I have an Ekco U332 and it looks SO similar to this, so of course at first I assumed it was the same (valve) chassis inside. I was SO surprised to find it was a transistor set! Back then, valves were thought of as old-hat, and transistors were the cutting edge, so it is surprising that they made a 'modern' transistor set deliberately designed to look like an old valve set. But, I suppose on second thoughts, maybe it's not so odd, as today we get DAB/Internet/Bluetooth sets made to look like 1960s transistor radios.
@@michaeldranfield7140 Maybe at the time, Pye still had a lot of bakelite cases & metal chassis to use up from the previous valve version. Even the Back cover & the dial plate makes no mention of being a transistor version!
On the front tuning display near the beginning you can see red and blue diamond shaped stickers. These were sent by the BBC to I think all households to mark the new station positions due to the big frequency changeover in late 1978. Radio 4 took over from Radio 2 on longwave and Radio 1 moved from 247Metres/1215 KHz to 275/285 metres.
@@michaeldranfield7140 1978, i vaguely remember it, i was 6 and had a fidelity radio as a birthday present and stickers came with it as it was made just before the change, still got it! they brought out more, and bigger stickers when radio 5 started, in the mid 90s, i have some somewhere
I have a couple of the EKCO versions on my to do pile. I also have a valve version that looks similar. I believe there was an issue on these sets , if the rectifier fails it took out the mains transformer as well. Hence we used to put in a fuse between the transformer and rectifier as a precaution . Another enjoyable video
i have one of those, used to have 2 others of the alternative brand versions, Ekco A455 and Ferranti 5700...it suffered from internal short to can in one of the output transistors, i've come across it a lot recently, i had to chuck over half my stock of AC128s because of it, many wouldnt recover after attempting to blast the shorts with a large charged capacitor, try this with your bad ones, it worked in my Pye!... i'd advise fitting a fuse in these somewhere as it could be very easy for it to fry the transformer or rectifier otherwise. These use the same cabinet moulding as the Ekco U332 /Ferranti U1015 valve models, i have one of each of those also 😉 the gang rubbers always seem to rot and tilt the gang in these , the transistor models use a strange 'tighter'/'flatter' log type volume control, fitting a normal log results in the volume increasing quite quickly as you turn the volume up from minimum, they seem to have too much AF gain anyway, and may be better to add a resistor between wiper and audio board or remove the emitter decoupler cap of the preamp transistor ...
Love the video, I have the original Pye radio sat in front of me so I recognised it, and it is still working well. They don't make then like they used to.
Hello Michael. This video came just at the right moment. Last week I tackled my vintage 1971 Dynatron audio system, with an srx 25 tuner amplifier and Goldring Lenco GL75 turntable. One channel had no signal through the output stage. It was full of those classic germanium Newmarket transistors. The audio driver was the same encapsulation, and the problem was exactly that, worked when released from its heatsink. It could have been an Ac 128 equivalent. I left the transistor and its heatsink floating in free space, so now i have work out how to connect it thermally to chassis, maybe with something like a to 220m type mica insulating kit. Its only my own personal set, so professionalism is not so important. I shall never part with this unit, it provides remarkable reproduction for my tv sound and dab tuner, through a pair of floor standing LS 200 speakers. Was it not the case that Dynatron, Phillips and Pye all used Newmarket NKT types ? I believe the srx25 amplifier went to production in 1969. And to think, back in the70s, I had ac128s coming out of my ears !
Yes , you might be wasting your time trying to obtain good AC128 transistors , the brand new one I had in stock was faulty so I considered this mod to be as good as anything .
It seems like Philips is plagued with tin whiskers. I have a Philips scope from the early '80s in which the housing of almost all the potentiometers have hundreds of tin whiskers on them, the length of some of them is in the cm range. Many commenters say they have whole batches of shorted Philips germanium transistors due to tin whiskers. I suggest to buy Hungarian made Tungsram germanium transistors, I've never seen one with a short to the case, and they made the most common types that Philips also made. East German and Czechoslovakian ones are also probably good, and Soviet ones too, although those are in weird packages usually.
This was a major problem when solder went lead free quite a few years back , as its the lead in solder that prevents tin whiskers growing , it was the cause of all the pace sky boxes having no satellite signal and LG TV having so HDMI input.
Man i was about to use a broken philips tape pcb for parts, im a bit nervous now lol. Thankfully i have a good few tungsram and soviet and eastern German transistors that havent failed me yet
I’m no expert but maybe the original manufacturer had a large stock of chassis’s & trays for valve sets that they couldn’t shift, so with a few tweaks hey presto transistor radio.
Spot on as always Michael, is it still ok to come over for a quick visit, you did tell me the best days but I can't remember it was about 12 months ago, Keep up the good interesting work. See you soon Dave Fletcher.
Fascinating last Harrah of British table top receivers It is not much different from the Valve Pye P75 from the early 1950s layout and tuning capacitor wise. Do you think they were using up inventory making these sets? British radios sounded great compared to the imports. Would shorting all 3 transistor leads together and passing high current to sever whisker to the case work like in the AF117/5s?
Yes , shorting 3 leads and passing a current from the case would destroy the tin whiskers but they grow again , in modern semiconductors tin whiskers can also be destroyed by heating the device to a high temperature , say 200 degrees but I wouldn't risk that with germanium .
Great repair, sourcing good AC128 transistors at sensible prices is difficult these days, I'm actually surprised the Mullard if strip module was ok, they're notorious for dud AF117's, can't say i remember that model, might've been a short production run as the concept of mains powered table radios was getting a bit dated about then.
This is from '69, tabletop radios were made until the '80s (I've seen a Blaupunkt one from the early '80s), but in the eastern bloc, they were made until the late '80s - early '90s, by RFT in East Germany, TESLA in Czechoslovakia, Unitra in Poland, Electronica in Romania, probably by Radiotehnika in Latvia (part of the Soviet Union back then), and probably by several other manufacturers in the Soviet Union.
No, originally not, because the case is internally isolated from all the leads. But germanium transistors from some makers tend to develop tin whiskers, which can cause internal shorts.
I would have put money on that being an old valve radio. Especially when seeing the back of it. They must have had some old valve chassis to get rid of. 😁
Hello Michelle Hello everyone love the videos michael keep them coming allso does anyone know what backlights will fit a medion md 31369 65 inch tv can't find any anywhere please anyhelp would be great thankyou
The IF Mullard Module used in many Phillips aind associated other makes that used it has Germanium AF117 Transistor s that often went Faulty . Germanium material Terrible. The Faulty Audio Transistors Michael showed us highlights how bad Germanium Transistors were .
The ones that are bad in NOS condition are either had a seal failure and the mositure EOL'd them, or they have tin whiskers. None of which is the problem of the germanium itself. It seems like Philips had a problem for decades with their tin plating procedures, Philips products have tin whiskers in them a lot more often than other European brands. Yes, germanium transistors are very sensitive to heat and prone to thermal runaway, but they are nowhere near as bad as some people think. But it seems that ones made by Philips should be avoided.
Reminds me of the 4-terminal germanium transistors where the screen terminal goes short to one of the other connections.
Had that, just have to cut the screen lead off.
@@michaeldranfield7140 Yes, done that a few times.
I have an Ekco U332 and it looks SO similar to this, so of course at first I assumed it was the same (valve) chassis inside. I was SO surprised to find it was a transistor set! Back then, valves were thought of as old-hat, and transistors were the cutting edge, so it is surprising that they made a 'modern' transistor set deliberately designed to look like an old valve set. But, I suppose on second thoughts, maybe it's not so odd, as today we get DAB/Internet/Bluetooth sets made to look like 1960s transistor radios.
I must say I was a bit disappointed when I first took the back off but this is a nice addition to my collection .
@@michaeldranfield7140 Maybe at the time, Pye still had a lot of bakelite cases & metal chassis to use up from the previous valve version. Even the Back cover & the dial plate makes no mention of being a transistor version!
On the front tuning display near the beginning you can see red and blue diamond shaped stickers.
These were sent by the BBC to I think all households to mark the new station positions due to the big frequency changeover in late 1978. Radio 4 took over from Radio 2 on longwave and Radio 1 moved from 247Metres/1215 KHz to 275/285 metres.
those stickers are horrid to remove!
I remember the stickers but can't remember the year.
@@michaeldranfield7140 Late 1978, have a search, quite a lot of info on it.
@@michaeldranfield7140 1978, i vaguely remember it, i was 6 and had a fidelity radio as a birthday present and stickers came with it as it was made just before the change, still got it! they brought out more, and bigger stickers when radio 5 started, in the mid 90s, i have some somewhere
I still have my radio that I took to university, with those stickers on it, and yes it would have been 1978.
Nice video Michael - very surprised to see it was a transistor set!
I have a couple of the EKCO versions on my to do pile. I also have a valve version that looks similar.
I believe there was an issue on these sets , if the rectifier fails it took out the mains transformer as well. Hence we used to put in a fuse between the transformer and rectifier as a precaution . Another enjoyable video
i have one of those, used to have 2 others of the alternative brand versions, Ekco A455 and Ferranti 5700...it suffered from internal short to can in one of the output transistors, i've come across it a lot recently, i had to chuck over half my stock of AC128s because of it, many wouldnt recover after attempting to blast the shorts with a large charged capacitor, try this with your bad ones, it worked in my Pye!... i'd advise fitting a fuse in these somewhere as it could be very easy for it to fry the transformer or rectifier otherwise. These use the same cabinet moulding as the Ekco U332 /Ferranti U1015 valve models, i have one of each of those also 😉 the gang rubbers always seem to rot and tilt the gang in these , the transistor models use a strange 'tighter'/'flatter' log type volume control, fitting a normal log results in the volume increasing quite quickly as you turn the volume up from minimum, they seem to have too much AF gain anyway, and may be better to add a resistor between wiper and audio board or remove the emitter decoupler cap of the preamp transistor ...
Oh that was a surprise Michael. Didn't expect a transistor set ! Yes the whiskers are a big problem. Never thought to use that approach
Love the video, I have the original Pye radio sat in front of me so I recognised it, and it is still working well. They don't make then like they used to.
Don't make anything like they use to now, had a TV in for repair Monday 13 months old LCD panel failed.
Hello Michael.
This video came just at the right moment.
Last week I tackled my vintage 1971 Dynatron audio system, with an srx 25 tuner amplifier and Goldring Lenco GL75 turntable.
One channel had no signal through the output stage.
It was full of those classic germanium Newmarket transistors.
The audio driver was the same encapsulation, and the problem was exactly that, worked when released from its heatsink.
It could have been an Ac 128 equivalent.
I left the transistor and its heatsink floating in free space, so now i have work out how to connect it thermally to chassis, maybe with something like a to 220m type mica insulating kit.
Its only my own personal set, so professionalism is not so important.
I shall never part with this unit, it provides remarkable reproduction for my tv sound and dab tuner, through a pair of floor standing LS 200 speakers.
Was it not the case that Dynatron, Phillips and Pye all used Newmarket NKT types ?
I believe the srx25 amplifier went to production in 1969.
And to think, back in the70s, I had ac128s coming out of my ears !
Yes. I chucked them all away when I closed the shop...😢
Yes , you might be wasting your time trying to obtain good AC128 transistors , the brand new one I had in stock was faulty so I considered this mod to be as good as anything .
Another great video thanks again , I would put money on that saying that was a valve radio😊had the same fault with a bush radio with AF 117 transistor
theyre very commonly afflicted by internal tin whisker shorts, even NASA investigated it
Me to, especially with the aerial and earth sockets on the back.
Nice repair. Great to see the Sanwa multimeter on the bench ready for action 😊
Sanwa is an old company , they were making mulitmeters back in the 60 s
It seems like Philips is plagued with tin whiskers. I have a Philips scope from the early '80s in which the housing of almost all the potentiometers have hundreds of tin whiskers on them, the length of some of them is in the cm range. Many commenters say they have whole batches of shorted Philips germanium transistors due to tin whiskers. I suggest to buy Hungarian made Tungsram germanium transistors, I've never seen one with a short to the case, and they made the most common types that Philips also made. East German and Czechoslovakian ones are also probably good, and Soviet ones too, although those are in weird packages usually.
But where to find good source of Tesla OC170 and GC5XX or hungarian AC?
This was a major problem when solder went lead free quite a few years back , as its the lead in solder that prevents tin whiskers growing , it was the cause of all the pace sky boxes having no satellite signal and LG TV having so HDMI input.
Man i was about to use a broken philips tape pcb for parts, im a bit nervous now lol. Thankfully i have a good few tungsram and soviet and eastern German transistors that havent failed me yet
@@michaeldranfield7140 But this problem with Philips germanium transistors is here from 60s :-)
Looking at the schematic, nice and easy set but oh those awful AC128s. Notice use of a thermistor for stabilisation requirements as well.
Keep em coming Michael
Loads more on my pc, coming soon.
Of course, more soon.
I’m no expert but maybe the original manufacturer had a large stock of chassis’s & trays for valve sets that they couldn’t shift, so with a few tweaks hey presto transistor radio.
Well I never guessed that radio was solid state!
Richard
Me to, I was shocked when I removed the back, an interesting little thing though as part of my collection.
Spot on as always Michael, is it still ok to come over for a quick visit, you did tell me the best days but I can't remember it was about 12 months ago, Keep up the good interesting work.
See you soon
Dave Fletcher.
Yes of course , just let me know the day before, closed Wednesday and Sunday .
Will do Michael. 😀
Fascinating last Harrah of British table top receivers It is not much different from the Valve Pye P75 from the early 1950s layout and tuning capacitor wise. Do you think they were using up inventory making these sets? British radios sounded great compared to the imports. Would shorting all 3 transistor leads together and passing high current to sever whisker to the case work like in the AF117/5s?
Yes , shorting 3 leads and passing a current from the case would destroy the tin whiskers but they grow again , in modern semiconductors tin whiskers can also be destroyed by heating the device to a high temperature , say 200 degrees but I wouldn't risk that with germanium .
Great repair, sourcing good AC128 transistors at sensible prices is difficult these days, I'm actually surprised the Mullard if strip module was ok, they're notorious for dud AF117's, can't say i remember that model, might've been a short production run as the concept of mains powered table radios was getting a bit dated about then.
This is from '69, tabletop radios were made until the '80s (I've seen a Blaupunkt one from the early '80s), but in the eastern bloc, they were made until the late '80s - early '90s, by RFT in East Germany, TESLA in Czechoslovakia, Unitra in Poland, Electronica in Romania, probably by Radiotehnika in Latvia (part of the Soviet Union back then), and probably by several other manufacturers in the Soviet Union.
Hiya Michael I have got the manual for this set and just about every other british made radio
Lovely to see the old technology working, better then the cheap rubbish you get these days, Thanks Michael
I had the identical set , it's an EKCO , remember them
Back in the 60's car radios came in either EKCO (EK Cohen I think) or PYE. The only difference was the name on the dial.
E.K. Cole.
Yes, dont those transistors require a MICA wafer for isolation?
No, originally not, because the case is internally isolated from all the leads. But germanium transistors from some makers tend to develop tin whiskers, which can cause internal shorts.
I would have put money on that being an old valve radio. Especially when seeing the back of it. They must have had some old valve chassis to get rid of. 😁
Not replacing the selenium metal rectifier? Which can be very failure prone, with nasty cat piss stink.
Not while its working .
Hello Michelle Hello everyone love the videos michael keep them coming allso does anyone know what backlights will fit a medion md 31369 65 inch tv can't find any anywhere please anyhelp would be great thankyou
It would be better searching for your led bars using the panel number of the back of the LCD screen rather than searching the model number .
Another great video, first comment? 👏
The IF Mullard Module used in many Phillips aind associated other makes that used it has Germanium AF117 Transistor s that often went Faulty . Germanium material Terrible. The Faulty Audio Transistors Michael showed us highlights how bad Germanium Transistors were .
The ones that are bad in NOS condition are either had a seal failure and the mositure EOL'd them, or they have tin whiskers. None of which is the problem of the germanium itself. It seems like Philips had a problem for decades with their tin plating procedures, Philips products have tin whiskers in them a lot more often than other European brands.
Yes, germanium transistors are very sensitive to heat and prone to thermal runaway, but they are nowhere near as bad as some people think. But it seems that ones made by Philips should be avoided.
cool!