Sunday 23 April 2017

CTARC Photos of April 22 Meeting

Here are photos of the April 2017 meeting at the CTARC:

ZR1WLH & ZS1HJH doing final assembly of the antenna
before the meeting

Hendrik / ZS1EEE contemplates the antenna in its temporary tuning location.

Rob / ZS1SA opens the meeting
Hendrik shows an example of an SDR-enabled handie

Hendrik shows an RTL/SDR dongle

There are Arduino-based component SDR kits
Diagram of the traditional HDR (Hardware-Defined Radio) signal path
with RF amp, oscillator, mixer, detector & audio stage

An intermediate phase -  Software Controlled Radio

Software Defined Radio, where the whole signal path
is processed digitally by software

Three-dimensional graphs illustrate the Quadrature principle.
Above is an example of Frequency Modulation

Amplitude Modulation, showing the variation of amplitude of the signal
over time

The classical SDR waterfall and oscilloscope display

A  comparison of various SDR specifications and prices,
ranging typically from $300 to $1100 (and more!)

ZS1HJH checks readings using his Network Analyzer

Ian / ZS1SX (right) brings some goodies along to the SwopShop

Tea, biscuits and catching up from last month

Yet again, the Club's ricketty wooden ladder defies the laws of physics
and remains intact and vertical at this crucial stage

Rob does some last-minute soldering work

Walking up the antenna

Some branches had to be held out of the way as the antenna went up

We had to temporarily lower the antenna again to disentangle
some of the guy wires

Danny / ZS1BL fixes the mast to the upper mounting bracket...

...while the strong arm of the Ward holds the mast in place!

Club members admire their handiwork

The satisfying feeling of a job well done!

CTARC Report-Back on April Meeting - 22 Apr '17

On Saturday afternoon, 22 April 2017, the CTARC members met for the April club meeting.

At this meeting we were treated to a talk on Software Defined Radio by Hendrik Visage / ZS1EEE.

Even before the meeting, Hans-Jurgen / ZS1HJH and Wolfgang / ZR1WLH were hard at work doing final assembly on the MFJ multi-band vertical antenna that they started putting together on our previous Work Party. He raised the antenna in a temporary vertical position to do some preliminary tuning tests.

Our chairman, Rob / ZS1SA, started the meeting about thirty minutes after normal starting time, to allow for the late arrival of visitors who had been at another meeting over at the Cape Peninsula University of Technology. Rob gave a report back on recent events and Club issues, and then introduced Hendrik, who delivered a most interesting talk. Some of his Powerpoint slides are reproduced on the photos page.

Afterwards, the usual natter with coffee & biscuits took place, then all hands assembled outside to assist with the erection of the vertical antenna on its outside bracket. It was a bit tricky raising it up past the nearby tree branches, and we had to jiggle the elements a bit to release the guy ropes, but eventually the antenna was successfully raised and fastened to its awaiting bracket. In due course the feedline will be connected up and final tests and tuning will be done.

Once again, it was great meeting and most pleasant to enjoy the cameraderie and teamwork in working towards a common goal for our club.

Photos [here].

Saturday 15 April 2017

CTARC Ragchew April 2017

The April 2017 edition of the Cape Town Amateur Radio Centre's bi-monthly newsletter "Ragchew" is now published. Grateful thanks once again to Anne for another fine edition!

Download the PDF file [here].

Ragchew is also on our Newsletters page