Coming Events

Antique Wireless Association Valve QSO Party - 11&12 October 2014

AWA Valve QSO Party AM and SSB:
This is a phone contest held over 2 sessions on Saturday 11 and Sunday 12 October 2014.
On Saturday afternoon 11 September, 15:00 to 19:00 SAST the AM section will be held with contacts on both the 40m and 80m bands for points.
On Sunday 12 September from 15:00 to 19:00 SAST the SSB section will be held with contacts on both the 40m and 80m bands for points.
Frequencies: 40 metres: 7,053 to 7,100 MHz and 80 metres: 3,603 to 3650 MHz
Exchange: Call sign, RS and consecutive serial numbers starting at 001, plus type of radio used, eg HT37 Tx.
Points scoring: All valve radio -  3 points per contact; Hybrid (valve & solid state) - 2 points per contact; Solid state - 1 point per contact.

The aim of the AWA Valve QSO party is to create activity on the 40 and 80 metre bands. It is a phone only contest. Preferably, valve radios, or radios with valves in them may be used. No Linear Amplifiers may be used.
The event takes place from 15h00 to 19h00 CAT on both Saturday 11 and Sunday 12 October 2014.
More info available on page 36 of the SARL 2014 Contest Manual - http://www.sarl.org.za/public/contests/contestrules.asp

Valve presentation @ SARL RTA 2014

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

KARTS & AWA Flea Market and Open Day

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.

For table bookings or any queries, contact Selwyn ZS6SEL at 082 804 2782 or email to This email address is being protected from spambots. You need JavaScript enabled to view it. or Nico ZS6QL at 083 269 9939 or email to This email address is being protected from spambots. You need JavaScript enabled to view it.

KARTS and the AWA are looking forward to welcome you there!

Alexanderson Day

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.