World's Smallest All-Tube Spy Recorder
Added 2019-04-12 01:35:56 +0000 UTCCold War amazement! This is the 1955 Minifon P-55, an all-tube hand held wire recorder that was true high tech for its time. Without all the batteries it is the same size as a Walkman! I do a tear down to reveal the genius and craftsmanship that lies within. Enjoy!
Read the P-55 manual on cryptomuseum.com:
https://www.cryptomuseum.com/covert/rec/minifon/p55/files/p55_manual.pdf
Comments
A very advanced system by the look of it. You could split a suitable belt and super glue it back together
Andi Archer
2019-04-16 22:33:51 +0000 UTClooked to be another tube (valve) near the motor shaft. I wonder how well those capacitors fared after all this time. I think the term "wearing a wire" might have been referring to this type of machine. With the impedances that valves deal with or the crystal Mic 3meg for the pot might be valid but I recall some schematics etc use M to refer to K ohms, if the pot measures close to 3k instead of 3 meg this may be why
William
2019-04-14 05:07:05 +0000 UTCThanks Fran! Very interesting. :-)
2019-04-13 21:59:40 +0000 UTCIt's so good to have Franlab back in business. This contraption is excellent!
SpringRat
2019-04-13 12:37:16 +0000 UTCClassic Fran. What a great find!
Mark Wilkes
2019-04-13 09:29:57 +0000 UTCIt's like Christmas in April! So happy to see you back in your element, Fran. Congrats.
Michael S Wilhelm
2019-04-13 01:31:43 +0000 UTCThat is a fascinating device. And I never even imagined they could get tubes down to that sort of size. Made in England too! Super! So as to how to get a replacement belt on, does not look overly complicated you just have to release the two spindles to have access to the side profile. The clutch wheel will probably need to be lifted just over the gear so you can loop the belt over it but assuming there are not calibrated gears (ie they need to be in exactly the same place as they are removed) it should not be a problem. It would be a fun project and definitely an interesting video to be sure.. Thanks for enlightening me.
veritanuda
2019-04-12 17:26:44 +0000 UTCcool!
2019-04-12 13:03:12 +0000 UTCWouldn't you love to see film of it being assembled at the factory? Everything inside looks so handmade. It seems like it was put together as a single thing, not as a composite of subassemblies.
Andy Ihnatko
2019-04-12 09:56:02 +0000 UTCI wonder how the wire speed was regulated. Is there a controller loop in there too? Or was "close enough" good enough?
BobC
2019-04-12 04:30:25 +0000 UTCYes the other tube easy to see in video. What a masterpiece of engineering, likely the efforts of several dedicated teams of people. And from the new lab!
Inventor Pardue
2019-04-12 02:58:35 +0000 UTCThank you Fran,m that was great. Yes I did spot the other tube. The "Penlight" battery took me back to my youth in the UK; now called an AA battery. We literally put these in what looked like a fountain pen with a "Lens end" bulb at the end. Thanks again. Rob
2019-04-12 02:53:00 +0000 UTCWow. Impresive.
William Alsing
2019-04-12 02:05:37 +0000 UTCCan you spot the other tube? I did after it was edited!
Fran Blanche
2019-04-12 01:59:08 +0000 UTC
