LaSonic Funny Electronics AM Transistor Radio Repair
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- Опубліковано 31 лип 2021
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About 20 years ago I was at a garage sale and saw a bright red plastic radio about the same dimensions as this, maybe a little bit bigger. Its a Westinghouse, and from what I've been able to find out, seen a couple for sale on ebay, it a 1967 or 68. Fortunately it runs on a 9 volt battery which lasts about 4 months! I bought it for 5 bucks. AM ONLY, this radio works, and sounds great. Its in my bedroom and every morning when I wake up I turn it on while getting ready for the day, I listen to the news for about 10 minutes. I mean this thing basically gets used every day!! Always works and sounds good. Definitely got my 5 bucks and more from this old red radio!!
According to what I learned in college, the "transistors" used as diodes in these radios were floor sweepings that were not usable for amplifying current.
The transistors in question were typically alloy junction devices. The base was a small wafer of n-type germanium. A piece of indium was held onto one side of the wafer, and the assembly was baked to cause a heavy concentration of indium to diffuse into the germanium, thereby forming the emitter (indium is a p-type dopant). A second piece of indium was later held on the opposite side of the wafer, and the assembly was run through a second bake cycle that had the goal of releasing a much smaller amount of indium into the germanium, thereby forming the collector.
This manufacturing process was not very precise. As the emitter and collector regions came closer and closer together, the result was a transistor with improved beta. However, if the emitter and collector were too close, the result would be a transistor with a low collector-emitter breakdown voltage. If the emitter and collector touched, the result was a diode.
Technicians tested each transistor coming out of the production line. A manufacturer might have used several different part numbers, depending on whether the device tested as low beta/high breakdown voltage or high beta/low breakdown voltage. The shorted devices sometimes had one lead snipped off at the factory to identify that they could only be used as diodes.
Some of these “bottom-feeder” radios are better than a lot of the junk made today.
📻🙂
Probably superior to those new cassette boomboxes.
LOL
I find this superior because while it is crusty it still can be worked on. Stuff today seems like glued together junk with some surface mount components. The glue is usually stronger than the plastic.
i agree
Yea, at least it's a real radio with IF stages and not a radio on a chip.
I cannot get over that they just blobbed solder on the letter "O" in Funny radio MODEL. Classy
sloppy O's
The thing was most likely soldered by "partial wave" - soldering iron with big blob of solder was just swiped over a group of joints to solder them at once. When solder masks weren't used, it tends to do cover such "o's" by the solder. Same way as dip or the later wave soldering.
The comment you made about the Teflon wire exceeding the value of the radio is exactly what I was thinking before you said it. The reason they did not put values on the schematic is that particular genre of set was made out of any surplus components that the low end manufacturer could lay their hands on. How could you provide a value when it may change on a daily basis? Design calls for a 220k resistor but there's a deal on 270k's in the surplus chain use the 270s. Can't get rectifier diodes use surplus switching transistors. Can't get miniaturized capacitors use oversized axial. Hong Kong in the 60 to 70s era was some of the worst build quality electronics that functioned I have ever seen. Even the junkiest Japanese stuff was light years ahead of the Hong Kong products.
Yet it still lives.
That supposed "Hong Kong junk" from the 1960's and 1970's is still many miles ahead of any modern Chinese korona infused garbage made today.
@@jsciarri TRUE! While they might have been primitive in design they were STILL built simply and built to be durable! Todays' China junk is built to be cheap, and VERY disposable with little longevity and at times are very complex too.
I'm hong kong and i approve this commercial.
3:20 Sometime during this period, the FTC cracked down on marketing that touted a "transistor count" that included transistors that were wired as diodes, or not connected at all. A lot of these imported sets were made with surplus military transistors that didn't make the cut, so it was easy to use them frivolously. They might have built the board this way, then found out they could only call it a "7 transistor" design.
19:33 It was very common in transistor radios to let the driver current (2-3mA) through the speaker, the solution is called "bootstrapping": When the driver transistor closes down, the upper resistor (under the label "TR6") pulls the power amplifier up, which drives the speaker to positive. If the upper resistor was connected to Vcc, it would run out of driving current, as the voltage across it would decrease. But since the voltage on the speaker rises, the voltage on the upper resistor won't change, hence it's able to drive the power stage constantly.
The exact same thing is happening in virtually almost all output transformer-less radios (e.g. Sokol 308, yesterday's Hazar 403, etc..).
At first, I thought it might be negative feedback, but on second thought, there is no inversion, so it would almost look like positive feedback, but with no voltage gain. So is the intention to get the swing of the driver to range up to maybe 6.5 V (using the inductance of the speaker and the charge on the cap as sort of a ballast), so the output transistor doesn't cut off .6 V early? Seems like a clever hack, but with only 6V of swing, it probably makes a significant difference.
I never even took the time to look at or think about the design and im surprised they would put that much thought into the circuit design. thanks for the info on why
@@pcno2832 That resistor is a leakage sense from output cap to shut down output transistors if output cap goes leaky. With no 8 ohm speaker load, normal leakage thru cap will mis-bias outputs. Advent used a similar circuit in one of their videobeam models.
@@rfburns5601 no it isnt, its a 'boostrap' as said above, some circuits use 2 resistors but connect the mid point junction of the 2 to speaker via a large value capacitor, it does the same thing but takes more components, but that way they can have the speaker at 'ground level' instead of supply level , many IC output chips use same idea, such as a TBA820/820M.... there 'may' be circuits that sense 'leakage' or abnormal load, this isnt one of them ...
Some little girl from 1969 is wondering what ever happened to that cute yellow radio she used to have.
no..... she died in a car crash back in '87
@Glenn Cerny
Marsha Brady wants her radio back...lol
Hanging cardboard cutouts on vintage radio = retrochads
"Here we have..."
This bias connection is very common with these complementary push-pull amplifiers. It is connected there as the bootstrap, to maintain the bias over the full output voltage swing - during the positive halfwave the resistor is fed from the sum of battery and speaker voltage. Most IC amplifiers intended for such applications are designed to allow this connection as the cost optimized BOM variant (TBA810, TBA820,...), as that way you can save the dedicated bootstrap capacitor and resistor. Most such cheap electronic uses that connection.
It disappeared only with the modern low voltage rail-to-rail capable amplifier IC's (do not need bootstrapping to achieve full swing; 90's and later) and most recently the CMOS BTL amplifiers (HXJ8002,...; 2000's and later), which need even less components around (mainly the bulky speaker output coupling capacitor).
And judging about the sound quality, it seems some capacitors are still weak there...
Ha-ha. That was awesome. I think these bottom end sets can be just as interesting to work on as super high end.
Shango needs to head east to the desert and give this quality receiver a good sensitivity test.
I remember seeing Lasonic brand radios in discount stores back in the ‘80s and early ‘90s. They really were bargain basement, but worked.
I wonder if the same people made the large cheap boom boxes in the 80s, branded Lasonic as one word.
I was wondering that myself.
LASONiC is an American brand of electronics made by Yung Fu Electronic Appliances of Tainan City, Taiwan. Their American import division, Lasonic Electronics Corporation, is based in Irwindale, CA. I can't find anything on LaSonic, or Funny Electonics Co., based in Hong Kong.
Love the "Funny Electronics" on the board, even they know it.
I really like this. It looks a little like a waffle. Takes me back to my childhood years. The speaker is permanent magnet. Your friend, Jeff.
mmmmmmm waffles
“The hell with it let’s fix the damn thing. I wanna see this happy times electronic company very nice sunshine radio very good work” 😂😂😂
I love that they used a whole one screw to attach the tuning cap.
I sent one to my Girlfriend in Ohio. She said she wanted it! They all have basically the same board. Even when it is turned off part of it will be live. Risky by today's standards but they do sound good. Who needs a Zenith when you can use Funny Electronics?
Even when I was a kid, the "Battery or Electric" designation seemed a little silly, as if batteries were not electric.
Which reminds me of the "metal versus aluminum" thing. Boggles the mind, especially when it comes from otherwise very knowledgeable persons like a certain Mr Carlson.
How about the coin counters in the supermarkets that advertise "Turn Your Change Into Cash", LOL, as if coins are not cash :-)
Right up there with “available as digital and DVD” as of DVDs aren’t digital.
I can’t even tell you how much I enjoy your videos!!! I like them because we think alike. Why did they do it this way? Lazy, Plastic, junk that might work after fixing it, but, what ever. It keeps you busy, and all of us entertained. Keep on keeping on!!
Always nice to see these retro radios. I just love the old school stuff. I have a variety of old school radios. I just display them in my shed. Thanks for posting.
Looks like a solder-yourself radio kit my dad gave me in late 70's. Minus the enclosure. Soldering looked similar too. Lol
Video was great. That radio looks like something you would get from grant's in the late 60's
Wonder if they had powder blue ones..
Come to think of it, that cheap radio *does* look like something W.T. Grant & Co. would have had in their electronics department.
G'day from Australia
Gday mate
Subscribed, Mate. From Adelaide.
Ello govner
The video exceeds the value of what's being video'ed.
Btw, that resistor biasing through the speaker is a too simple bootstrap connection. It uses the ac signal of the speaker to artificially increase the drive of the power transistor. It ends up delivering a few more milliwatts of power to the speaker, which using such a low voltage supply can be of help. More elaborated desings use a resistor network and an extra capacitor to do the bootstrap and avoid passing dc through the speaker (and avoid the circuit to go unbiased if the speaker is disconnected or the user inserts a crystal earphone).
As a young boy I would have thought of that radio as gold. I'm surprised that I didn't become a radio DJ when I got older.
Stupid mistakes are sometimes the best teachers (don’t ask me how I know that...). It’s amazing that you can even get something like that to work. Great video!
I can swear I remember LaSonic branded Boom Boxes in the early ‘80s. They were huge, but not too sure the build quality was.
I remember LaSonic too...early mid 80s
Big with loads of extra LEDs and text that meant nothing. Big, gaudy, and very low quality. They had the look people in the hood wanted, though.
Lasonic was famous for their giant boomboxes in 80’s
I saw them sold out of white vans at flea markets! They were big, lots of plastic and colors, and probably little more than a simple radio and cheap walkman knock off tape transport. You don't see those around any more, not that you saw anyone actually buy them in the first place.
Yay! a triple header weekend! Love the genuine simulated plastic yellow pleather.
You 100% blow me away at how you can fix things..........I look at the screen and say WOW...
This is just amazing. "Funny Electronics". Just awesome. Shango's diagnostic skills are spectacular...
Love Sounds is the sort of music I expect to hear from Pages from Ceefax when the BBC broadcast that for decades.
Sometimes the junkiest radios will surprise you with superb sound and DXING.
Thank you very much for sharing your quest with us Sir. This surprising lesson about audio output transistors is priceless!
Ooooooh! A LA Sonic! I bet that brand is more better than Sorny, Magnetbox or Panaphonics.
LOL .... here we got in the 90s: Panasoanic (using the Panasonic Font), SQNY, of course using the Sony FONT.
I know a genuine Panaphonics when I see it!
@@38911bytefree Really?!! What country? That's nuts.
My uncle who was a machinist in the heyday USA said that (I think he said Japan) Japan had a region they called Usa... "Ooohsah" That way they could stamp "MADE IN USA"
Theres were also names like "PANASONIA" made in HongKong and "PANASANYO" made in Indonesia..
A Kelrcotwinqulated Sonyo, oh sorry Malulated in this case
'The Sounds of Love' - is this K-TEL? Gotta LOVE IT!
MSFB T.S.O.P.
The electricity consumed by your soldering iron cost more than what that badly designed radio is worth.
The two transistor by the output transistors are for the bias of the output transistors, this would always be done with diodes but my guess they had tons of transistors and it was cheaper just to use them instead of buying diodes.
Nice to still see the 'S' in Sonic capitalized, as it should be! On later boomboxes, from the 1980s onward, it was "Lasonic". Assuming that was the same company
Yes, it should be a guitar pedal! You’ll get rich selling that vintage telephone tone!!
$299.99 for the model with grab bag, out of spec transistors and $25 for the one built properly.
Thank You Shango for making these videos. You should be on TV. I watch (and-rewatch) your videos, so my TV gets less mileage than my iPad.
State of the Art Quality Radio you lucky thing.
I just about quit watching in the first minute, but each minute thereafter got more fun (and interesting) than the one before. Well done!
Great video as always Mr Shingo
Tango
Shanghai
Another loss soul brought to life by the blue wonder of transistor radios! Enjoyed watching.
Historically speaking, selling a radio with a needlessly large number of transistors in it made sense to purchasers in the late sixties. Transistors were much more expensive items at the time, whilst being an unknown technological factor to much of the general public.
24:59 Alexander Borodin ... String Quartet No. 2 in D major, 3rd movement
This music was used in the musical Kismet for the song, And This Is My Beloved.
I have to setup a bench one day and start fixing those basic electronics. Thanks for letting us learn with you!
Darn you're human! Still you're videos are my favotites. The thing is you always figure it out. Wave64 and Michael Robertsons comments gave it even more impact! "Bootstrapping" Hope you never get tired of doing this, cuzz I love em.
Those two transistors in front of the audio output transistors are bias "diodes" for the output transistors.
I do love the cheesy woodgrain and yellow with chrome combination That is such a 60s look!I’m kind of sad because On ebay I could not find any radios like this radio!
Lasonic was around at least till early to mid 90s, but manufacturing in Korea as oposed to Hong Kong. I had a Lasonic HD2000 black and white portable from 1991 and it worked quite decent (for what it was).
A gem in the rough! Actually a nice radio!
*I swear this radio was a prop sitting in the bedroom of the Brady Bunch girls!*
Very cool vintage well done.
Nice going shango066
Yeah, what a strange circuit. Funny Electronics is right
Looks oh so pretty in sunshine yellow
1968 or '69 sounds about right for that radio, given how it looks. It's an el cheapo portable radio of its era, I could see it costing like $7.99 at TG & Y, or someplace like that.
Funny made circuits from a Funny company out of HK. Thanks for sharing your experience with this radio. Cheers 🙂
This radio would have looked great on the set of 'Trailer Park Boys'.
These cheap radios were a masterpiece of brilliant design , using every fudge and method to cut costs. The circuitry was fluid enough to use any and all components that were available at that time. These output stages were very common, the bias from the speaker also applied NFB to the driver and used no extra parts. The cost cutting was just an extension of the same economy with the earlier valved sets, thats why they all tend to be very similar in design.
Great work! I just subscribed.
My Realtone AM-FM has a similar schematic I think. Thank you for explaining this.
Thinking about the bias circuit I wonder if the engineer was actually more clever than initially thought. Since the speaker is in series with the bias Network, when you would plug in an earphone (which is usually a higher DC resistance than the speaker) could the change be a primitive power saving function? It would definitely reduce the bias and the output stage would draw less quiescent and active current when using the earphone. If this is truly what the engineer was thinking he's pretty damn clever.
hmm yea ... i didnt see the headphone jack on it... is that the "Z" symbol below the speaker on schematic?
For Class AB it should be biased at the bottom of the transistors' linear region, no matter the load. So this doesn't really explain it, and it probably only works with low impedance headphones because of this. Maybe it's really just for NFB.
I was thinking it was for negative feedback.
It’s a bootstrap circuit, standard with complementary symmetry output stages. It effectively increases the voltage to the driver stage by adding the speaker voltage in series with the supply. This allows the driver transistor to swing over a greater amplitude.
R1 feedback bootstrap makes its ac impedance much higher.
Check that the voltage at the output emitters is mid supply, and adjust that lower dc feedback resistor if needed.
That works fairly well! Good lessons for me.
I'm guessing someone who bought that at the check-out line at the grocery or pharmacy might have been satisfied if they all worked like yours.
Another great 👍🏻 video and another radio saved!
I literally laughed down to earth when you say 'happy electronic' instead of funny!!
Indeed, Nothing But the Best
LaSonic made my sister's first vibrator. She got her kicks back in '66!
I have watched hundreds of hours of Shango, and this circuit board has to be the most dogs**t POS I have ever seen!
What some of my fellow electronics hobbyists referred to as 'Hong Kong Horrors' back in the 1960s, they looked as though the assembly method was to fire a blunderbuss filled with components as a bare PCB and just solder up the result.
Shango, you got upset about your mistake but many would have made that same mistake, and, probably wouldn't have figured out what they did wrong. One thing you can say about that radio. It may be cheap but it is still working after all this time. That is not bad.
As far as I know there are two ways of arranging a Bootstrap Circuit for an Audio Power Amplifier and this is the cheaper one which involves passing a little bit of direct current through the Loudspeaker and it's quite conventional.
I have never seen Transistors used as Rectifier Diodes for the Mains P.S.U. before though.
I would probably take the mains out completely and just keep it as a battery one
Yeah , I had 2 of them. Cassette player boom box. They worked fine and had better sound then all of the name brand boom boxes of the 80's and were less money. 1 of mine was the 6.5" speakers and the other 1 had 8" speakers. Both had 2 " tweeters.
The specs. said 50watt per channel, all lies. The bigger one I tested, actual power without distortion was 7-9 watts per channel. 15 watts per channel maximum with full distortion. It still sounded good and was loud. Makes sense, big speakers. I believe Yung Fu Electronics made them at point in time. I still have the bigger one and it works.
The smaller one was louder and had better sound quality with better Bass and better Highs. Never tested power output on that. Specs in the book were the same 50w X 2.
I have a feeling it put out more power than the bigger LaSonic.
I just love that Gruen Amp meter, It's got soul...
Great Job. BUT Tecsun, may not sell too many new radios after you show how to give life to old junker radios.
Keep up the good work!
Cheesy crusty radio. LOL 😂 Laughed my arse off when I actually read "Funny Electronics" on the circuit board..........Priceless!
Much Funny, Lot Quality!
Very cool radio!
I like it no bad solder connections works good your to hard on the little thing
20:08 funny electronics at full glance 🙂 What a funny way to get power to the transistors 😆
Funny Electronics lol. Nothing but the best!
I miss the Rockford Files.
Great work
I think Funny Electronics is still around, I believe they made some stuff for NAD in the 80's or 90's. They're one of many contract manufacturers where essentially a marketing company will ask them to build a radio to go in the cabinet they've designed. Bright yellow seemed to be popular for radios in the late 60's, I've got a vertical FM/AM portable marked "Douglas" also in bright yellow, laying around here somewhere. Made in Japan though.
"We'll never know if that one was shorted, because it fell apart when I took it out" 😂
Still better than a Crosley.
My first solid state shortwave radio was a massive multiband thing with FM, shortwave, and aircraft, I forget the brand, I believe it was indeed Sonic-something, but what will always stick in my memory is that it was made by "Funny Electronics." And yes, it was very sloppily built, but after alignment worked quite well. I believe, by some convoluted path, its manufacturing facilities became part of Samsung. There were a LOT of radios made by Funny in the 1970s, they could be bought very cheaply in bargain stores. And yes, I've seen transistors used as diodes or rectifiers before in consumer electronics.
Looks like one cheesie gizmo from Hong Kong or beyond. Still enjoyed your video.
Funny Electronics what an appropriate name.
Genuine simulated vinyl .
Great video
The stuff on the right of the schematic is push-pull audio. Prob has a pnp and npn transistor working in the output.
speaker as B+ delivery - called bootstrapping the output stage.
Luscious solder excess!
It's what grandmother bought a teenager for birthday when they didn't know what else to get
The yellow carry handle and vinyl case look to be the same as on the black "Vintage Ross Transistor Radio Repair" done two months ago.
Yo Shango ... Just a FYI ... you got a nice shout-out from Mr. Carlson's Lab. Paul speaks quite highly of you.
Very nice my friend