I have the Japanese version of Sanyo M-GT7 "The Outsider" - the MR-U4M "Marine Sports" Everything works, only the tape speed is to slow. Does anybody know, if there is a screw or a variable resistor that I can turn to adjust it? Or does someone have the service manual for M-GT7? Thanks
OK, found it by myself. There is a screw on the motor, that can be turned. To the right - faster, to the left slower.
That is a very good looking radio in the red colour. It tunes up to 108MHz as well which is more than some early European and Japanese Radios. Well done on the repair.
How about that? A Japanese-market boombox (or, in this case, "mini-box") that tunes from 76 MHz to 108 MHz -- familiar to residents of that kingdom or to users of her domestic tech -- and tunes shortwave in two bands and tunes the audio of television (TV) channels. Certainly atypical (right down to the black strap replacing a traditional, solid carry handle). And, if I may say so, rupi99, even more striking than your still-fetching Hitachi TRK-6700H. As others say: good going with your promptly finding and applying the motor-adjustment tape-speed solution.
I've been wondering about the tv/fm band and will have to ask my friend when he visits. I'm guessing the tv band is up there were we get fm, so for other markets they just throw it in since it's more economical. I think I have a few around here that I really didn't try out enough to see first-hand. I love the screw adjustment, it's not on every motor but it helps out, did you tune it by ear?
You are right. To have AM, SW and FM at a Japanese domestic boombox is not typical. They have mostly only AM and FM. The real FM Radio frequency band in Japan is from 76…92Mhz (at least in the past). So, in boomboxes from the 70’s you find only these frequencies (e.g. Victor M70, Aiwa CS-J88) I think, beginning of the 80’s they extended the FM band with analog TV channels (1,2,3). These TV channels are between 92…108MHz. Luckily with this change the old boomboxes are usable also for European and American FM radio. See here the closeups
For the speed alignment I used an old universal adjustment cassette. There is a frequency recorded (I think 3000kHz) were you could adjust it with an oscilloscope. But additional there is also a signal with a predefined length for those, that don’t own an oscilloscope (like me). Together with a stop watch I adjusted the speed so, that it has fitted to the defined signal length. It took some trials until it was perfect.
I am not a technician or "savvy" with electronics. But I think that rupi99 meant "3000 Hz" and not "3000KHz" in his October 5, 2018 reply to the message of the same date from Mister X . A 3000 kHz signal equals a 3.0 MHz signal: a shortwave broadcast, in effect! (Well, probably navigation-related; probably not much by way of news- or entertainment-related programming ) I seemed to remember seeing people selling 3000 Hz speed-calibration audiocassettes on eBay. And I certainly found some sellers of them on eBay tonight. This is maybe the second time that I have found sellers of those speed-calibration tapes. They often seem to cost quite a bit of money: dozen of American dollars. Perhaps the reason for such prices is compensation for the labour and expertise to open up the sound system and then connect sound cards to its cassette-deck mechanism and to calibrating computers while the cassette deck connected to the sound card plays the speed-calibration cassette. (Or thereabouts.)
I'm just going by my old memory but K=1000, M=1,000,000. The calibration tapes are ultra expensive because they were made for a very limited group, mostly tape duplicators or repair shops. The tapes themselves have to have the smallest amount of recording error on them so they can be used to determine if the tape equipment being tested has speed fluctuations, typically defined as wow and flutter. The equipment used to make the tapes was the best possible and calibrated at regular intervals.
Wow, I'm a technician, and made this mistake The "k" of course has to be removed. 3000kHz is already ultra sonic This is the tape, that I used for calibration. I used (2) and (3) which had a total length of 100s. Every second would be 1% speed deviation.
I've now started to wonder: in the digital-based Internet Era and in the Social Media era, does the TV channel on certain audio systems such as rupi99's good-looking Sanyo MR-U4M still receive audio broadcasts? A check minutes ago on Wikipedia indicates that frequency modulation (FM) and TV broadcasting were/are done in very high frequency (VHF). I suppose that the technology used for FM broadcasting (between 88 MHz and 108MHz in the U.S.) is the same technology used for commercial TV broadcasts, including the audio of such programming?
I think it was a lucky coincidence that the Japanese VHF TV band was the same as the American FM broacast band and that both used FM sound. I suspect that a radio with a wide fm band like that could receive the sound from American Low VHF TV channels 5 and 6 on 76 and 82MHz respectively. Of course just about everyones TV has gone Digital nowadays so there would be no chance of picking up TV sound. The Norweigans don't even have Analogue Radio any longer although I saw some surprising figures on how many cars there don't have Digital Radios fitted, probably due to the difficulty of fitting a new radio in most modern cars.
https://buyee.jp/item/yahoo/auction/p1117524347 Good condition! SANYO MARINE SPORTS MR-U4M Marine sports stereo radio cassette player Sanyo Showa retro with AC adapter Stored indoors with additional images Current Price 19,000yen (US$139.46) Closing Time (JST)20 Dec 2023 21:51:39 - recent sold listing
Why is this model going for so much? I've got the USA Yellow Version, yes I love it, the build is wonderful and they are kind of cool looking but they don't go for much over here.
Just now I won this - nobody wanted it as it is missing the SW-fine tuning knob. I do not listen to sw so it dont matter to me but the price was right I think in these times. This is a model where the cassette deck has to work, otherwise why have it just for the radio? Vintage Sanyo boombox The Outsider MGT7 M-GT7 AM/FM cassette - READ DESCRIPTION US $39.99 actually with tax 43.29 & free ship so yes. https://www.ebay.com/itm/156017358579 07 February 2024 so that link will be valid for about 3 months or so from this date? I have the belts, Knowledge to repair, and this can sound fairly good for its size, so I have stuck my neck out here again. I never knew this model could be had with sw and maybe a can find a knob for the sw fine-tune that will fit in there or I will just block it off. yes I still have the sickness of buying these cassette players.
