The worst part for me is when I go to museums and see the old radios B/W and colour TVs i used to work on. I sold of all my circuit diagrams, PAT tester, component stock as a job lot to a competitor (and friend) when I stopped work. The only item I wish I’d kept was the AVO 8. Should have sold the scope and kept that. My really good 24v Weller soldering iron finally went wrong and got replaced with an inferior one.
I still have some relics from the past.
The toolcase that I took into people’s houses.
Soldering gun.
Solder sucker.
Solder wick.
Freezer fluid (for faults that only occurred when things warmed up).
A huge bench isolating transformer with 240v and 24v secondary supply.
Thick rubber floor mat.
Rubber bench mat.
BA and metric wooden handled box spanners.
A few odd TV PCBs and VHS parts.
An analogue multimeter that fitted inside the tool case.
2oz tobacco tins with tiny screws and washers.
…even a bit of tag strip that I know is from a 405 to 625 line conversion kit.
Here is the site where I copied the drawing and details from Mart.
Having used the 555 on many occasions I altered the layout to a more Vero friendly configuration. I found the links you posted very interesting, especially the second one. It contains a Pulse Induction Detector very similar design to the one I’m building.
Work producing the search coil body was slow going today, but when I ordered the parts I also included an Integrated circuit that I haven’t used before, but I have read about previously, and think it might be very useful in the future. Nothing to do with the metal detector though…
It’s a CD4017D…A decade counter.
Over the years I have used the 555 to make lots of oscillators and timers, but the longer the timing cycle, the less accurate the 555 can be. The 4071 can time very accurately for days or even weeks, but it can also be used to make a very effective light chaser. And that was the purpose that I bought it for.
Watch this space for future experiments…
Before we set about soldering all the components on to the veroboard, we must arrange them on this computer version of the veroboard to see how it would all fit together. There is nothing as messy and annoying as trying to reposition components on the board after they have been soldered in…
Nice project chap. Being a mechanical engineer, electronics is one of the black arts as far as I am concerned.
I used lots of electronic equipment including the scopes pictured earlier for “simple” jobs when I was gainfully employed, as well as all sorts of other electronic kit.
We had banks of single or twin beam 'scopes in multiple groups of fourteen, then when we saw something out of the ordinary we selected each wiggly worm to appear on frequency analysers, but I hadn’t a clue how any of it worked.
I learned how to read complicated electrical drawings and was licenced to repair combat aircraft engine control amplifiers down to board replacement level, but not board component level a-cause I hadn’t a clue what each component was, let alone what they did.
I haven’t a clue what most of the components in your circuit diagram are, or do, but I am impressed by your knowledge and skill and that of the other “wizards” that have posted on your thread. I hadn’t realised Besoeker is also located in dear old Donny. I have fond memories of my time there.
I’m also impressed by your woodwork design and construction skills as well.
Please keep us updated. I think it is a really interesting project, and it will have a use at the end of it all.
Thanks Fruitcake your support is much appreciated. I’ll try to keep it easy to understand and hope that more posters look in on the project. I just thought it might add a little more interest and take our minds of covid and brexit for a while…
Todays job was to produce a MDF disc to fit inside the coil to give it some support and it will form part of the search head.
After roughly cutting out the disc with a fretsaw, I then mounted it onto a spigot on the table of a bench drill.
By rotating it against the rotating tool in the drill chuck, it was possible to create an accurate circle that just fit inside the coil…This photo shows how it was done…
I hope you had suitable PPE for cutting MDF. It’s nasty stuff if you inhale it.
I’m impressed by your engineering-uity to make the disc circular. That’s the sort of thing I would do.
That’s one heck of a chuck-key you have on the bench. I’ve never seen one that big before. Fnarr, fnarr
Is it an adaptor that goes in a ratchet wrench? I’ve never seen one like it afore.
Is that an all steel hammer with rubber grip on the bench in front of the seat? It looks identical to the haft of the one I have had for decades.
Well spotted Fruitcake…
My old chuck key was a bit worn and kept slipping on the teeth, so while visiting the tool shop I saw the ratchet one, it’s actually a stand alone chuck key not an adaptor…:shock: It’s the best chuck key I’ve ever used. Plenty of leverage so you don’t need to swing on it, and it’s never slipped once.
You are right about the hammer also…I found it broken in a skip twenty years ago (the head had come off) I glued it back on and it has been a very useful tool ever since, and it’s kept his head…I must point out that I don’t make a habit of scrounging around in skips… Although sometimes they are a proper treasure trove…
I was so absorbed in the job I never gave the MFD dust a thought , but I will now that you’ve mentioned it thanks. It’s not like we are short of masks is it…:-p
One of the first projects I undertook when I started doing electronics was to build a regulated power supply, and it’s saved me pounds over the years…
It delivers a range of DC voltages…0 - 9v 0 - 15v and 0 - 25v… It also trips out on three settings if the current exceeds 100mA - 1 amp and 2.5 amps. For most jobs the 100mA is ideal, tripping out before thermal runaway destroys a delicate component. The left panel meter reads Voltage, and the right panel meter reads Amperage. So a visual check on how a circuit is performing also helps to prevent damage. I would much rather read an analogue meter than a digital one, I think the analogue meter tells a far better story of what is going on inside the circuit.
I don’t want to hijack your thread, but I thought you might like to see my hammer that’s the twin of yours.
It’s the one on the left underneath and between the floorboard saw and Japanese pull-saw.
One of my friends had an all steel hammer when I was an apprentice in the seventies, but it had a habit of bending in use which put me off. Fifteen or so years later I was given this one and it is still as good as the day I got it.
As for skip diving, my Dad and Uncle/Fil had it down to a fine art.
Perhaps I should start a thread about the things they liberated from skips or hedgerows.
Again, I’m impressed by your skill and ability. That looks like a professionally made stabilised power supply.
We used Farnell power supplies on the Tornado engine control system rigs, and Tektronic jobbies on the Beurofighter control system.
The former were so heavy they could cause back problems when we had to move them around, but the latter were lightweight.
Did you make the case and handle as well? That’s some serious tin-bashing skills if you did.
No tin bashing involved just alloy front panel and metal chassis, surrounded by a wooden enclosure. Boxes have always been my thing Fruitcake, I’ve made lots of them over the years, from speaker boxes to project enclosures. If you look carefully at the surround of the voltage stabiliser you will notice the joint holding it all together. All my boxes and enclosures are usually held together by proper joints.
And yes, the handle is home rolled…
That’s an impressive wall of tools by the way Fruitcake and I love the horse…
The voltage stabilizer looks well-made and handy. Good to see the detector project coming along.
Looking at the veroboard reminded me of one of our engineers. He was an amateur radio enthusiast who was always building his own circuits. He made the circuit boards using copper-clad Paxolin boards. Etched the tracks using wax and acid.
Things were quite relaxed in our workshop in those days. We were left alone providing all the work was getting done. This gave him a bit of time for doing his etchings. There were often a couple of dishes on the bench tops that we had to be careful of.
Thinking about home-made items, I say I’ve only ever built a guitar amplifier (valves) but there was also a ‘tube (CRT) blaster’. I made my own using the mains transformer from power supply that was part of a Thorn 3000 television. Different blasting voltages were selectable using switches.
The blaster could rejuvenate a low-emission colour CRT. It didn’t mean that a new tube wouldn’t be needed in the near future but it gave a quick fix that lasted up to a few months. A bit of breathing space for customers and engineers.
A professionally made CRT tester-rejuvenator was available but the one I made myself served me well.
Although sometimes they are a proper treasure trove…
