newsletter of the australian / new zealand chapter … newsletter december2017.pdfjanuary; vk3img,...

FDU Newsletter December 2017

Editor: Bill Kirkwood #15215 VK1FWBK email: [email protected]

VK Secretary / Administration: Garry Cottle #14151 VK2GAZ email: [email protected]

ZL Administration: Nigel Hardy #9040 ZL2TX email: [email protected] Newsletter Distribution: Derek Dawkins #14125 VK3KX email: [email protected]

FDU Web site: www.fdu.org.au Facebook https://www.facebook.com/groups/1765058520392148/

Recommended FISTS calling frequencies (MHz):

1.808 3.528 7.028 10.118 14.058 18.085 21.058 24.908 28.058

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From the Editor: Bill VK1FWBK #15215

The Silly Season. I love this time of year! Family get togethers, reunions, and, my wish to you all, a happy relaxed time with family. I am also only too aware that it is not always easy. Who will be on air on Christmas Day? I certainly hope to be at some stage after a traditional Christmas lunch, and I hope to activate a mountain top

on New Years Day with SOTA. Hopefully this Festive Season will result in some additions to our key collections, rigs and antennas! This is the last FDU Newsletter for 2017 ( that wasn’t rocket science Bill!). The first Newsletter for 2018 will come out in February. It gives me a chance to reflect on my first year as a Foundation Licence holder – it will be a year in Feb since I was issued my Amateur Radio Foundation licence. Perhaps some more reflection on that when the time comes , but if someone had suggested to me as I sat the Foundation exam in late January this year, that I

Newsletter of the Australian / New Zealand chapter of the International Morse Preservation Society

December 2017

mailto:[email protected]




http://www.fdu.org.au/

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would end the year as the editor of the FISTS Down Under newsletter, I would have at first asked,” What on Earth is FISTS?” and, said “ Don’t be ridiculous!” . Well, here I am! Thanks to the many new friends I have made through this wonderful group and through the amateur radio world, I am really enjoying everything there is about the hobby. Welcome to our new members …..OK..hmmm ////crickets! . Time for people to start

recruiting! 😊 My apologies if I have overlooked a newcomer!

Subscriptions: List of members whose subs become due in October, November December November: VK2ASB, ZL1BHQ, ZL1MH, ZL2BJC December; VK1AI, VK2CAO, VK3IJB, ZL1AOM, ZL2APV, VK6IS January; VK3IMG, VK5AW, VK3AGQ, VK3JY,VK3XU, ZL1ALA, ZL1RP, ZL2AIM, ZL2DF, ZL3AA, ZL2ASQ

We ask that you keep an eye out for your callsign in the subs section and treat that as your reminder for you to pay your subs. Our website http://www.fdu.org.au/join_renew.php has all the details for making payments. Don’t forget that if you are paying your subs to include your callsign. Please do not send cash in the post as this causes problems for us in banking.

FISTS would like to thank the following member for the generous donation included with their subscription; Chris VK3CGB #9087

All members please note that Bank deposits MUST include YOUR NAME AND CALL SIGN for reference purposes, not your account number.

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Silent Key Last month we advised the passing of Mike Kerr ZL2BCW #9079. We have received a moving epitaph to Mike, however this will be published on the FDU website and not the newsletter.

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http://www.fdu.org.au/join_renew.php

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From You – Our Members! Garry VK2GAZ #14151

When is a Flagpole NOT a Flagpole?

The Manly Warringah Radio Society (http://www.mwrs.org.au/flagpole-challenge/ ) ran its yearly Flagpole Challenge on Saturday, 16th September, 2017. I have taken part in the Flagpole Challenge on a couple of occasions now and was looking forward to the event this year, so much so I even posted the details on the FISTS Down Under Inc. Face Book page (https://www.facebook.com/groups/1765058520392148/ ).

Bill VK1FWBK and others indicated they would take part

as well. So on the Saturday morning I collected all my

portable gear along with my Flagpole and set off for

Kurrajong Heights and the Bellbird Lookout, a wonderful

location for portable operation overlooking the

Hawksebury Valley.

At this point the day took a turn for the worse, it was blowing a gale. I did try to put the flagpole and antenna up but common sense prevailed and the attempt was abandoned.

VK1FWBK's effort!

http://www.mwrs.org.au/flagpole-challenge/

https://www.facebook.com/groups/1765058520392148/

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Not wanting to give up entirely, it was home to set up in the backyard. Even though the wind was still quite strong the flagpole antenna was set up and I started calling “CQ Flag”. After about an hour or so I finally gave up, not one station was heard at my QTH. I later found out that Bill VK1FWBK had also been calling CQ as well and again he gave up after not hearing any stations. So, even with the best of intentions events which have worked so well in the past can turn out to be disappointing.

The pictures which accompany this article are of happier times, last year’s Flagpole

Challenge at Bellbird Lookout.

Upward and Onward – I’ll give it a go next year and hope it turns out to be an outstanding

success.

73, Garry VK2GAZ

Thanks Gaz!

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Tony Goldsworthy - VK3CAB #15204

The following article was originally published ‘NERG NEWS’, the newsletter of the North East

Radio Group and is reproduced with their permission as doing so encourages co-operation

between radio organisations.

Thoughts on a Linked Dipole

After having disappointing results from the magnetic loop, I decided to look at other

portable antenna designs.

The design criteria are that the antenna must be portable and light weight, be capable of

being erected in say twenty minutes, be free standing, be an Inverted ˄, be sufficiently

robust to stand up to a bit of a blow, be capable of being supported by a Squid Pole and to

cover the CW portions of the 21MHz, 14MHz and 7MHz bands. As the wise old Ham said,

‘It’s easy to build a good dipole but it’s difficult to build anything that’s as good as a dipole’.

So, I decided that some form of multi-band dipole was the way to go. Apart from having lots

of frequency specific dipoles spreading out from a central boss, which if you think about

would be like a maypole and a nightmare to erect, the only other options open to me were a

multi-band trapped dipole or a linked dipole. I ruled out the trapped dipole because 1) I

have never ever made a successful trap that resonates at anything like the desired

frequency, 2) my GDO shows all sorts of spurious nulls between 7.000 and 20.000 MHz so it

can’t be trusted and 3) the weight of four coax/PVC pipe traps would bend the Squid Pole so

it would look like I had just snagged a two kilogram trout (I should be so lucky!).

This left the linked dipole.

Essentially, a linked dipole is a higher frequency antenna to which you can ‘link’ pieces of

wire to lower the resonant frequency. A 21MHz, 14MHz, 7MHz linked dipole would have the

two elements necessary to resonate at 21 MHz at the centre of the dipole and then some

form of insulation to which is attached a wire that if connected to the upper bit of wire

would make the antenna resonant at 14 MHZ and then after some more insulation a further

bit of wire that will lower the resonant frequency to 7MHz. Fortunately, a truly wonderful

site www.sotamaps.org/extras.php has a link to the ‘Linked Antenna Designer’. This program

allows you to put in your desired operating frequencies, specify how high the centre of the

dipole will be off the ground, how high your end supports will be (as I was building an

Inverted ˄ there wouldn’t be any end supports) and the length of the guys to hold the ends

out. I plugged all these figures in and got a readout in metres of the three wire lengths per

side. From bitter experience I have learned that antenna calculators are notoriously

inaccurate, so I increased the length of each element by 5%.

So, how to attach the 21MHz elements to the coax feed line? In the past I have drilled

Perspex sheet and threaded the wires into it. An SO239 socket is then attached to the

http://www.sotamaps.org/extras.php

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perspex by an aluminium bracket, and the ends of the elements are terminated at the

SO239 socket. Trouble is that the constant flexing of the elements either break the perspex,

or fatigue and break themselves. Also, although perspex looks ‘professional’ and rather cute

it doesn’t like sharp sudden knocks and will break. So perspex was out. In my box of

salvaged bits I had some 1940’s, ‘quarter inch’ Paxalin sheet insulator (Paxalin - a phenolic

type of ‘plastic’ mixed with organic fibre). It is not a happy material to work, stinks of

Formaldehyde and probably does terrible things to one’s reproductive system. But it is a

sturdy insulator and fitted my purpose. This picture shows how the centre bracket was

fabricated. (You will also notice a multitude of black cable ties. Cable ties are very good for

wire antenna building as they stay nice and tight, but you can snip them off if you have to

make adjustments.)

I went to great lengths to reduce strains in the antenna. The bracket is hinged at the top –

i.e. the bit with the hole in the centre - and the Squid Pole goes through this hole until the

taper of the pole stops it. The other side of the bracket hangs vertical under its own weight.

So that the elements don’t have to take any undue tension strainer-wires are attached to

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the top. Notice how the element wires generally have a lot of flexibility. Also notice how the

element wire and the strainer wire are cable tied. Eventually the connector will be swathed

in silicon sealant to offset the effects of moisture.

The links that lengthen the elements are literally three ‘links’ of decorative plastic chain. I

don’t know what the dielectric constant of decorative plastic chain is, and I don’t care but it

works well as an antenna insulator. The end of the higher frequency element is tinned and

knotted and cable tied to one of the links and the end of the next lower frequency element

is knotted and cable tied to the lower link. The lower frequency element has a crocodile clip

on it. To lower the frequency of the antenna you attach the crocodile clip to the tinned wire

and voilà.

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To set the antenna up attach the highest frequency elements to the centre boss, put the

plastic chain on the end of the elements AND ATTACH THE NEXT LOWER FREQUENCY

ELEMENT TO THE CHAIN BUT DON’T ATTACH THE LINK. Why do this? Because the proximity

of the next lower element may/will modify the resonant frequency of the higher frequency

element. So, you have to set it up with the lower element present but not attached. Tune

the higher frequency dipole by generating a frequency from your transmitter and reviewing

at the SWR. Because the elements are 5% too long you will inevitably have to shorten the

elements by folding them back on themselves and twisting them back along the element.

Keep shortening and testing till you get the SWR you feel you deserve. Then repeat the

process for the next lower frequency elements and then the lowest frequency elements.

When you are happy with the results unwind and knot the element and then secure the

knot with yet another cable tie.

My antenna took me 5 hours to make, erect and test.

Here are my test results: 1:1 SWR @ 7.030 MHz, 1:1.5 SWR @ 14.080MHz and 1:1 SWR @

21.125MHz. (I might shorten the 20Mt element a bit more to improve the SWR, but it was

too hot when I was building it.)

The only draw backs I can think of with link antennas is to change band you have to lower

the Squid Pole and change the linkages. (You might be able to get around this by having a

pulley to raise and lower the centre boss, but the additional weight might be a problem.)

The other drawback is the quality and integrity of the crocodile clip links. They are notorious

for disintegrating, rusting and fatiguing of the end of the wire. There are probably other

connectors – maybe inline BNC for example but I only had crocodile clips!

It’s worth a try!

Tony Goldsworthy - VK3CAB #15204

Once again thanks Tony!

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Key of The Month

Tools of the trade - by David G3SCD/VK3DBD #3756

Keys, - they are only a switch -why are we so obsessed with these "tools of trade" Plumbers

don't collect and polish their blowlamps and dentists don’t sit and ogle their various

instruments...... ! (I must introduce you to my dentist one day! Ed)

But having said that, there is something about Morse keys, an aura of history perhaps in

many cases, the beauty of a well-made and finished instrument which started as a chunk of

brass or stainless steel. The way these items are so very individual in the operation of using

it to make the "music" we like so much. Like many, I have a small collection which has

accumulated over the years and in fact really ought to be displayed in a nice cabinet - I have

been thinking about it, but it has not happened yet.

I will be sending our new and capable editor some photos with which he can enhance the

news sheet for months to come, should he feel the space warrants it. (Flattery will get you a

long way! - Did you really think I would ignore your photos after my appeal for photos, photos, and more

photos? Of course I’ll use them and thank you – and by the way, you’re being published! Ed)

The VK/ZL newsletter is now the only really regular monthly missive in the now very big

FISTS group spreading across the globe. Geo our founder would have been delighted.

I recently acquired (in England) a new key which originated from Down Under and I am sure

some readers will probably be familiar with this. I have no knowledge of its origin and look

forward to someone informing me eventually.

The key is pictured with a PL259 plug to demonstrate the small size. The metal base has a

beveled edge and it is obvious that it was made to slide into a matching base, probably fixed

on the top of a small radio?

There is no external adjustment for gap or tension, I have not yet looked inside which

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requires removal of 5 screws in the base and/ or maybe the 7 screws on the top.

As is, it has a very usable gap and quite a firm pressure to close the contacts. That of course

may be ideal for the likely difficult conditions it was intended to be used under. Rather like

the ubiquitous Bath Tub key (the UK Flameproof) I once made a comment about the

somewhat heavy-handed action of this key. It was answered very sensibly by an op who

had used one in a Wellington or Lancaster bomber. He said, "Not when the temperature is

about minus 10c and you are wearing thick leather gloves and you are trying to keep in your

seat as the plane is bucking about in the clouds!"

The knob and case appear to be made of some kind of composite material , most likely a

Phenolic Resin and is a light brown colour. Cast into the top cover are the words

KEY TELEGRAPH

LIGHT WEIGHT

(AUST)NO1

TSE(W) 9-2 and DD

( the DD = Defence Dept. I assume.) There is also the makers logo, the familiar AWA and

the date 1956 which at least offers some clues.

Thank you David!

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Position Vacant – STILL!

KIWIS! - Come On team! We need someone to step up to be the ZL Admin and Membership Coordinator. Seriously – you don’t want us Aussies running the entire ship!

😉 oooooOOOOOooooo

From us all in FISTS Down Under, have a safe and happy Christmas and New Year – whether or not you celebrate Christmas, it is above all a chance to take stock, appreciate life and rejoice that the sun comes up every day, and we can use, or at least cherish a CW key!!!

Merry Christmas and Happy New Year!

See you all in 2018 – Stay Safe, Stay Healthy, Stay Keyed-Up and Stay Tuned. de Bill VK1FWBK #15215

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