One phone scammer called me and I got him to pray with me. We were praying very seriously, or so he thought. He told me all about his son, and we prayed for a while. 15 minutes on the phone with the guy. "And, Dear Lord, we pray that his son may contract inoperable colorectal cancer, for this we pray, Dear Lord." The scammer started to cry on the phone. Well, fsck you, you were trying to scam me. I don't really hope the guy's kid gets sick. But I do hope I traumatized him enough that he won't try his scams anymore.
I love it when he speaks jibberish to the spam scammers. Most times they get frustrated and hang up! That’s pretty amazing when you can annoy them enough to hang up. I come here for the humor as much as the great tech tips.
Another great and entertaining video Mr Shango sir. I don't know if anyone else has ever noticed but unlike every other channel Shango never begs for likes or does he ever ask anyone to subscribe to his channel. Shango is a blessing to all electronic hobbiest!
That audio stage is a complementary symmetry amplifier, the transistors connected as diodes in series are used to establish a bias voltage between the bases of the output amplifier to eliminate cross over distortion. It acts as a push pull amplifier, but is actually a totem pole series circuit, with the upper and lower transistors driving on alternate half cycles of the signal.
Yeah, I'm gonna pull Sedra and Smith off my bookcase and pause on the schematic shango066 showed us, I think you're right. But WHY do you need a convoluted push-pull circuit to run that tiny little speaker? Oh yeah, so it can say 12 transistors on the front of the radio.
@@KennethScharf If all you want to do is drive up the transistor count, why not just make a much better receiver if all the transistors to do it are in the circuit anyway? I can't imagine the extra transformers cost all that much in comparison to transistors. They could have made it a decent DXer.
I read in some old popular mechanics books (do it yourself) that multiple transistors was a gimmick. It said, the more transistors it has doesn't make it better. Quality transistors do. Great video. Love the Saturday Shango special. 😊
I've seen radios of the period with transistors soldered into the board but not connected to anything. It was a way of using quality control failed parts to get the transistor count up, con the consumer into thinking they were buying a better product, and keep the marketing department happy. In this case, it seems to me that they've found a bunch of failed transistors that they can use as diodes rather than scrapping them, saving money and increasing the marketing bullsh*t factor into the bargain!
27:37 so someone is most likely selling off items from a relatives estate, and they are using "veteran owned" to try and increase the money they get for this guys stuff.... That's a quality person right there.
The problem of these faked transistor count radios was big enough for congress or the FTC to pass a law about it in the sixties - I have an article about it in an old Consumer Reports somewhere I'll copy when I run across it someday.
Would that have been a law which said that the more transistors, the more tax you paid? I remember a time when transistor counts went the other way with ridiculously low counts of two, or three transistors, and marketed as a "Boys' pocket transistor radio" - This supposedly lowered the radio's status to that of a toy, thus obviating the purchase tax that would otherwise apply to luxury electrical items.
In 1967 you could get a Nobility 12 for $4.47 ($40.26 adjusted) at a Wal-Mart Discount City or in 1968 for $3.88 ($33.54 adjusted) at your Thrifty Discount Drug in Salinas. Mind you these were an "$8.88 ($76.76 adjusted) value! It seems the discount retailers were awash with Nobility brand radios from the early 1960s to the mid 1970s. A whole lot of models and transistor count AM sets, and even some AM/FM. One store in New Mexico even advertised "Nobility Brand Radio in assorted colors for the Rest Room". I guess that is so when it crapped out you could drop in the toilet, loose it in the mix and flush it down as repairing it wasn't worth the effort.
Nice to see another transistor radio video! I actually just did my first transistor radio that I got from a thrift store. A $5 GE from the late 50s with 5 transistors and a diode. Wasn’t working initially but after cleaning the battery contacts and letting the electrolytics reform it’s working well now!
It's diversity 1960s style, they have multi-color and types of transistors even if some of them are useless. The worthless epoxy dome transistor by the tuner is for affirmative action.
2:01 AGC to reduce fading. 3:18 isn't a P/I it's class AB bias with automatic temperature compensation, 2 diode drops it's supposed to be, though there's usually a resistor in series. If all 4 PN junctions were in series the output transistors would burn up and flatten the battery. Maybe 4-series was a manufacture error then was recovered by adding a link instead of desoldering. Reduced bill of materials complexity by reusing 3 pin devices as diodes. Smart move. NFB around output stage to reduce distortion. 1 ohms more NFB DC to protect against thermal runaway damage when loud volume. 4:25 linear amplification . Not bad on the whole! Factory obviously bought a enormous quantity of "transistors" and the design brief was have as many as possible doing something credible and then market as high transistor count. In the early 1970s a UK electronics constructor magazine article covered mini radios in detail going through all the tricks to boost performance one by one.
Cost and labor aside, it is pleasing to see there is a useful product with a second lease on life at the conclusion. Sure is better than being e-waste.
Kind of reminds me of watches from around this period where they upped the jewel count for no reason apart from perceived quality , they would literally glue jewels to the case.
I have to thank you once more. I have been buying up cheap transistor radios and fixing them up. Most have been sort of disappointing as a cleaning of the switch on the ear bud plug fixed several, a couple more needed 9 volt plugs, most needed a few caps replaced but at long. last I got one that I needed to trouble shoot. It was branded O M G S, never heard of the brand but it is US Built, the genuine cow hide leather case is stamped JAPAN on it. At any rate it came to me listed as dead but it did have a pop on the speaker when I switched it on. I did a lot of checking with my home built signal tracer and nothing. Then I remembered one radio you had where the detector diode was bad. I checked that and sure as hell that was the problem. I have a bag of geranium diodes they are much smaller then the one in the set but when I replaced it, and, of course replaced 2 resistors that were broken in the middle for some strange reason, she began to get the signal. All her caps were dead as hell and when replaced the radio came back to life and works great now. Thanks for the education, I love getting these old sets working once more I now have a collection of 9 that I have fixed in the past two months. They all work most very well a few still need a cap or two replaced to get the volume back up but they are in a difficult position on the board so I haven't done them yet.
Hi from England, I don't know if you have come across a British brand called Hacker which made high quality radios up until the 70s, not sure if any made it to the US or if they were sold there but they were the Rolls Royce of portable radios.
The number of transistors in a radio set was a selling point to the the public the implication being more transistors equals a better radio. I once owned a Lifetone set that had 14 transistors in it and the sound quality was abysmal and only 6 of then really did anything. The transistor count could of made 2 wonderful Sony TR-75 sets but numbers at one time blinded the public. I used to collect transistor radios and repair them and my collection was nearly 2000 radios collected from 1987-2012 when I sold the collection
What the hell was I thinking? When you showed that last week, I spied that there was no audio transformers. With a 12 transistor count, that's enough to build an H-bridge output capacitorless and transformerless directly coupled to the speaker. Had they done that, the radio mighta had decent sound. Who'da thunk they'd put a buncha diodes in the circuit? Some of my better sounding radios have split battery supply with the transistors tied direct to the speaker. In the early 70s, Radio Shack had a few OTL/OCL radios that sounded fairly clean.
Wow! Some new circuit to come across! Times when the public would pay for shortened transistors. I always wondered how we could detect both half waves in an AM detector. Thanks for you showing us patiently all details.
I like when you start to speak like a Comedian about all these extra transistors put in there. It is laughable when you start to speak. And it suits the listener. Good sense of humor!
My dad fell for the 12 transistor hoopla go a new radio at a flea market they sucked power from the battery. I read the articles about the these when I was getting my electronics degree.
It's so oddly cool that you have the original boxes for these. And I'm really surprised how the box is modern looking with text and colors that look modern.
Great Video Shango -- a few thoughts: First, those transistors wired as diodes should be for temperature compensation. I an very dubious of the schematic because of their shown-configuration. The Vbe of germaniums really moves around with temperature with gain going up and Vbe going down. The reason they use transistors is 3-fold: first the transistors will have the same tempco as the others, where diodes have to be characterized; next it can be because they bought a butt-load and just used them; and lastly, for the reason you talked about in that they come with bragging-rights. On the converter, they can be finicky for biasing to get a good conversion ratio. The 2N5086 is actually a high-gain (150-600) low-noise, and low-frequency(40MHz) but are silicon so this will affect the biasing. Since the gain is so high, you got away with it both in biasing and conversion efficiency. If you played with the 2N5086 biasing, you might even make the front-end hotter than the 'mushroom' transistor that had the really low hfe. The diode-connected TR6 is just sets a emitter voltage for TR4 to work off of; also because it uses the BE-junction it will also track with temperature.
While I only understood maybe 1/2 of what you were showing and saying I truly enjoy your commentary, your choice of words at times :) . Use to make these with my ole radio shack stuff, I actully draw ( not real) schematic diagrams randomly as relaxing art . Thanks again for the pocket radio show and your unique commentary!!
I'm in my 70's and remember very well when transistor radios flooded the market in the late 1950's and 60's. People didn't know any better and were led to believe that the more transistors a radio had, the better it performed. Many manufactures took advantage of that falsehood and advertised the high number of transistors in their sets. In the electronic magazines of the time they addressed this topic. They called those extra transistors gimmick transistors. I remember one magazine that had photos that showed that some transistors were used as diodes with one lead cut off and some did nothing at all since all 3 leads were soldered together on the foil side of the board.
i love how you piss off the telephone marketers shango. markel farval larbin blad . i can't make out what you are saying to me, your markel farval deck La tay is drooping lady. I DON'T HAVE TIME FOR THIS . lol lol lol lol HA HA HA HA. i love you brother shango,
They used transistors as diodes because early diodes were extremely unreliable, and whenever you see a chinese QC sticker, you know youre dealing with an extremely high quality piece of technology. good enough to be used by the armed forces for critical communications.👌
A diode is always more reliable than a transistor (of the same material/quality) and this isn't early, it's from the 70s. Made in Hong Kong from surplus and factory rejected parts probably. People thought "more transistors = more better", or at least that what they thought back in old Hong Kong...
At 54:29 the transistors form a two diode bias network for the output complementary pair, but with each diode formed paralleled with another - the whole thing has R11 (300R) across it to set up the bias voltage correctly. It's a bit weird, I have to say :o
You mentioned getting chinese transistors at a few cents a pop. Nobility probably found transistor "seconds" for less than the cost of resistors, so they used them to get the transistor count up. I would have used diodes for audio phase inversion/bias for the output transistor. I appreciate shango's logical approach to troubleshooting, although I would have lost $$$ trying to repair this pos back in the day. Being retired, it's now fun taking on these kind of challenges, but I could have never made a living estimating bench charges. Congrats on restoring some "nobility" to this radio. I look forward to your next desert DX shootout vs more noted radios. Hope the Nobility kicks some... I look forward to your next post.
Great to enjoy my coffee and Shango Mornings This was a nice change and never seen the 4 transistor phase shift. This is a push pull configuration as you know. sure enjoyed my mornings been a ahile other than the short fireworks in the France on fire video
Seems to have quite a bit of positive feedback in the RF. (regen). Not sure if this is by design or a defect. Mushroom for the win! Now I pine for an aircheck of the Real Don Steele. Thanks Shango066. 👍
TR4 and TR6 looked like a current mirror to me. But a current mirror in a signal path? I have never seen that before. Normally, current mirrors are used in ICs to avoid lots of bias resistors (and therefore heat). This is a really stupidly overcomplicated radio which was designed to meet the target of 12 Transistors on the label without investing in the engineering to make full use of all 12 transistors. They were probably using rejected transistors as diodes to keep the cost down and the transistor count stupidly high. Beta of 8 on one of them. 8. And we're not talking about a massive power transistor here. I bet the schematic varied by the day depending on what defective transistors they were getting at the time. Crap, we've got a lot of PNP transistors this week: "Okay, employees, you know the drill, we reverse all the electrolytic capacitors and you solder the battery connector backwards!" What pieces of crap. It is fun to watch shango066 fix them.
@@BrainDamageBBQ It's hard to read because of how it's drawn. If you redraw it with power coming from the top instead of the bottom, it starts to become understandable. I see a typical audio stage with TR6 as an emitter resistor (or level-shifting diode).
Well it performed much better than I thought it would. The pink mil spec transistor may be improving the overall performance however; I am a little unsure exactly what it is doing, local oscillator perhaps? I guess the transistor count was a big selling point back in the day. Loving the videos as usual, please keep up the good work. Best regards from the UK.
@@westelaudio943 NO, only depends if the flux is acid core, which should ONLY be used on plumbing! Rosin core NEVER needs cleaning, except for cosmetic purposes. FACTS.
Good job shouldn't we take that 1 on your next hiking trip and see how it does it out in the middle of nowhere that's gonna be interesting a good job for a proud of you for what you do and it's very interesting what you can make these old radios do this with a few changes and transistors
Thanks for naming that popcorn song at 30:00. Haven't heard that one in decades, I stopped the vid and did a search on what I remembered it was called, totally wrong of course, then started searching on the more generic synth songs from the 70s. That drew a blank too. Then you named the track haha and that was it. Had a listen to the real thing then came back to watch the rest of the radio.
3:09 I'd guess that those 4 transistors-made-into-diodes are there to regulate the voltage drop needed to keep the upper emitter-follower in the push-pull output stage turned-on. That, and to increase the transistor count to 12. I don't know why they needed 4 instead of 2 in series; maybe they were rejects that were just good enough to sort-of work as diodes, so doubling them up reduced the chance of failure. I've read that these early imported pocket radios were made from the many transistors rejected for use in the computer and defense industries in the USA. Also interesting is that they tied the emitter and collector together to make the detector diode, but bizarrely tied the base and collector for the rest of them; could it be that they were using transistors sorted according to their failure modes?
I'm thinking part of the reason for the sensitivity to the oscillator transistor is the transistor's RF gain. The feedback is transformer coupled and I'd expect it to decrease as you tune down the band. If there isn't enough gain at that frequency, the oscillator will drop out. That magic mushroom probably has good RF gain.
GREAT 👍 Nobility radio 📻 complete with leatherette case, warranty and box 📦. Just needs fresh electrolytic capacitors, the case is in a little rough shape, but it’s still a GREAT 😊 radio 📻. Your friend, Jeff.
Might be worth cutting the top off one of the fully shorted transistors to see if there is actually a transistor in it - they may have simply bonded the 3 leads together.
The shorted transistors are a GREAT way to get rid of your defective stock and make money off of them, marketing a higher transistor count. Almost criminal, if anybody could prove it in a lawsuit.
Great. I wish my current project my no transmit on HF & 6 Metres was as easy as this. My Kenwood TS2000 ham rig with tiny surface mount components. I'm pretty sure I know what the issue is. Wish me luck I must repair it.
4:08 Two of these four transistors serve to slightly open the output transistors to reduce the step distortion, and another two are there just because)) Actually, they are just paralleled two by two, but the schematics looks like it's not something that stupid
Man glad you fix this stuff i would just look at it in confusion not because i am to dumb to fix it but like why does this even exist Thanks for your videos
Well done, never gave up. I took it outside with the mushroom and it's hot, can't say that I have ever heard that phrase before. If it's ok I have recorded your response to the sales caller and will use that for similar calls.
Polishing turds, another form is Water Reclamation, your doing a fine job at it. City of L.A. has openings for Wastewater Treatment Plant Operators, your qualifications are excellent. Dig your videos. Peace
The am detector diode transistor can be biased as an active detector increasing performance even more. I recall the best AM transistor radio I built used a unbiased germanium transistor as a detector. had 3 transistors and was TRF. simple.
@@Bob-1802 unbiased germanium transistor has sufficient base current to make it work very well as a detector - it was known as the power detector circuit.
Many years ago when I was a kid, I was working on one of those 10-12 transistor radios and one transistor all three leads were inserted into the SAME hole and soldered. It did nothing! Too long ago to remember what the radio was, but the most egregious lie of number of transistors in the radio.
8050/8550 are transistor pair used in h bridges in some chinese rc cars, c945 should be high frquency general purpose with high power output used in walkie talkie amplifiers (27mhz range) bc 327 337 and 547-548/557-558 should be as you said basically the same in any regards anyway by datasheets, the beta would be indicated by last letter a,b or c and non sorted for beta are with no last letter so rage of amplification is wide, 517 might be a darlington and 550 could be a low noise version a1015/c1815 were used by taiyo rc as h bridge drivers in 1986 version of posche turbo targa (i have 2 of them so i know) i have no idea why do you need so many general purpose transistor variants while they are almost the same but a nice set to have
AM Converter transistor is very susceptible to parasitic oscillations if they have FT higher than 20mhz. You can tamea high ft transistor with a stopper resistor in the base of about 1k. creates a lowpassfilter and effectively reduces FT
I love how they used transistors as diodes, just so they can say 'We've got 12 Transistors in here' LOL Well, why not a solder blower instead of a solder sucker ? 👍 Small mushrooms for the win. Nice one.
