CassetteMaster
GE M8010 R2R Tape Recorder Remote Jack Mod
updated
The Minifon Mi51 first came out in 1951. From 1951 to 1953, they were manufactured by Monske & Co, the original makers of the Minifon. Then from 1953 to 1955, they were manufactured by Protona. The designs are very similar, but different at the same time.
The earlier Monske units (later Monske units were not this way) used a mechanically-goverened motor, with mechanically-adjustable speed. The later Monske and all Protona units used a more common electro-mechanical speed regulator, but did not have adjustable speed. However, the electro-mechanically-regulated motor was much more stable in its speed (the drawback being added "governor noise" in the audio).
This precision-made Western-German unit was, at the time it was introduced, the smallest recorder in the world. It was popular with the CIA, spies, investigators, and the like. The CIA, spies, investigators, and soforth all had the oppurtunity to use DC-bias for recording their subjects. Yes, this unit is DC-bias. Erasure is with a permanent magnet, mounted AFTER the record/play head. So you have to erase separately BEFORE making a recording, but not WHILE making a recording. You can even erase while playing back, such that a message will be heard only one time, instantly erased after it is played.
Here are several weblinks showing interesting websites that showcase Minifon Mi51 units and their history:
Crypto museum, which has history about Monske & Co. and Protona. This site also has links to old CIA documents, including an evaluation of the version with the speed control:
cryptomuseum.com/covert/rec/minifon/mi51/index.htm
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Vintage Technics Russian Website. This website features multiple fascinating recorders with detailed information and pictures:
https://vintage-technics.ru/Eng-Minifon_Mi51.htm
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PRC68 Website, article on Magnetic Recording. It has not only info on the Minifon but other stuff about the Telegraphone and lots of old patents:
http://www.prc68.com/I/MagneticRecording.shtml
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Patent for the Minifon, on the PRC68 site:
http://www.prc68.com/I/MagneticRecording.shtml#2866009
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Red Free Circuit Designs, with the 2W amplifier circuit:
redcircuits.com/Page33.htm
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In 1954 in Australia, the late David Warren invented the Black Box Flight Cockpit Voice Recorder. His inspiration was a Minifon Mi51. Here is a website about his invention:
https://www.nma.gov.au/defining-moments/resources/black-box-invented
I hope you enjoy this presentation about this fascinating device!
And on a different note, I want to mention that Jesus Christ is Lord!
It is DC bias and DC erase. It boasts both automatic and manual level control, switchable--something seldom seen on lower end recorders.
This marvel had to get its pinch roller pressure increased, and also benefitted by the replacement of three electrolytic condensers.
To quote an old GE ad from the '80s: "No one lets you experience it. Like General Electric."
I hope you enjoy this lengthy video.
Music by Modern Art.
Last audio portion shown on the recorder is from a video about almost 100% deposits of sulfur (still flammable) found on what is almost certainly the remains of Sodom and Gomorrah.
This is the Amplifier Corporation of America, aka Amplicorp, "Magnemite" tape recorder, model 610 DV. The Magnemite series spring-driven portable reel-to-reel tape recorders came out in 1952, a whopping 44 years before Pokémon was introduced in Japan in 1996 and 46 years before Pokémon's introduction in American in 1998. In other words, Magnemite was a tape recorder long before it was ever a Pokémon. And considering catching them all, there were quite a few different models of the Magnemite available in the '50s:
steampoweredradio.com/pdf/audio%20devices%201959_1960%20tape%20recorder%20directory/1959_1960%20tape%20recorder%20directory.pdf
The link above shows many models they made. It is possible this model with the meter, aka the "VU Magnemite" may have been more around 1955 than 1952 (I need to do more research) but the original non-VU metered version of the Magnemite came out in 1952.
The Magnemite series was available in single-speed units ranging from 15/16 IPS (with a terrible frequency response) to 15 IPS. There was a multi-speed model, that had no meter, but all the models with a meter had a single speed, and you had to order it to that speed. They were also available in either half-track or full-track, and there was even a stereo version produced.
The model shown is 7 1/2 IPS, full-track mono (a format I am becoming more and more fond of). There is no erase function, so the tape has to be bulk-erased. Rewind is performed manually.
This is a spring-driven recorder, therefore no electric motor is used. You wind it up, like a music box. Due to the geared spring mechanism being flutter-prone, an external flywheel (looking like a steering wheel) is included, which greatly helps in speed stabilization.
This vacuum-tube/valve recorder is AC bias, running off a 1.5V filament supply and a 90V plate supply, and also another 1.5V cell powers the little light that indicate when the spring needs rewound. When that light turns on and off rapidly as the mechanism slowly starts or stops, it electrically induces a very interesting and rather satisfying static sound!
This unit previously had work attempted on it, with the capacitors replaced, but I had to do additional troubleshooting to get the unit to amplify again. Still needed is to send the pinch roller off to get new rubber and to install a balanced microphone jack on the side, but that is for a future time. Even with the current pinch roller, the machine is performing rather well, and it is just a pleasure to use this machine! I can't thank you enough, Ed!!
It is fun to bring to show friends this machine, and record music on it with them. In the future I will upload some songs, recorded live using this delightful piece of 1950s technology!!
Three machines have been gifted to me. Let's see what they are!
Long rants and responding to text messages and dropping screws left in video. If too long, you can skip to different parts. (PROTIP: The left and right arrow keys on the keyboard move you back and forth 5 seconds. 'J' and 'L' keys move you 10 seconds, with 'K' or Space Bar acting as a Pause key).
The three units include a Nakamichi 600 II cassette deck, an Akai 4400 reel-to-reel deck (2-speed, 4-track stereo), and the Magnemite 610 DV reel-to-reel portable tape recorder, full-track mono at 7 1/2 IPS, and SPRING DRIVEN!!!!!!!!!!!1
Keep checking for more videos. I need to get back into it. I have been going for too long times not making videos. Although not fixed in the video, I have as of writing this video description got the Magnemite recording and playing. The mike input is currently not working, but the hi-level input is. The VU meter is working for record level, but not for playback level. Still more troubleshooting to follow. So far it has been broken wires and even a broken pin off a tube socket, causing a failure of the bias oscillator.
This device is 5-transistor, DC bias, DC erase, with manual level control (no VU meter). The amplifier runs off 9VDC. Only one slightly leaky capacitor had to be replaced, even though it was good enough for the amp to still work nicely off all original parts.
Sadly, the original crank is gone, so I am using an M8 x 1.25 bolt with a ratchet to wind the recorder. For maximum wind you wind it with about 50 rotations (the max I have got it was 55, but once it gets hard to turn, don't push it!). It will run for a few minutes before petering out. One nice thing is that it can be wound "live", that is, wound while the unit is running. That way, if someone was recording a speech or something that went for longer than about six minutes or so, another person could be winding the machine to keep it running for longer.
Tape speed is 3 3/4 IPS. I did not mess much with the little speed control it has, as I have once, and when going to the max, it starts making a "clink-clink-clink..." sound and I was getting afraid I might mess up the mechanism, so I want to leave that alone.
According to an online source, the recorder's spring motor was manufactured by Garrard (known for record players) in England. So this Japanese machine has a touch of Britain in it.
P.S. If anyone knows more history of this model, please let me know. Another source claims it is "military", but I highly doubt that, being that this is NO where near anything MIL-SPEC.
Another thing of note is that the circuit board in this, although looking like a regular PCB on the component side, is actually not a printed circuit board. On the other side, it is point-to-point wiring with bare wire for some connections and component leads going to anchor points. The transistors of course are germanium, and thankfully, none of them were noisy.
This unit has a fast flutter in the audio thanks to the gear-driven design, but otherwise, the sound quality is rather decent. Sure, a little muffled, but still it has a pleasing tone with low distortion. The bass sounds pretty good, and there is little to no "DC bias 'S'". Treble response is there to some degree, especially noticeable playing back recordings of music from this on a different machine (sorry, not part of the video).
Fun recorder, and I LOVE the grey.
And the music, OBVIOUSLY, is NOT by me. It is by Twilight Ritual, amongst my most favorite bands of all time, hands down.
AC bias
DC erase
Recapped the amplifier. Uses six germanium transistors: 5 for the amp, 1 for the bias osc. Lubricated the pinch roller bearing; the rubber's hard as a rock.
Silly machine uses a very small oval speaker. They could have used a much longer oval. Oh well.
***---LYNX---***
Zap Aura:
https://vocal.media/authors/zap-aura-the-hyena
Music---3 3/4 IPS:
youtube.com/watch?v=BXclun8oYDI
Music:---1 7/8 IPS:
youtube.com/watch?v=98k3SZ4ySBU
And if you check out the compilation this music is from, it will BLOW YOUR MIND if you are into this kind of music!!!!!!
So so sorry I have not uploaded in over SIX MONTHS. Time FLIES. ABSOLUTELY FLIES. LIFE JUST RUSHES ON BY!!!!!!!!!!!!!
These are two very similar looking, but different designs (probably made by the same manufacturer) rim-drive DC bias reel to reel recorders.
The first is an Electra TC-501, single-motor machine.
The second is a Ross Mark 85, a dual-motor machine.
Link for the Amiga Music:
youtube.com/watch?v=gm2b9vuRG3o&t=9574s
Recorder from 1962.
Link to music:
youtube.com/watch?v=gm2b9vuRG3o&t=9574s
This recorder records voice will with a dynamic microphone, but sucks with a crystal mike.
ALL-METAL construction, except for the Plastic handle.
Single speed-7 1/2 IPS. Full-Track Mono.
AGC/ALC/Compressor/Limiter--what ever you want to call it recording level control with two selectable sensitivites.
We have a really cool guy phone in, called Zap Aura. He has been featured in some of my past videos, and is now on air!!
This was filmed at the JTRadio Studio, not my studio. I was on a trip to visit SpeakerFreak95.
Zap Aura is a science-fiction writer and artist. You can find some of his literary works on Vocal.Media. Here is a link:
https://vocal.media/authors/zap-aura-the-hyena
Ricky Radio, from the KlineCo. Studios, brings you silly goofin' about.
Ricky interviews James (Terrilmob on YouTube, here is a link to his channel):
youtube.com/user/Terrilmob/videos
James interviews ZAP AURA, a writer amongst other things, link to him on Vocal:
https://vocal.media/authors/zap-aura-the-hyena
And a funny, odd telephone call occurs with George and Gabriel.
This video even has featuring of Hank Hill, Bob Ross, and a certain well-known figure who if I mention him could bring backlash from the opposite direction to the right. Let us simply say he has an interesting hairdoo and has a thing for the color orange.
I hope you enjoy this vidya.
DISCLAIMER: MUSIC BY AC/DC, NOT ME! PICTURES FOUND FROM INTERNET. BEAVIS AND BUTTHEAD AND KING OF THE HILL AND HANK HILL FROM THAT ARE MADE BY MIKE JUDGE, NOT ME. DUHHH!!!!!!!
Audio level is around -20db. I.E. 0dB on the UV meter is -20db on the computer. Soundboard is a PR&E AMX-18. Microphones are Electro-Voice RE20 and a Shure SM58. Mikes processed using Symetrix 528E VOICE PROCESSORS. Telephone system is closed circuit simulated landline, using the home's telephone wiring, a nine-volt battery, and a Gentner Digital Hybrid 1 to take landline signals to the soundboard (and separate the send and receive of the telephone). The noticeable grainy carbon microphone can be heard. Although on of the telephones on the circuit has a condenser mike.
This fascinating piece of German Engineering came out in the year 1958. Yes, one of those few times you see a PORTABLE BATTERY-OPERATED recorder from the FIFTIES, a rare breed that I want more of. Especially a Butoba spring-driven wind-up vacuum tube portable reel to reel, one of the models I want the most out of all, but I digress.
This unit is a two-transistor recorder, with germanium gransistors. It is also DC bias, and permenant magnet erase. Amazingly, unlike ALL other DC bias recorders I have encountered whether reel or cassette, this is the only one I have ever seen to natively in its design include a trimmer potentiometer to adjust the DC bias voltage. That amazes me. Many times I have tweaked the DC bias voltage of reel to reel portables, by changing a fixed resistor.
This machine works off original parts but needed some TLC. I did put a piece of thin cloth to raise the level of the supply reel table as its rubber was scraping against the plastic case causing friction. I had to adjust the pressure holding the motor's spring so it pushed up enough against the reel tables.
Original capacitors are good, amazingly enough.
This unit comes with a CARBON microphone. That is a win. I love carbon microphones.
I hope you enjoy this video. Yes, I know. It has been over three months. What a terrible person I am.
Gabriel, a good friend of Zap's, interviews Zap IN STUDIO. Gabriel operates the PR&E AMX-18 sound mixing console, quickly learning the basics after I showed him a little about setting the levels.
Zap promotes his Vocal website page where he posts some of his written works. And he is a very good writer. I have read his works, and he is an amazing author.
Here is a link to his published writings, under the name :
https://vocal.media/authors/zap-aura-the-protogen
The song for intro and outro were recommended by Zap and Gabriel--the Caillou Remix of the Caillou cartoon. It was played off YouTube from the computer, through the soundboard, and back into the computer to record it in the interview's audio. DUH, I AM NOT THE AUTHOR OF THE SONG, I DO NOT CLAIM TO HAVE MADE THE SONG, yadda yadda yadda.
The video portion had it's original audio muted and synchronized to the soundboard's audio. Sorry the video part was so short, I was originally only recording the audio and thought after the fact to grab my camera to get video footage of the event. Gabriel really enjoyed using the Soundboard!
Byinshi mu majwi yiyi videwo biva mubyuma bifata amajwi ubwabyo, bigahuzwa nijwi ryumwimerere. Mikoro ikoreshwa hamwe na majwi ni SHURE SM57.
Nibintu bihendutse byandika, kandi ikoresha DC premagnetisation, kimwe na DC gusiba.
Ariko, iyi ni capstan yerekana amajwi. Irashobora guhagarika 6VDC yinjiza hanze cyangwa kuri bateri enye 'D'.
Nizere ko wishimiye iyi video !!
Nyamuneka tanga ibitekerezo, dusangire, kandi wiyandikishe kumuyoboro wa CassetteMaster.
I shot the video on my phone, then synchronized the audio with the audio from the tape recording, and muted the original video's audio. All sound in this video is captured with the Dokorder, including the "seagulls". The Seagull picture is not by me, but found off the InterWebz.
I am by no stretch of the imagination a sportsball fan; sports never interested me. However, it is good to spend time with people, and I thought it would be fun to try seeing how video footage of the game would be like with its sound coming from the Dokorder reel-to-reel tape recorder from 1962! Its the 1960s meets the 2020s.
I also have a video about this tape recorder, uploaded before this one. You can see it on my YouTube channel.
This six transistor tape recorder is very nice. Its bias will be revealed in the video. This unit is from 1962, as I found an article online about it in a British magezine. It was early enough in 1962 that this recorder might even date to 1961.
This unit works on original parts, but I modified it so only the motor would turn off when the remote switch was turned off. I also installed NiCd cells, and built a battery charger for the recorder.
This two speed recorder is manual level control only. Frequency response is 200Hz to 7kHz. Its cousin, the PT-4H, uses manual rewind and has no meter. Its response only goes to 5kHz.
Music presented in the video is NOT BY ME, DUH!!!
First is an excerpt from the album "Castles of Sand" by Jim Kirkwood.
Then is an except from the album "Desert Island" by Cusco.
Third is an excerpt from the album "Kaleidoscopic World" by Michael Law.
Currently, it is loaded with two microphone channels and ten line channels, and I have a spare mic channel and some line channels sitting around that I can install if desired. Plus a few extra EQs.
This is a trememdous gift from Jordan Tuck (SpeakerFreak95) for my 30th birthday, as he is changing his studio to physically smaller Wheatstone equipment.
This studio includes the Console, the Arrakis furniture, and a pair of JBL model 4312A 3-way control room monitor speakers. Oh, and other rack-mount equipment to follow.
I do not have it entirely setup yet; it is a work in progress. I will be setting up more equipment as time permits...
It is a fantastic deal to get, that is for SHURE!! (pun intended)
The models:
M-8020A (rim-drive)
M-8010
M-8130
M-8040A (aka the "Swinger")
Three of these recorders already have videos on my YouTube channel:
M-8020A:
youtube.com/watch?v=VKXLOOZf1V8&t=707s
M-8010 (and M-8070A, a similar machine):
youtube.com/watch?v=F50BdLcPOwM
youtube.com/watch?v=yTBSw_APZag
youtube.com/watch?v=_kdhFMkvHf0
M-8040A (Swinger, parts one through three (2009):
youtube.com/watch?v=p1U-hCLDV_w
youtube.com/watch?v=77JNHJIubls
youtube.com/watch?v=QJNuoja9SNc
youtube.com/watch?v=5oMOYHJa530
Magazine Article (only has a small snippet about this a GE M-8000):
books.google.com/books?id=KCkEAAAAMBAJ&pg=PA46&lpg=PA46&dq=general+electric+radio+receiver+dept.+utica+ny+m8010&source=bl&ots=DdkkclNU_Z&sig=kk4OYSARsI9Mc3HN27zrv_FcDzc&hl=en&sa=X&ved=2ahUKEwj-v_z61s_cAhWBTN8KHTbuCNIQ6AEwBHoECAcQAQ#v=onepage&q=m8010&f=false
The M-8130 was acquired this year, so this is its first appearance on my channel. I plan to do two more videos on this recorder, one that shows the insides, and another as a "Maurice Presents", done in Rwandan!
All four of these machines are DC bias, DC erase. Another interesting note is that these all use SILICON transistors, which although are ubiquitous today, were at the time these were made, less common. Back in the '60s, Germanium transistors were most common, and the grand bulk of my collection of 1960s tape recorders use Germanium. Yet all of these GEs use silicon transistors, with some of them if not all, made by Fairchild Semiconductor.
Another interesting thing is that, as far as I can tell, these recorders are American made (though many parts are imported). The low cost these machines were was to compete the Japanese tape recorders. I believe the cheapness in construction of these recorders in competing was due to higher labor costs in the USA than in Japan. So these used much plastic, even in the mechanism (save for the M-8130A, whose metal mechanism is still as bare-bones simple as possible), and DC bias (to save on the extra electronics needed for a bias oscillator). Even low-cost Japanese capstan-drive recorders at this time almost always had well-built metal mechanisms.
I believe these four recorders showcase the only four varieties of BATTERY operated General Electric tape recorders. There were many models, more than the models listed here, but as far as I have seen online, all of the GE battery-powered recorders are a variant of one of these four basic designs. If there are any other GE battery-operated (no AC-only recorders, because there are plenty), please shoot me a comment and let me know, because I am very curious. I would love to know as much history I can on battery-operated General Electric reel-to-reel tape recorders from the Radio Receiver Dept. in Utica, NY.
These may not be the highest quality machines in the world, but I love these; there is just a certain charm to the GE recorders, and they all share certain traits in common, including GE's strange use of oddly thick wires inside when they did not need to!
Music played on the M8130A by John Bender, a most fantastic musician.
This is a YASHICA tape recorder, made by YASHICA, known for their film cameras. They did make radios and tape recorders, too, but they are more rare than their cameras. This site mentions some of the stuff:
yashicasailorboy.com/tag/yashicorder-77
This recorder uses a rim-drive mechanism manufactured by COPAL, another camera manufacturer, which also made shutters for some of Yashica's cameras. The same exact mechanism used in this recorder is also used in the Standard Unicorder 88 and 89 tape recorders, and the Yashica 77. The same button-switch mechanism is found in a LLOYD's rim-drive recorder, and another similar model I saw on eBay once (don't remember the brand or model, but it was very similar to the LLOYDS).
Link to my video on the Standard Unicorder 89:
youtube.com/watch?v=N0Lw_y3RfGg&t=409s
Link to my video on the LLOYDS:
youtube.com/watch?v=GhHZm68CAAE
Rim-drive technology is an inferior technology to capstan-drive, only pulling the tape from the takeup reel. They have a constant _angular_ velocity on the takeup reel, such that the linear velocity of the tape (normally constant for a capstan-drive machine) continually increases slowly as more tape accumulates on the takeup reel. Most rim-drive machines were built to a price, and the drive systems typically had the motor shaft directly against the rubber rim of the takeup drive wheel. That combined with no motor governor to regulate the speed of the motor greatly contribute to wow and flutter problems (more wow in this case) with your typical rim-drive recorder. BUT!!! The Copal mechanism is very different than most rim-drive recorders. Yes, still constant angular velocity, but it uses a high quality governor-controlled motor with a belt-driven flywheel, which then drives the rim of the takeup drive wheel. The result is not only considerably more torque, but a lot more stable speed. Yes, rim-drive, but very low wow and flutter. The Copal drive system used in this one is surprisingly well-made and solid, which for a lower-cost rim-drive system is a bit odd.
Unfortunately, the circuitry is a bit lacking in this one, only four transistors (PNP germanium), and DC bias recording. There is plenty of DC bias 'S' with this one, the strong distortion in the sibilants in speech, although with some de-essing, or other conditioning of the incoming signals, it can sound a bit better.
I had to replace the amplifier's electrolytic capacitors, as it had very weak sound when I first tested the recorder. Then afterward I found the recording quality was atrocious, with heavy distortion, especially in bass frequencies. It was a particular distortion, a dead giveaway to the bias voltage not being correct. Increasing the bias resistor from 25kΩ to 39kΩ made a tremendous boost in recording quality, although there is still plenty of "DC bias 'S'", likely due to the pre-emphasis of the high frequencies during recording to try to get better frequency response.
I am on the lookout for a Yashica Yashicorder 77, and any other Yashica recorders or especially, recorders using this particular mechanism or even just the same button-switch system like used on the LLOYDS (I am beating myself for not getting that one I saw on eBay; it was a while back).
Here, finally, is another mechanical pencil video by the CassetteMaster, presented by 5KB productions.
Sony EVO-210 8mm VCR used to record this composite-videoed video.
Shure SM58 microphone for the voice
Sony lapel mike for the pencils
Shure M267 Series mixer with limiter
Sony Handycam DCR-TRV103 (just using the camera), and as pre-amp for lapel mike
CONTEC KRB-1541 portable TV/Video monitor
A number of pencils, from brands including PENTEL, BIC, PIERRE CARDIN, PAPER-MATE/SANFORD, VENUS, TOMBOW, and MORE...
Thanks goes to JORDAN (SpeakerFreak95) for the CONTEC video monitor, Shure mike and mixer, and mike stand, and The GOOGLE COFFEE CUP!!!
RADIO SHOW OF ME AND SPEAKERFREAK95 DOWNLOAD:
mediafire.com/file/rynid8bhoximcvm/New+Years+Show+2021+-+TRKE+-+JTRADIO.wav/file
This speaker is a scapegoat, or a "scapespeaker" for the horrible year of 2020. In honour of 2020 coming to a close, Jordan did the Last Rites of this speaker, blowing it out, once and for all, but not until after writing "2020" on its cone.
The destroyed unit was a Realistic MC-800. Please don't stone me!
The song at the end is a song I made earlier this year called "Corona-Scare". Jordan and I will be doing a "radio show" tonight for the turn of the year, where I play more of my "hits" (many that are not on YouTube), and I will put a link into that once it is uploaded, into this description box.
Shoutout to Lord Dookster!
RADIO SHOW OF ME AND JORDAN PLAYING MANY TRKE SONGS DOWNLOAD:
mediafire.com/file/rynid8bhoximcvm/New+Years+Show+2021+-+TRKE+-+JTRADIO.wav/file
The telephone audio was tapped directly from the "line" through an isolation transformer, and sent to the Sony TCM-5000EV cassette recorder. I thought it would do a better job with keeping up with sync, but I had to keep tweaking the placement of the audio in the video to keep it from getting way out of sync. Yeah, I know I could have hooked directly to the camera, but I wanted the audio to come from analog tape.
And don't worry, there will be more tape-recorder videos coming. I have not been in a "video mood" for a good while; my apologies.
Finally, thanks to YouTubers axie and Mylifeis4me, the identity of this song has been found!
Here is the previous description before finding out:
I have no idea who made this wonderful piece of music, nor the actual name of the song. Perhaps the YouTube detector will put up the title and band.
I recorded this onto cassette off the radio back in 2010. WHAT?! THE RADIO?! Radio doesn't play cool, obscure music like this! Well, KABF 88.3 is the exception.
Minimal wave goodness.
After requests to upload this song, that I played on a Sony reel-to-reel on a video uploaded years ago, I finally upload a direct transfer, from a rather poor quality cassette tape (I should have put a better quality tape in the deck. Oh well).
No, I am NOT the author of the text nor the circuit design! I am reading from the manual.
The circuit board shown in the video with resistors and the 7-segment display in it is from an original kit.
I don't know the year of this one, but it is no later than the 1990s. Probably from the 1980s or 1990s.
I don't know the year of this one, but it is no later than the 1990s. Probably from the 1980s or 1990s.
Sorry about the hiccup edit in the early part of the song, that tape we had for years, and as a child listening to it, I accidentally hit record on the stereo for a split second, so tried to edit that part out on the digitized transfer.
Inside, it is labeled "Sample F". Sample, eh? No serial number? I believe this is a prototype unit(!), one of at least six (I mis-counted in the video and said five, I must have subconsciously thinking of grade letters skipping 'E') made (assuming there were Samples A through E). I don't know if any of the other samples still exist or not.
I found this at a hamfest years ago, and have not done much with it for a long time, with it sitting in storage in my garage in a box. Finally, I pulled it out again and desired to get it to operate. It had an overheating mystery audio amp IC (they scratched off the part no.), so I jury-rigged an LM386 IC in there (the pinout was almost the same, but slightly different) and it works now. Original electrolytics are still good. Some tantilums were high-ESR, but still OK. I ended up using them as I did not have capacitors of the same value on hand (and they are used for timing functions, not audio).
This is a phun device for speakerphone! A condenser mike picks up your voice, and sends it, amplified to listenable levels, to the telephone line. When audio comes in from the telephone line to the device, it senses the presence of a signal, switches from the microphone to the speaker, and out comes the voice on the other end. When the person on the telephone stops speaking, the lack of audio signal causes the device to switch off the speaker and back to the condenser microphone to pick up the guy using the Speakerphone.
Now this is not the first speakerphone to exist. The original speakerphone was invented in 1948. And there were plenty of MA-BELL Western Electric speakerphones. But this one is special, as it was a product that as far as it seems, never went into full production. It is a rarity, and really cool.
I know, some of you are probably raging at me because I replaced a part in a prototype, even jury-rigging a different IC in a socket. I am aware that it is no longer 100% original, but I was more interested in having it be functional than just serving as a paperweight.
I just LOVE carbon microphones:)
I got this at a flea market while in Louisiana on a trip visiting SpeakerFreak95. Still works off original parts (though sometimes I have to free the bell ringer from getting stuck). I lubed the generator shaft and gears, and cleaned some contacts.
This video features some phone calls at the end of the video, so I recommend you listen to them. This phone was hooked to a Western Electric WE500 C/D rotary telephone. To make it work with the field phone, a 6V battery was fitted in series with the WE500's carbon microphone, as the FF33 has a decoupling capacitor in the audio circuit, blocking DC.
The first call is with the man Gabriel, a rebel, breathing in a manner reminiscent of The Zodiac Killer. Then, a more pleasant conversation with my friend Maurice, of "Maurice Presents" fame. Maurice first talks on the WE500 with me on the FF33, then we trade places. All audio in the phone-call section is direct from the telephones, recorded with a Sony TCM-5000EV, then synchronized to the video.
Remember, I am not the author of the circuit nor the text. I am reading the manual.
A basic latching circuit, using a relay.
Spometimes, I can't keyboard. And I get tired of correcting typos.
I am NOT the author of the circuit nor the text, I am reading from the manual.
I have added a Sonalert II beeper to the circuit on the relay contact side, as a better indicator than just the click.
Light to the photocell activates the relay. Sensitivity adjustment provided by the 50kΩ potentiometer.
AC bias, freq response 100-7kHz, two-speed, and has pitch control and mechanical pause, cue and review, and a tape counter. Runs on four C batteries or 120VAC.
So almost 20 minutes of video and no inside shots? Remember the instructions regarding the gun? I think you get the idea...
Music in video NOT BY ME, that should be OBVIOUS, save for the music at the beginning and end of the video.
Video by ~COUGAR PRODUCTIONS~ in HONOUR of WINDOWS 98.
It's not Pierce, it's actually Peirce!
The recorder is AC bias, AC erase. Microphone used is an Electro-Voice 635A.
But years earlier, in around 1962 or so, APOLLO INDUSTRIES had a very special tape recorder. The APOLEC RA-11 transistorized portable rim-drive reel-to-reel tape recorder. The RA-11 and similar variants of the basic design were extremely popular, simple-design, basic tape recorders. A "bare-bones" tape recorder, you could say.
I have two RA-11 units in my collection. One I got back in 2011, the Apolec RA-11, and one I get just recently in its original box in (near, but not quite) mint condition. First, I noticed the units were a bit different in color schemes. My recent acquisition, the Apollo Industries labeled unit, was a 4-transistor unit--very typical for rim-drive units. But the other RA-11 I got back in 2011 is a 3-transistor unit, and each unit has totally different speaker types, too! Also, the Apollo Industries labeled one has an additional brake for the reel tables.
It is interesting to note the significant differences between two recorders that are both known as the Apolec RA-11, but only one bears the grandious name of APOLLO INDUSTRIES.
Both are DC-bias. What do you expect?
Don;t worry, I will be doing more tape-recorder videos soon. I have some more units that have not yet been videoed. As to the typo in the word "don't" using a semicolon in place of an apostraphe, no, I will not correct it. Nor will I look up the correct spelling for "apostrophe".
I am not the author of the text nor circuit design. I was reading from the kit manual.
Keep in mind the second paragraph in the text is a copy-paste mistake from project 49, courtesy of the original author(s) of the manual.
DISCLAIMER: I am NOT that author! I did not write the text, nor design the circuit.
AC bias, AC erase.
Frequency response is 250Hz to 5kHz, though I think perhaps it can record lower frequencies than 250Hz, though I have not verified that with a signal generator.
A fascinating collector's website of tape recorders, with its entry on this model recorder, is linked here:
http://vintage-technics.ru/Eng-Topaz-D202.htm
Remember, the music shown in this video is NOT BY ME! It is presented to show sound quality of this machine's recording.
Hope you all enjoy this recorder's presentation. It is long, that I am aware. I chinwag a whole lot, and some has even been edited out completely, because I chinwag so much. The first part of this video has the descriptions and presentations on voice recording and music recording, then followed by footage of the inside of the recorder, showing the mechanics, electronics, and some description of part of the circuit where I had to troubleshoot the Automatic Level Control (ALC) that was not working properly.
Original belts still good, but needed some new capacitors, and a different value resistor to keep the amp from drawing too much quiescent current.
And you'll see it is surprisingly easy to power this recorder from two 18650 Lithium Ion cells, as opposed to the six C cells. But keep in mind a fuse, as if anything were to short out the rails of the power supply, and short out the Lithium Ion battery, it could result in a fire.
I am not the author of the project text nor schematic. I am reading from the manual.,
This machine uses a 3-phase brushless motor, with special driver circuitry. Information of this model's (and some other Soviet cassette recorders) history is provided here:
weekly-geekly.github.io/articles/442358/index.html
Music link:
youtube.com/watch?v=3MBBlrGxL_E&list=FLhebXLWtkSERZkByHc0Q9wA&index=35&t=1696s
Very cool recorder, good sound quality, except that mine has extreme flutter. AC bias, AC erase. Two-speed. At standard speed, the freq response is 63Hz to 10kHz, and at half-speed it is 63H to 5kHz. And thankfully, it changes the equalization for half-speed. Manual level control. Runs on six D cells or external 127V/220VAC selectable mains power. Speaker has really good bass. Amplifier selectable between 0.5W and 1.0W max output apparently.
I am not the author of the text or the circuit. I am reading from the manual.
I am not the author of the text nor the circuit design. This comes from the 200 in one kit's manual.
I am not the author of the text nor the circuit. I read it from the manual.