Electronics - Solder On

[Shark Bait (Stu)]

My main motivation for dabbling in electronics is to construct the dew controller that Al Sheeny has detailed in the Projects & Articles section of the IIS forum. To get there I have picked Jaycar Electronics Short Circuits #1 series and two of the project kits from Short Circuits #2 series. I had never used a soldering iron before, so it took a little while to get the technique right.

Our eldest wanted to be a Dalek, so the first kit was 'Sound like a Dalek'. It works really well and is spot on, especially when run through the guitar amp. Lots of Dr Who goodness. I wanted to run it through the Aux jack on the car stereo to turn the family wagon into the TARDIS but the fun police (SWMBO) canned that idea.

The second was the 3 Digit Counter to use with the slot car racing set (photo attached). With the addition of a reed switch it will automatically count the number of laps and after few small errors we have it up and running.

Each little success gives the confidence to move onto a slightly more complicated task. It is great fun and working through Series #1 is a good way to spend time with my Son and learn some basic electronics as well.

Thanks to all member of IIS who have provided information regarding their electronic projects. It was the main source of encouragement prior to taking the plunge into the 'dark arts'.

[Matt Wastell (Matt)]

You sound like a pro to me! Good luck with others!

[Larryp (Laurie)]

Building electronic devices is certainly a satisfying pastime.

[mswhin63 (Malcolm)]

Even after 30 years working in the industry and 5 years prior as a hobby, I still enjoy creating things and putting my mind to a lot. It seems to never go out of flavour

[midnight (Darrin)]

Good on you! You'll never stop learning. I remember when I was younger and trying to figure out why I kept getting holes in my teeshirt over a few months. Turned out to be flux in the solder - I was probably soldering, doing something nearly 7 days a week for a few yrs there.

Good luck.
Darrin...

[Barrykgerdes]

My first attempt at soldering was to heat up the iron (copper) in a coke fire and try to solder an aluminium pot. Needless to say I had no success. No one told me that you could not solder aluminium. I was 12 at the time.

Next venture into soldering involved sweating brassware to make a power bogey for a train. I managed to borrow an electric iron from a neighbour and was successful. About 14 at that time.

I next made an electric soldering iron (12 volt) after that. A real work of art made from scrap copper, hoop iron, broom handle and wire and mica from an old toaster element, and wound a transformer to drive it.

By this time I was well into making radios so my soldering improved greatly as there was a lot of soldering (un-soldering to salvage parts) necessary with valves in those days. (1950)

Barry

[Baddad (Marty)]

Hi Barry,

Aluminium can be soldered. There is a special technique if you don't have the necessary flux. Its difficult but it does work.

Cheers

[Barrykgerdes]

Originally Posted by Baddad

Hi Barry,

Aluminium can be soldered. There is a special technique if you don't have the necessary flux. Its difficult but it does work.

Cheers

Yes I know but in 1947 I knew little about that sort of thing

Barry

[erick (Eric)]

Have lost count of the number of soldering irons I have had over the years. Building circuits (and seeing them work!) = FUN!

[Shark Bait (Stu)]

Thanks to all for the encouraging comments.

I thought the learning curve with Astronomy was steep but electronics looks to be steeper. It is good fun and I like the fact that it either works or it fails, which means the error is with me.

I have just had a go at putting together an AM radio from Short Circuits Volume #1 using springs to hold the transistors, resistors etc.

Years ago my Father helped me to build a crystal radio set. At the time I was not that impressed with the sound quality of the finished product. Even then AM was losing ground to the FM bands.

I have to say that I am still unimpressed with home spun AM radios. No matter what I do there is no way to avoid listening to three stations at the same time.

[Barrykgerdes]

Originally Posted by Shark Bait

I have to say that I am still unimpressed with home spun AM radios. No matter what I do there is no way to avoid listening to three stations at the same time.

This is a failing of all simple tuning circuits. To get station discrimination (high selectivity) with a single tuned circuit you need a very high "Q" (quality).

The "Q" is degraded by the loading on the circuit caused by needing to couple the output of a simple crystal set to headphones for example and still get enough signal to hear. That is why high impedance headphones are specified and crystal sets were never very selective.

In a simple radio circuit eg one transistor the selectivity and gain of the circuit can be made regenerative (feed the output back to the input to re-amplify it). This has the effect of raising the "Q" to a very high figure. However the control of the amount of feedback to avoid uncontrolled regeneration (oscillation) is quite fiddly.

Barry

[Baddad (Marty)]

And so came forth the super hetrodyne receiver, with its highly selective intermediate frequency stage. (IF stage). Of-course it then required a local oscillator and mixer stages preceding the IF.

You are on the basics to developing the super het' from need of better selectivity.

I remember building my first one transistor radio. The received signal itself powered the transistor amplifier.

Cheers