Amateur Radio Station ZS6AA

QSL Policy: I QSL every QSO via Logbook of the World. I will happily respond to QSLs sent direct to the address below. I do not QSL via the bureau because this results in sending many cards to people who don’t really need them. My postal address is:

PO Box 1060
Gallo Manor 2052
South Africa

Andrew ZS6AA

Welcome to the web site of Andrew ZS6AA, an amateur radio operator and contester living in Johannesburg, South Africa. You will find most of my recent posts on my Diary of a ‘Little Pistol’.

I was born in 1965 and first licensed in 2001 as ZS1AN. I am married to Stacey ZR1SC and we have a wonderful daughter. I work as manager of the RF Electronics business unit in the Defence division of Poynting Antennas where I design antennas, RF electronics and embedded control and signal processing systems. My projects have included very high speed (sub-50 microsecond) antenna matching units for frequency-agile transceivers, high-speed tunable RF filters, a DSP-based direction-finding system, EHF radomes, high-impedance preamplifiers for active antenna systems, and a variety of antennas covering frequencies from 100 kHz to 6 GHz. I also designed the amateur radio payload for South Africa’s “Sumbandila” satellite which will hopefully be launched real soon now!

My principle amateur radio interests are:

  • CW ragchewing
  • Contesting
  • Electronics
  • Antenna Design and construction

My station is a single tower, single operator two radio (SO2R) station designed for low-power (100 W) contesting. Here is the operating position:

SO2R Operating Position

The HF transceivers are both Kenwoods – a TS-850SAT (left) and a TS-930S (right). All my HF transceivers have been Kenwoods – I started with a TS-430S, then replaced it with a TS-680S, then swapped that for my TS-850SAT, and finally added the TS-930S for SO2R. The small shelf above the radios contains a Top Ten Devices DXDoubler which switches the paddle, microphone (when I use one) and headphones between radios, either manually or under computer control. Next to the DXDoubler is a WinKeyer for CW keying and in the unpainted aluminium box a home built dual band decoder. The band decoder automatically selects the correct antenna for each of the transceivers according to operating band. The antenna switching is done by an Array Solutions SixPack (not visible). The Prosistel antenna rotator (top shelf) is also under computer control.

The FL2100B linear doesn’t see much use as the bandpass filters I use to minimise inter-station interference are only rated for 200 W, so I have to manually plug the antenna coax into the linear if I want to use it – needless to say I don’t use the linear when contesting. The Palstar AT-1KM tuner above the linear is also unused at present, but it’s such a nice piece of equipment that I can’t bear to part with it. Finally, a pair of monitor scopes allow me to monitor my output signals. One also has a panadapter but to be honest it’s nearly useless. I don’t really need two monitor scopes; one came with the TS-930S as a “package deal” and I haven’t got around to disposing of it! There’s a Kent iambic paddle (mostly for ragchewing and the occasional fill) on the desk; and you can see the masking tape along the top of the computer keyboard with the WriteLog function key designations!

Tower Sunset

My antenna system consists of a Force 12 C-31XR tribander at 18m (60′) and an Optibeam OB2-40 2-element 40m beam at 66′ on a telescopic / tilting tower. Both are amazingly good antennas. I feed the C-31XR with three separate coax feeds, one for each band, and using W3NQN bandpass filters for isolation I can operate on any two bands simultaneously with little inter-station interference. My 80m antenna is a vertical dipole suspended from the tower in an inverted “L” configuration; it’s new so I don’t know how effective it will be.

2 Responses to “Amateur Radio Station ZS6AA”

  1. Jim Smith VE7FO Says:

    Hi Andrew,

    Hah, I found you.

    Long time no chat.

    I’ve immortalized you at

    as indeed the author of such an excellent piece of work should be.

    However, if you don’t want your link there, let me know and it will vanish.

    You may be interested in making some contributions yourself – it’s fairly easy, even for a dinosaur like me who barely knows what a wiki is (some kind of HC8 marsupial?)

    If we ever get some spots I might actually hear a ZS some day.

    However, to my amazement, 20, 17, 15, 12 and 10m are all open to W6 right now (0053 hrs local time)

    Go to to see what propagation is like for Vancouver. Read the text file first. Antenna is a Cushcraft R5 vertical at about 50 ft sitting on top of my TH3 tribander. Radio is a 1k MP MKV

    Info on Faros at

    73, Jim Smith VE7FO

    • Andrew Says:

      Thanks for your kind comments Jim! I have updated the wiki with the address of the latest copy of the FAQ. Unfortunately I haven’t been doing much contesting recently due to the birth of my now 3 month old son, but hopefully I’ll be back for CQWW later this year.


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