 
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I think its incredible that despite the sparse technology they had back then, they were able to create something like this! We are very lucky with much recent technology that we use today, but what we take for granted today would not be possible without this early technology. Thank you for the video
An excellent operations overview. Documentation is weak so this was very informative. I just acquired one of the Mystery Control boxes and spent time fixing the warping with very good results. Next is to add batteries and see if it works.
I cheated on my warping issue. I found a washer just the right size to fit under the plastic dial to keep the drooping edge from touching the cabinet as it spins. Can't even tell its there from the outside!
This was amazingly helpful and clear, especially your long-hand, detailed look at each aspect, really appreciated. I just bought one of the remotes (mainly because it is quite sculptural, in an Art-Deco sort of way) and will repair it. Then I need to find a radio chassis. Just the way it sits on your bench, with the bare thyristor flashing purple is far better looking than any cabinet the radios originally came in. I also thought relying on a tube to come to working temperature so quickly, by overdriving the filament voltage is, at best, an iffy proposition. In the 70s they had these tube substitute transistors called FETRONs. I wonder if a suitable one can be found or made? It may make the set up more reliable. All the best.
Thanks for the kind words! Considering that the set is just looking for a pulsed signal at a fixed frequency, I imagine it wouldn't be hard to setup some kind of transistor replacement for the 30 tube; any basic signal generator can trigger the set with a decent antenna.
@@Eclec-Tronics Yes, I thought I could keep it all original by just plugging a substitute into the Type 30 socket and reducing plate voltage, eliminating filament voltage. There are lots of triode to N-channel JFET conversions on the web.
Great reverse-engineering and explanation of the operation.
A lot of people thing this stuff is gimmickry but I feel these were stretching the boundaries and making the future come true!
Thanks for making the video and 73...
Thanks! I'm curious as to whether or not the Philco system predates the use of similar mechanisms in Jukeboxes; wallbox control is virtually the same except for the dialing mechanism.
@@Eclec-Tronics well, you can actually research the patents (many times of which are affixed to the receiver) and see if this is a
Philco-centric, Philco displaying a 3rd-party patent which they be using by license. Not finding any, it can be thought that the mechanism patent has previously ran out; as so many mechanism-patents go way back prior to use in electrical devices. You may find a blanket patent that Philco (or someone else) filed that describes the whole thing as a unique invention.
Sometimes, it can be very interesting to just start entering patent numbers and see not only what pops up, but the lineage and history.
73…
I wonder if the remote range could be increased today by inserting a transistor to boost the transmitted signal.
I just acquired a 39-116. Looking through and cleaning it, I came across a 6K5G in the remote control receiver, where the schematic shows a 6J7G. This makes no sense as the 6K5 is a triode whereas the 6J7 is a pentode. Yet everything looks unbastardized, with all original Philco tubes. Now, you have a moment in the video, when you are talking about the various tubes and you seem surprised by something (at 21:55). I was wondering if you also came across something like this, like an unexpected tube? I will appreciate.
I honestly can't remember what threw me off; I just looked at the schematics again. Some versions of the Mystery Control radios had a 6ZY5G in the remote circuit, but this one did not. It is entirely possible Philco made a chassis revision and changed to the 6J7G early on, and simply didn't document it; would not be the first time a radio manufacturer did that. If the 6K5G works, I would roll with it.
@@Eclec-Tronics
Makes sense. I want to try each part separately before I turn everything on. Can you tell me what voltage I need to apply to the thyratron grid to make it turn on? Is it 7VDC? Does AC or DC matter? You mention the plate voltage is AC.
I'll have to look at a databook at home later. Can't find anything online that lists the striking and holding voltages for the 2A4. The AC plate supply is used so that the tube turns off every half cycle, otherwise it would remain on even if the remote is not transmitting.@@atoptip6193
That old paper CAP *IS NOT* OK...It's Dried-out and has *HIGH ESR !!*
Jesus dude, chill out. It's got barely 45 volts across it from a battery pack, and I do plan on replacing it.
@@Eclec-Tronics - Hay, OK, don't take it so hard. ;-)
NO, *Tesla* was a *Brilliant Man !* Edison, not so much...
I think its fair to say that both men were brilliant in their own rights, although Edison was certainly a jealous dick who didn't like being beaten at his own game.
@@Eclec-Tronics - True.