My Ongoing Research On Radio

[total-recoil]

This is still ongoing. I've also been wondering lately if the arrival of the semiconductor in the mid fifties (marketed in the very early sixties) cut short an interesting advance in the tube as the world embraced transistors. I now find that just before Japan started to dominate the market for pocket transistor radios around 1960, the latest tubes were only an inch in length and able to run on just 60 odd volts. It was mainly the fact that the standard 90 volt battery portable tube radios required was too big a headache once transistors were able to run happily on just 9 volts.
However, tubes still to this day have an important edge over the semiconductor, namely the sound is kind of better and tubes are not damaged by radiation so are more useful in space.
I've been trying to get my hands on one of these latest portable tube radios of the mid fifties because I wonder how much more they might have been improved. Given finding a 90 volt battery is a bit of a headache unless you wire up 10 nine volt smoke alarm batteries in series, my plan is to either make or just buy a battery eliminator. These allow you to just plug into mains and get a 90 volt feed to your set.

 

[total-recoil]

The other night I opened up a course book on modern electronics and was a bit in shocked as to to how much harder it seemed to me compared with the tube electronics I specialise in. Seems as if stuff has moved on a lot since the fifties. The old tube radios I work with only had a maximium of five valves and some had less than that. All you need is a decent knowledge of Ohms Law, resistors, capacitors, coils and tubes to cover vintage audio electronics. Students have to learn a lot more today.

 

[Xavier Marik]

i'm more interested in HF communications

 

[StephF]

Ham Radio is an absorbing hobby that involves both Radio and Electronics.

 

[Levinus]

I think there is more opportunity when dealing with transistors. Tubes are ingenious, without a doubt. You have to admire the simplicity and efficiency of the design. But solid state transistors allow for more precision, digitization, miniaturization, regulation, distribution, and a lot of other "tions".

Radio wave propagation is a really fascinating study. Each frequency is almost an individual in how it responds to certain environments, with unique reflection coefficients and impedance factors. Unfortunately calculating a lot of that requires a firm foundation in calculus, some handy algebraic shuffling, and a little trig. But after a few calculations, you start to really visualize the properties of EM spectrums.

I personally investigated using high frequency EM radiation as a source of power (especially because it is ambient and everywhere!). I ran through as much of the spectrum as I could...legally...and it turns out that photovoltaics are really the best EM generators we have, and hopefully getting better once we can mass produce graphene.

I would be interested to know if you have an old tube tester? Have you tried making your own tubes? You might be able to use some solid state pieces to really improve efficiency. Instead of a heatsink, why not a peltier module and a heatsink?

 

[StephF]

I very much agree about tubes. They are so hard wearing in the sense of what voltages and currents they tolerate. Your common garden bipolar transistor is very finicky. Too much and it literally goes poof!

I've mever considered blowing my own tubes and I don't have a tube tester. Most modern radio equipment is solid state nowadays.

It is cheaper but there's always a downside to be had. At least transistors only need dc.