Showing posts with label show and tell. Show all posts
Showing posts with label show and tell. Show all posts

Saturday, 18 September 2021

CTARC Forthcoming Meeting - 25 Sept '21

The September meeting of the CTARC will take place on Saturday, 25th September 2021 at 14h00, on the lawn outside our clubhouse in Rondebosch. Yes! We will have an open-air meeting again - the first proper one in three months.

Strict adherence to the Covid regulations will be required by all for everyone's safety. Properly-worn masks, social distancing and hand sanitiser (please bring your own along).

The meeting will be a show-and-tell event where members are invited to bring interesting ham items to show off and demonstrate to those present. Don't be shy - bring your project along to the meeting!

Refreshments will not be provided, but you are welcome to bring your own along.

A mini-flea market will also take place. The club has a number of items to be disposed of. You can also use the opportunity to bring along your own ham-related gear to sell or swop.

See you there on Saturday 25 September!

______________________________________________________________

This event has now taken place. A full report appears in Ragchew of October 2021

Monday, 20 January 2020

CTARC January Meeting - 22 Jan '20


[From previous Show and Tell meetings...]
Mike ZS1FP demos a handy utility box he made
for reading current consumption
with a clamp ammeter.
The Cape Town Amateur Radio Centre kicks off the new year with its first meeting, to be held at the clubhouse on Saturday 25 January 2020, starting formally at 14h00, although we encourage you to arrive a little earlier if you want to get a seat!

The topic of the meeting will be a Show-and-Tell Session. We encourage all members to bring along an interesting radio amateur-related item [or items] they may have designed, built or acquired along the way. Don't be shy!

Chris ZS1CDG shows a nifty digital keyer
and readout that he constructed and programmed
Past events of this nature have been very interesting indeed, with fascinating and sometimes unusual radio items being dusted off from workshops and garages / rediscovered in  attics / dug up from buried caches in back gardens... We're confident this meeting will be no exception.

We also remind you of the opportunity to bring along surplus radio-related gear to sell, swop or buy at our regular informal regular monthly swop shop after the meeting. Please remember, whatever stuff you bring to the meeting, [whether it's been sold or not] must please be removed from the clubhouse afterwards because we have no space to keep it there and cannot guarantee its safety.

____________________________

Please note: This event has now taken place.
A report will be published presently...

Richard ZS1RIC shows a wind-up
coaxial mast he is putting together

Sunday, 27 January 2019

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
MILL STREET
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].

Monday, 7 January 2019

CTARC Forthcoming January Meeting - 26 Jan '19

 The CTARC will hold the first monthly meeting of this new year on Saturday 26 January 2019 at 14h00 at the usual clubhouse venue in Rondebosch.

The topic will be a "show-and-tell" format, where you can bring along one or more of your homebrew constructed projects [complete or not] to show off at the meeting. These sessions have always been very interesting and all can learn from and be inspired by the home contruction efforts of fellow radio hams.

Your project could be anything related to ham radio, as simple as a crystal set or as complex as a spectrum analyser.
 
Don't be shy! We would all really like to see what projects you have been busy with.

Do please arrive early to ensure your seat.

Don't forget the usual bring-'n-buy Swop Shop of amateur radio gear that takes place after the meeting. A gentle reminder to kindly remove all your non-sold items from the clubhouse after the meeting as storage space is limited.

---------------------------------------------------------------------------------------------------------------------

This event has now taken place.

The report-back on the CTARC January 2019 meeting is [here].

Photos of the meeting are [here].

Sunday, 24 September 2017

CTARC Photos of 23 September 2017 Meeting (2/2)

Here are the photos of the September 2017 "Show and Tell" meeting of the CTARC:
The report-back on the meeting is [here]. The first page of photos is [here].

Chris / ZS1CDG shows off his homebrew CW keyer

The keyer / decoder in action

Chris / ZS1CDG's 28 MHz mini beacon

Chris's box of well-constructed projects

John / ZS1AGH demo's a smartphone CW app

The app by IZ2UUF teaches Morse Code by the Koch method

Richard / ZS1RIC demo's a crank-up coaxial mast design,
similar to that he built for the CTARC's main mast.

...and a fold-over mast that can be rotated from below.
Note the thrust bearing on the platform to protect the rotator.

Hans-Jurgen / ZS1HJH demo's a very nifty
Software Defined Radio unit.

Here Hans-Jurgen runs the SDR via a tablet PC
10 kHz to 2 GHz coverage...

Noel / ZS1FW shows his Code Practise Oscillator

Hylton / ZR1HPC ran the raffle for antenna funds

Paulo was invited to randomly select the winning ticket, which was won
by Tony / ZS1TK, who generously donated his winnings back to the CTARC.

Afterwards discussion and debate was the order of the day

Left to right: Gerald / ZS1GRM, Rob / ZS1SA, (unid), Danny / ZS1BL

Ian / ZS1SX had a variety of goods for sale

Widgets in boxes...

There are still some swops left for sale at the CTARC.
They will be up for swop again at our October meeting.