EPE Mag - Free projects downloads

[Yorkie]

I've just noted from the EPE Chat Zone that EPE magazine has made available older projects online for free download. Quite a nice mix too, such as metal detectors, audio amps, guitar practice amps, portable valve radio HT supply, bench power supply, frequency standard locked to Droitwich etc. It harks back to the days when I used to be a subscriber for many years.Some may use components which are now obsolete, but I've looked at several which seem OK.

http://www.epemag.com/lib/free-projects.html

Most projects in EPE these days are PIC based, and though that greatly simplifies the project in many ways, and blends computing with electronics, I'm just not into PICs, so having subscribed to EPE for many years I stopped several years ago.Most EPE projects nowadays seem to be re-prints of the sister magazine from down under - 'Silicon Chip' using obscure components. Jaycar do kits for some projects, but by no means all.

Elektor projects always were a bit esoteric and whacky, but nowadays, although I always have a flick through the mag at WH Smith's, PICs abound and I rarely find anything that appeals.

Hope the EPE legacy projects are of interest.

[Geaney]

Thanks David, some interesting projects there. I'm tempted to have a go at the active ferrite loop aerial.

Many years ago I made an FM tuner project featured in Elektor. It was in the days when I used to etch my own circuit boards. To my delight it worked flawlessly for many years. Just as well, if it hadn't worked I would have had no idea how to trouble shoot the thing!

Cheers, John

[Nick]

Elektor is excellent if you don't want to make yet another windscreen wiper delay unit or something made on Veroboard.

My main issue (excuse pun) with EPE is that they simply haven't moved with the times. Not on design. Not on content.

Whilst there is a lot in Elektor that I'm not directly interested in, there's a lot of stuff in there that piques my curiosity and I file it away in some dark recess of my mind for rainy days... for those "AHA!" moments...

Their "3xx" series books are excellent design references (I have a complete set from the start at 301 to 311) - their analogue design quality is so much better than EPE that there is no comparison.

Having said that, I've written for EPE in the dim and distant past, but a few years ago I wrote a letter about the extremely poor quality of an article they published about a pic-based frequency analyser based on fast Fourier transforms -(FFTs) - it was obvious that the author hadn't a clue about the maths (or even the basics) and as a result the project was misleading and inaccurate.

They published an abbreviated version of my letter (March 2002) with the editor admitting that they couldn't understand the issues and trying to gloss over the errors.

That was the last time I bothered with them. (just noticed that's not true - I wrote another letter to them in 2003).

[Yorkie]

Back in the early 'noughties' Raymond Haigh produced many interesting and nicely designed projects, both from a constructional and aesthetic angle. Various receivers and amplifiers. (It was he who designed the Radio Bygones Wobbulator, later re-published in the BVWS Bulletin). He wrote a 4-part constructional series in EPE back in 1982 on simple amplifiers, and on speakers and crossover networks etc. The four parts can be found at these link:

http://www.epemag.com/lib/free_projects/...rt%201.pdf
http://www.epemag.com/lib/free_projects/...rt%202.pdf
http://www.epemag.com/lib/free_projects/...rt%203.pdf
http://www.epemag.com/lib/free_projects/...rt%204.pdf

I'm very much in John's mould - right back to being a schoolboy in the mid 1950s, my constructional ability has always exceeded my technical knowledge and I've always built things neatly, or at least, to the best of my ability. Sometimes they worked fine - too often they didn't! I know that many people say 'I just chuck things together and if they don't work, I haven't wasted much time on them'. That just isn't my style, but as a consequence, over the last five decades, I've built countless projects in which I've carefully and unwittingly replicated the errors. Having nicely boxed projects up, which will never work, I've then not had the heart to pull them apart and rob them for bits. At one time, I had quite a showcase of elegant, (but entirely ornamental!) non-functioning projects.

As I moved into my teens, I came to realise that article in Practical Wireless such as 'an enthusiast's TRF' meant you had to be an enthusiast to redesign it so that it would work. An 'experimenter's power supply' didn't mean 'a power supply to help you with your electronics experiments', but power supply design for you to experiment with to try to get it working. I did have my successes though - back in the mid 70s I built the PW 'Tele-Tennis' project for our two sons and our house became a magnet for other kids to come and play. My younger son (now 45) still has it and it still works!

[Keithstv]

I very rarely built projects from magazines preferring to take bits from the projects that suited what I wanted. Over the years of subscribing to a number of magazines I have nottced many glaring errors, one classic one which has been repeated many times, is fitting an LED as a power on indicator on a piece of battery powered equipment. You may say what is wrong with that. The designer has obviously looked at the LED data sheet and seen figures for the forward current of 10 to 20mA therefore the dropper resistor for the LED is set for that current in the LED resulting in a piece of equipment where the power on indicator takes significantly more current than the rest of the circuit.

I've also written for several magazines in the past and wondered how many people actually built the projects I wrote. I don't think many people did. I only had two queries from one article on electronic ignition, one of which was probably using the wrong components which is why it didn't work, and one plus follow up letters in Television on an article on a Nicam stereo decoder add on.

Keith

[Refugee]

In the 1970s I built the ETI sweep generator and it would not work with the fast chips and the square waves were poor so it only served as an audio sine wave oscillator for many years.
It was not until nearly two years ago that I finally sorted it out.
http://www.forum.radios-tv.co.uk/viewtopic.php?f=15&t=1915

[Nick]

The reason Elektor win is that all designs are vetted and built by their own professional engineers in proper labs. You pay a bit more, but what you get is (generally) very high quality articles.

This is why Elektor have a certified paid-for circulation of about 125,000 copies per month and EPE has a circulation of only about 1000

There are a number of "privately published" engineering journals, like Linear Audio (to which I also subscribe), which are of exceptional quality.

[Yorkie]

Over the years of subscribing to a number of magazines I have noticed many glaring errors, one classic one which has been repeated many times, is fitting an LED as a power on indicator on a piece of battery powered equipment. You may say what is wrong with that. The designer has obviously looked at the LED data sheet and seen figures for the forward current of 10 to 20mA therefore the dropper resistor for the LED is set for that current in the LED resulting in a piece of equipment where the power on indicator takes significantly more current than the rest of the circuit.

Oddly enough, for bits of test gear which is only used occasionally and for a few minutes at a time, I usually do include an LED, because although as Keith says, it will most likely use more current than the circuit itself, without a warning LED it's so easy to leave things switched on, so next time I come to use it, the battery is duff anyway. Really, for such projects it would make much more sense if I fitted a power socket and plugged in a wall-wart to power them as and when needed, rather than using Poundland PP3s!

[Kalee20]

I used to get EE (before the merger with PE, giving EPE) and it was a good little magazine. i stopped around 1982 when they started introducing computer-based projects.

Thanks for the link to these archives, Yorkie!

I'm not in a position to comment on accuracy etc, as these days I may get one copy every couple of years. However, availability of simple microcontrollers such as the PIC series has opened up another dimension in digital electronics.

Granted, programming of PICs isn't electronics, it's another discipline again, but it does allow a big simplification in the operation of many sequence-based projects. I reckon these devices have an important place within a properly engineered piece of electronic circuitry.

I'm thinking in the early days of PW, F J Camm always tried to give his readers the opportunity to try up-to-date techniques - screen-grid valves, class B push-pull, superhets, etc while other magazines were a couple of years behind. It worked.

[Keithstv]

Perhaps there has been a little misunderstanding over the LED. There is no problem with fitting an LED to indicate the equipment is on but why run it at 10 to 20mA when most LEDs will be quite happy at 5mA. At a lower current the batterries would last longer.

When I wrote constructional articles there was never any question of "Does it actually work", I think they assumed it did and it would have been a lot of effort to check every constructional project. Only one magazine wanted the finished item and that was only for photographic purposes.

Keith