A Madcap look at Radio Valves (Thermionic tubes) – part two

While I am on a roll decided to write up part two of this series. Some idiotic things you can get away with when working on valve or tube equipment. (Yes, I forgot to tell you in part one that they are the same thing – American = Tube and Europe, more so the U.K.  = Valve, both thermionic devices). I mentioned the story about the transmitter set incorrectly but how about a disconnected aerial. The ship had a ‘bird-cage’ aerial, see fig one below. These were very popular on merchant ships.

Bird Cage Antenna
Bird Cage Antenna - courtesy RCN

Continue reading “A Madcap look at Radio Valves (Thermionic tubes) – part two”

A Madcap look at Radio Valves (Thermionic tubes) – part one

I think everyone over the age of 40 should be culled! Youngsters at work have never heard of the Holocaust, the Berlin Wall and now, thermionic tubes. Remember the book Logan’s Run? Sometimes I think I am in the book. Well for starters when I was about 13 I took up electronics as a hobby – finances at 13 don’t normally allow one to build snazzy circuits but I do recall getting a lot of parts from my dad and grandfather both whom were avid tinkerers. Remember the OC71, the OC72, the AD161 and the AD162? The OC71 lead to disasterous results when used in amplifier  circuits once the layer of black paint becamse scratched. The OC series were old MULLARD devices but due to cost ‘tinkerers’ kept to thermionic tubes/radio valves. Can you imagine that today?

Power Tetrode
        Power Tetrode http://www.indiamart.com/impex-international/vacuum-electron-tube.html

Continue reading “A Madcap look at Radio Valves (Thermionic tubes) – part one”

Akai M8 – Vintage Audio

Akai M-8

Akai M8 Semi-professional reel-to-reel vintage audio

Many years ago my father owned an M8 – it was an expensive piece of equipment in those days, I recall it was about 1966/67 and he purchased it from the proceeeds made from the profit of a sale of our (his) house. What fascinates me now about this piece of equipment definitely wasn’t the power but the quality of the sound – these units only delivered something like 2 x 6 watts to the loudspeakers but  good quality vinyl on a turntable (I remember Cat Stevens music) produced some really good audio.

Akai M8
Akai M-8 – courtesy http://www.bassboy.com.au

Akai M8 – Cross Field Head

The BIG thing about this machine was the marketing around cross field heads and 27 ips (by changing the capstan diameter). 27 ips was no big deal but the quality at 1 7/8 ips was. Compared to latter day cassette decks this thing was simply archaic but you know what? Who cared. It looked good and was very well made. For the price I doubt one could have found a better piece of machinery. Have a look at Revox pricing and you’ll know what this is all about.

I often think about all the hype associated with thermionic tubes versus semiconductors these days and although I built a few speaker busters in my hay day, the amplifiers on this unit would really have been a good add-on to my sound system now. In those days I think the Akai M-8 went for something like 300U$ and guess what – that’s what they still reach today – in good working condition.

The Akai M8 Amplifier

My dream is to go into a pawn shop and pick one up for 50U$ but this will remain a dream – I think most pawn shop owners know what valve amplifiers are worth these days – a pretty penny. The Akai M-8 had two removable class-A modules or monoblock units as I believe they are called now. So for anyone out there looking for a fine solution to their wanting a tube amplifier problem – look for one of these.

I’m looking for the schematic of one of these – hopefully someone can send me a link or the actual schematic – it’s time to do some cloning.

(Update: schematic attachment here)

Akai M8 - Schematic
Akai Schematic M8

Interestingly enough research brought up this article: http://www.tdpri.com/forum/shock-brothers-diy-amps/333890-akai-m8-conversion.html – someone with similar ideas.

The small s in BRICS

To Build or not to Build

[Editor’s comment: for visitors from countries outside BRICS the wiki article found here is fairly detailed and outlines the BRIC or now BRICS strategy (as coined by Jim O’Neill, Goldman Sachs]

An article in the Time magazine inspired me to write this:  Obama wanting to get more manufacturing in the USA, not only for the financial reward but more innovation. I agree with this. I live in RSA (republic of South Africa) a country where free enterprise is stifled by unions and the labour act. Oh yes, and millions of lazy people. Where we do have some form of manufacturer it’s normally along the lines of some state subsidised endeavour, not always but quite often.With Cape Town’s Vision 2040 I ask myself what happened to Stellenbosch, our own little village of intellectuals and Silicon Valley Wannabes. I don’t care for BEEE and neither do the thousands of black south african intellects.  I often hear about Cell C CEO Alan Knott-Craig (ex-Vodacom) being an opportunist but the joke is on the joker, his sentiments are heard – my money is always on the doer and not the speaker. I’d vote him into Telkom (the local government backed telecomm’s giant) and let him do the necessary, cull the top dogs, improve efficiency (which should not be too difficult considering that they run at about 1%) and start showing some innovation. Yes, my DSL line was down for two weeks – try this trick with any ‘proper’ privately owned company relying on services to generate revenues. Without a proper telecommunications backbone we are back in the dark ages, with Dark Fiber Africa or not.

Brazil’s President Dilma Rousseff, Russian President Dmitry Medvedev, Indian Prime Minister Manmohan Singh, Chinese President Hu Jintao and South African President Jacob Zuma hold copies of the BRICS report at the summit in New Delhi yesterday (Photo: Reuters, article here.)

Continue reading “The small s in BRICS”

The Joomla Vs WordPress Vs Drupal debate.

wordpress - joomla - drupalI’m not going to plagiarise here, neither duplicate content which I found to be important in our own personal quest to determine the king of CMS currently.  We used to use Joomla but on a personal level found that the updating of plug-ins and Joomla core was a bit clumsy – which included a major crash whilst updating a plug-in. Not so with WordPress, at least not yet. Drupal however made me feel more like a developer only because it felt more sophisticated.  But then again some of the simplest things to operate are very complicated engineering wise. Is this the reason why so many developers are switching to WordPress?

Mike Schinkel’s website and his personal blog on “17 Reasons WordPress is a Better CMS than Drupal” is a great read, it’s also refreshing to see that the comments made are objective and obviously written by informed developers.

Just to close off this short article I think one needs to be an experienced developer (what makes an experienced developer?) on these three CMS platforms to be in a position to be objective here. This is what made this article so interesting. Making something so simple to use can only come from developers with great insight and a very high level of expertise.  Cell phone manufacturers often come across as being a bit arrogant in their ability to show off their technical expertise but miss the point by a mile. But that’s a whole new debate.

See also:  http://www.theopensourcery.com/keepopen/2010/best-open-cms-wordpress-vs-joomla-vs-drupal/