As announced last week Tony Voorveld ZS6CCD will be delivering the keynote address at the upcoming "Radio Technology in Action, entitled "The Magic Lamps". The lecture is accompanied by demonstrations depicting the evolution of the valve from the early experiments by
Thomas Edison (the Edison effect) to the development of the diode, triode and x-ray tube, thus opening the door to the modern electronics industry.
As all with previous lectures by Tony, this one promises to be full of action and interesting demonstrations.
SARL Radio Technology in Action
Gauteng: National Amateur Radio Centre 23 August 2014
Innovation Hub, Pretoria 13 September 2014
Get all the details, programme and booking form here
The Kempton Park Amateur Radio Technical Society (KARTS) and the Antique Wireless Association (AWA) combined flea market and open day event will take place on Saturday 24 May 2014 from 08:00
The venue is the Impala Voortrekkers Centre, Rooibos Avenue, Allen Grove, Kempton Park. Please visit the KARTS website at www.zs6kts.co.za for directions to the venue.
Apart from the flea market, a display of antique radios and associated equipment will be put together as well as an active HF + V/UHF station from where the Saturday AWA SSB net will be operated.
This event promises to be a most interesting, enjoyable and memorable day.
KARTS and the AWA are looking forward to welcome you there!
Alexanderson Day will be held on Sunday 29 June this year. This day commemmorates the Swedish radio engineer Ernst Alexanderson and is celebrated by having an open house at the Swedish VLF transmitter, Grimeton. The transmitter operates on 17.2 kHz with the call-sign "SAQ".
Alas, it probably can't be heard in South Africa (Please someone prove me wrong.)
The remarkable thing about this transmitter is that the signal is produced by a rotating machine called an Alexanderson alternator. In essence this is a series of rotating iron discs swith cut-outs arounds the periphery. The field coils are also placed on the periphery and the iron induces an alternating voltage of very high frequency in the field coils. The spaces between the cut-outs are filled with non-magnetic gunmetal to reduce air-resistance.
The signal can be received using a tuned circuit attached to a PC sound card. A program such as "Spectrum Lab" can be used to decode the transmission. There's even an SAQ receiver script for this software.
Alternatively, a TRF receiver could be used.
For those who like to experiment, a stepper motor from an old disk drive can be used as a high frequency alternator, but keeping the frequency steady is another thing altogether.
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