WOW something older than me! I just turned 70 December of 2022 so this Ducati is a decade older than I am! And I'm sure it works better than me too lol

Hello Mark, Those little twisted wires as you surmised are under 10pf and were used extensively in early radio and early TV chassis to peak IF tank circuits. The twisties were called gimmicks. Cheers

@James_Bowie

Жыл бұрын

Yep.

You owe me a new keyboard. I spit my coffee at first glance. It's beautiful!

Also, I was taught during my apprenticeship in the '60s not to solder the wire straight onto the valve lug, but to loop it around after pushing it through and squeezing it with pliers. This gave it mechanical strength and helped avoid dry solder joints. It also looked way better.

Great to see you working on something twice your age.

I believe the old-timers called those wound capacitors 'gimmicks'.

The twisted wires are there to tune or tweak the circuit. You find them in Telequipment scopes amongst others. It's a genuine technique, not a bodge. I'd have replaced the wire going to the top cap, the insulation was damaged, still, we all do things different.

when people say 3w of power output.. People automatically giggle, and think its not much.... I once heard a 5w DIY valve amplifier, and it absolutely rattled the walls... i was like :O So now, I know there is more to audio systems, than just the output wattage :)

@andygozzo72

Жыл бұрын

proper watts, not these piddly 3w peak music power things 😉 , as a 'rule of thumb' divide pmpo by 4 to get approx rms watts out so, 3w pmpo woild be 0.75w rms 😁

@TerryClarkAccordioncrazy

Жыл бұрын

Depends a lot on the speaker efficiency.

@andygozzo72

Жыл бұрын

@@TerryClarkAccordioncrazy certainly can...

You would be an excellent teacher Mark. I have no skill in your area but you make it look so easy and furthermore...interesting! You should think about doing online workshops for future electronics repairers. People would sign up in droves I'm sure!

@MorriSoft

6 ай бұрын

Absolutely agree. Fantastic content, very informative with none of the waffle that some channels have. Brilliant work, I hope we have lots more content to come from Mark, great technician.

Fascinating to see the electronics and Mr. Blobby would've been proud of that soldering.

The days before circuit boards and even ceramic strips - scary stuff.

Loved this! I recently re-capped a 1950s Grundig reel to reel using polypropylene caps and it sounded and worked great afterwards. Kinda fun working on old equipment that don’t have PCBs. I also had to map out which caps went where since they were not labelled either.

top work Mark,looking forward to part 2.

Very interesting Mark.Looking forward to the next one.👍

A great part 1 Mark. Looking forward to part 2.

What a mess... Good job... Makes me think about old TV repair days.

Wow that was very impressive and so detailed. Well done.

Great video, Mark. Always interesting to watch your work...and I know nothing about electronics.

Very impressive craftmanship, knowledge, patience and attention to detail. Thumbs up!

There will be an old man somewhere shouting "I added them to stop oscillation"(I'm only guessing here) There are some old guy tricks to work around maybe some issues with certain valves back in the day. I'm sure we are now losing some of that knowledge of this old technology. I personally would like to attempt a repair on something like this but I could not guarantee a fix. If this came to me I would pass on it, I wouldn't want to ruin such a beautiful device. Looking forward to the speaker repair.

@kurthuber7639

Жыл бұрын

Yes like the old Big Iron mainframe computers, everything was tweaked in situ based on the actual hardware quirks, similar to overclocking solid state these days

You said something wrong in the beginning.Normally top cap of HF tubes like 6A8G is the grid. in this case for HF/Mixer. A critical cap is in the audio section is C2 if it leak bring the output tube 6V6G to go with to high current bring the output transformer to burn. It is not so easy when somebody before you tryed to fix things in this old radios without knowledge. Sorry for my bad english (I am a Swedish ) I like your you tube channel . Keep going with the good work!!

A sticky knob can be a real problem. But you fixed it again . Good job

great Mark, would be nice to drink a pint with you but I am not from the UK

Excellent work, Mark. Don't envy your job on this one. This kind of valve equipment with no PCB is the stuff of nightmares for me. Gives me colds sweats thinking about making the wrong connection and releasing the magic smoke only to find no parts available😲

What a lovely old piece of kit. I remember an old Ferguson Radiogram from the fifties that my parents bought new that had a similar style. But it had FM as well, and played 33 and 45 records. Used to listen to 'Journey into Space' on it. Wonderful! BTW. The reason the old caps you tested were reading 'high', is because they have gone electrically leaky. It effectively puts a resistance in parallel with the capacitor. It means that when the tester charges up the capacitor, it takes longer than it should, so it reads a higher capacitance than the true value. It is just as well you replaced them. If you had left them in, it could have damaged some critical and difficult to replace bits and pieces.

Wow gorgeous radio! Cool mod.

The twisted wires are called gimmick capacitors. In this case they have been connected between the two tuned coils in the IF stages. They will increase the coupling between the two tuned circuits. This will increase the sensitivity a bit and also reduce the selectivity. Connected differently they are also used to provide negative feedback to prevent oscillation. Are they added or were they originally installed and shown on the schematic?

brings back memories at my grand dads workshop on my School holidays helping him repair tbs and radios got me to use the mallard valve tester he used to buy components and give me a project out of practical wireless good times

Thank you for posting 👍👍

Fantastic work as always. Love watching your videos. My OCD is on full-tilt because it looked like a lead you cut @ 23:00 fell in the hole...

What a beautiful device! The funny thing is that this can hurt you with ease, just like the motorcycle ⚡

@eolobrontolo9117

11 ай бұрын

It comes from the same builder of the motorcycles, from the radio branch. 😊

Hello from slovenia.nice work

I think the reason old capacitors seem to increase in capacitance is a consequence of the way the measuring instrument works. If it works by measuring the rate the capacitor charges up, and assumes the longer they take to charge the higher the capacitance, then it seems reasonable that if the component is 'leaky', that is, it lets some DC current through (acting like a resistor) then it will take longer to charge, so a higher than specified capacitance indicates a 'leaky' capacitor.

@andygozzo72

Жыл бұрын

yep, thats pretty much it, leakage will skew the testing unless you use a lcr bridge which has an adjustment for 'loss'/leakage that can cancel it out, these simple testers like in the video cant handle it 😉 but some capacitance drift isnt an issue, or leakage, depends where they are in the circuit , if in a low impedance/low voltage part such as across a cathode bias resistor, no need to replace (except if electrolytic decoupling audio) , similar if ac af negative feedback network from output secondary to bottom end of volume control

@y_x2

Жыл бұрын

Yes you should check the leakage first.

@andygozzo72

Жыл бұрын

@@y_x2 and/or try to reform..

@andygozzo72

Жыл бұрын

should always try to power it up someohow in a controlled manner to make sure no major and possibly unobtainable parts are faulty, before even thinking of recapping, or all that effort and money will be wasted

@y_x2

Жыл бұрын

@@andygozzo72 You can only reform electrolytic cap... Wax caps always need to be replaced.

In the US those twisted wire capacitors were called gimick capacitors. Common back then.

@andygozzo72

Жыл бұрын

yep, in some cases its a necessary tweak, and should not be removed, they're usually there for a good reason

Fantastic work. I wish they were all moved to a small mb style where all the wires can meet neat in the local soldering

Robert Crumb would love to have that.. Sounds gorgeous too even without a resto-mod..

Via passo subito alla part 2 ❤

You make good videos.

Smashing stuff.

best channel!

Genius.

Marvellous stuff, I was unaware Ducati made electronics, ironic really, when Italian bikes had a reputation for doggy/poor electrics. (the 851 is still the sexiest bike ever made)

@ortzinator

Жыл бұрын

Yeah they made radios until the Allies blew up their factory, after which they switched to motorcycles.

I worked in Electronics for over 40 years. My early career during the 70s was with Rediffusion Television for 13 years (later taken over by Granada Television). My question is; doing all this 'Transformer Winding' and all sorts :-D how do you "make a living" in our modern world!! Maybe you have a full-time job? :-D

@MendItMark

Жыл бұрын

You are quite right. I do have a 9-5 day job (nothing to do with electronics), and I often make more money from the KZread video, than the repair itself. I do however, enjoy the repairs, and making the videos!

Yeah, I remember this style of wiring....it's called "birdcage wiring". Used before there were insulated cables (or maybe because is was cheaper!).

I'm betting based on the age, that grub screw was a 5/64" (a pretty common size). There only a 1/2 of a thousandth of an inch between the two (

Yeah, the twisted wire cap is called a "gimmick capacitor". The I.F. transformer is a classic "Optimum Coupled, Double Tuned" transformer. It is tuned by means of the two slugs and the fixed caps, so that gimmick cap is entirely redundant. You should have deleted it (although maybe the slug was broken, so the previous Tech couldn't adjust it). However the little "coil of wire" caps were very commonly used as trimmers and are original..

Insulation tape there was in the 40s and even long before them, but it was textile, not PVC.

Brilliant Mark. My go to place for Valve amp repairs and reconditionung ius Uncle Doug's channel. Now for part 2

Insulation tape was around in the 1940's but it was made of cloth. Developed from the mid 1920's

Please note that these old caps will develop significant leakage (DC parallel resistance) over time, which may be the reason why the capacitance reads higher.

I see that according to the data tag that it has 5 valves, being Ducati one assumes that they have desmodromic operation!

@daleburrell6273

Жыл бұрын

...whatever THAT means-(!)

Hello Mark, nice work as always. I’ve seen a lot of your work and I know that you know what you’re doing, but I can’t for the life of me figure out why you’d even think of keeping those main filters in there. While new 10 uF caps would have been completely fine for the rectifier, they do make and I do have 8.2 uF high voltage electrolytics. The reason those measure over 10 even though rated for 8 is because they’re electrically leaky. I just don’t think it’s worth the risk, especially since it seems like this is a commission for a local business where it will be used. Being as old as they are they could short and then you’ll really have to worry about the rectifier or worse the transformer or the business building where it resides. With less than $5 worth of capacitors it would give peace of mind, not to mention new and perfectly functioning filters.

@Morinaka25

Жыл бұрын

Yes you are right, old caps that read higher than their rated value on an LCR meter are leaky and should be replaced, it's a false economy to not to. LCR meter does capacitance by seeing how long it takes to charge the cap, and if it's leaky it's going to have more resistance, and will appear to be higher value, it's a shame more people don't realise this.

Ducati radiogram that,s very rare !!

you can still get ducati branded capacitors, our tumble dryer has one for the motor run 😉 had to change it a couple of years ago as it went almost open circuit , common problem with modern over miniaturised caps, too thin metallising film on the plastic dielectric

Mr. Carlsons lab, he is the guru of vintage wireless and capacitors turn out to be directional. Try it and see!

I'm surprised that there was any civilian radios being made especially of that quality, considering there was a major war going on.

@paulmichaelfreedman8334

Жыл бұрын

In 1942, Italy did not experience much of the war, as they were Axis allies.

They stopped making electronics when the factory got bombed.the allied operation was called operation pancake

@Jonathan_Doe_

Жыл бұрын

Ducati Energia still exists, they mainly make motor run capacitors.

Super !!!

The twisted wires are called a gimmic.

You are on GOD level 🙏

Nothing like a rumble of a big V twin lol.

78s are about a £1 a pop in charity shops.

Swinging Shepherd Blues !

@verasherwood3140

6 ай бұрын

Yeah, I worked with a saxophonist here in Canada who made a lot of money from that song. Hmmmmmm.

Mark you dld well to fix this birds nest and sort out this mess nice piece of furniture

saludos desde peru amigo

WOW almost Marconi-old. Died: July 20, 1937

Found 1 ;) just need my brew now

Are you going to give us a video on reconing a speaker Mark? I hope so as i have up in my loft a 50watt guitar amp from the 60's that needs reconing and maybe i'll give it a try :-)

If it were me I'd have a cabinet craftsmen refinish the cabinet and then put a new expensive turntable in it as part of my home audio setup.

It appears that Bubba has been at that radio.

Braver man than I...

2:44 or you can use a DIY kit to build a medium wave Transmitter with a 3.5mm Jack input. There’s a lot on Ali for a few quid It just a bit of solderingwork to do

I've been an electronic hobbyist for years, although I never took it to this guy's level. And, people want me to fix old vacuum tube equipment, on occasion, and I'm like I don't want to get involved in things like this.

Could you please explain how a twisted wire can achieve capacitance? The other thing you mentioned in waveform-modulator video, was that there were polarised, as against non polarised capacitors and their position in the power circuit governed whether they needed replacing, could you possibly flesh that out.

Insulation tape was around in the 1940s, but it was cloth tape not plastic.

I have never seen a soldering iron like the one you use. What make is it? Cheers Ian

Ever heard of J hooks, or twisted wire spring connectors?

This is not electronics repair, this is wireframe soldering! 🤣

I think this device is before 1942 (probably 1938) because during the WW2 le production was converted in military radio device and in 1943 the factory of the neiborough of Borgo Panigale was bombed by american B17.

😮 wuao funciona

Can you print a PCB board for old radios like that?

Ducatti made cameras too

3M company engineers invented "modern" vinyl electrical tape just after WWII ended but it wouldn't have looked like that as black became the standard color later (and this radio predates the tape by a few years for sure), and gutta-percha/Chatterton's "tape" would have been around about 100 years earlier but this obviously wasn't that, maybe it had some originally?

That first valve with the wire on top is not anode it is control grid. Pin3 and 6 the anodes pin 3 being the main and pin 6 being the oscillator supply.

@andygozzo72

Жыл бұрын

yep, most of those octal valves dont have top cap anode , similar with the later 6.3v UX based types

Who needs a PCB when you can just wire-solder everything like a cheap electric guitar :D

Ahh Bluetooth, little AM transmitter would be better and more fun!

Do you have a battletrak video?

What I dont understand is if you have the schematic why not rip it all out and put it back nice and proper with all the caps and wires replaced or updated so it looks nice and proper. Unless it is to preserve the way it was originally wired? I would think all the wires and things need to come out...

Where are you getting the schematics from? 🧐

Wow someone butchered that in the past . Did you spot that heat damaged resistor when you were replacing the braided connection that annoyed you?

Why did a wartime Italian radio use American series valves? Was this before the sanctions were imposed? These tubes all had European octal E (6.3 volt) equivalents.

you are a genius what a mess ?

I bet you learned your skills in the Royal Navy..? Not many know about thrapping.

Hello salom

the weird capacitor is a "tickler" coil....

I can't believe you don't make a mechanical connection

Clearly turret board wasn't a thing back then. What a rat's nest!

Questiom Mark.Why do modern televisions have to have backlights seeing as they use LEDs.

@MendItMark

Жыл бұрын

The LEDs are the backlights. Unless the TV is a plasma, or OLED ( which glow on their own), it’s actually an LCD display, and it requires illuminating from behind. They originally used CCFL (fluorescent tubes), then they changed to LEDs for the back lighting.

🔖

@CuongVan-kh8pb

Жыл бұрын

🔖

Please where are you from ?