Thank you for taking your time to post this one Tony! Just looking at the real estate inside this tuner makes a person want one for FM listening. You mentioned the designers stretching the limits of the technology of the time, I wish all brands made the top 2 or 3 levels of their tuners like this. FM listening then (70's & early 80's) was very different from what it is now though.

@JCWise-sf9ww

2 жыл бұрын

FM sure has changed for the worse since the 60's, 70's & 80's

Tony, nice job! Thanks for putting this video together. I learned something new, "always start with the power supply."

No matter the outcome, the journey is always the most important thing, and, as always, I found this to be very interesting. A big cheers from the azores, Portugal! Your friend, Marco!

Thank you Tony. What a beautiful tuner. 😍 Looking forward to the Lafayette.

I thought it was a great explanation all the way through! I learn new stuff every time I watch your vids, and I appreciate the in-depth explanations you go though.

Great session, enjoyed the adventure. Thanks for the look.

Hi Tony, great video, I was a HiFi salesman back in the day when this was a current model in the Kenwood lineup. They sounded fantastic, and the matching integrated amplifier was no slouch either.

The biggest problem is that the FM broadcast is practically dead by now. A lot of stations still, but everything is overcompressed, mutilated and littered with commercials that are twice as loud as the music. With very few exceptions, the format is dead. Very good study on a fantastic piece of equipment though! Thank you, Tony, for all the hard work!

@lornespry

2 жыл бұрын

I think NHK in Japan is still OK. Some broadcast has better sound than others, but each region has a clear signal and good stereo separation.

@johnparichuk8367

2 жыл бұрын

I have to agree with you. I just brought two H. H. Scott AM-FM vacuum tube tuners back to life: a 333 and a 333B. These are beautiful tuners, but the FM broadcasts for the most part are horrible. With the dynamic compression, the bass is overwhelming. The exceptions seem to be some classical and jazz stations.

Great episode, just as you said "it looks like a storm coming in " we had a big clap of thunder here in the south of England and it started to pee down, that was spooky and yep that was a jump scare. The demo with the Pre Emphasis was very distinct...cheers.

Perfect candidate for a home use tuner for an FM transmitter playing MP3s through it. I'd use it!!!

Hey, nice tip on audio channel corellation - having volunteered at a campus radio, I'm familiar with this concept. Oh, and put some Oscillofun or something similar on the scope in X-Y mode! It's nice to look at. I made a special X-Y scope out of a gutted old Polish single-channel scope. No timebase, but it has a curve tracer (Mr Carlson style) and will have a built-in clock for the sheer fun of it.

Hey Tony, I'm 62 and up -grade the older vintage Amplifiers just wanted to say you off Excellent teaching skills for mid-level to entry level folks wanting to either set the Bias of an Amplifier replacing Caps Resistors that have gotten warm etc. Thank you for all you do, and should you need any Transistors please let me know as I collect them and like you, I also like the rare TO-66 Transistors. Best regards John

Excellent! you find the most interesting Amps and Tuners, I had no idea Kenwood ever made something like this,:)

@lornespry

2 жыл бұрын

Kenwood/ Trio made some nice tuners!

The official FM Band in Japan is 76mhz - 90mhz. I stopped a friend of mine buying a Sansui TU9900 because if this, he was telling me how "mint" is was and so forth, he then told me it was 100V only and that rang alarm bells for me, so got him to get the seller to send a pic of the dial scale, and there it was, Japanese FM band!! There are a lot of Japenese Domestic models of popular tuners and receivers out in the wild now and it always pays to check.

Thanks, Again, XRAY!!! I have to say NO APOLOGIES are necessary for your great video... I know Pioneer handcrafted some extreme tuners way beyond your favorite TX-9100/SA-9100 or the SX-1010 I bought from Acrosound Electronics in 1975 for $470 with Employee Discount where we did Authorized Service on Pioneer, Sansui, Revox and others. On the Power Supply, the only suggestion I have is doubling the wattage of those zener resistors which overheated enough to change value. JUST LIKE our Pioneers, too many power components are tucked under the chassis, with some ventilation hopefully thru the bottom chassis plate, BUT all the radiant heat rises and cooks the non-FR4 PCB's just ABOVE the components, and dries out the electrolytic caps as well. I was waiting and waiting for the best part of this outstanding Video on what may be one of the world's most advanced NON-Synthesized Tuners - that is revealing the most tuning gangs I have seen, the only Tuner IF with what looks like Stagger-Tuned custom Murata SAW filters, and then a nice looking filter for the lower IF as well. It looks like Kenwood went with One Dual Gate VHF MOSFET for the first RF Amp, but only a JFET for the second RF Amp. Our Pioneers have 5 FM gangs, plus TWO 3SK45 DG VHF MOSFET stages. MORE amazing stuff goes on with the 4th Tuner Board in the signal chain, the Stereo Demux with Peak Sampling of the 38KHz switching frequency must be similar to the PLL in extracting a clean clock for the decoding' Thanks for explaining the advantage of this compexdecoding scheme is to reducing the FM MPX Decoder NOISE. Correspondingly, your Separation Test showed it's exemplary results! I liked the CALIBRATED FemtoWattmeter Signal Strength feature, but like using uV's instead - so I copied your chart to post on my HP8648D SG (sorry never found a Sencore or Sound Tech i could afford yet). The benefit of using that new-fangled unit introduced by the IHF? years ago, is the IMPEDANCE can be either 75 or 300 ohms, because it is a power reading. Hope you had a well deserved Christmas, and continued success in your demanding Career and producing such detailed KZread content on Stereo Restoration & Electronics Mentoring/(Ham Radio Elmering?) - where I think your sharing expertise came from. Thannnnxxx, HilaryW4HDL

Excellent presentation on repairing the KT-917 and explaining the FM tuner's features and that it was for the Japan market. Only I was confused why on the Scope you had the Right channel vertical (X) and the Left horizontal (Y) with the mono (L+R) at a 45 deg angle for inphase signals. When I hook stereo channels to my dual trace scope in XY mode, I use the X as the left channel and the Y as the right channel. Makes more sense that way to me.

I had a Pioneer TX-9500 MkII for a number of years ---- that was a big, heavy, beautifully built and high performance tuner. Years ago I worked on a similar looking Kenwood to this that was half-empty inside but still worked quite well. Sometimes you'll come across a simple "gutless wonder" that performs quite well, regardless. There was also a Yamaha analog tuner that had a lot of empty real estate but still worked well..

@SinnerSince1962

Жыл бұрын

I have to agree. I am a fool for Pioneer gear. I decided I "had" to have the best built and regarded Pioneer tuner of it's day, the TX-9500 (first edition). All was good, so I thought, until I found a cheap TX-7500. It was heads above in performance of the 9500. A quick look inside of it proved that it had half of the circuitry and componentry of the 9500, yet it sounded so much better, and picked up stations in superior fashion. Of course, maybe my 9500 needed work, I don't know.

Most welcome Tony. You deserve the kinds words and thoughts.

i was stationed in Japan from 1970-1981. My first duty station was Naval Security Group Activity, Kamiseya as a Communications Technician Maintenance (CTM). In my experience, the electronics sold in the Navy Exchanges were configured to operate on 120 volts 60 hz. I only converted one reel-to-reel tape deck from 100 volts 50 hz to 120 volts 60 hz. This was in 1970. Fortunately, the manufacturer provided a primary tap for 120 volts and a capstan for 60 hz. I am not sure where my buddy purchased this unit.

when you asked how you knew this was for the Japanese market, my first thought was because the volume only goes to 10. In seriousness however, love your content. I told my wife it is your fault I need to spend more on my test equipment :)

I lived in the Cleveland area during that era as well, and I had a Lafayette LA-224 tube amp that I wish I still had.

I had a Kenwood KT-7000 back when my pet dog was still on the planet. Used that Tuner from 1970 to 1992. Traded it in for an ADCOM amp.

Kenwood, sansui, pioneer were some of the best tuners. My pioneer F99X had a "direct digital decoder". Pretty sure you fixed a pioneer with some similar complex decoder a few years back.

The Kenwood 917 is one of the best FM tuners ever. It listed for 1000 dollars in 1979. It was so built. Since it was made for Japan, you're probably going to need a transformer to run the right electricity to operate correctly in the U.S. Also, can you get the replacement parts, since this tuner is 43 years old

Sorry 4 your loss.

Hi Tony. Very interesting. Great work again. Hope you dodged the hail...

@xraytonyb

2 жыл бұрын

We did :))

The FM broadcast band in Japan uses 76 to 95 MHz. with the southern part of the country operating at 100 volts "60 Hz" and the northern at 100 volts "50" Hz , "Unless" it was sold on a US Military base .

Looked up the Kenwood KT-917 tuner in the Orion Audio Bluebook (1997). Made from '80-'82 and retailed for $1,000 new. They may have started selling the '80 year model in fall of 1979 like cars? Of course the Orion Bluebook has been known to have errors. It lists the Realistic STA-2200 as being made from '79-'83, 60wpc, and retailed for $600 new. Vintage Radio Shack catalogs are all online now, that is easy to check.

Many Japanese electronic devices will be max rated to 120V, even though they have 100V nominal. The difference is minuscule, and most transformers are wound for 100V, but are designed to handle 120V. I think this is the fact, because of the US military influence in Japan (and US servicemen buy a lot). By WWII treaty, the USA is Japan's military. They aren't allowed to keep a military beyond a minimal National Guard, per the surrender treaty. The JDF is a token military force. Very old Japanese devices will require a transformer, but most modern devices work fine in a USA plug.

I believe that bad transistor happened due to heat. Note how near to a heat sink it was. Plus, if it was plugged into 120v vs the 100v like it is supposed to be, that heat dissipation transfer may have been significant enough to cause failure.

At around 12:00, it obviously just got the wrong tag applied at the factory. Even the rear is the Japan version as the US version has the 25/75u switch on the back as well.

Xraytonyb your Kenwood R9 17 FM Tuner receiver is so awesome

Thank you!

Really like the Tick Tock clip.

Bahahahahahahahaha! THAT was good! I jumped also Tony. 🤣

This unit, back in the day was known as a "Supertuner"!

Having not watched to complete video,. my guess as to the size: to match the size of its 'companion' integrated amp. I'll bet the inside of this tuner is mostly empty space; maybe some concrete attached to the chassis to give it some heft!

pulse count detector was used a lot in the Wireless world UK magazine articles. Needs LOW rf freq to give good output.

@conservative599

Жыл бұрын

TrueDat!!! I subscribed to the UK Wireless World, in HS and College in the 1970-80's, and built the Sinclair Tuner, and bought the external WW Dolby Kit. I bought built their early WW Phase Locked Stereo Decoder board from England, in HS. Excellent and the most inquisitive Engineers, Scientists, and Technologists contributed to that long running Publication. I still have every issue of WW from that time in my lab, AND just missed getting later issues from my Employer, Nortel/Bell Northern Research when the Alpharetta GA location library got rid of them!!! The reader feedback would go on for months about TIM and TID, and which way Electrons spun. What I am saying is that the UK Engineering folks are way less lazy than us in the USA, writing passionately at length debating many aspects of Electronics. Thanks for acknowledging their advanced technology, and of course, look where Quad, Mullard Tubes, Dolby, B&W, Mordant-Short, Leak, and the specialist Audio firms which for example PEARL ACOUSTICS founder Harley Lowgrove now so passionately explains on KZread - filling in gaps in my 50 years of ET and EE career with my favorite job working in NJ doing Lafayette, Pioneer, Sansui, and REVOX authorized service in HS and College.

@mohinderkaur6671

Жыл бұрын

@@conservative599 Wireless World had lots of awesome circuits and amplifier designs! fantastic stuff! Wonder if I can find an archive somewhere !

Condolences for the family Tony.

Hello! The FM band is something problematic for these Japanese units. FM band was also different in Europe in the early 1960's, with an upper limit of 104MHz: it's still something you have to check if you buy or restore some old tube tuners or radios. The 75 or 50 uS de amphasis filtering option is generally only offered on best international models, with multi voltage choice and AM digital scale set options. You have here the typical unit normally only sold in Japan and designed for the Japanese market? In north American version, this is typically some of these models you can ask around 1.000$ and more if sold with the same series amp. The history of this tuner could also be something really interesting... Someone working in a US base some 40 years ago? Trio Kenwood is still a reference in the tuner domain, as they also have developed expertise in radio emission and reception material and technologies. They show here one of these unique technologies that explain why they produced many reference models over the years. Among these, the KT 917 is still in the top list of many experts, DXers and high end HiFi enthusiast. It was also listed as a high end model with relatively few in common with entry level units, wich generally have only 2 or 3 gangs and more classic circuitry. And is was sold to follow the dimensions of a very large high end powerful and heavy integrated amplifier, with a following prohibitive price tag. First thing you mentioned is the weight of this unit, and dimensions. But you could also notice how the different boards are populated and mounted, with a relatively easy access compared to other brands, and the quality of shielding of the RF unit. The use of SAW and other specific ceramic Murata or TDK filters is also something still technologically impressive and a costly solution, and apart from the power supply and output level problem, there was no drifting nor need of alignment: something impressive for a 40 years tuner! This peculiar model and later KT1100 are still the best choice for those having specific needs, when you have emitters with adjacent frequencies but with enormous difference in reception level, it's the famous discrimination and detection level capacity. It's also perfect for DXers for which the quieting of background overall static noise is important. And the overall audio quality is really interesting if you have the chance to listen some of the few remaining stations. The unique 9 gang Low noise amplified entry stage , IF pulse count technology and high end low noise low distortion Decoder and audio output still offer a competitive product wich compares to most finest digital synthethized or analog tuners, with priciest models from McIntosh, Sequerra, Accuphase or Sansui.

Although there is math involved ( And we ALL hate math!) It looks like the wattage of 55 Watts @ 120VAC on the rear panel tag, and the transformer marking of 47VA @ 100V ( although the schematic says 120V on it) makes sense when you raise the voltage. ( 47 X 1.2 = 56.4, give or take some for the VA/W conversion due to the power factor percentage). Can you please create a post with links, and pin it, ( for quicker access for us lazy folk) with the URL's for the SGS-Thompson transistor cross reference and the FM Pre-emphasis info sites? Enjoyed the video and info, thanks! I always like to get any info I can on BJT cross references, Octopart is handy, but gives a broad of available ranges that you have to normally sort through to pick he best match.

@zulumax1

2 жыл бұрын

Nice catch on that, think you nailed it.

I have an air compressor in my office/computer room/workshop that has a slow leak somewhere. It cycles every 24 hours or so. That darn thing starts up at the most inoportune times...Scares the tar out of me...Just like the radio did you. I should fix it but it is sort of like a fault with an old car, the annoyance just sort of grows on you.

Hi Tony, what is the price for this tuner ? i am intrested

A bit of an oddity... Japan has two different electrical grids, one running at 50Hz and the other at 60Hz but both at 100v.

Notice that tuner has multiplex outputs for H and V on the rear. I have a Sansui TU-7700 that has those also. I think that is where you can hook up your XY inputs to your scope, is that correct?

@xraytonyb

2 жыл бұрын

Correct. You can. Some manufacturers even made audio scopes to go with these units. Pioneer had two different models that are impossible to find now.

@zulumax1

2 жыл бұрын

@@xraytonyb Thank you for your response Tony. I have a Pioneer DT-400 timer with the blue clock display that was sold as an accessory.

Hi Mango...🐱

Don't you mean PLL (Phase Locked Loop)?

Me and my cousin are going to a Swap meet June 5th 2022 Sunday morning at 8 am in Milwaukee

I was surprised you didn't put the smaller parts in first, and then the transistor's. And left the TO-92 Transistor a bit to tall. '-)

@xraytonyb

2 жыл бұрын

I raised the TO-92 transistor above the board to allow for better airflow. As long as I can properly reach all the parts to install them, it really doesn't matter in what order I replace them. Thanks for the comment!

@tubeDude48

2 жыл бұрын

@@xraytonyb - Understand!

So instead of pulse modulation, it is pulse demodulation.

👍

Tony, what was that cross-reference you mentioned? The guy that was gripping, is probably a 'Lindenas' follower!

@xraytonyb

2 жыл бұрын

I got the reference from ST microelectronics. Their website is www.st.com. People gripe in the comments for many reasons. Sometimes they are just trolls, sometimes they don't understand something or are frustrated and sometimes they are just having a bad day. Regardless, I wish them well. As for the other KZread content creator you mentioned, I'm sure he is just another person who loves his hobby and is kind enough to share it with others. We all have different skills and learn at different paces. I wish Mr. Lindenas and his subscribers all the best and am happy that he and they can enjoy his hobby.

@tubeDude48

2 жыл бұрын

@@xraytonyb - Thanks!

"you never show us anything"??? That's exactly what you do, as well as explain what, where and why compared to other channels. The word is fickle. People are fickle.

Taiwan operates on a 110V supply voltage and 60Hz.

Maybe someone at the factory only had 120V stickers so they stuck it on.

I think it’s also strange that all of the markings are in English. Was that common in Japanese consumer products made for their domestic market? It may have been made for sale in US Military exchanges. Other than that, it’s just a bit mysterious…

@richpayton7162

2 жыл бұрын

I used to think the same thing, but having visited a lot of Hi Fi shops in Japan and elsewhere in the 1970s, I have not ever seen a piece of Japanese hi fi gear or shortwave radio, etc. with anything but English markings. If I had I would have grabbed at least one.

@SinnerSince1962

Жыл бұрын

@@richpayton7162 Everyone forgets how much power the English language carries in regard to product sales. Air traffic control is also in English.

japan has different voltages in different regions, 100 v in one part and 120v in others

@RalphRacc00N

2 жыл бұрын

its 50hz or 60hz your thinking of.

@mallacai

2 жыл бұрын

@@RalphRacc00N my mistake, you're correct

@SinnerSince1962

Жыл бұрын

@@mallacai I was getting ready to hit you up on that assertion as well. :)

Doesn't quite make sense, that the dial seems to indicate the Japanese market, while the voltage does not, since they are 100VAC.

@randyr.parker2698

2 жыл бұрын

A previous commenter posted this comment that may help explain this. Seventh Anubis 10 hours ago US navy on-base military family housing in Japan is 120 volts.

Japan has mutiple voltages and frequencies depending on where you are. According to Wikipedia, in Western Japan 'Osaka Electric Lamp"the grid was established with General Electric equipment and runs 60hz, and the Eastern side was established by 'Tokyo Electric Light Co' and ran AEG equipment from Europe at 50hz. Most areas now run at 100 volts, but some 200 volts, with the US bases at 120 volts. There are 10 ""incompatible" regions. en.wikipedia.org/wiki/Mains_electricity_by_country and en.wikipedia.org/wiki/Energy_in_Japan

My other hobbys lisining to records CDs and fmstreo on my Yamaha reciver

Tony, it's KT, not KR :) B.R.

@xraytonyb

2 жыл бұрын

I see that now. That's what I get for trying to get this posted before going to work!

Xraytonyb ware do you live I live in Franklin Wisconsin in a mobile home

@len9518

2 жыл бұрын

PA

I dont think it is a big deal between power really. Us voltage is not 120.volt always. It can go below 100 to 140 i think. Stuff is made to handle this. I would say anything 100 volt can be used 120 without problems really. Same with 120 on 100. The big thing is frequency. 50 hz or 60 hz. Japan uses both so 60 hz 100 volt stuff should work just fine on 120 volt power really.

@mangist

2 жыл бұрын

Why would frequency matter in something like this? The AC voltage is rectified to DC anyway, so shouldn't matter if 50Hz or 60Hz

@james42519

2 жыл бұрын

@@mangist because ac power is 50hz or 60 hz. Us is 60 hz, uk 50mhz, and japan has both of them

@mangist

2 жыл бұрын

@@james42519 Yes but it doesn't matter, the AC power is rectified into DC in the power supply.

@Slartibartfas042

2 жыл бұрын

@@mangist Well, read about how transformers are designed. It *does* make quite some difference if your transformer has a core being designed for 60 Hz grid frequency and you do "misuse" it at 50 Hz grid. You have to remember - transformer is used to suck in current at some input voltage and transform it into magnetic energy. For perfect transformation the transformer itself has to be kind of "in resonance" or it will get hot, lose quite a bit of power capability. Why is it so? At 60 Hz the transformer will get "filled up with electrical energy" 120 times per second with either positive inrush current or negative inrush current (positive or negative half-wave) that it can store in it's magnetic core. The the secondary coil will use up the magnetical energy being stored there to produce it's electrical output of energy. Now, think of it - what will happen if the core is designed to have capacity for 60 Hz grid (120 half-waves/sec.) but now the transformer will have to fill up the timeframe for 50 Hz (only 100 half-waves of electrical inrush)? You will see quite some gap of "need fresh energy" and "can deliver energy out of magnetic stored energy"! So, transformers will only have the given power capability characteristics at the grid frequency given on the labels. Driving at a slightly different input voltage will also affects the power supply capabilities, depending on the type of power supply. Modern switching type regulated power supplies will burn fuses if you try to drive them from to low input Voltage at some given output power rate. Lower input voltage will mean it pulls a higher inrush current to get that power demand done. If it is some in-line regulated non-switching power supply it will lose it's capabilities to regulate the output power to the right output voltage, in some case it will lead to wrong quiescent current bias or sometimes it will lead to hum from an power amp output because the output transistors will reach the saturation of output voltage earlier if there is no more room for regulation. In the case of higher input voltage you are risking of blowing up the electrolytic caps because the transformer output voltage may exceed the maximum capabilities of the cap. Sometimes cap can survive fine quite a bit of "over-voltage" but most capacitors are kind of allergic to over-voltage... If that's the case you will pretty soon hear the problem... ;-) Long term short meaning: Setting right voltage input type is essential for cool, effective and optimal operation of the power supply. Both, input frequency and input voltage will affect how well all is working. BUT, of course, most devices are made to work on some range of input power supply. Even if my grid is designed to have 230 Volts (in Europe) at frequency of 50 Hz - you may see a little variation of frequency if grid is out of balance (which led to lots of kitchen clocks freeking out and running completely out of the right time some years ago all over europe...) and, more severe variations of input voltage. If you have long and heavy loaded lines to your settlement or house you may see all kind of voltages down to maybe almost 200 Volts and in some cases input voltage may reach top voltages of up to almost 240 Volts... Most devices will be able to handle a variation of voltage of up to about +/- 10% volts well. It always depends on the design and the quality of the circuit and of the used parts.

@SinnerSince1962

Жыл бұрын

It never goes below 110. if it does, they are troubleshooting the problem as it can ruin appliances.

LAFAYETTE, or Laff a Lot was made by Setton in France

Such a complicated tuner. Advanced or just going a bit too far for most people to notice. Most peoples lug holes are not that perfect. Just my mad opinion of cause.

44:05: 🤣

@paulnicholas5452

2 жыл бұрын

Great video I always learn something from you

Hmm… I’ve always pronounced “lissajous” as “lissy us”. But I think that’s because the word is French, and - well - it’s French. Nuff said. 🤣😂

Cats are okay, but they aren't dogs, our best friends.

Have always been skeptical of a Japanese tuner functioning in US. Those little volume output Pots have always been an issue for me. 9 Gang is why I want 1 of these, American version.

Xraytonyb my hobbys are painting pictures and lisining to shortwave and ssb iam thinking about getting my ham license I have 4 shortwave receivers

Xraytonyb the Kenwood sond good