From practical wireless August 1955 to Christmas 2024.

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Michael Dranfield

Michael Dranfield

Күн бұрын

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@user-rf9me7xm1w
@user-rf9me7xm1w Ай бұрын
Oh Michael, that was true nostalgia for me. At the age of 6, I "helped" my uncle construct that project in 1955. Although he was coal miner, he had an avid interest in all things electronic and tutored me whenever possible. I had a fascination with his AVO minor which he taught me how to use without destroying it ! Happy days which fired me up and resulted in many enjoyable years of employment, culminating in 30 years of teaching at my local tech college. As late as 1980, thermionic device theory was still on the syllabus for the B/Tech and City and Guilds courses I used to present. I therefore owe a lot the Practical Wireless, and my uncle of course. Many thanks for sharing this with us, best Christmas wishes.
@vulgivagu
@vulgivagu Ай бұрын
In 1962 as a 15 year old I built a HAC (Hear All Continents)radio from a kit. It had two valves and I remember the thrill of seeing the valves glowing in the dark when I had gone to bed and was listening to it in the dark. Something very special about a lit valve.
@Bartok_J
@Bartok_J 29 күн бұрын
I wonder how many careers in radio those HAC radios launched? Mine was about a decade later, the one valve "Model DX Mk3": I ended up with an amateur licence at 14 and a career as a BBC Monitoring Service engineer.
@bill-2018
@bill-2018 18 күн бұрын
Aged 14 I made the one valve H.A.C. DX Model and bought two extra coils. A few squeals and whistles then a bird whistling, then an announcement, "This is Radio South Africa." I've bought several PM2DX type valves to make a similar radio. I still have the 2,000 Ω headphones my neighbour gave me. I think I overdid the valves, I kept buying them at every rally, £2 - £3 each and ended up with 22 of them. One type 30, one 6 Volt heater, one 215P power valve and two dud ones. Surprisingly one valve marked B.B.C. and D.E.R. with an intact tungsten heater and top sealing pip and info. says it was made between 1924 and 1926. G4GHB.
@electron0002
@electron0002 20 күн бұрын
I’m new to the channel.my grandfather used to make value radios I never new what happened to them he may of gave them away.I think you should sign the radio inside and hope it stay in the family may handed down to the grandkids
@m0dad
@m0dad 18 күн бұрын
Brilliant video Michael and thanks for sharing. Your homebrew radio turned out looking good and sounds like its working well. I love looking back at the old Practical Wireless magazine archives in World Radio History and have a 160/80M AM transmitter project I am building on the bench now from the Jan 1965 edition by F.G.Rayer. It can be very challenging and frustrating just getting hold of the parts as the good stuff is drying up now. Hope you may have some more radio projects in the future. Best wishes for the New Year.
@michaeldranfield7140
@michaeldranfield7140 7 күн бұрын
Of course there is more comming! I would love to make a transmitter for 27Mhz.
@BarbaraPape-y4g
@BarbaraPape-y4g 21 күн бұрын
I was only a baby when that copy of Practical Wireless was printed. From about 12 years old i would eagerly await each months copy to arrive on the shelves of my local newsagent. My mother worked in a greengrocers opposite the TV shop, and having built a radio from a kit that failed to work, i askewd them to have a look, instead they said comeback later in the afternoon and we will show you where you have gone wrong. This got me started in a hobby that became a trade after leaving school and going to tech college for my C&G certs and later the colour diploma. Thanks for another journey back intime to a sadly missed era.
@michaeldranfield7140
@michaeldranfield7140 20 күн бұрын
It was a very enjoyable trip back in time for me too and Im hoping to make some more projects in the not too distant future .
@philipwardle6820
@philipwardle6820 24 күн бұрын
Brilliant video Michael - somewhere in the shed I still have the Q-Max cutters I first used in the 1960's when I started buiding valve equipment as a young lad. As you may know, the development and manufacture of EF50 valves had an interesting wartime history.
@michaeldranfield7140
@michaeldranfield7140 20 күн бұрын
Yes , I have heard the EF50 was an important valve back in its day , I believe it was used in Radar because of its high sensitivity. I cant say its a valve I like because I like to see a valve working but they do look quite impressive if you take the screening can off.
@_a.z
@_a.z 29 күн бұрын
I still love the valve stuff that I started on, even though everything I do is tracked and gapped down to 7 thou now! I started off wiring valve bases, used a lot of veroboard over the years and progressed onto PCB's.
@blackpoolbarmpot
@blackpoolbarmpot 19 күн бұрын
I've just noticed that the biasing and interstage coupling arrangement is similar to the "Mullard 3-3" audio amplifier, that came out around the same time; but using valves EF86 and EL84, (with an EZ80 rectifier).
@walker55able
@walker55able 8 күн бұрын
hope you had a great Christmas Michael I write this on 17th January.
@paulperry7091
@paulperry7091 Ай бұрын
The EF50 was probably chosen because it was so common at the time, with huge numbers used in WW2. Developed in Holland, British production quickly ramped up.
@NiallWardrop
@NiallWardrop Ай бұрын
For a wooden case, the easy answer is to start with a box of about the right size and make the chassis to fit. An old drawer on end, packing case, 70s cheap stereo speaker, sanded down and varnished if necessary.
@matambale
@matambale Ай бұрын
I am a goof. When you mentioned the daughter and the grandkids asleep downstairs, I turned down the volume and kept it quiet in here. For a video I am watching. Recorded earlier. 4690 miles away.
@followthetrawler
@followthetrawler 11 күн бұрын
Happy New Year Michael - brilliant project. Wish I had kept all my PW mags - I started collecting in 1974 - probably stopped in 1985 when I started working with real computers as a job
@fredfarnackle5455
@fredfarnackle5455 Ай бұрын
I was 15 in 1955 and had a paper round, as well as papers I had to deliver magazines - among which was Practical Wireless. I used to sit on the kerb and read them every time they came out, it took me a long time to deliver those papers! I had always had a keen interest in all things electric/electronic and later built many projects when I could afford it. Loads of fun and at 84 I am still fiddling with electronics and computers.
@martprice7726
@martprice7726 27 күн бұрын
I became hooked on electronics when my sisters bought me a Phillips electronics set cost them more than a weeks wages back in the 60s.
@DavidCohen-p9m
@DavidCohen-p9m 29 күн бұрын
A trip down memory lane for an 80 year-old. Thank you.
@gjt2209
@gjt2209 Ай бұрын
Thanks Michael, you are living proof that once electronics gets you hooked, it’s forever. For me the thrill of finding the cause of a difficult fault, never gets old.
@frankowalker4662
@frankowalker4662 Ай бұрын
You did a better job on the cabinet than I could have. Looks great. Growing up in the 70's, I didn't read comics, I read Practical Wireless. LOL. 🎅Merry Christmas Everybody🎅
@DavidCohen-p9m
@DavidCohen-p9m 29 күн бұрын
It was called "Camm's Comic". I bought every issue from the late fifties.
@NigelDixon1952
@NigelDixon1952 Ай бұрын
I had a subscription for Practical Wireless from being 12 years old. I'm 72 now! I used to read it from cover to cover. Anyone remember the Sinclair kits? Oh, and the army surplus. I bought a 31 set, and took out the BBC TV 6pm news for the whole of my village! I was soon informed of my mistake, by violent hammering on our door! Happy days!
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
I have loads of sinclair stuff.
@NigelDixon1952
@NigelDixon1952 Ай бұрын
@michaeldranfield7140 Thanks, Michael. A schoolfriend who was also into radio, had a go at the Sinclair Slimline, transistor radio kit. He got into a bit of a mess and couldn't get it to work, so he brought it to me in class. He said he'd done everything right but it was rubbish, took him all day and it was no good. I was straight up to my room after school. It was just a diode the wrong way round, and it worked great, or at least as good as the tiny number of transistors in there could! I proudly handed it back to him the next day at school. Do you remember the Audio amp Sinclair was selling in the late 70s? Well, a lady I worked with said her husband bought one to make his record player sound better, but he couldn't get it to work. Of course, I said for him to call round at mine with it. I'd take a look. As soon as he took it out of his ASDA carrier bag, I told him to throw it in the bin. He'd only connected the 240 volts AC mains, direct to the 12 volt DC input terminals! Those were the days, Michael! Here's hoping you and yours, together with your extended family of viewers around the World, have a truly wonderful Christmas and a Happy New Year. And for those who don't celebrate Christmas, enjoy all the extra movies!
@steve83803
@steve83803 Ай бұрын
Must be a trade issue with cutting wood straight as a now retired TV engineer I can’t either. I was OK with Fablon at Radio Rentals when we used to re-cover the teak cabinets in black. Great project Michael and have a great Christmas
@klausphotobaer5754
@klausphotobaer5754 7 күн бұрын
I am impressed , very well done 👍🏻
@JrsJota-u6c
@JrsJota-u6c Ай бұрын
Boa tarde 🤔falo aqui do Brasil 🇧🇷 trabalho com eletrônica gostei do projeto brigado senhor 🤔👍
@crr8297
@crr8297 Ай бұрын
Excellent job, thank you for bringing 1955 back to life... Merry Christmas
@dingnextstop
@dingnextstop Ай бұрын
What a shame we can’t hear the Light Programme again or the Goons show or Cltheroe Kid… I have a 1952 Bush valve set but all those wonderful old radio broadcasts are silent now.. I can think back as a child in the 1960’s sitting with my Nan listening to family favourites, it’s so sad we have lost all that
@elshiftos
@elshiftos 27 күн бұрын
I have a Bush BAC31 that I'm planning to retro-fit a Bluetooth receiver into so I can stream period-correct broadcasts and music to it. First listen on the agenda is the Goon's parody of Orwell's 1984, aptly name 1985 - seems like a very fitting choice given the current state of things! 🙂
@kennethmcclure29
@kennethmcclure29 Ай бұрын
Well done sir. I love the older tube design. Trf radios do work well . Thank you, Ken from gpt ms
@tenmillionvolts
@tenmillionvolts Ай бұрын
What a lovely result. Most of my kits didn't look like the original. They ended up in ice cream containers and the like. Presentation was not important when I was a kid. My dad would sometimes build a case if he had time. As I get older, I've been considering mentoring some younger children in electronic projects to keep the hobby alive. I'll see if I get enough time. Just got back into audio repairs and it's busy.
@joshhoman
@joshhoman Ай бұрын
A very good Christmas and New Year to you and yours as well! I am no expert wood cutter myself, and have used a technique similar to yours! The radio came out well and is a nice flashback to the 50s! Well done sir!
@German_byte
@German_byte Ай бұрын
Thank you Michael. I really enjoyed watching you completing that Practical Wireless project. What a great job you made of it.
@iancooper2338
@iancooper2338 Ай бұрын
Great job MD! Enjoyed your articles in Practical Television (along with the rest of its content), the anticipation of a new magazine, sadly missed now, was a highlight of the month. Thank you for continuing to deliver and share your great content on KZbin! Merry Christmas and Happy New Year to you and your family!
@davidjennings9253
@davidjennings9253 Ай бұрын
Hi Michael, that took me back in time. I started to take Practical Wireless magazine in 1960 and was so keen on building circuits but not so much wireless. I was building my 1st electric guitar and realised I needed an amplifier so trawling through the pages I found a kit to build a Mullard 510. I saved my pennies and ordered it and I can still remember the smell when I opened the box of parts. So exciting !!! I duly assembled the amp and it provided me with a few years of service until I could afford one with 30 watts. There really isn't anything to touch valves for guitar and again the smell is magic. I wish I had saved all of the copies of that mag as I had it right up to 1966. I then started sn apprentership with the Marconi Company in Chelmsford where I worked for 22 years when they folded. Great times and a great video - Thankyou !!!
@johnrudd9550
@johnrudd9550 Ай бұрын
Thanks for the video Michael, I was born in the late 50’s so grew up with valves and transistors… best wishes to you and your family for Christmas.
@electechyt
@electechyt Ай бұрын
Just found your channel. Subscribed! Thanks for a great video, it takes me back to my projects in the early 70s.
@gpo746
@gpo746 28 күн бұрын
Brilliant ! Well done Michael , nice vintage build right there . Sounds better than I expected . MERRY CHRISTMAS !!!
@eddyaudio
@eddyaudio Ай бұрын
Excellent work Michael and good work the cabinet well done it looks Wonderful,Ian from Australia,
@mikegreen2079
@mikegreen2079 Ай бұрын
Hi Michael, thank you so much for all the time and effort you put into your viideos. I was born in 1957 and was an avid reader of P. Wireless from the age of about 11 then started my radio and TV apprenticeship roughly as transistors were making their presence felt in the trade, hard to believe how things have changed in so short a time. Incidentally I look forward to your releases as much as when I was waiting for Practical Wireless and Practical Television each month. Thanks again, Mike
@samslots1234
@samslots1234 29 күн бұрын
Great video. Really enjoyed it. You made quite a good job of the cabinet. Well done.
@leedale4008
@leedale4008 Ай бұрын
Excellent job and you cut wood with precision,spot on 👍
@ronroberts34
@ronroberts34 Ай бұрын
Excellent work. I love those old Practical Wireless projects. You did a brilliant job. Have a great Christmas and thank you for a cracking channel.
@Lyndalewinder
@Lyndalewinder Ай бұрын
Case looks very good Michael - well done - nice project overall, thanks for posting. Best wishes for Christmas and new year and looking for ward to the next video!
@richardwoodwards1202
@richardwoodwards1202 Ай бұрын
That brought back memories from the late sixties when I was a apprentice Radio and TV engineer thanks to
@rriflemann308
@rriflemann308 Ай бұрын
very nice, (especially the cabinet) happy Christmas to you and yours
@richardh100
@richardh100 Ай бұрын
thank you Michael a great video and what a great Project to pick , and great cabinet work Merry Christmas 🎉
@Televid4
@Televid4 Ай бұрын
Hi, Micheal. Merry Christmas and a Happy New year...
@heifferman9021
@heifferman9021 Ай бұрын
Brilliant job. Looks very much the part.
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Many thanks for that.
@knight19681
@knight19681 Ай бұрын
vary nice job. well done. happy xmas.
@Steve-GM0HUU
@Steve-GM0HUU Ай бұрын
👍Nice and thanks for sharing. Certainly in keeping with the original article.
29 күн бұрын
Brilliant! It looks and sounds antique. When you turned it on, I half expected to hear Britain declaring war on Germany. I am now in the USA where valves are called 'tubes'. Happy New Year from Arizona, USA.
@xyredmax
@xyredmax Ай бұрын
Bringing life to a handful of components always makes me smile - Nice job MD. have a great Christmas and if you're down in South Somerset next year, pop in for a cuppa and a workshop tour. All the best MJ
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Sadly we don't go away too far now we have two small children in the house as well.
@andymouse
@andymouse Ай бұрын
Awesome ! Merry Christmas to you and yours !
@MichaelBeeny
@MichaelBeeny Ай бұрын
The first time I had ever seen a EF50 was at tech collage on a very old, even then, TV that seemed to have dozens of EF50s in every stage except those needing power valves. The big red can made them look lifeless as you could not see inside, not even the heaters.
@michaeldranfield7140
@michaeldranfield7140 20 күн бұрын
That's why im not a fan of the EF50 , I like to see a valve working, they do look very impressive though with the screening can removed .
@audibell
@audibell Ай бұрын
Merry Christmas and a happy New year
@AstonsVintageTechnologyWorkshp
@AstonsVintageTechnologyWorkshp Ай бұрын
Happy Christmas to you Mr. D. May you have lots of easy repairs in 2025. All the best from me.
@SmokyPondFarm
@SmokyPondFarm Ай бұрын
I was born a few months before that magazine was published. Also, I've been a radio guy my whole life. You did a great job with that build. I believe your realization of the design is better than the magazine version all the way around!
@kendom33
@kendom33 Ай бұрын
Another great video Michael. Thank you so much. Merry Christmas ans continued success in 2025. You sir are an absolute legend..I've been a follower since your articles in practical television
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Many thanks for that
@glasslinger
@glasslinger Ай бұрын
I can't say much for the weird circuit but the dad gum thing plays! That's what counts! Good job! Merry Christmas to you!
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Thank you for that, we both have a similar interest in valves, the only thing is I can't make mine like you do!!!
@johndunleavy
@johndunleavy Ай бұрын
Splendid. Well done Michael.
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Can't belive I made such a good job of cutting the wood, I think someone's looking over me.
@Turbojetkart
@Turbojetkart Ай бұрын
Thank you, all the best for the new year
@radio-ged4626
@radio-ged4626 Ай бұрын
Great job Michael. Makes me want to try it myself - but I'm a little busy right now. If you remember, earlier this year you went to J. Birkett's in Lincoln and filmed the inside of the shop of vintage electronics and various aeroplane instruments. I decided to visit that shop and bought a Marconi R1155 "Lancaster Bomber" receiver. Well I'm currently deep into its repair, checking resistor values, replacing crumbling wires etc. Not going to be finished for Christmas next year at the rate I'm going at (especially as I've decided to reconstruct the DF circuit), but an enjoyable project none the less. Wishing you and your family a Merry Christmas and a very happy New Year!
@hugso47
@hugso47 Ай бұрын
I had a R1155 in the 1960s. My uncle had been in signals in the RAF during the war and it was left in our shed in the garden. Used Practical Wireless to get a circuit diagram and manually copied it. Made a power supply/output amp and used it for a few years as a student. Finally gave it away, but now wish I still had it. Lovely piece of kit.
@Timothycan
@Timothycan Ай бұрын
Thanks for sharing that, a great project.
@mistermikeanson
@mistermikeanson Ай бұрын
Have a great Christmas Michael!!
@truthreigns7
@truthreigns7 Ай бұрын
Merry Christmas Mr Michael
@MrSte2222
@MrSte2222 Ай бұрын
very good build... i remember practical wireless late 60,s till 80,s then it deteriated till it has just become a ham radio review mag made many a project from the take 20 articles and radios and treasure tracer great stuff shame its lost its way even the radio hams seem to just buy stuff new now i loved the surplus stuff would strip down old boards the hobby has died somewhat over the years many off us now pensioners or older the radio rallies are less busy every year i still do the odd one but its not like it used to be.. great article thanks for posting
@philipjones3093
@philipjones3093 22 күн бұрын
Great video took me back to my teens built a push button.
@philipjones3093
@philipjones3093 22 күн бұрын
Radio to listen to AFN music in bed when I should have been asleep wonderful times for ex gov surplus😄.
@matambale
@matambale Ай бұрын
Really enjoyed this Michael, thank you. That's some fine cabinet work! Merry Christmas to you and yours.
@michaeldranfield7140
@michaeldranfield7140 20 күн бұрын
couldn't believe I made such a good job of the case , it has inspired me to try some more cabinet work !
@jimsimpson1006
@jimsimpson1006 Ай бұрын
Nice project Michael and love the nostalgia, especially that copy of PW from 1955. I think you managed to get a very genuine 1950s look with that cabinet! A very merry Xmas to you.
@matthewgriffin4761
@matthewgriffin4761 Ай бұрын
Another great one. Merry Christmas and Happy New year to you and yours.
@TimHollingworth
@TimHollingworth Ай бұрын
Brilliant project. My dad's friend gave me a lot of vintage stuff. I remember dumping hundreds of old PW and PE magazines by F.J. Camm, years later. Probably worth a bob or two now, but I needed the space. I wonder what other gems I lost over the years. I remember he gave me a power amp that came in two giant metal boxes. I think one of the boxes had 4 KT66 valves and some seriously heavy transformers. I was probably around 10 or 11 years old. The best device was an old dictaphone that recorded onto paper magnetic disks valled a "Recordon." To erase the disc was a hand held bar magnet. Now that one is still in the garage with recordings of Radio Caroline and my long dceased grandad. Must get it working one day... 😳
@hugso47
@hugso47 Ай бұрын
My lovely uncle made our first hi-fi in the early 1950s by building the Williamson amplifier with 2 KT 66 output valves in push-pull. Valves the size of small milk bottles. Seemed hugely powerful at the time through a 15 inch loudspeaker. Happy days.
@davidausterman5915
@davidausterman5915 29 күн бұрын
Amazing
@Falco45able
@Falco45able Ай бұрын
Thanks for taking the time fella stay lucky, stay safe, and a merry Christmas to you and your family!😉🎉
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Many thanks for that
@petervideos8699
@petervideos8699 Ай бұрын
Hi Michael great job works very well Merry Christmas and happy new year thanks for all videos all the best from Peter 😀🏴󠁧󠁢󠁳󠁣󠁴󠁿
@ukfmcbradioservicingTango21
@ukfmcbradioservicingTango21 Ай бұрын
That's a great fun project you've built there, Michael. My only snag would be obtaining the coil. All the best to you over Christmas, Richard
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
The coil was a lucky chance buy, I saw a load of radio coils adverized on e Bay, most of it crap and I could see what appeared to have part of the correct number on so I tool a chance!
@normanm5979
@normanm5979 Ай бұрын
I worked for the BBC on transmitters from the early 1960s. EF50s were used for a lot of RF low power units and they rarely needed replacing even running 24/7 for years. Well done Michael even if you mistook the suppressor grid for the screen grid!
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
I was pointing to the wrong valve, it's V1 where the screen grid is returned to cathode.
@wireless6
@wireless6 Ай бұрын
I actually built this radio in the early 60's when I was about 13 years old! It worked well with just a short aerial in fact I used to listen to Luxembourg in the kitchen at home. Later I built a valve amp and used to play it through that with the volume of the radio quite low to improve the sound quality. Happy days!
@michaeldranfield7140
@michaeldranfield7140 20 күн бұрын
Excellent
@Linkvagen
@Linkvagen Ай бұрын
Nice job! Have a really Merry Christmas!
@Wekkkojeffko
@Wekkkojeffko Ай бұрын
Wow! So nice to see a wal of parts and a guy with knowlege !!!! The dont make people like this anymore hahahahha! Wow just great! Big respect!
@BongbongA99
@BongbongA99 Ай бұрын
What another great posting Michael - thank you! It’s amazing how that seems to perform - who know what 2 x EF50s could do?! No hum either. I bet it’s quite a balancing act between tuning, reaction and volume, but that’s the fun of TRF I guess. One thing that would frighten me off would be the ‘L’ coil. There’s no way that I would ever be able to source one, and I guess the project article in PW didn’t go into how you might wind one. It looks like it’s wave-wound, so that would be tough to hand wind, even if the details of no’s of turns, direction and wire gauge were known. It’s great that you had one though - your stock of parts never ceases to amaze me - quite amazing. You also seem to know where said components are located. I wish I could do that. I’d be spending most of my time hunting stuff down rather than building the set! I like the box Michael - it absolutely looks the part. A good choice of control knobs too. Simply magic! Thank you again Michael, I really enjoyed this.
@michaeldranfield7140
@michaeldranfield7140 20 күн бұрын
I know where most of my stuff is but occasionally things disappear or sometimes I know I have something but cant find it and end up ordering more .
@jameselder1631
@jameselder1631 Ай бұрын
Great video. Liked the silent bits. If you listen to some creators now, they will say 'What are we gonna do in this video, well in this video, what we are going to do is we are gonna...' Too many words saying nought. Sorry to hear about your talented friend, I think I might know him. Re the sawing, I am happy to pop up and show you how to do it really easily, take about 15 mins, failing that, if you want to send me specs of anything in the future, I can soon knock things up.
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Graham wasn't realley my friend as such, more or a customer but I have known him for well over 40 years, he was always coming into the shop I worked as a kid buying tools. Re the wood, I can't belive I made such a good job with a hand saw, I think someone's looking over me.
@steveurquhart5895
@steveurquhart5895 Ай бұрын
A really enjoyable video Thanks. Happy Christmas Michael.🎄
@barrymayson2492
@barrymayson2492 Ай бұрын
The EF50 probably the most important valve during the WW2 made by Philips in the Netherlands. The basic valve for most radar sets display system. I suspect that is why they were used in the circuit as they were very cheap and plentiful.
@buttyboy100
@buttyboy100 Ай бұрын
While the Philips factory at Eindhoven was under Nazi occuption from 1940, EF50s were made by Mullard in England. Later Sylvania in the USA produced vast numbers of them.
@acj2789
@acj2789 Ай бұрын
I seem to recall an article in Practical Wireless, or a series of articles, entitled ‘The versatile EF50’. But maybe my memory is deceiving me.
@hymermobiler
@hymermobiler Ай бұрын
Merry Christmas Michael!!
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Many thanks for that
@RobertSchmitt-u7l
@RobertSchmitt-u7l Ай бұрын
Have yall heard of BRUCE ROSENBLIT He has made Transcendent audio with very very well designed amplifiers, There is a 300b that can use rectified mains, and no output transformer and only 1 gain stage, 4 300bs in parallel. Absolutely right on. The schematic is in a very informative book Tubes and Circuits. Hes the one that makes sense, out of all the other recirculations of circuits, this guy explains it without confusion or obfiscation.
@tubeDude48
@tubeDude48 Ай бұрын
It seems to being a pretty good job! 👍
@marssiantenni
@marssiantenni Ай бұрын
Nice project!
@Colin399
@Colin399 Ай бұрын
That looks great to me👍
@blackpoolbarmpot
@blackpoolbarmpot 19 күн бұрын
A very quirky circuit indeed, but what superb results. EF50 valves were used extensively in wartime equipment, and post war, often in TV's too, so were cheap and plentiful in the post war years. Just one point I'd like to make.... You mentioned at 4:42, that the output valve's "Screen grid" is going to the cathode; it is actually the "Suppressor grid". The Screen Grid is going up directly to the H.T. line in the circuit. The reaction sounds very smooth and with no backlash, and the tuning selectivity is remarkably good. I still can't decide whether V1 is a "leaky grid", or an "Anode bend detector" but looking carefully at the circuit, I think it is the latter an "Anode Bend Detector". These are notorious for introducing distortion with low level inputs, but have the advantage of an extremely high input impedance, thus introducing minimal damping effects on the tuned circuit. Maybe that is why they have a volume control in the negative feedback line - to help counteract possible distortion ? But I must say, you have a good radio there with excellent audio quality. 10 out of 10
@Udmudmudm
@Udmudmudm 5 күн бұрын
Wow ! Questa si che è una cassettiera! La invidio molto! Io avrò si e no solo 100 cassetti😢....!
@andrewbirkett-q9e
@andrewbirkett-q9e Ай бұрын
Sorry Michael, that appears to be the suppressor grid, the screens are up to HT+ and resulting HT on the kathode, suppressor grids are normally tied to the kathode or ground but can be used as secondary control grids. Keep up the good work, love your videos.
@ericrawson2909
@ericrawson2909 Ай бұрын
No, he was pointing at the wrong valve during part of the video. Yes, V2 screen goes to HT, but V1 screen is at V2 cathode potential.
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Yes, you are indeed correct, I should have been pointing at V1, where the screen grid is returned to cathode.
@dennissmith8199
@dennissmith8199 Ай бұрын
Well done Michael! Nothing like a nostalgic project for the holiday season. Many years ago I built a converter that received aircraft frequency broadcasts, 108-136Mkz, and rebroadcasted them on an AM 650-1700 Khz frequencies. I also built a Knight Kit oscilloscope kit, sold by Allied Radio in Chicago, when I was in high school, arounf 1965. I still have it and it still works. Question: I'm not familiar with the reaction control, what is that for? A gain control?
@martinpickering8463
@martinpickering8463 Ай бұрын
Hi, Michael. "Jack Armstrong" here of "Television" magazine fame. I built at least one superhet valve radio in my teens. In fact I blew my Dad up with it: I fitted the reservoir capacitor the wrong way round! Anyway, your plywood cabinet looks just fine to me. Ideally, the plywood needs to be cut with a saw bench, using a fine tooth circular saw but you did OK. Merry Christmas, my friend.
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Hi, Martin, good to see you here, someone gave me one of your books the other day, the sattellie screwdriver one.
@martinpickering8463
@martinpickering8463 Ай бұрын
@@michaeldranfield7140 Ooh, very rare. I'm not even sure that I have a copy.
@peterhancox6962
@peterhancox6962 Ай бұрын
i used to read practical wireless
@bill-2018
@bill-2018 18 күн бұрын
I bought two circular metal punches years ago to make things easier, I had previously chain drilled and filed holes. I made 3, 4 and 5 valve sets later aged about 19 after an H.A.C. Model DX made when I was 14. Circuits from P.W. and S.W.M., none worked any better than the previous ones but it was good for learning. I found an interesting circuit for a single EF50 c.w. transceiver. Nothing heard on it yet but I can hear my own signals. G4GHB.
@valquiriobatista5311
@valquiriobatista5311 Ай бұрын
Estiga mesmo kais da miha idade eu aitou patesedo um rapazinho limdo demais
@andygozzo72
@andygozzo72 Ай бұрын
wonder how later valves such as EF91s, EF80s, or even high gain frame grid types EF184s would work? EF91s were certainly used a fair bit for home built stuff maybe a EF184 first valve feeding a PL84 output, for a bit more oomph, PY82 rectifier , and a nice big hot dropper resistor 😉 live chassis, of course, but class Y2 isolator cap for the aerial..??!!
@AndyDoz
@AndyDoz Ай бұрын
Nice work. Where did you get the chassis from? Merry Christmas
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Had it a long time, someone was making these and selling them on e Bay, not cheap though, think I paid about £20 but it's good.
@lookoutleo
@lookoutleo Ай бұрын
Realy nice project . Interesting design , does it produce alot of heat and how many watts does it draw
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Total HT current is only 20Ma
@turboslag
@turboslag Ай бұрын
I am exactly the same with wood, can never get a good result! Metal, no problem! I have that issue of WW, interesting. Impressed that you had the metal rectifier! So, come on, own up, did it work first time?
@michaeldranfield7140
@michaeldranfield7140 Ай бұрын
Yes it did work first time due to the ready made coil, but for safety I did power it first from a bench power supply just to make sure there was nothing amiss.
@rogerbarton1790
@rogerbarton1790 Ай бұрын
I share your pain regarding cutting straight lines! I can't even drop a brick so it falls vertically. IIRC Practical Wireless did a a series of articles called "Cabinet and Chassis Techniques".
@rambo1152
@rambo1152 29 күн бұрын
Michael, V2 circuit is not as unconventional as you say. The screen grid does go to the HT line, it's the suppresser grid that is connected to the cathode
@andygozzo72
@andygozzo72 Ай бұрын
dont know if i have that particular issue, but i do have a load from late 50s to late 60s, most with the original free 'blueprints' in the ones that had them, but i have that circuit in a 'practical wireless circuits' book, always wondered how well or not that circuit would work! i have a radio that was 'home built', using 3 EF50s, but a more 'normal' circuit, i think from a 'wireless world' magazing doesnt work very well , plus another home built one. in style of a wood cased pilot major maestro, normal superhet, and works fairly well, and yet another one with a unique style case, also superhet, doest work too well !
@MirlitronOne
@MirlitronOne 28 күн бұрын
4:55 What you are referring to as the "screen grid" is actually the suppressor grid, which here, as with the screen grid below it, is correctly connected (suppressor to the cathode). Could you not have fashioned a capacitor clamp from a strip of aluminium or copper? Nice build! But, as you say, what will you listen to on it in a few year's time?
@v8pilot
@v8pilot Ай бұрын
4:53 - that is not the screen grid going to the cathode. It's the supressor grid and it is normal and correct for it to be connected to the cathode. The circuit diagram shows the screen grid going to HT+.
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