World's Smallest All-Tube Spy Recorder - The Minifon P-55

[@bobatron2639]

Would love to see more restoration videos of this. This thing is amazing

[@becconvideo]

2:36 Translation of the manual in German: "10 simple hints for the correct handeling of the Minifon P55 "S" and "L" 1) Install the batteries in the correct manner i.e. + on + y - on - 2) Check the motor battery meter - the indicator must be in the white field. If the playback volume is to low, replace the anode and fillament battery. 3) Insert all plugs completly into the sockets until the end. 4) Check the adjustment of the potentiometer (keep in mind the distance) 5) Use the right accessory for the intended purpose - e.g. (neck/throat microphone when dictating in the car) 6) When changing the reels make sure that the recording "speaking" head is in its uppermost position. 7) Put the recording wire reels on until they latch, make sure that the wire runs through the recording head's slot 8) Work only with the minifon when the lid is closed. Don't touch the rotating reels or the recording ("speaking") head 9) Press buttons quick and firmly until they latch. When rewinding, if the red light shines, press stop button immediately 10) *For the sake of optimal recording and play back quality use minifon original accessories and sealed minifone recording reels.* Beautiful 1950ies wording. Written by the engineers themselves - no marketing speak - except in the last line.

[@EEVblog]

Fantastic! I wonder what else do you have in the vault...

[@FranLab]

It's a few things. Some things.

[@Romaobb]

@@FranLab "a few"

[@mysticvirgo9318]

How about that little sub miniature tube? what a bobby Dazzler!

[@olipito]

Dave, it's spelt fRantastic

[@deadfreightwest5956]

She's only finding these due too the tidal sweeps of moving. I'm often amazed at the things I find looking for something else, even if that something else is a functioning ball-point pen!

[@best_pilot]

Fran, in case you have to repeat such an actions with lots of screws, use my trick: (i) Place the plate with all these screw heads upside down onto a scanner and scan it. (ii) Print, cut and glue the image onto a foam plate of same size (thickness > expected screw length). (iii) Drill small holes into foam at screw positions. (iv) Start disassembling your item and stick screws at corresponding location in the image-on-foam, screw by screw. By these means you will never mix up screws while re-assembling your item !

[@lordmuntague]

Oo! Techmoan is so going to want to get his hands on that! 8o)

[@AaronJackson1]

Pretty weird because the first time I watched Techmoan's wire recorder video was last night, and then I wake up and Fran has made a video about one too. I'd never even heard of a wire recorder until last night

[@JT-hi1cs]

Fran beat Techmoan on this one!

[@lordmuntague]

@Marcel H True, but not this dinky little thing. I suspect Mat will be looking up flights from John Lennon Airport to Philly right now to get hold of it. It'll be like Spy vs Spy! #o)

[@Jah_Rastafari_ORIG]

@@AaronJackson1 I guess you've never watched Hogan's Heroes... They featured wire recorders a few times.

[@ubergeeknz]

Where do you think the term "wearing a wire" came from 😉

[@Rick-td7qh]

Looks amazingly well designed and assembled! Thanks for sharing. Gotta be worth trying a new drive belt if nothing else. Also, can't help but wonder, what you might eventually find on that wire...

[@deadfreightwest5956]

5:56 - Literally "wearing a wire"!

[@andrewyellstrom2585]

That is indeed exactly where the term came from lol

[@override7486]

@DARK APPERITION No shit, Sherlock.

[@override7486]

​@DARK APPERITION Ekhm, it's a Meme.

[@Max_Marz]

@@override7486 "Its just a meme bro" "Just saying" "No offense"

[@joycetyner7643]

Thank you so much for sharing this Fran !!

[@QsTechService1]

Holy cow that is one awesome artwork.. A piece of wire can’t wait to see you get it going fully restored

[@montageproductions]

One of your best Fran, thanks

[@rickschrager]

You never cease to amaze me with the relics of days gone by that you present. Thanks Fran for all the work you put into your videos.

[@aserta]

The green battery padding is identical with the stuff you used to find on old Ping Pong paddles. That's a neat thing.

[@docpaul]

so - the big question is - what's on the wire?

[@jeffking4176]

docpaul YES. That’s the question ‼️

[@drasco61084]

I wanna listen to it

[@owenmerrick2377]

The long-lost Nixon-Elvis tape!

[@dashcamandy2242]

Cuba Baion?

[@mrnmrn1]

Longitudinally fluctuating magnetic flux.

[@wiretrees]

Wow Fran thanks for showing us that 😊

[@MedSou]

*That's what makes franlab unique on youtube* ❤❤❤

[@mikeoliver3254]

That is such a cool piece of history you have there.

[@jeg1972]

It's so great to have Fran back taking apart some antique audio equipment... Yeah!

[@PaulinesPastimes]

Wow Fran, what an incredible piece of miniaturisation. Must have been assembled by watchmakers. So great to see such engineering. Looking forward to next installment.

[@goodun6081]

"Fran, your mission, if you decide to accept it, is to rebuild this Minifon tape recorder, making it faster, stronger, better..... this spool of wire will self destruct in 5 seconds". A conflation of two TV show opening themes, obviously! Or perhaps re-using the same spool of wire to record both shows, except that the bias oscillator isn't fully erasing the original audio as the second TV show audio is overlaid on it. Is print- through more of a problem with a wire recorder, or less of a problem, compared to actual recording tape? I realize I am showing my age by actually knowing what print- through is...

[@randalltufts3321]

Bring the term wearing a wire into the light of day doesn't it. Magnetism being magnetism it will depend on how it was stored. On top of the old cerwin Vegas not so much lol

[@pohkeee]

🤫

[@misterfixit1952]

@@willrobbinson1 Danger, danger...Will Robinson (as I madly whirl around , metal tube arms flailing wildly) ;-)

[@lesrogers7310]

Wow...what an interesting piece of history you have there Fran. Thanks very much for showing us this.

[@GadgetUK164]

Thanks for sharing this! Lovely piece of equipment!

[@goodun6081]

At about 9:00 in, reminds me of un- snarling an open-face spinning reel when teaching little kids how to cast and fish. When I was older we would sometimes troll in the ocean with springy Wireline, designed to take the fishing lures down deep and have minimal water resistance , but if you snarled that spool of wire (from too much back pressure on the spool with your thumb as you were letting the line out) you might never get it untangled without putting kinks in it and ruining the wire. My grandfather got me into fishing, starting at age 5. An excellent introduction into the philosophy of patience, useful later in life when attempting to repair small gadgets such as this one.

[@UpLateGeek]

When you zoomed in at @21:21, it looked like there was another little tube tucked in there under the yellow wire. Wouldn't surprise me if there were another one tucked somewhere else in there too. What always surprises me is how few components are in these sort of vintage devices - radios, volt meters, etc. I've seen teardowns of early walkmans, and there's probably a hundred components crammed onto those tiny boards, whereas there's probably less than a couple dozen components in this thing. Not to mention how few active components there usually are in them, compared to how many ICs, transistors, etc. there are in modern devices. Anyway, it might be interesting to see a teardown of the power adapter as well. Being from the 50s I'm guessing it used a vacuum tube diode to rectify the AC from the transformer, or maybe a selenium diode. My money would be on the vacuum tube diode though. From what I've seen, selenium diodes were fairly large, and it looks like they've managed to shrink tubes down pretty small by that point, so just going by the small size of the power adapter I'd say it's a tube diode.

[@supercritical5582]

OMG this is the most impressive piece of electronic equipment I've ever seen for it's time period

[@dans381]

Crazy Glue (Cyanoacrylate) will glue belts together (works for old VCRs, Turntables etc)so make the belt whatever length you need right on the recorder without taking it apart.

[@denisohbrien]

this. wurth universal o-ring kits just come with a cutting jig and a bottle of super glue.

[@djszabo418]

Thank you. Will try this on some old equipment that needs belts.

[@njmikec]

She probably fixed it ages ago but I don't think an O-ring would have worked. Probably has to be a flat belt. There are repair belt kits for antique Zenith radios sold the same way. Cut the ends on the bias to length, krazy glue it and it's good for another 75 years. Has to be belt material though. Anything with more than a very little flex would likely introduce warble into the drive mechanism.

[@WindjumbieFPV]

So cool, some of tech you feature I’ve never even heard of before 😍

[@OutbacksurveyPerth]

Yep Fran. I agree. Superb for its age. I’m a 69yo Retired electronics technician so I appreciate this high tech recorder. I was in Toronto, Canada at 11 yo (1961) when I first took interest in electronics. Tubes then & Transistor radios by about 1963 if memory serves me correctly. This must have been a very expensive device at that time. Hope you can restore to working order. Cheers - Trevor in West Australia

[@larryrouse6322]

Hey Trevor, I got interested in electronics at about the same age, just ten years after you. I joined the Navy and started out as a WLR-1G tech, all synchros, servos and vacuum tubes. I can't recall for sure, but I don't think there was a transistor in the entire system. What I learned from it was how to troubleshoot. Now, almost 40 years later I'm a Network Engineer and am constantly shocked at how so many college-trained minds cannot look at a system in its totality and narrow down its functional components to isolate a problem.

[@michaelcarey]

Incredible engineering... it's beautiful

[@EnUsUserScreenname]

*[Techmoan wants to know your location]*

[@invisi1407]

@@pearlmax Pretentious? He's one of the best on KZbin for old audio equipment. Why's he a douche? The joke here is just that I'm sure Techmoan is envious of this recorder.

[@divyajnana]

I can hear him salivating in the "Tube" background. Hope Fran can get that thing working.

[@hvrock13]

pearlmax Jesus chill out lol

[@Bleats_Sinodai]

​@@pearlmax ...Why not plug these tech youtubers yourself then, instead of attacking Techmoan? Just say "hey, not really a fan of Techmoan, so here's other tech channels I recommend", or something like that. Here, I''ll help you with some tech channels I follow: Tanner Tech - kzbin.info/door/R1ARVDHnmTC3sUOkS4mUsg Uncle Doug - kzbin.info D-Lab Electronics - kzbin.info 8-bit guy - kzbin.info Big Clive - kzbin.info Retro Radio Farm - kzbin.info/door/NXdUWfWZHpaDdrOyesz1Cw NearFarMedia - kzbin.info

[@Anonymous_Man]

@@pearlmax You should probably labor on having a bit of self awareness. You come of as extremely pretentious. Among other things.

[@mik7713]

Very nice! Thanks Fran.

[@paulschuessler8477]

Hi Fran, really great Vid! If you sometime want to make that thing function, please take care of this "Mylar"-Cap. This is not a Mylar, it's a Paper-Cap, called ERO 100 and these are notorious for badly leaking after all these years. Here in Germany we call these often "Zahnpasta-Kondensatoren" ("Toothpaste-Caps") cause of the whitish-brittle sealing compound. But there should be some more electronics hidden somewhere. The P55 has 3 Tubes (DF67, DF67, DL67). The original price for the P55 in 1955 was 730DM -or roughly estimated around 3000...3500$ today...

[@mseven125]

And not to forget another bad capacitor: WIMA tropydur, also known as "Malzbonbon" these were even worse than ER0 100

[@mattikaki]

I have this too. I bought in 1966 or something in Helsinki. These were already obsolete then. I have a green plastig bag for it. I’ve never tried to run it and never opened it so this was interesting.

[@daveb5041]

*When you get it going can you play whats recorded on the wire? I always wonder what is on those*

[@CommodoreGreg]

Awesome, Fran!

[@livesportsvideo02]

That explains the baggy clothes back in the 50's, to conceal all that - high tech!!

[@mrsjohnson1743]

I'm loving your 60's analog equipment on your bench. My dad's bench looked like that when I was growing up. Course, he wouldn't teach his little girl about much of it. He did show me how to sort resistors for him. Bad Boys, etc. Love your channel!

[@Screamingtut]

My dad had one of the larger wire recorders when I was 16 I found it that was like 1969. I got the thing to work after repairing it.

[@goodun6081]

The commonest vintage, "portable" wire recorders in the U.S. are those manufactured by Brush, and Webster, also known as Webcor. And by portable, I mean they're usually about the size of a small portable typewriter.

[@chuffpup]

I heard the really big ones were extremely dangerous if the wire broke or came off the machine. It would whip around and slice anyone in the vicinity, so they would stay in a different room while it was operating.

[@goodun6081]

@@chuffpup , Thomas that kind of sounds like an urban legend. But, one wonders if any early computers that used magnetic storage were actually built to use wire as the recording medium rather than magnetic film or tape. If one of those refrigerator-size machines used wire for the recording medium and the wire broke or ran off the spool, in fast forward or rewind mode anyway, I don't think I'd want to be too close to it!

[@mikek5633]

From one technician to another. Very well presented. Good camera work.

[@deadfreightwest5956]

22:06 - I see what appears to be another tube, bottom center of the screen, perpendicular to the drive motor.

[@atrumbell]

Yes certainly, well spotted, to the right of the transformer and deeper than the other components. I was so hoping Fran would spot it!

[@dashcamandy2242]

(I thought I was seeing things...)

[@BobWiersema]

I think that's a neon bulb. Commonly used with tube devices as a voltage regulator.

[@deadfreightwest5956]

@@BobWiersema - Neon bulbs don't have numbers silkscreened (or rotogravered) onto them, much less getter.

[@Alfonsodag]

Yes, agreed, that is another tube deeper in the circuitry.

[@InssiAjaton]

Brings some memories! I demonstrated one as an educational student lecture to my classmates some time around 1957. I recorded a few seconds of the teacher’s voice before it was my time to give my presentation and then played it back at the beginning of my speech. Amazing!

[@juannunez5767]

Whoever designed this machine was truly a genius.

[@AndreasDelleske]

Juan Nunez A Genius is a man with a boss that says money is not an issue then.

[@bratwizard]

That was definitely one of the cooler items I've seen you showcase in awhile. Very, very cool!!

[@bostedtap8399]

Absolutely fantastic, the mechanical design, and implementation is superb, that must have cost the equivalent of a small house. Totally exquisite. Would the translucent feels be original fitment. Some O-ring cord could be wrapped around, and super glued to form a belt. Thanks for sharing and best regards from the UK.

[@alberttatlock5237]

Amazing how much was crammed into this tube recorder, its unbelievable, I only thought they made things this small when they started transistorising electronics, but this is actually smaller than the earlier transistor cassette players

[@SurajGrewal]

Techmoan and his sentient puppet army has you surrounded... Give it to them or be overwhelmed

[@kevinalm6686]

What strikes me is that though the modern Walkman and this "cold war" recorder have mechanisms approximately the same size, this recorder does it with precision machined steel, aluminum alloy, and maybe some brass or bronze. The Walkman does it with cheap molded plastic. What do you think the chances are that in 50 years It could be refurbished. I would guess a snowball's chance in … LOL.

[@yorgle]

That spiral progress cylinder is the way I remember the speedometer worked in our 1968 Volvo 144. :D

[@russellwillmott5637]

same with our 1968 122s !

[@birdwing98]

My family had an early 60's Dodge wagon that had what appeared like a red line that moved from left to right as speed increased. It was probably a drum which rotated behind a long horizontal rectangular window.

[@crabsodyinblue]

@scott yes!

[@seanbatiz6620]

birdwing98: I own two ‘55 Buick Super 2Dr Riviera’s that are equipped with a ‘Redliner Speedometer’ that functions like this. I believe first introduced by Buick in ‘54. Just a drum with the spiraled red zone contrasted with an opposing black spiral that rotates horizontally and only visible through a thin slit to give the visual illusion of this ‘red line’ filling up this slit, left to right, as speed increases.

[@xcalibre222]

WOW Fran, I'm impressed with that recorder for sure. Ahead of it's time for late 50's,lol. Thanks for the Vid

[@goodun6081]

At 5:40, " I said be careful, his bowtie is really a camera.... they've all come, to look for America....." (That's from a Simon and Garfunkel Song, in case somebody didn't catch the reference. It's the song with the line about hitchhiking all the way from Saginaw Highway. Was that one also recorded by Yes?).

[@PhilipvanderMatten]

yes

[@EskWIRED]

Yes. Yes did a great cover, making the song their own.

[@Toobula]

Good one Fran!

[@robert8192]

When you removed that spanner screw from the back - you voided your warranty... DUH-DA-DUH!!

[@redoverdrivetheunstoppable4637]

that must have a 100 years warranty

[@jk9554]

@@redoverdrivetheunstoppable4637 it was "made in West Germany" after all :)

[@redoverdrivetheunstoppable4637]

@@jk9554 actually i repaired a W.Germany amplifier with a blown NE555 for the speakers delay, only time in my life i saw a 555 in actual appliance... but yeah, those were really good

[@stephanforray4987]

As soon she removed the back screw... all the audio recorded was erased... (Signed: Austin Powel) Ha!!! ha!!! ha!!!

[@misterfixit1952]

@@stephanforray4987 I believe you men't (Signed: Austin Powers) Ha!!! ha!!! ha!!! Mini-Me

[@MultiDesignGuy]

Awesome Fran 👍👏☺️

[@DOCTOR_SONG]

Really amazing little machine! This is the way I like to build things

[@Amp497]

I have one of these units. I acquired it as an 11 year old as a gift-repair, in its original advertising box. Fortunately, I fortuitously did not tear it apart. The unit was saved by the fact that I could not get the one rear main screw out. My unit is in like new condition on the exterior. Unfortunately, I have no accessories. Great vid!

[@stevenhoman2253]

Really curious Fran, are the batteries supposed dry cell, and b leak proof of the time? I used to have a rather fancy transistor radio in the late 60's which had an ever ready 9 volt cell, which had a cardboard shell. Used to extend their life by heating them in the oven. Driving my mother to despair.

[@millenniumtree]

Amazing piece of history, and amazing video quality! Congratulations on the new lab!!

[@Equiluxe1]

A few years later and that could have been Transistor. I have a National (Matsushita comunication industrial co.ltd) four transitor reel to reel tape recorder which my grandfather purchased in the late 50's not quite sure but smewhere around 57 or 58, one of the reels still has a recording that he made of my sisters and myself when we were very young he died in 61, so the recording is before that date and from the sound of the voices the recording was made before 1960 as my eldest sister would have been ten by then and she sounds younger than that. When I I first tried it in the 90's after my grandmother died and I fopund the recorder in one of her drawers all I had to do was remove the old batteries that had leaked and put some fresh AA batteries in , 12 of them and it worked. Since then I have recapped it but dont play it often as i am worried about the tape one day I will have to didgitize the tape before its too late.

[@toonvanderpas7604]

Wow Fran, what a fantastic little machine. And how wonderful to see you firing on all cylinders again!

[@jeffking4176]

Now THAT is cool ‼️ Reminds me of Mission Impossible. Oh, please restore it ‼️ 📻🙂

[@AndrewLohmannKent]

It is much too old for Mission Impossible

[@MrBanzoid]

When I was a kid in the early sixties I took apart one of my Grandad's old Medresco hearing aids. It had three tiny valves in it. It had a huge 1.5 V battery and a 22.5 V one in a big pouch which you kept in your pocket connected to the main unit which was clipped to your clothes with another lead going to an earpiece. I made a headphone amplifier with it. As far as I can remember the 22.5V battery lasted quite a while but the 1.5V one had to be replaced every few days. Compare this to my hearing aids that use a tiny zinc-air cell that lasts nearly a week!

[@eggy68]

That's a beauty. As good as it is, I'm sure Q would provide 007 with a version that somehow eliminated all those bulky batteries.

[@deniskhakimov]

What an amazingly neat workplace!

[@MyNikolaas]

I seemed to see a glimpse of another tube at 22:38, bottom-middle of the picture.

[@KARENOAKESBRANCH]

i think your rite! it certainly was reflective like a glass tube

[@wimwiddershins]

I would've messed up the wire with that tangle for sure. Nice demonstration of care and patience. I was given several working adding machines from the 40-50s when I was a kid. I kinda regret tearing them down for parts, now that I have some appreciation for this stuff. :/

[@HavanaWoody]

it's kinda funny that it uses latex belts and padding along side so much high quality materials when leather might have held up

[@rog2224]

How would a leather drive belt be self tensioning in that chassis?

[@blurrrrrr44]

Those caps might still work, test them. I'm using a century old one in my car. I love how the people of the early 1950s still had so much detail in their work. As for the drive belt maybe you could cut and sand some old tire tube & lap joint it around the large drum until the vulcanizing sets.

[@hi-friaudioman]

Ooooooh Techmoan would be extremely interested in this! You should reach out to him and share!

[@PayrollTips]

Good thing you have steady hands Fran.

[@Wrackey]

This is the kind of stuff that I was hoping for when I subbed to this channel :) I would be very interested to see if you could restore it. I would love to hear it play back something :)

[@misterfixit1952]

Wouldn't it be hilarious if when Fran got it running it played back Thomas Edison saying "Mary had a little lamb...", Just sayin.

[@petertrebing6875]

Danke!

[@boelwerkr]

The bottom of the power block said: _Achtung! Vor dem Abnehmen der Schutzkappe Netzstrecker ziehen._ ===> _Attention! Before removing the protection cover pull the powerplug._ Is there a hidden German fart joke? ;-)

[@MrPeetersmark]

Now that is an amazing piece of tech. I’d like to see more of that!!!! I hope you get it working and show us all

[@fredstocking3812]

You need Minox B to take incriminating pix to go with the recording.

[@nilswegner2881]

I actually have a minox model c in my collection... Sadly the films are so expensive to develop that using it is not justified for me as a 17 year old student

[@seanbatiz6620]

Fred Stocking: Crazy how algorithms work (or, ‘not’ work, in my case). I’ve attempted as much research as possible via the Internet off and on over time, in my quest for learning as much as possible in just exactly how these Minifon recorders function and anything else regarding how to properly repair/restore them, as I myself have collected a fairly substantial number of these units and the adjoining accessories (have at least one of every model made; if memory serves me correctly, I own around 12 of them) ‘but’, just today, discovered this channel and video! Hence the comment about algorithms not working as good as folks might think. Roughly back about the time that this channels creator, Fran, posted this video, I was incredibly fortunate to have been able to find and obtained an extremely rare and original, fully illustrated ‘minifon P55 Service-manual’, IN ENGLISH!!!! It’s dated, ‘EDITION P 55/01 NOVEMBRE 1955’. This info is followed by ‘369’ in large, bold font type (November is spelled Novembre in this literature; possibly something to do with whomever translated the content from german?). On a side note: I’ve also been a long time collector/obsessor (lol) for anything and everything ‘MINOX’ ironically! Have at least one great condition example of each model and variation of models of them and, accessories/literature to boot. I believe that particular collection is at about 25 MINOX ‘spy’ cameras now.

[@InterneteCoisas]

Really amazing Fran!!!

[@el1260]

There is a second tube left from the drivebelt of the motor...

[@hiteck007]

I saw that too.

[@ewaldikemann4142]

Very well made! At 21:04 you can see another tube left of the motor in parallel with the yellow wire. The big capacitor with the red mark is an old ERO brand (AFAIK, they don't exist any more). Obviously a foil capacitor. And the blue one is an electrolytic 6μF/8V. I assume it's a Philips brand.

[@PracticalCat]

Ewald Ikemann noticed that also!

[@jasonbone5121]

Alright now Fran, your going to make me late for work!

[@drasco61084]

Same

[@mrsjohnson1743]

THAT was fun! Thank Fran

[@DOCTOR_SONG]

I see another tube

[@FranLab]

YES! You win the prize! I spotted it in editing, thought it would be a good Easter Egg.

[@DOCTOR_SONG]

@@FranLab :0)

[@redoverdrivetheunstoppable4637]

it's a GU81M ...they sneak there all the times

[@derofromdown-under2832]

Great presentation Fran, and I commend you for taking the risk of dismantling it for your viewers sake... 10/10

[@davidchristensen6908]

It is very elegant design. It is beautiful, thank you for sharing this

[@philipwalker4919]

Thanks Fran. I love your enthusiasm and your sensitivity to this old equipment. I noticed the tube (valve) was from England where I am. Interesting we supplied this highly specialised part to a German manufacturer not long after the war. Show us if you get it working

[@rbmwiv]

Sooo coool very impressive for the time. I had no idea anything that small existed pre transistor.

[@Projacked1]

woah, that circuitry is still futuristic....awesome video! mind=blown

[@nikmilosevic1696]

Very cool first tear down in the new lab!

[@texhunter1820]

Years ago I used to buy a lot of government surplus items. I thought of advertising as "Yesterday's Technology, Today!". I was a caretaker in the graveyard of technology. You have an amazing collection of old electronics.

[@gettingpast4391]

Ok, I am a HUGE fan of old tech. Your detailed analysis and admiration of this old device won me over. I find, repair, and resell old tech like this simply as a way to play with it, admire it, and buy the next one. This thing is AMAZING. Subscribed. Where in the HECK did you find this!?

[@hugeshows]

By now you've probably seen the other tube hiding underneath. Regarding those ratchets, they're likely used for pre-tensioning springs and then glued down when the desired pre-tension is achieved. If you have to undo them, try to gauge how much energy is stored in them for future reference. The construction has a lot in common with German made clocks of that era.

[@GraemeRobinson]

As a sometime repairer of typewriters I immediately thought 'escapement' when I saw those ratchet elements. It seems like a lot of deadweight to leave in the machine just to hold spring tension. Although they are tiny.

[@eliezerriveraperez3810]

Thanks for brought this out,nice. There's always something new to know out there.

[@JerryEricsson]

I would love to see this run! Fantastic machine, I love the old style, and the workmanship put into something like that compared to today's on a chip technology that takes zero craftsmanship to build. Thanks so much for putting this up!

[@pcallas66]

That's so cool. You're amazing at what you do. Thank you for posting this one. Hopefully you'll have an updated version of this working someday. Take care.

[@jonathanpeters1039]

I owned one of these. It belonged to a friend of the family who handed it on to me - this was in the late 80's. He said I could keep the recorder, but he wanted a copy of whatever was on the wire reels (there were 3 reels with it I think). I was into electronics so I was able to power the thing up with three separate power supplies. The rewind mechanism was broken, but it still recorded and played back OK. The reels spin very quickly even on playback - I think the wire runs at over 1 metre per sec. It's so fine though (like cobweb) that a reel still lasts 2 hours or so. The recordings I got off it I copied onto cassette. The gentleman I did this for has long since passed away, but I made myself a copy which I still have. One fine day I'll dig it out and digitise it. The piece he wanted most was a recording of a speech he'd given at a college here in the UK. I got some of it off but the quality was awful, mostly because of the hall acoustics (test recordings I made on it myself sounded much better, about par with a very cheap cassette recorder). Also, at the time the speech was recorded, the motor battery must have been failing because on playback the speed increased gradually until it was unintelligible. If I do ever digitise it I'll have a go at speed-shifting it down again. I sold mine eventually - you might think this a bad decision but we'd recently moved to a very humid part of the country, and the little recorder being in permanent storage was starting to succumb to mildew. I felt it better to sell to a collector.

[@markpotter6186]

That was awesome, thanks Fran.

[@martinh.3058]

I guess the meter @ 13:35 is the motor battery meter. Point 2 of the instruction says: that one has to check it. The indicator has to be in the white area. (and after that there is a remark that if it is too quiet during playback one has to replace the other two batteries).

[@rkirke1]

I only have limited experience with tech from that era (Spent many hours enthralled disassembling a 1950-60s telephone exchange switchboard among other things as a kid), but even by today's standards, that is some impressive attention to detail and amazing engineering. Will be watching keenly for updates on this one!

[@chiquita71]

Thankyou Fran, for an amazing tech history lesson. The sensor & tube detail mind blowing. In awe as ever.

[@keithking1985]

so is that where the saying "wearing a wire" come's from??? Fran always has the coolest stuff... : )

[@jamiej.tilleyphotographyar5177]

I know next to nothing about electronics, but I enjoyed having a look into this little piece of history. Thanks Fran!

[@alasdair4161]

Layers of amazing cutting edge technology in that Minifon. I was also amazed at the quality and condition of the plastic spools, possibly very early polyethylene terephthalate, and like modern PET, it still appears clear and solid. PS, I thought I could spot another tube below and at right angles to the top one. Also amazing that a square shape gave enough strength to hold up to vacuum in a very portable device. Thanks again for posting.

[@zero0ryn]

Did yo notice that the trimmer pot next to the tube was broken? The wiper looks like it had been bent and the track had a piece missing from it :( That tube or valve (as we call them in the UK) looked amazing. I wonder if Mr Carlson has ever seen one of those?