Tuesday, 25 August 2015

CTARC In The News! - 25 Aug '15

The following article on the CTARC's involvement in the International Lighthouse/Lightship weekend at Mouille Point Lighthouse in Green Point, written by Sellecca Lang, appeared in the Atlantic Sun community newspaper on 25 August 2015.

For a PDF file of the article, click [here].


Monday, 24 August 2015

ZS1CT Photos from the past - ZS1AGH

We gratefully  include these photographs, kindly supplied by John / ZS1AGH, from his formative years...






Sunday, 23 August 2015

CTARC Report-Back on August Meeting - 23 Aug '15

On Saturday 22 August, the CTARC met at the clubhouse for the monthly meeting. This time, it was a "Show-and-Tell" session.

Below are some photos of the event.

The meeting started with our chairman, Rob / ZS1SA welcoming us and reporting the sad event of two silent keys, Mike Rolfe / ZS1EW and Ozzie Elliott / ZS1NL, for whom a moment's silence was held. Rob then gave a brief report-back on the Lighthouse Weekend which was held at Green Point on the weekend of 15 / 16 August, and on our recent Committee Meeting of 17 August.


John / ZS1AGH (recent recipient of the SARL Jack Twine Award) will be giving a talk in a future CTARC meeting.


First up on the Show and Tell session was Mike / ZS1FP. He showed us two photos of a "Go-kit" mounted on a frame-pack for portability, constructed by Dennis / ZS1TC (thanks to ZS1TC for allowing us to reproduce those photos here). The rig is a Yaesu FT-857, powered by two 5 Amp/hour gell-cell batteries. The HF antenna is a multi-section whip, and the VHF/UHF antenna is a helical Rubber Duck. The setup includes and antenna tuner for HF matching to the whip.



Mike then showed us an adaptor that he built for testing equipment, consisting of a mains utility socket box with a (very well-) insulated loop on the Line circuit, around which a clamp meter can be fastened to make easy readings with the equipment in use.

Here Mike demonstrates how to use the clamp meter with the utility box to get a reading.


Mike also showed us another utility box which facilitiates plugging in of mains equipment with different formats of mains plugs.



Next on the list was Paul / ZS1S, who showed us some fascinating equipment. Paul's interest in high-end Hi Fi equipment (and very high-voltage electrostatic speakers) is evident in his Electrostatic DC High Voltage meter and Fluke HV probes he demonstrated. The electrostatic speakers (which deliver, apparently, phenomenal audio reproduction quality) are driven by a signal in the kiloVolt range (but with very little current).


Here Paul points out the Quad amplifier unit that is used to drive the speakers


These Fluke probes (as shown below) are needed to be able to measure the very high voltages involved.



Paul adjust the meter. At the rear of the unit is a metal rod that is drawn out and clicks into position at three points (corresponding to three voltage ranges to be measured). The rod connects to capacitive plates inside the meter, whiich when charged deflect the meter needle to provide a value.


Because the meter provides an infinitesmally small loading on the circuit being tested, it is possible to be highly accurate. The meter scale has an anti-parallax mirror. Paul managed to get a reading of several kilovolts from the HV power supply he brought to show us.


Next up was Hans-Jurgen / ZS1HJH, who showed us a very impressive, accurate, stable miniature HF oscillator kit that he built. The unit operates from 10 to 810 MHz. The circuit would be suitable for HF gear where, for example, the oscillator or exciter needs replacement (which is often the case, for example,  in old military boatanchor rigs).


The block diagram of the oscillator. Note that it is not a Direct Digital Synthesis oscillator.



The frequency on the LCD readout display (accurate down to single Hertz level) is easily set by the rotary encoder to the right of the LCD. Rotate it and the Hz digits can be set. Press the button in the middle of the rotary encoder and you can similarly adjust the 10 Hz digits, Press the button again and you can set the 100 Hz digits, and so on, up into the 100 MHz digits. So neat!



The size of the oscillator unit is evident below, as Hans-Jurgen holds it between finger and thumb!


Next demonstration was by Nick / ZS1ZD, who demonstrated a JRC-NRD-545 DSP receiver, the last consumer communications receiver produced by the very excellent Japan Radio Company.

Covering 100 kHz to 30 MHz (and higher with the optional VHF/UHF converter), this particularly sensitive triple-conversion receiver can demodulate AM, AM-S, AM-ECSS, USB, LSB, RTTY, CW, FM, WFM & WFM-S modes. It provides continuously adjustable (in 10 Hz steps) passband filtering from as narrow as 100 Hz to almost as wide as 10 kHz. It offers switchable DSP noise reduction, narrow- and broadband noise blanking, tracking band-stop filtering and adjustable AGC time constants.1000 channels can be stored (each channel contains frequency, mode and filter settings) and scanned or swept through. Software control (offering theoretically limitless channels) via PC is an optional extra. (Because Nick couldn't take photos while doing his demo, we've used a substitute image here, courtesy of Universal Radio.)


Our chairman, Rob / ZS1SA had two things to show us: First was an ultra-miniature crystal-controlled (7 MHz) QRP CW transceiver kit that he managed to obtain and assemble. The kit comes with an etched, pre-drilled PC board, all essential components and could be assembled in an afternoon.


As is evident, the transceiver is very compact.


The kit comes with a parts list and component placement diagram. There is not too much to go wrong here.

Rob also showed us a trap from a trap dipole that he has built and used regularly. Using stainless-steel lugs it has lasted reasonably well after a couple of years up in the air.



Finally, Rob showed us all an example of a fine embroidered CTARC cap that John / ZS1AGH and his good lady Elsabe are taking orders for. You too can order one for a very reasonable fee, and have your name and callsign embroidered on the side.



And so another CTARC meeting came to an end. This had been a particularly interesting one. Afterwards, we all had the chance to chat with each other over tea, coffee and a particularly delicious cake very kindly supplied by Elsabe.

We do look forward to seeing you at the next meeting which will be held at the same venue on Saturday 26 September at 14h00. Details of this forthcoming meeting will be announced presently.

Tuesday, 18 August 2015

CTARC Seventieth Anniversary - 2015

Where were you in 1946? Some (most) of us were neither born nor thought of in that year. But that was the year that the Cape Town Amateur Radio Centre, in its original incarnation, was founded. This date corresponds with the end of the Second World War and the return of thousands of soldiers back to South Africa. Many of them were former  signalers. Some of them had even acquired their amateur radio licenses before the War.

In 2016, the Cape Town Amateur Radio Centre will commemorate seventy years of it's existence, making it the oldest Amateur Radio club in South Africa.

To celebrate this significant milestone, we would like to do something rather special, at the end of this year. The CTARC committee is considering various options, and invites members and interested parties to contribute their own ideas.

Please contact our chairman, Rob / ZS1SA or our secretary, Anne via e-mail with your suggestion/s.
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Thanking you in advance!

Monday, 17 August 2015

CTARC Forthcoming Meeting - 22 Aug '15

Members of the CTARC are reminded of the forthcoming (August) meeting, to be held at the usual venue at 14h00 on Saturday 22 August 2015.

The meeting will be in the form of a "Show-and-Tell" session, where members can bring along pieces of amateur radio gear of interest, to demonstrate how it works, what makes it interesting, etc.

If you have not yet paid your club subscription fees, this meeting will be an ideal opportunity to do so, should you wish to renew your membership of the Cape Town Amateur Radio Centre.

We look forward to seeing you there!

Sunday, 16 August 2015

CTARC Committee Meeting - 17 Aug '15

There will be a committee meeting for members of the CTARC committee, at 19h00 on Monday, 17 August 2015, at the CTARC Clubhouse. Please diarise accordingly.

This will be an important meeting because it takes place just prior to the CTARC Show & Tell meeting on Saturday 22 August. It will also be interesting to swop notes on our experiences of the ILLW event that takes place on the weekend of 15 / 16 August 2015.

CTARC Lighthouse Weekend Report-Back - 16 Aug '15

Despite rather moribund solar figures combined with rather wet weather overnight on the western seaboard, the CTARC held a successful Lighthouse Weekend on 15 / 16 August 2015.

Members met at the clubhouse on the morning of Saturday 15 August and loaded up the Force 12 beam antenna, gin pole, rigs and associated hardware.

We then made our way to the Green Point Lighthouse, where the antenna hardware was unloaded onto the lawns under overcast skies and the ham radio rigs moved into the Lighthouse building.

By now, assembly of the rotatable beam antenna is a reasonably well-rehearsed operation and erection of same was done smoothly and without mishap. Kevin, an interested member of the public, got into the spirit of the event and assisted us with assembling the antennas! At the same time, the club's 40/80m W3DZZ dipole was strung up between the lighthouse proper and one of the outbuildings, and a 2m antenna was also raised for VHF operation. Barry / ZS1FJ assembled and erected his very portable DX-pedition 20m vertical dipole fed with 300 ohm twin-feed. The club banners were flown from the top of the lighthouse, from the operating room building and at the base of the main beam antenna. Danny, Shaun and others set up the rigs and ATU's  in the operating room. ZS1CT/L was ready to go on air by about 11h00.

The station continued throughout the afternoon, with club members visiting and operating the station. As dusk approached, the weather looked as if it was going to deteriorate. However, it would be a betrayal of a sacred tradition to let that dampen out enthusiasm for our traditional sundowner braai. Even if it required a feat of imagination to actually see the sun... The charcoals were thrown, the fires duly lit on the raised entertainment platform and the sizzle of meat and snapping of beer caps could soon be heard. We managed to get our meat done before the gathering rain became too intense! The Lighthouse Braai is always an enjoyable social occasion.

A dedicated core of operators (Shaun / ZS1RA, Barry / ZS1FJ, Rob / ZS1SA and Matt / ZS1MTF) remained at the rigs throughout the small hours. Owing to security regulations, those staying overnight had to be registered in advance.

Over the weekend the station worked approximately 100 stations on Phone and PSK31, under very poor band conditions. The W3DZZ and Force 12 beam antenna both worked well.

More visitors arrived in the morning. The rains had more or less ceased and a fresh, cold wind was blowing. The CTARC bulletin was broadcast as per usual at 08h30, and Rob / ZS1SA delivered a Field Station report. The station remained active until 10h00 on Sunday morning. We had quite a few members and friends come to visit the operation over the weekend – thank you for doing so, including Dirk, Audrey and their new harmonic!

At 10h00 on Sunday morning, we started dismantling the station and transporting the antennas and rigs back to the clubhouse.

We have subsequently learned that the Lighthouse staff were very pleased with the way we looked after their facility and cleaned up afterwards.

All in all, it was a good Lighthouse weekend. Thank you to all those who assisted and participated. We look forward to doing it all again next year!

Paul / ZS1S kindly made his trailer available for transporting the heavy gin pole.

Danny / ZS1BL transported the Force 12 beam antenna

A brief discussion in the clubhouse prior to setting off for Green Point

At Green Point, Noel / ZS1FW and Paul / ZS1PXK assemble the Force 12 beam on the ground

Danny / ZS1BL strings up the W3DZZ dipole from the top of the Green Point lighthouse.

Noel / ZS1FW (left) and Kevin (right), who kindly assisted us with assembly of the anetennas!

Shaun / ZS1RA lays out the main feedline for the beam antenna

Kevin and Paul / ZS1S make adjustments to the rotator


Hylton / ZR1HPC puts his back into the task of sinking stay rods for guying the antenna!


Final touches to the Force 12 beam by Noel / ZS1FW and Paul / ZS1PXK
while Rob / ZS1SA holds the bag of rivets


Saun / ZS1RA pulls the feedliness from the antennas through the window

Assembly of the gin pole for raising the antenna

The prevailing weather was windy and stormy, rains predicted for later on.

Danny / ZS1BL and Shaun / ZS1RA setting up the operating position
One of the CTARC banners marks the operating room as well as the raised entertainment area above
where we were later on to hold our braaivleis
Kevin fastens the beam antenna on to the rotator. At this stage, the whole assembly
has to be lifted on ladders so as not to damage the fragile antenna

Danny / ZS1BL and Rob / ZS1SA scan around the 40 and 80m bands using the W3DZZ dipole


Prior to raising the antenna, the corner guy ropes are manned




Taking the strain...

Raising the beam antenna with the gin pole

Almost there!
OK. Antenna vertical at last

Noel and Paul stabilise the beam antenna with guy lines, essential in the winds
at Green Point on a stormy day

Hylton / ZR1HPC at the controls




Barry / ZS1FJ's vertical dipole



Shaun / ZS1Ra wasted no time in starting to put out calls on 20m


At midday there was some activity on 14319 kHz

The base of the mast is stabilised...

Dirkie / ZS1X and his new harmonic graced us with a visit!
All in all, a successful and enjoyable Lighthouse Weekend