Monday 28 January 2019

CTARC Ragchew - 28 Jan '19

The January/February 2019 edition of the Cape Town Amateur Radio Centre's bi-monthly newsletter "Ragchew" is now published.

Grateful thanks once again to our editor, Anne, for all her excellent work in putting together this month's edition, and to all those who contributed articles.

Remember please, Anne is always on the look-out for articles to publish in Ragchew!

Download the PDF file [here];

Ragchew is also on our Newsletters Page

Sunday 27 January 2019

CTARC's Postal Details Have Changed ! - 27 Jan '19

The Cape Town Amateur Radio Centre's physical postal address has changed.

Henceforth, all non-electronic communications are to be sent, please, to the following P O Box address:
P O Box 12187
Cape Town 2018
Republic of South Africa

CTARC Photos of January Meeting - 26 Jan '19

Here are photos of the January 2019 meeting at the CTARC clubhouse. Grateful thanks to Chris ZS1CDG and Nick ZS1ZD for providing the photos.

The written report-back is [here].

Before the meeting, a great opportunity to catch up on the skinner

Chairman Rob ZS1SA reports on the recent Committee Meeting,
welcomes new guests and informs us of progress at the
mornings antenna work party.

Rob kicks off the Show and Tell session by showing us his
fine tape-measure VHF DF antenna

Detail of the antenna
Detail of the antenna

Detail of the antenna

Rob also showed us his nifty DF attenuator,
made from a BNC plug and co-ax adaptor

Keverne ZS1ABU assembles his AMSATSA dual-band VHF/UHF
satellite antenna

This antenna is very portable and lightweight, and available from AMSATSA
for a very reasonable sum.

Mike ZS1FP demos his coax stripper tool, which he
kindly donated to the CTARC after his demo.

Mike also showed us his Snap-On coax cutter,

Nick ZS1ZD showed us his cheap Chinese portable receiver,
which is proving very useful for hunting down RFI problems in the shack

Chris ZS1CDG showed us his finely constructed weather station,
consisting of an LED readout, an Arduino-type chip with code
cobbled together from various internet resources, and a WiFi link to
his laptop PC, that download the data from weather websites

Close-up of Chris's unit.

Rob ZS1RDM showed us some military rigs that will be very familiar
to some of us of a certain era...

A close-up of the front fascia of a B25 transceiver

The internal construction is modular, to assist rapid servicing

Configured as a base station, with the transceiver. a 100W linear amp
and an automatic antenna tuning unit.

The B25 was also configured as a manpack.

No doubt about it - green radio are cool!

Mil-spec construction of the innards of a B25

This handset will look familiar to some of us signalmen...

Rob has a growing collection of green radios, which he restores
and considers very useful for demonstrating amateur
radio to potential newcomers to the hobby.

Chris ZS1CDG tries out the military headset

Paul ZS1Z shows us a 60 GHz point-to-point data link unit
that can send a 1 GHz-wide stream of BPSK data
to a similar unit, up to 8 km distant

The cadioptric feedpoint of the business end of the 60 GHz unit

Fred ZS1FZ takes a look at the cast-aluminium chassis of the microwave unit

Outside the clubhouse, David W5TN (visiting from Texas USA}
set up his impressive Elecraft K3, laptop and 40m loop antenna
and started making FT5 contacts straight away.

Lem ZS1LEM and Fred ZS1FZ

Danny ZS1BL, Enzo I2VZL {visiting from Italy}
and Rob ZS1SA

Enzo I2VZL, Dennis ZS1AU and Enzo's XYL

The man with two hats!  Dennis ZS1AU proudly wear's Enzo's club cap AND his
Bouvet Island DxPedition cap. Chris ZS1CDG kindly provided Dennis
with transport home

CTARC Report-Back on January Meeting - 26 Jan '19

CTARC Report-back on January 2019 meeting.

On Saturday, 26 January 2019, the first meeting of the year for the Cape Town Amateur Radio Centre started earlier than normal with the Antenna Work Party which began at 11h00.

The main monthly meeting started at about 14h20, a few minutes later than scheduled, as we were still finalizing the antenna workshop. By the time our chairman, Rob ZS1SA called the meeting to order with the customary “ding!”, the clubhouse was packed. Rob welcomed us all to the meeting, gave a brief report on the morning’s work party, and welcomed the new members who have recently joined CTARC. They are Bruce Mitchell, Peter Fenwick, Thian ZS2Y. Colin ZS1RS and Rob ZS1RDM. Rob also welcomed visitors Anne, Malobu and David W5TN who is visiting us from Texas USA. Rob also passed on the sad news and our club’s condolences to Peter ZS1PGC, whose wife Jenny passed away recently.

The clubs physical postal address has changed. Henceforth, all non-electronic snail-mail is to be sent, please, to the following P O Box address:
P O Box 12187
Cape Town 2018
Republic of South Africa

Rob mentioned that the Morningstar remote station is in regular use, but there is still capacity for more members to subscribe to use it. There is also a regular subscriber to the system, Andy, who uses the station to connect with yachts offshore from Cape Town, but this is only for a short period each day.

Rob also thanked Chris ZS1CDG for putting CTARC on Instagram, which we all hope will increase interest in our club among the youth.

Thanks were also offered to Barry ZS1FJ who has most generously donated the 40m dipole that has been installed on our main rotational tower, as well as the RG-8X co-ax feedline which had been installed that morning.

Dennis ZS1AU offered to show us a video of the DXpedition to Sable Island; sadly, we didn’t have time in this month’s meeting, but that’s a good possibility for another meeting.

The other usual admin notices [to please collect your CTARC magnetic club badges, which are stuck on the club fridge; remember to remove your unsold Swop Shop items at the end of the meeting] and then we were ready for the main event – Show and Tell.

Rob kicked off the first presentation with a magnificent portable tape-measure DF Yagi antenna, hand-made out of tape measures, plastic conduit and coax. The antenna is lightweight and features a wound coax balun half-way down the boom to match the antenna and to reduce the effects of hand-capacitance while pointing the beam at the fox.

Rob also showed us a very nifty hand-made DF attenuator, consisting of a BNC plug attached to a coaxial PL-259 plug, that screws into an SO-239 adaptor which in turn is mounted on the handie radio. The attenuator works by way of a capacitive link, and as you unscrew the device, the gap between an insulated pin in the BNC and the actual SO-239 socket is widened - to provide up to 65 dB of attenuation - a very necessary signal reduction when one is close to the fox itself! If further attenuation were needed, further such widgets could be daisy-chained together in series.

Next up was Keverne ZS1ABU, who showed us a very nifty dual band VHF/UHF Amsat antenna. Being dual-band (2m & 70 cm), one can work uplink on one frequency and downlink on another, with your dual-band rig connected to the antenna. Consisting of a carry-bag, several colour-coded plastic insulators and several light steel poles, the item is very portable for SOTA-type activities, and can be assembled in under a minute. The whole thing including cable and carry bag is on sale for just R250+postage from AmsatSA.

Mike ZS1FP was next, an he showed us a coaxial cable sheath stripper and coax cable cutter, which make cable and plug assembly quick and easy. As a bonus, Mike donated the cable sheath stripper to the CTARC. Thanks, Mike!

Nick, ZS1ZD followed on. He showed us an inexpensive portable shortwave receiver of Chinese origin, which is insensitive, provides distorted audio of dubious quality into its tinny little speaker and unsurprisingly was bought for the price of a boerewors roll at the flea market! However, it is lightweight and is ideal for hunting down sources of noise and RFI in the shack, around the house and in the neighbourhood. Being multi-band, the little AM/FM receiver also gives a broad indication of where the noise happens ion the HF spectrum.

Chris ZS1CDG was next. He showed us a beautifully-constructed little weather station-on-a-chip. Using an Arduino-type of microprocessor and wi-fi, it connects to his PC which in turn fetches the relevant local weather data from a website. Chris humbly described his project as “cobbling together stuff he found” but he is the one with the wit, vision and initiative to have actually made the project happen and work. Well done!

Next up was Rob ZS1RDM who loaded down the speakers table with three large B25-type green military HF radios. Rob collects these and has a number of them, which he has lovingly restored to working order. He gave us a breakdown of the variants - a manpack, a mobile station, and a base station with a linear amplifier. It was interesting to see the solid mil-spec construction and design of these rigs of the 1970’s and ‘80’s era, which when properly aligned, can still give a good account of themselves in terms of sensitivity, stability and cleanness of output. Robs believes they also are great for showing off amateur radio to the public at meetings and displays.

Finally, Paul ZS1S showed us a solid [cast aluminium] rectangular microwave unit that operates on 60 GHz band. Using BPSK modulation at a 1Gbit rate of transmission, these parabolic dish units provide reliable point-to-point data links over a range of around 8km.

Later on outside, David W5TN Set up his magnetic loop antenna and Elecraft K3 to show us portable QRP operation using FT8 mode. Most impressive!

With that, the formal meeting was ended and we carried on to discuss matters, skinner and catch up on the news over coffee and biscuits until about 16h45. A most productive and successful meeting indeed.

Our next meeting, on 23 February 2019 at 14h00, will take place in the form of another fox hunt. On 2 March we will have the annual Mega Flea-Market, and on 23 March Robs ZS1TA will present a talk on LEO [Low Earth Orbit] satellites. So, plenty to see and do in the next few months!

Photos of this event are [here].

CTARC Report-Back on Antenna Work Party - 26 Jan '19

On Saturday, 26 January 2019, the first meeting of the year for the Cape Town Amateur Radio Centre started earlier than normal. At 11h00, we assembled at the clubhouse to tackle the next phase of our main antenna refurbishment. Under a cloudless sky with a mild south-easter blowing, the coaxial mast was cranked down and then folded over on its main hinge to rest on a conveniently positioned ladder. The next stage was to replace the main feedlines with fresh RG-8X coax cable, generously donated to the club by Barry ZS1FJ. Thanks to ZS1BL, ZS1BOK, ZS1EQ, ZS1FJ, ZS1FW, ZS1PGC ZS1S, ZS1TK, ZS1ZD, ZS1ZKZ and others who attended the work party.

There was a minor set-back when the stainless steel cable snapped while being winched [fortunately with the mast still lying horizontal!], but we still had the old steel cable that was now redeployed as a temporary measure. The mast was winched back into vertical position just as the other club members arrived for the main meeting.

The purpose of the work party was to replace the main feedline to the antennas with some RG-8X coax [kindly donated by Barry ZS1FJ] , and to do some work on the baluns and attachments for the new 40m beam that was recently mounted on the tower. This was achieved in time for our main meeting which followed on at 14h20.

Thanks to all those who attended and assisted with the Work Party!

Wednesday 9 January 2019

CTARC Antenna Work Party - 26 Jan '19

Hello Everyone

On Saturday, 26 January 2019, before the Monthly meeting, the club is going to have a work party to replace the two co-axial cables on our tower.

The Committee asks if members are able to help, please come to the clubhouse about 11h00 .

With appreciation,

CTARC Chairman


This event has now taken place

The report-back and photos are [here].