5 Core Radio Update: AM distortion fix and battery voltage thoughts
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- เผยแพร่เมื่อ 9 พ.ค. 2021
- In my previous video on the 5 Core T22 Radio, I found that I had bad distortion on AM radio station when playing music. In this video, I figure out and completely fix this issue. I also talk about the power requirements of this radio and if using a Lithium Ion battery is bad.
First 5 Core radio video where I test and upgrade the power source to Lithium Ion:
• Upgrading the Indian 5...
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VWestlife's Original Video:
• Searching for the last...
• Secretly made by Sony ...
Shango066's 5 Core radio review:
• Modern 5 Core AM FM SW...
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I work in rf repair all day we make low end adjustments; this is what I thought the issue was right off the bat. Excellent trouble shooting! I'm probably gonna buy one of these now 😄
Wow.. I remember having this same issue years ago with my 5 Core T22 and I did the same mod with the 1µF cap replacing it with a 10µF cap. The AM sounded super clear after that. I also thought it was a manufacture fault with my unit, I didn't realize other units had the same issue until I saw this video. lol
How many people in the world bought this shit???
@@phs125
😂😂😂
This has more cores than my PC.
@Benson Ryker yea, been watching on instaflixxer for since december myself =)
It's a piece of junk. I have no idea why people in this sphere are buying them. They are very, very poorly made and pretty expensive for what they are. Once Vwestlife and shango did videos on it, that made the price go even higher.
This radio is so fast....
The ant is looking into the mystery of the dissapearing Haribo candy
Packaging: Wow such quality!
Internals: Can't even follow the datasheet.
I love how simple and robust this device is, but a little bit of attention to detail (like selecting the correct passives) could make it so much better!
I just did the fix on mine, it was overloading even on my Part 15 in-house transmitter. Now it works perfectly!!! Thanks for this video.
I just use mine with two D batteries.
Excellent work..you are getting better and better at troubleshooting.
Cool. Good piece of detective work, Adrian!
sounds like the 1 microfarad capacitor was an error (should be 10) but probably slipped through what little quality control there is, but made sound marginal on high power stations, also cheap low value caps can be under value and get lower with age as well. Good fix Adrian.
C21 is a DC block, It blocks VCC from the audio amp transistor from shorting to ground through the speaker winding.
I love radios, I love Adrian videos. Great combination!
Your common sense is amazing. Great job!
That cap value change was probably providing the 'high sensitivity' feature! ;-)
Amazing troubleshooting!!
Great video. I love fix videos.. keep it coming
Hi Adrian I am a Amateur radio operator and good job spotting the incorrect capacitor.
But there is one mod you can do to improve the AM receive if you choose to do so.
Simply take a 22gauge insulated wire and put about 4 or 5 turns of it around the ferrite rod antenna and put a simple RCA female connector on it. It doesn't matter the polarity.
Then take a long wire 40 - 50 feet long out doors for a long wire antenna and one wire to ground and connect it to a male RCA and plug it in the radio.
The coil around the antenna in the radio will couple it to the antenna out side and give you better reception.
BTW I did send you an Email about sending some E-proms from the 90's
Just let me know how many you want if any. And I will include a variety pack of my fav retro candy as well.
Keep up the great work.
Oh and if you tie the wire to a tree or other item. Make a loop in the end of the wire and tie on some nylon cord at least 12 inches from the tie down object to act as an insulator.
And un plug it when not in use or when a turned storm is coming.
A longwire antenna will definitely help for DX. I have a GE Superadio, and I’ve gotten very weak stations with a longwire on it.
Great job 👏 more radio 📻 videos please!
You might enjoy this channel if you didn't already know about it. Mr Carlson's Lab
great channel and informative as well. Thanks.
Simple fix indeed, amazing how using the right parts can make something work properly... :P
Oooo, a secondary channel... Subbed👍🏻
That coupling cap in af out is not a bass/treble cut, it's a DC block so the speaker doesn't DC short out the IC.
All transformerless transistor output stages AC couple to the speaker via a LARGE capacitor.
You have ANTS.
AGC cap size will change the AGC attack and decay time. No biggie, the lower value should have been ok....unless it also keeps bass from modulating the AGC. Maybe the higher voltage caps have a higher ESR?
I noticed after using this radio with the new cap for a while the AGC and AFT works properly now. Overall AM performance across the entire band is noticeably improved (not to mention the bass no longer causes distortion.) It also seems to have affected AFT on FM as well, because before the mod, FM would seemingly drift as if AFT wasn't working. Now it seems to stay locked on day to day on the same station.
@@adriansdigitalbasement2 Guess Sony knew what they were talking about. Someone in India must have lost a decimal point!
@@scharkalvin too low an agc cap will result in bass frequencies affecting the agc volts and therefore the gain in time with the bass, making distortion , this was an issue in a few thorn(ferguson, hmv, marconi) made valve sets here in the uk, they used a 0.005uf for one chassis, used in several models, where pretty much all others makers, and thorn in other models, used 0.05 to 0.1 ,
I'll join the choir to sing the praises of a properly working AGC on AM.
I'm wondering if the design difference is due to differences in understanding where the Radio is being used. I don't recall the detailed history behind the radio other than it's from India. I have no idea what the conditions are there, how many stations and how far apart. I know some areas of the planet use different "channel" spacings than other areas. If this version is designed for the North American or US market, then it should be set up to work best there.
You can also install missing IF filters, I believe I have seen wire bridges instead of them on the board (labeled CF2, CF3)
The small capacitors are often only produced with higher voltages. Maybe it is just not worthwhile to produce a 10µF for many different voltages, a 50V Cab is then for all voltages.
thats exactly it, difficult to find low voltage low capacity electrolytics these days
I love these videos! I find it pretty neat when you ‘upgrade’ old pieces of equipment in minor ways. Or I guess in this case fixed it? Watching your videos gives me the itch to maybe give fixing old computers or improving them a go even if it’ll be mostly failure it might be fun.
These are actually brand new! It's believed that these are the last fully analog am/FM radios made anywhere in the world. Everything else tunes digitally.....end of an era.
@@aaronblair9583 very true, albeit the chip isn’t being made anymore and thus was likely recycled from the Sony model this cloned, or their mini hifis, and that kind of thing. I guess it’s kind of like if you bought one of the last 2CVs in 1990 (IIRC that was the final sale year) it was simultaneously a new car that was also very old.
@@kaitlyn__L yep, one of the many lazurus chips. Back from the dead. It's also possible that a company in china cloned it....but I digress
Also, 2cv's are incredible cars. I've had the luck to drive one on several occasions. Shifts like magic. Far superior to it's only real competition that I've also driven, the vw beetle.
Great work!!! Thanks so much!!
I’ve seen “mistakes” like those on schematics before and I wonder if they were done on purpose for some sort of copyright tracing on the schematic
With cheap electrolytic caps ESR goes down with higher voltage ratings and with larger capacitance ( generally ). However this is a "trend" only but may help in electrolytic cap selection. ( temperature makes a big difference - so much so that an increase of 10 deg C causes many cheap electrolytics to fail in half the time. ) THANK YOU for your videos!!
doubt if esr would be an issue in a fairly standard radio circuit, a psu , maybe
When I saw the bent ferrite core on the antenna, I thought "Wow, that speaker has a really strong magnet!"
Sharp thinking. Good job.
Nice videos about radios Adrian! If you're planning for more videos about radios in the future you might try to setup a small fm (or am) transmitter to broadcast (between the walls of your house) free library music, so we can get a good impression of the audio quality. Vmr6512 for instance is an excellent affordable transmitter (running for years here :-)
Amazing how low quality sound people accept nowadays
very interesting video.
The only low quality on this 5 core radio is poor plastic case but not the dound!
@@paididoy Do not understand! Mono radio with a simple speaker in a bad plastic box. Do not people know what good sound is?
logitech squeezebox radio had very good sound quality! logitech used a good 3 "midrange and 1" dome tweeter.
Everything is made with a lower quality, i cannot overstate this. I'm 15 and sometimes i buy vintage stuff and see how well built it is. Its a race to the bottom with manufacturers and the public kind of accepted it
Hi! Great job on this fix. My T-291 by 5-core has the C14 position cap value of 50v 10uf. So this confirms your fix is correct. I'm assuming the T-291 is the next generation and they fixed the incorrect part problem. My radio never suffered from the bass distortion on AM.
I have the T291 version. Same exact board. Same exact problem. Same exact fix got it going good. It's not an upgrade, just a different housing.
nice!
Commodore springs to mind
I decided to buy one of these. I am curious how I can better this unit. I am thinking USB power jack and if I want to battery power, I have many USB banks. For $25.88 it's worth the price to experiment with.
It probably is just stock availability replacement, but might also be a desired effect. This capacitor defines reaction time of the gain control and what you've heard aint a distortion, but in effect a parasitic modulation. In certain situations people who ones were professional radio operators and now are HAM radio operators used to regulate time constant of or disable AGC in order to hear very week signals very near to strong ones, but to have desired effect this would also require to narrow the RF bandwidth which is not the case with simple receivers like this one.
A little bit of Big Clive vibe here 🙂
I was thinking the same thing, camera angle, printout of schematic. Let down only by using a screwdriver worth more than £1
@@falken_gt4 Haha yes, that china screwdriver in every video.
Even the desk top has the vibe
I'd 3d-print an adapter for the battery compartment that has the same form factor as two regular batteries and contains the cell and the board :)
How?
Smart!
Great work. I am impressed with the size of the speaker that came with it. Looks like the magnet is pretty big. I am guessing the bass response is pretty good for a small portable radio. I may order one for a work shed radio.
I own one, tobe honest, The highs are clear, the mids are excellent and no it does not have any real bass.
Yeah, 5 core's other products are speakers and microphones, so their speaker is manufactured in house
I appreciate the fact that it's one of the very last analog radios... But I still don't get why 5core radios receive so much attention from so many TH-camrs. Look like crappy radios to me : packaging is not sufficient to protect the device, quality control looks inexistant otherwise the 1 vs 10 uF issue would have been detected and fixed. And they're not even that cheap. Any decent used 80's or 90's device looks like a better option to me.
the higher voltage rating for the caps has a simple reason:
availability and potentially price and also the way the manufacturing plant purchases their stuff.
And, in some cases, you can go with higher voltages and go with a shittier series and have the same value.
The speaker mounts look straightforward, and I bet you could replace the speaker with a better 'full range' driver easily. Use the appropriate capacitor for the filter, and I bet that little Sony chip can drive a really high quality sound....
That actually already is a pretty darn good full-range 4" driver. I own two of these. One in new condition for my collection and one beater knock-around for casual use outside.
Adrian, based on what little I saw of the schematic (no charge pumps or DC-DC boost conversion), the voltage rating on the caps only needs to be 2x (10V max) the supply voltage for safety sake. I would guess that the factory was able to get the 60-ish volt caps for cheap so that is what they used.
Small value capacitors you find the amount of foil is small, so to get a length that is workable with the automatic machinery they use a higher voltage foil, so the length is something the machine can wind up with ease. That the voltage rating is now 50V is immaterial, the case cannot really be smaller in the leaded parts, so the manufacturers do not bother. If you open one up the foil is around 5 turns, and there is more paper than foil there.
As a bonus the higher voltage foil is actually slightly cheaper, as they do not have to etch it so much, and growing the oxide layer thicker is only a slightly longer time, plus the tolerance on it can be a lot looser. That is why the leaded capacitors under 10uF often all are the same size can, as you really cannot make the seal smaller cheaply.
Ah ok -- great to know!
@@SeanBZA That was really insightful. Sometimes the kind of knowledge I don't really need to know is what I like the best.
@@SeanBZA hey, that brought back long lost memories of my electronics teacher saying something similar. Thanks!
👍👍
Let the manufacturer know! Maybe they'll replace the capacitor to your spec??
Speaker crossover caps are usually non-polarized electrolytics.
If RS is anything to go by, a 4.7uF at 25V which is the lowest through hole mount voltage they do at this value, is twice the price of a 4.7uF at 63V.
The selectivity of the radio seems poor and there's ghosting of stations across the dial. Do you think that replacing the filters with better ones would improve this?
wow, no new car speaker? :) im telling you, if you install one you are going to see a major improvement in sound quality. id really like to see you install a 4in speaker in that radio :)
The more you can split up projects, and the more ideas for projects you come up with in the mean time, the better the long term health of your videomaking :) why combine upgrades into one week when you can split them into multiple :D
Of course people will sometimes bemoan their list is forever growing, but really, if your list of ideas starts shrinking, that’s when you gotta re-examine the situation. As that means you’ll run out if it keeps up like that.
Coming up with new ideas under time pressure, or worse throwing off your schedule if you can’t think of any, is far more unpleasant than wondering when you’ll finally get around to this or that project!
Basically: I would be surprised if a speaker upgrade isn’t in the pipeline already :3
I posted some thoughts and mods on Twitter and tagged you. I'd love to do a mono line-in mod to this.
I have exactly the same problem on a similar radio called Geepas. Also Indian I think . How do I locate the cap that needs changing. Are the ic pins numbered . If so which pin is it . Thanks.
It looks like they were just throwing in whatever capacitors they had laying around.
Inductors and capacitors can both be a high-pass or low-pass filter; depending on how you configure them in the circuit. I’m not going to try to explain in a TH-cam comment; but I would encourage googling for it - there’s lots of tutorials online.
nice fix, maybe the ferrite rod is intentionally bent in order to have close clearance room for the back side.
Dot is 1 line too high - connect vcc to battery ... Lipo is a good substitute. Its also missing a 465khz ceramic filter - too wide on AM . Easy fix replace jumper with 465CF
Looks as though you lost the screw under the ferrite antenna after all. I thought you might forget the one in the battery compartment when you took it upstairs for testing.
What happened to the VCC not being directly powered, or did I miss something.
was just a flaw in the schematic, the vcc was connected like it was supposed to be.
@@dcfuksurmom Ah, I thought the circuit was that way too.
Adrian, you have put the dot to the wrong place, you have connected VCC pin to the AGC pin. Put it 6-7 mm lower. Edit: you have corrected it. Should have watched it to the end.
The data sheet lists C8, C12, c13, c14 and c17 as 50V yet the radio, even with the old power supply configuration, would hardly get above 10v. Seems a bit high for standard electrolytic caps. I might suggest DigikeyPN 445-181284-1-ND. It is a ceramic and won't need the electrolytic re-formed nor will they leak.
Thanks, going to get that for mine.
Soooo...do we have a new Big Clive?
Good find but too long a video for such a small fix. The Sony chip is used everywhere and still in use today.
It's the same on all of them - mine has a 1uf cap - replaced with 10uf 50v
My personal experience with the Sony chip is that the audio power amplifier does not work well driving low impedance loads, it acts as if it is current limited (protection?)
My guess: increasing the AGC capacitor will probably make the AGC slower. With a smaller value, it will start to 'beat' along with the music.
thats it, the agc will vary with the bass, causing amplitude distortion, this was an issue in some uk made valve sets when they used a cap value 10 to 20 times lower than whats normally used, like here 😉
Swap that 18650 for a 26650 for longer play time. 😉👍
18:05 can you replicate the tuning LED
Could somebody link to the (correct) resistor? Not an electronics expert, but I did just order one of these radios, and can use a soldering iron. I feel confident enough to have a go :-)
capacitor, you mean.. if you're in the uk?? i can supply you with one, i have plenty of used but tested good capacitors removed from scrap equipment, you can have one for the postage cost
I wonder if the ripple filter is related to an external power supply.
stops/reduces chance of self oscillation when the battery ages as develops high internal resistance, but this wont be an issue with a lithium cell 😉, only zinc carbon/zinc chloride
You have a hyper active ant... Explains the mystery of missing lollies!
Get in touch with the factory owner let them see the video and a note about the "10 Cap".
thanks for offering
What an asinine suggestion.
The cap logo is Samwha but missing the text, so maybe counterfeit?
Could be Samwha, but printing on a small case is hard. Could be counterfeit, but for this use even the counterfeit part will be fine, no high currents and no heat, so they can last decades.
@@SeanBZA Well it wasn't fine for this use but that wasn't my point. I didn't mention performance because it was being replaced with another value. Just noting that it appeared to be Samwha based on the logo Adrian didn't recognize in the video.
Re capacitors... 50v because it's the most common dirt cheap voltage value. Nothing whatsoever to do with the circuitry, everything to do with the cost.
I'm thinking the capacitor going to the speaker is for filtering DC to the speaker.
WTF are you posting this stuff? - just kidding - absolutely love it 😁 more repair vids of old stuff like this please 👍
Can't see any reason why the caps would need to be any more than the next standard voltage above the maximum battery voltage, no idea why the schematic specifies 50V for a lot of them, but 6.3V for the main VCC decoupling and 10V for the output coupling, maybe it's a "house standard" in that lower value caps are a standard case size and 50V, while higher values have to be tailored to operating voltage otherwise they would be large and expensive.
Perhaps? I wasn't sure either. I was thinking maybe the RF reception could somehow induce some higher transients?
In small values voltage is not easy to get in low value cheaply, as the case determines the amount of foil used. Thus the small caps invariably are higher voltage, just making production easier. When you get to higher values yes lower voltage foils mean higher capacitance, but sub 10uF the can size stays the same, no matter if it is 0.1uF, 2.2uF, 4.7uF or 10uF the case is the same, just the length of foil inside changes. Hard to cut a thin low voltage foil to length accurately, and still expect to roll it up, so you use a higher voltage foil that is going to be longer, but is much more robust in the machinery.
Where is the Fifth core?
Vcc doesn't actually go through the diode, there is another resistor R7, that is acting as a shunt around the LED.
Note the LED does have a 1K current limiting resistor R6, but the R7 doesn't have a resistance value posted.
Admittedly, however, this schematic is drawn very poorly, as clearly, Vcc needs to go to the Vcc of the IC.
Further, you placed the sharpie ink dot on the incorrect trace in the schematic...
I think you draw the joint dot in the wrong cross line. It should be on the cross under where you draw. It will joint the power switch - vcc - LED (meter)
I wonder if the reason for the cap change is that maybe in India the number of "local" high power AM stations is lower? Maybe they wanted to make the AGC more sensitive for people in more remote areas?
I'm not sure the level of engineering extends to such design decisions. This is clearly at the sloppy backstreet factory level.
@@jasejj - Entirely possible; But this thing has been in production for how many years? No chance of a circuite tweak in that time for performance/market reasons?
@@JanEringa8k OK it's certainly possible.
Wouldn't it have been easier just to buy 2 D cell batteries? Asking for a friend...🙂
I'm not sure I would have even noticed anything wrong with the audio in the beginning if you hadn't put some text on screen about it... I'm still not even sure what the problem was supposed to be? lol
17:40 - now the ant is on your wrist :D
20:17 - that bar is probably bent like that because the speaker magnet is too close and it's too powerful.
I'd go with the extrusion machine being a bit worn out pushing out curved ferrite cores, or the sintering process not being done properly and it bending as it is being fired, it'd need to be an awfully powerful magnet to bend a rod like that, as in, in the magnitude of something that could pick up the crane that picks up ferrous scrap at a recycling place... :P
Maybe the ferrite was done in a banana bend machine. You know where they bend the bananas... Haha
@@twocvbloke That minute when the magnet grabbed the end gave me the idea but you must be right. I didn't know that is that rod made of.
These days only cottage industries are making radios in India. The country manufactured world class radios such as Nelco, Telefunken, Jetking during 1970s and 80s. This 5 core radio is not available in India. It is manufactured recently by a Delhi based company making speakers and amplifiers since mid 80s. 100 p. c of the product is exported. In India it is a prestige issue to visit an electronic and appliances store and ask for a radio. Most costumers would be there to buy HD LCD TVs, Washing machines, refrigerators etc. some of which are also indigenously made. Let the West know that today we are sending their satellites from our cosmodrome and rockets.
Kick off your High Heeled Sneakers, It's party time! AM Band Party, not 8 bit!
Test the value of the capacitor with your multimeter or esr meter .
esr wont be that important in a standard radio, psu, yes ...
Just got my T22 and it's wrong also.
50kW AM transmitter? Huh... There's a 2 MEGAWATT AM transmitter within 65km of my house.
hu.wikipedia.org/wiki/Solti_r%C3%A1di%C3%B3ad%C3%B3
You put the dot to connect the voltage on the wrong trace. You need to drop it one trace down. but I see you put a note on screen saying you caught that! :D
It's junky AND janky! :)
I'm sure the a.m. antenna is not assembled properly, the coil should be centred on the ferrite rod. Google image search for "am radio coil antenna".
Maybe it depends.. I saw most of AM radio that the coil is on or near at the end of the ferrite rod. I remember back in school when we assemble am radio kits and it won't receive any signal when the coil is on the center of the rod. I slowly move the coil to the edge and try to tune any stations when it could tune to a station, I try again to move either directions to the find the max sensitivity. When set, I drip it with molten candle wax or something that can hold it in place then continue the alignment by the IF cans. Not sure what others do but it works for me.
Why is this called a 5 core radio?
brand name.
Maybe because it has 5 IF cans on it.. those metallic thing with colored screw holes on it. That contains ferrite core or slug on it.
Why are they so proud of the fact that this thing is made in India? It couldn't possibly be more cheapy (or poorly) made.
Looking at a schematic almost think am watching big clive
16:10 anyone else thought a bug was on their screen?
14:50 Made in India.
Shortwave on that radio stinks!
you put the dot on the wrong line, one too high.
Sadly Sony just is not what they used to be, they were once the gold standard for electronics after the Zenith era, and now they are nothing special.
Microphonics.
you mean christian’s ant?