Michelle's Bonkers blog

Chemicon, due to low price, great range, and they're usually very slightly smaller than the Panasonics in real life. This is due to their slightly smoother casings. Their MVY series is excellent, and they tend to max their height out at 5.2mm, 0.2mm smaller than most competitors.

The easiest way to search for caps is: value first, ignore voltage, 4mm diameter for small values, 5-6.3mm diameter for 100-220, then choose height of either 5.2, 5.4, 5.5.
These are the most common sizes for Walkmans.

 

So, time ticks and the weeks pass until the capacitors are with me hopefully in the middle of next month.

Tinnitus is proving a problem which I hope that the two boomboxes will solve. Quality audio without the necessity to run full sized speakers, or headphones. I should be able to have them physically closer to me, without having to turn the volume up too much... and as they'll be closer, I can get some stereo imagery out of them. Of course, they're going to need a re-work, but I've got to get a few other projects off my small work bench before I can open them up.

Looking forward to the walkman work. Now need to source lubricant and oil for the cogs and motors. Difficult in the UK, as I don't know what I'm looking for. The discussions I've read, have mostly pointed out products which aren't available in the UK... but I'll put more energy behind this when the time comes in a few weeks.

Slow and steady progress. Slow and steady.

 

The first steps with the Aiwa boom box, are daunting. Everything is soldered into everything else. The wiring is a rats nest. The only good thing is that the switches mostly appear to be armatures that go back to switches that are actually on the main board. The tuner is going to be difficult for a newbie like me to work on, and I already know that the caps are going to need replacing on that. I'm dreading removing the main board, because the side sockets are on daughter boards which appear to be connected... but there are also ribbon cables around there. - This is going to be a slow job.

 

OK - so... I managed to get the tuner circuit out and I've mapped the film capacitors, but not the ceramics. The question is... should I replace the ceramics as well, or is there no point? There's a lot of them.

 

nope, ceramics and films rarely need replacement. All out electrolytic replacements are only applicable to walkmans, as there are relatively few, and they tend to leak and go bad faster than larger types in other products.

If the box sounds good, and does not have very obvious capacitor aging issues, I don't recommend recapping it.

 

I looked at the construction of the ceramics, and I thought that they'd likely be fine, but that was a pure guess. Unfortunately, there are issues with the radio not tracking, and a channel is out, which is most likely the amplifier... so I'll just leave it at replacing the electrolytics. I've also noticed a few links broken on resistors where the leads were bent tightly, so those will need replacing anyway.

I'm still making slow progress with finding someone local to me, to teach me electronics properly.

 

Channel out is usually a bad radio/tape switch, not capacitors. Radio is usually due to alignment of some sort. Random replacement of parts usually is a waste of time of money, it's better to find the causes.
Replacing random capacitors is not the answer to random problems! Unless it's early surface mount types...

 

That's my weakness. I don't know enough about electronics to track the causes. I'm still hunting hands on electrics courses where I can ask questions of a human being, and possibly take circuits to class.

 

My favorite Horror Story is here:
Fixing a Legend... as Part I
The Saga Continues as Part II

the best How-To tutorial that I know of

 

Thanks for those. I'm still tracking down electronics courses but those that I've started to read, seem to fall into the usual trap of assuming a base knowledge and then they lose me completely.

I might save up for an Open University electronics course, but I really learn best when I'm hands on. That's how things stick in my memory.

Progress is slow, as the heat makes it hard to sit down and do fiddly work, but here's the progress so far, hindered somewhat by the fact that the service manual doesn't list components that are identifiable, but even when it does list resistors, it doesn't say what wattage to use.

 

Already have it. Part 1 is 338 pages... guaranteed insomnia cure!

 

In case people were wondering, life has gone a bit bonkers. Some family members have passed on, and I've had to juggle some legal balls along with other things which have just drained me. While I've been able to do some thing like do occasional blogging, the detailed work that requires sitting down with a soldering iron, has been beyond me.

I can report that one set of cables is too tight to put a socket in-line, and the other has a cover around the cables and, also being in the position where the transformer goes, I'm loathe to cut away that protection and install a socket.

That means I've got to take detailed pictures of the board, and then de-solder and label the cables. But with another funeral to attend next week, and another weekend guest vising soon, it's liable to be another few weeks before I'm in a state to do the de-soldering necessary.

There is an up-side to all this... which is that the Aiwa boom box is liable to be by far the worst maintenance job.

 

Sorry to hear about all the other things taking up your Hobby time.

I have only just caught up with this thread.
In response to the questions about electronics courses here are some that I found useful "when I was a lad"

https://www.amazon.co.uk/Making-Transistor-Radio-ladybird-make/dp/0721403247

I actually made this when at school. Although it worked it mainly picked up the local transmitter which was Radio 4 (when it was on medium wave) which was the last station a Schoolboy wanted to hear.

I have not had much success finding the others. I was specifically looking for the "Electronics It's Easy" specials published by Electronics Today International. Somewhere I have all three parts)

However, the American Radio History website is a treasure trove with back episodes of ETI, Everyday Electronics, and Practical Wireless.
If you have a spare half hour browse through one. I know that at one point Everyday Electronics included tutorials aimed towards GCSE electronics courses.

I would even suggest that 20th century magazines are probably better to learn from when repairing vintage electronics.
Last time I looked Everyday Electronics seemed to have turned into Everyday PICs (a small microprocessor) which means most of the clever stuff is done in software.
You might find the same with an OU course with the emphasis on things like VHDL rather than capacitors and resistors.

For more practical learning keep an eye out for something like this.

https://www.ebay.co.uk/itm/200-in-O...=true&nordt=true&rt=nc&_trksid=p2047675.l2557

Make sure you get the manual included as without it, it is just a load of components on a cardboard sheet. From what I remember the manual is a pretty good introduction to electronics, as the whole set was intended to be educational.

 

Thanks for that Longman. I did sign up to a year of Everyday Practical Electronics, after exiting the supermarket one day, and earwigging on the conversation behind me. I asked them for their opinion on the best way into electronics these days, and they recommended Practical Electronics (which became EPE) and particularly the back issues which are in the local library.

I have found that reading the back issues of things requires a base level of knowledge that I just don't have. Or rather... I think I do have it... I just don't trust myself, if you know what I mean.

I have a feeling that EPE will be exactly as you said... modern PIC related stuff. However, my subscription will come with a "teach in" series on CD Rom and... to be honest... I can probably make use of the Pic stuff going forward anyway, so not all is lost.

I did also contact the OU, and the course is knocking on for £7,000 which is too rich for my blood at the moment... especially after all the cash I've spent on e-bay actions lately - *whistles*

In the mean time, I've found a 200 in 1 on fleabay and I'm on the hunt :-D

 

When I was learning electronics 40 years ago there was a choice of about eight magazines

ETI
Hobby Electronics (a beginners version of ETI)
Practical Electronics
Everyday Electronics (a beginners version of PE)
Radio and Electronics Constructor
Electronics and Music Maker
Wireless World (which was aimed at professionals)
Elektor
Practical Wireless (which was more about electronics than Ham Radio)

Most of the magazines merged into EPE, although Elektor is still going, as is Practical Wireless but with much more emphasis on Amateur Radio.

For basic information in the old magazines I would start by looking at Everyday Electronics, which as the description says was aimed at Novices

https://www.americanradiohistory.com/Everyday_Electronics.htm

I subscribed to that for a couple of years before progressing to ETI

Sometimes on the way home from College, when I had to change buses in Bristol Centre I would go into Lewis's department store news stand to see what was new.
That was when I wasn't going into Target Electronics. I was such a regular customer there that they once gave me credit when I didn't have enough money for something I wanted. Nowadays there seem to be more magazines on car restoration than Electronics.

Of course the big change today is The Internet. Only 20 years ago I had to go to the central library to copy the circuit for my TV from their sevrice reference books when a capacitor blew up (literally) and I needed to to know the value for a replacement.

Finally an anecdote about Practical Electronics which they had a subscription to in the School Library.
In about 1977 they published an article for an amazing project that could be reprogrammed to do all sorts of tasks e.g. Calculator, Alarm Clock etc.
I had never seen anything like it before, and thought that like the UFO detector one magazine published I might never see anything like it again. I wondered if I should buy the magazine. The project was actually a Microprocessor training board and of course in less than five years Microprocessors were common place.
I would never have guessed back then that it forty years time my Home Computer would have a 3GHz processor and 12GByte of Ram.

 

The good news is that I secured myself a 200 in 1 electronics kit. However, the "People who bought this also looked at..." feature, has me concerned about the kinds of people who are learning electronics these days...

 

Ha ha that is funny