Thursday, 31 March 2016

CTARC Forthcoming Meeting - 23 April '16

The April 2016 CTARC members meeting, (usually held on the fourth Saturday of each month), will be on 23rd April, at 14h00, at the CTARC clubhouse in Rondebosch.

Directions to the CTARC clubhouse are [here].

The subject of this meeting will be announced presently.

Further details will be announced on the Sunday morning CTARC club bulletins transmitted on the 145.750 MHz repeater at 08h30, for listeners in the Cape Town area.

All club members and interested parties are most welcome to attend.

Tuesday, 29 March 2016

CTARC Committee Meeting - 19 Apr '16

There will be a meeting for members of the CTARC committee, at 19h00 on TUESDAY, 19 April 2016, at the CTARC Clubhouse.

Please take note that this committee meeting for April happens on a TUESDAY instead of the more usual MONDAY. Just this once. Future committee meetings from May 2016 onward will continue thereafter on the Monday evenings preceding the Saturday afternoon CTARC members meetings as per usual.

Please diarise accordingly.

(Just why there should be such a change from a Monday to a Tuesday is a mystery within an enigma within a conundrum within a koeksuster, tumbling endlessly in N-dimensional space-time. Well, to me, at least. I'm sure the CTARC Committee members have perfectly good reasons for doing so. Don't ask me why, though. I'm just a poor automatic robot tasked to print these time-stamped future committee meeting announcements at regular intervals until the end of the Universe as we know it).

Wednesday, 23 March 2016

CTARC Heard Island is QRV - 23 Mar '16

The DXpedition to Heard Island near Antarctica is now on air.

The team on the Braveheart spotted land at around 10h30z on 22 March. That afternoon they set anchor in Atlas Cove and did a recconnaisance of the area for safe access for the ATV that will tow the crates of equipment to the base camp site.

The following day (23 March) the unloading of equipment and antenna erection began. It is going to be a very busy three weeks ahead!

See the VK0EK report here

Sunday, 20 March 2016

CTARC 70th Anniversary Celebrations! - Mar '16


Above: The Wild Fig Restaurant
All CTARC members - please bookmark Saturday 25 June 2016 at 12h30. That is the date for the Cape Town Amateur Radio Centre's forthcoming celebration of having been in existence for all of seventy years! Such venerability makes us the longest-running amateur radio club in all of South Africa.

We have booked a private room at the prestigious Wild Fig restaurant in Mowbray, and it promises to be a celebration of note. There will be a three-course meal with a choice of courses.

The CTARC is sponsoring paid-up club member's meals. Spouses and significant others may attend but their meals must be paid for by their CTARC member partners.

A formal invitation will be sent out to CTARC members presently. This invitation will require an RSVP (stating numbers attending) by a particular date, which will be necessary considering the expected numbers and the logistics involved.

Further details will be published closer to the time, but please reserve that date in your diaries NOW.

CTARC Why Attend A Work Party? - 20 Mar '16

There are some obvious answers to the above question, and some hidden gems.

Clearly, the first reason we should pitch up is that there is a job to be done. Yesterday, ten CTARC members arrived to sort out the rotatable beam antenna at the CTARC clubhouse, which has been giving intermittent and faulty readings. The antenna needed to be repaired.

Another (sometimes less obvious) reason is that the job requires several hands. So, we couldn't safely lower or raise that antenna without at least four (and preferably six) people to operate the winch, hold the stays and check for true in the process.

Yet another reason is the job requires expertise. Without the presence of Rob / ZS1SA, Danny / ZS1BL and Richard / ZS1RIC, that mast wouldn't have been lowered, We were also fortunate to have Fred / ZS1FZ at hand. More on this later

Then there are the less apparent, but no less tangible rewards of fellowship - working together cooperatively on a common cause can be very satisfying, and you certainly get to know your co-workers as the job proceeds. You also learn something about yourself!

But here's the crux. Yesterday I learned something new while watching Fred / ZS1FZ at work.This gentleman really knows his stuff, and it was both a privilege and an education to watch him at work.

I learned that you don't solder coaxial cable's copper conductors to lugs that will attach to a beam antenna's feed points. Doing so creates a brittle joint that will eventually crack. Also, soldering dissimilar metals together in that location creates an electrolytic reaction that will eventually corrode the joint.

What you rather do is to crimp the joints - with a proper crimping tool and a correctly sized lug, so that the co-ax's conductor and braid are tightly held in airtight grips that provide good conductivity and yet a little flexibility. Those connectors can then be protected with self-sealing tape or Denzo tape. (Think all this is still nonsense? The aircraft manufacturing industry uses this crimping technique on the thousands of electrical connections in any modern aircraft).

I also learned about self-vulcanising tape - a fancy (and expensive) product that stretches as you pull it and eventually amalgamates around the protected joint or piece of cable. And about using this tape to protect exposed parts of the feed line cable that might become brittle or corrode when exposed to wind and UV for years. And about some fancy waterproof UHF connectors that (again) don't require soldering the braid - just the centre pin.

I also watched how Fred checked the antenna and cable SWR with his MFJ antenna analyser, and how his background knowledge about what the readings should be in context caused him to go back and check and re-check, until all the faults were eventually identified.

So that's why attending your club's call to arms for work parties is such a good idea - you really do learn so much!

And there's another reason. Our club's guru's - who are our elders and very much our betters - have huge knowledge to share. Sadly, because they are our elders, at some point we will lose them and their knowledge (very long may that day be in coming). So we had better learn what we can from them, and  acknowledge their great contributions, while yet we can.

73

Nick / ZS1ZD

CTARC Report Back on Work Party - 20 Mar '16

Yesterday, Saturday 19 March 2016, starting at around 10h00, the CTARC ran a long overdue antenna work party at the clubhouse. Our rotatable HF beam antenna had been giving intermittent and high SWR readings for several months now.

Some ten radio hams pitched up to assist. Danny / ZS1BL managed the activities. Fred / ZS1FZ was there with his trusty MFJ antenna analyser and his insights contributed greatly to our eventual isolation of the antenna's faults to where they were found and fixed. Richard / ZS1RIC (so central to the design and manufacture of the tower's hardware) was there too. Jean / ZS1JPB and his brother were both particularly helpful throughout. Grateful thanks to Tony / ZS1TK, for providing cool drinks and snacks for the work party. And to all the other stalwarts, both new and existing, who pitched up to assist and without who's help we would not have been able even to lower or raise the mast in the first place!

Also present was a roving photojournalist from a commercial magazine who was there to take photos and ask us questions about our club and the hobby in general. We look forward to seeing his published article when it appears.

We began by slowly lowering the rotatable mast with its winch and resting the beam end of the mast on a ladder. As the antenna was winched slowly down, roped-in teams on either side of the lowering mast, guided by Rob / ZS1SA, held the mast true to it's required plane of movement until it was resting safely on a ladder with the back of the beam reflector just above ground level.

Fred then did some tests on the feed line coax cables. A physical inspection revealed one cable (to the upper beam) had deteriorated sufficiently to require complete replacement. The coax braid to one element of the dipole had snapped, probably due to buffeting by the wind. The lower beam and it's cable were still in good physical and RF (i.e. SWR) condition.

So a new cable (with a new "ugly balun" at the top end) was cut to length and prepared  for the upper beam. While it was being mounted on the pole, further tests were done on the feed-in patch box on the wall of the clubhouse. Further problems were discovered there in the form of corrosion of the connector sockets there.

Eventually the outside cables were fixed to a supportive stainless steel cable which in turn was fastened to the mast. Because the entire mast rotates at the base of the tower, the cables can be fixed to the mast without fear of preventing one complete 360 degree circle. Then the mast was winched up again. Danny / ZS1BL and Nick / ZS1ZD will have awoken this morning with protesting muscles they never new existed in their right arms!

All of the above sounds relatively simple, but it was robust physical work at times and managed to consume the morning and afternoon for most of us. We packed up at around 5 p.m. However, the benefits of being there were many and are discussed further on.

The job isn't entirely complete yet. We will need to fine-tune at least one of the beams, better secure the feedline cables running from tower to clubhouse and complete work on the incoming patch box. But the main problems have been identified and repaired and the end goal is in sight.

Some thoughts on the philosophy of a work party [here]

Above: "Hmmm. Now how shall we take it down...?"




Above: Very slowly the tower is lowered on its hinge. Rob / ZS1SA ensures that
the left- and right-hand guy ropes keep the tower in the middle as it lowers.

Above: Richard / ZS1RIC and Hylton / ZR1HPC (in front) were the
support stays on the RHS as the antenna was lowered.

Above: Almost down... The tower is winched down very slowly to avoid instabilities.

Above: And down! Danny / ZS1BL adds the finishing adjustments to the wooden support
ladder, which assumed the proportions of a trapeziod but nevertheless held fast.


Above: Close up view of the "Ugly" balun. We decided to replace it with new coax.

Above: Jean works on opening up and cleaning connectors in the feedline


Fred / ZS1FZ checks SWR readings (and checks again) on the
MFJ antenna analyser

Above: The patch-box leading into the shack was, we discovered, the source of a
lot of the problems. Bad corrosion has taken place here.



Above: Richard / ZS1RIC

Above: Meet "Rolene". She's quite an impressive lady.
The CTARC has acquired her on temporary loan from CCC Sports & Rec Dept
to assist with the extraction of overdue Club subscriptions...

Wednesday, 16 March 2016

CTARC Forthcoming Work Party - 19 Mar '16



Noel / ZS1FW has put out a request that CTARC members meet on Saturday, 19 March 2016, at the CTARC clubhouse in Rondebosch, for an antenna work party. There is a fair amount of maintenance work to be done.

Those able to assist please to arrive between 09h30 and 10h00.

We do hope you will be able to assist. We wish to get the CTARC antennae working properly so that all members may operate the station from the clubhouse.

Thanks in advance!

Monday, 14 March 2016

CTARC No Committee Meeting - 22 Mar '16

There will be no committee meeting in March of 2016.

This is because the CTARC's March meeting was our successful Annual Flea market, which has been and gone.

The next committee meeting will be held towards the end of April 2016

Thursday, 10 March 2016

CTARC Heard Island DXpedition Departs Cape Town - 10 Mar '16

This afternoon, at around 14h30, the m/v Braveheart departed from the Victoria Basin at the Cape Town Docks. Following extensive preparations and final packing, which had already been completed by this morning, the sturdy vessel loaded its crew and passengers for the 10 day journey through the southern Indian Ocean to Heard Island.

A number of South African radio amateurs, as well as harbour officials. were there to wish them well and see them off. Paul / ZS1S, who is on the CTARC committee, has been heavily involved with assisting the team with their preparations. He will now be able to heave a sigh of relief as his duties there (other than working VK0EK, of course) are now complete.

The team have erected a Hustler 4BTV multiband vertical antenna on the vessel, and we expect to hear and hopefully work them as they proceed to Heard Island. The DXpedtition team face a bumpy journey across the ocean, followed by the interesting task of transferring tons of equipment and antennae by inflatable boats from the Braveheart across to the island when they arrive. Followed by the DXpedition itself, removing everything they brought with them back to the Braveheart , and the remainder trip across to Australia thereafter.

Follow the DXpedition's progress and get the latest news from their website: vk0ek.org.

Photos by Nick / ZS1ZD

Bob / KK6EK

Paul /  ZS1S makes his farewells to the team

The m/v Braveheart - loaded, provisioned and ready to go. It was formerly a Japanese research vessel

The team pose for a group photo just before departure

Monday, 7 March 2016

CTARC Fleamarket Post-Script - 7 Mar '16

At the recent CTARC March flea market, somebody purchased a Curtiss 8044 series Morse Keyer IC from Mike / ZS1PE, whose photo appears below. Unfortunately, the purchaser forgot to take the documentation for the item, so we include both sides of the info sheet below for his (and others') convenience: (Documentation is copyright of Curtis Electro Devices, Mountain View, CA, USA.)
Above: Mike / ZS1PE, and his car boot stall at the flea market.




Sunday, 6 March 2016

CTARC Report Back on 5 March Flea Market 4/4

More photos are in Batch 1, Batch 2 and Batch 3

Some very solid green radios of a bygone era were on offer

Some homebrew test equipment...

ZS1AG and his good lady displayed their wares on their car bonnet

Two standard dachshunds (both very well-behaved) caused the dog-deprived
among us to feel huge envy...


ZS1OSK, ZS1GRM and ZS1FP


Andre / ZS1AN, Mariska (who kindly drew the raffle tickets) and Dirk / ZS1VDP


The weather cleared up later on in the afternoon


Danny / ZS1BL and Rob /  ZS1SA organised the three Raffle draws.
Mariska selected three numbers at random for the winning tickets

This and the following photo by kind courtesy of Mike / ZS1FP


While ham car boot sales offer a bewildering variety of items for sale, swop
or display, few can boast the presence of a woolly mammoth!
This one pitched up unannounced... Can winter be far off?

Back to Batch 1 of the photos

CTARC Report Back on 5 March Flea Market 3/4

More photos are at Batch 1, Batch 2 and Batch 4

Ham flea markets are definitely occasions for the whole family!

More boxes of interesting stuff!



Tony / ZS1TK acquired this magnificent Heathkit linear amplifier and PSU.
No wonder he looks pleased !

The polite enquiry, the discreet negotiation, the nod of confirmation, the soft rustle of
folding stuff, and another rig will very shortly disappear into the new owners car boot

For those fatigued with the strenuous pace of swopping Stuff
(and for those who's stations are now perfect and complete)
there was the option to sit and chew the rag with other hams.

Left to right: Dirkie / ZS1X, Avron / ZS1LA, Andrew / ZS1SBM and Dave / ZS1DFR

Miscellaneous mystery boxes for sale

ZS1PT (in red cap) had an assortment of interesting VHF antennae for sale


"Let good digestion wait upon appetite!" The hamburgers were a hit with all who attended

ZS1CM, ZS1MF and ZS1HA in conference

Cables, tables, antennas and lables !

Some test equipment, a decade switching box, a signal generator, a frequency counter,
a large coax balun. Of these things is excitement made...
On to Batch 4 of the photos