Category Archives: field and portable

VHF/UHF Field day/contest Jan 14/15 2017

The VHF/UHF field day in January is one of my favourite events.  I have had some great surprises on these weekends.  I had no idea what to expect this time, though the weather was forecast as damp on Saturday and dry on Sunday.

I arrived on site around 6pm Friday night.  Along the route from Yass via the Mountain Creek Road I had noticed a lot of debris on the road, including some tree branches that had been broken off by high winds.  I didn’t realise a storm had gone through Canberra while I was driving to Mt Ginini, breaking trees and strewing debris all over suburban streets and bringing trees down over some of the arterial roads, leaving damage that would be visible for weeks afterwards.

This is how far I got setting up on Friday night. After this, the wind came up and the rain and sleet started.

The weather at the time was windy and when I tried to set up the tent it was clear that it would not survive that wind.  In the hope that it would clear away in a few hours, I decided to sit it out and stayed in the car.  By 9pm it was dark and I had to decide whether to  re-pack my tent and go back to Canberra for the night or hang on.  I decided to hang on.  It rained quite heavily for a while and the wind kept howling so once it was really dark, I felt there was no other option.

In the early morning it seemed to be better.  The wind was still there but didn’t seem so bad.  The rain had cleared.  But I hadn’t slept much.

I set about the job of assembling the antennas, the tent, the interconnections and generator.  By 12 noon, the contest start time, I was just about ready to roll.

432 MHz preamp cabling
144 MHz antenna
1296 MHz antenna – end mounted

 

The erected antennas looked very much like they have for the last 10 years so I didn’t take any new photos of them. The 2m, ;70cm and 23cm yagis on one mast and the 6m 3el yagi on another, both rotated from the base using KR400 rotators.  Feedlines: RG9B for 2m, CNT400 for 70cm and 23cm, RG213 or similar for 6m.

Here’s a pic of the antennas from a previous operation at Ginini.  A few configuration differences for the 70cm antenna but otherwise very similar this time.

VHF/UHF antennas on Mt Ginini

 

Once I got on the air, I found beacons from VK3 were very low, the Sydney beacons were almost undetectable and few portables outside the VK1 area.  Only VK2IO was heard initially, but one or two others did emerge later in the weekend.  VK1DSH, VK1RX, VK1RW, VK1MT and VK1AI were all out in the field, most of them on 50/144/432 and Dale was on 1296 as well.  We had a small number of home stations operating the bands too.

After working Gerard VK2IO (Mt Bindo near Oberon) I then worked Phil VK5AKK on both 144 and 432.  We tried 1296 too, but although I could hear a signal from his 100w, my 10w was too far down to make it a two way contact.  A digital mode would have worked.  hmm.  More power on my end would have helped too.  Double hmm.

The day progressed without any more surprising dx, and I found it hard to convince myself to stay awake after 9pm, having got very little sleep in the driver’s seat of the car on Friday night.

At 5:30 in the morning, there were good signals from the vk3 beacons, Sydney was a bit better too.  And I had a very good signal from the Mt Gambier beacon on 144.550 plus a weak signal from Mt Lofty on 144.450.  I hoped this indicated something of the contacts to be made in the following hours.

It did, partly.  VK5DK at Mt Gambier was worked, as was VK5PJ.  But conditions were not good enough to give us contacts on higher frequencies.

My surprise contact on Sunday morning was being called by Mike VK3BDL/7 at Flinders Island.  After working me on 144 and 432, Mike went on to work Chris VK2DO at Batemans Bay on 144, a contact which they were both very happy with.

Eventually the contest ended and I followed it up with a short period of activating Mt Ginini as a SOTA station, using the IC703 running from a LiFePO4 battery.  I had at 6am set up the 20m vertical in the hope of making an S2S with a US station who was looking for VK contacts.  I may have been a bit unlucky with conditions, or jut not spending enough time listening for the US signals.  No luck with S2S but did have a good contact with home station NS7P on CW.

The packing process took about 4 hours and I left the summit at 5pm.  A 2 hour trip back to Yass and a welcome shower and a cold drink when I got there.

The 6m beam seen in the foreground (in the shade, sorry) travels in a partially assembled state. The gamma match stays in place, but the extensions just come out of each element and it then is not much wider than the 2m beam and is narrow enough to be carried quite safely on the roof rack of the car.

Mostly packed up and ready to be loaded into the car and trailer. 2m and 70cm mast still to be disassembled.

 

Contacts made:  183 total.

Band totals:

  • 50 Mhz:  39
  • 144:   70
  • 432:  51
  • 1296: 22

Total points claimed under distance calculation rules: 55916

Points lost due to a wrong grid locator:  about 10.

Points lost due to not enough other portables:  500,000.

haha

 

QRP challenge for 2017

My SOTA friend and collaborator Andrew Moseley VK1AD has proposed a QRP challenge for 2017.  He is going to aim to use 2.5w when activating summits during 2017.  

I have started to do the same and my activation at Mt Ginini on 27th December was made at 2.5w for SSB and 0.5w on CW.  I made about 20 contacts and although some chasers found lower signals a problem, I not only qualified the summit on several bands, I also qualified with CW at 0.5w.  One contact was with Steve VK7CW who also used an FT817 at 0.5w, the lowest power setting of the radio. 

The radio used was an FT817, powered by an internal LIPO 3S battery (windcamp).  I had a spare battery but it was not needed.  The 817 will not be as efficient in terms of output power/DC power consumed, as the bias current on the final amplifier stage will remain the same as it would be at 5w.  

A fringe benefit from using lower transmitted power is that battery life will be improved.  I had previously used the 817 with the internal battery at Mt Mundoonen on 26th December for a short activation.  I did not recharge the battery after that activation as it was only used for 5 contacts plus some listening.  After the Mt Ginini operation, the battery voltage according to the meter on the 817 was above 11v.  It can go down to 10v without any problem for the 817. 

Although we were on the downward slope of sunspot activity, making HF communications less certain, there are still sunspots and occasional sporadic E openings on HF bands.   

It will be interesting to see how the QRP challenge goes during 2017.  Progress reports will be made by both Andrew VK1AD and me.  

WWFF activations in the Canberra suburbs

Canberra is known to many as “the bush capital” and this means there are a lot of nature parks interspersed among the suburbs and hills.  The only National Park in the Australian Capital Territory is Namadgi, which is southwest of the city area, but there are several dozen other nature reserves.  Once they had been given VKFF numbers by the WWFF coordinator for Australia, it became a natural extension of my portable operations around Canberra to add the VKFF number of a park I was in while activating SOTA summits.

After activating Majura, Ainslie, Taylor, Isaacs Ridge and Tuggeranong as well as Namadgi NP many times due to the number of SOTA summits located in registered parks,  it seemed like a good idea to continue to activate parks in the spring weather we are now enjoying (November) between rain showers (it has been a very wet year).

In October and November to date I have activated Urambi Hills, McQuoids Hill, Cooleman Ridge, Farrer Ridge and Wanniassa Hills Nature Reserves, all in the Tuggeranong Valley or adjacent to it.  The next reserve activated was Mt Painter nature reserve.

All were easy to access, and for the hills you have the option of setting up anywhere within the reserve, not necessarily on the hilltop, though in several cases I was curious to look at the view from the top and did walk up anyway.   I was also using these activations as training exercises as I was acutely conscious of losing some of my fitness for SOTA walking due to various injuries during the year.

The operating position at Urambi Hills.  Photo taken by camera attached to the antenna pole at about 1.2m.

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At Tuggeranong Hill

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The nature park sign at McQuids Hill.

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Looking back down the hill from half way up.  Loose stones, take care here, especially downhill.

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Almost at the top, McQuoid’s Hillimgp2041s

Operating at Farrer Ridge Nature Reserve

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Lashing the pole to a fairly dead tree.  Using the branch to prevent the rope from slipping downwards, just as F1BLL calls me.

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Plenty of wildlife like this mother carrying a baby at Farrer Ridge

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I particularly enjoyed the walk up to Mt Wanniassa, which qualifies as a nature reserve but is not a SOTA Summit.  Nearby Isaacs Ridge is slightly higher.  But this is a nice mountain and has a great view.

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After these southside nature reserves I looked at the map and decided that a northside reserve was next.  Mt Painter is a hill to the south of the suburb of Cook in the Belconnen area.  It was many years since I visited this hill and it was an easy walk up from a roadside park, past the water reservoirs and to this bench with a view of Black Mountain and the lake.imgp2106s imgp2107s

 

On most of these activations I made at least 10 contacts in about an hour, using 40 and 20m bands on SSB and CW.  I was hoping for more dx contacts on 20m CW but conditions have been depressed, so it is even more difficult than usual for a 10 watt signal to get all the way around the earth.

Gerard, F1BLL did call me on most of these activations and even when very few others seemed to hear me in Europe, he heard and called me. Thanks Gerard, very nice to have your consistent signal on nearly all of my recent activations.

Another Gerard, VK2IO, attempted contacts with me from Sydney on many of these activations but the radio conditions simply didn’t give us a chance of making a contact via the very high ionosphere.

Equipment used on activations: Icom IC703 at 10w output.

Antennas:

  • linked dipole capable of operating on any band from 40m to 10m
  • vertical antenna for 20m, 5m vertical and three 5m radials, tuned to 14.200
  • antennas supported on a 7m telescopic fibreglass pole.

As all the nature reserves are intended for public use, there is no requirement to get permission to enter and use them.

 

Using the Wifi hotspot from an iphone for the android tablet

I was having some trouble getting reliable linking to provide the android tablet (a Lenovo Tab3/7) with internet access while on hilltops or in parks.

A bit of research found a lot of wave-away-the-problems type of solutions, which didn’t solve it at all.

Finally I discovered a comment about the type of hotspot that the iphone actually provides.  It is not an infrastructure type but an adhoc hotspot.  And more to the point, it does not advertise it continuously.  It only advertises the hotspot for a limited time after being enabled, or after you visit the Personal Hotspot option in the Settings menu.

After some experimentation I now find that the tablet happily links to the iphone every time, provided I go to the Settings > Personal Hotspot item in the iphone and then wait about 10 seconds.  Nothing else needs to be done, provided the wifi password has been set in the tablet.

The other solution I have used from some hilltops is to take a personal hotspot device with me.  As my phone provider uses a provider that does not have as good coverage as Telstra, this provides my tablet with excellent network coverage from places without any service on the other network.

Here’s a pic of the hotspot lashed to a tree on the Boboyan Range summit, 40 km south of Canberra.

 

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Telstra hotspot, tree mount variety.

Spring Hill VK2/ST-036 with diamond quad  

How would you find a new source of unique callsigns for your 10m log?  Operate in a dx contest.

The ARRL 10m contest ran for two days of the weekend of 12/13 December 2015.  I decided I would operate on 10m on one of the contest days.

I arranged to operate from Spring Hill, using the IC703 at 10 watts.  I had a 10m dipole and a quarter wave vertical that could be used for this event.  To give me another antenna option I decided to cut and tune a diamond quad for 10m.

The quad is a full wave loop, closed at the end opposite the feedpoint.  The conventional square quad is fed in the centre of one of the horizontal legs, usually the lower end.  By rotating it 45 degrees you have a diamond quad, a square with one apex closest to the ground.  This format has a great advantage for a backpack station, as it can be made using wire, with the outer corners held in place with guys.  The wire antenna is simply attached to a stock standard squid pole (aka telescopic fibreglass fishing pole).  I used a 7m pole and located the feedpoint about 1.8m above ground.

I used insulators made from chopping board plastic.  One was required for each corner of the loop, the top and bottom being used to attach the loop to the pole and the two lateral corners being points where the guys were attached.  I was unsure whether guying those points would maintain the loop in the right shape but it did seem to be ok.  If the insulators slipped along the wire, the guy would have to be attached to the pole at the top of the loop.

Matching the quad

The feed impedance of a loop is in the region of 100-120 ohms depending in the height above ground.  To feed this antenna with a 50 ohm line a transformer is required.  I decided to use a quarter wave of 75 ohm feedline, using the impedance transforming behaviour of quarter wave feedlines.

The transformer action is given by the formula ZL/Z0 = Z0/Zi

or Zi/Z0 = Z0/ZL

where Zi is the input impedance of the quarter wave feedline, ZL is the load impedance and Z0 is the impedance of the quarter wave transformer/ feedline.

For a quarter wavelength of coaxial cable the length required is the free space quarter wave adjusted for the velocity factor of the cable used.  Most solid dielectric coaxial cable has a velocity factor of .66 and the cable I used was of that type.

The “free space” length of the quarter wave transformer was 300/28.4/4 = 2.64m approx.  This length needs to be adjusted to account for the velocity factor, so our final length is 2.64 x 0.66 = 1.74m.

I had a “video cable” of almost that length so I set up the antenna with the 75 ohm section connected to the feedpoint, then connected a short 50 ohm (RG58) extension to the radio.  The antenna displayed a reasonable SWR of about 1.2 on 29.4 MHz so I had to add some wire to the loop.  the difference in a full wavelength at 29.4MHz and 28.4 MHZ was about 400 mm so I added that length to the loop.  The SWR then was optimum at 28.4 and acceptable (1.5) at 28.0 to 28.8 MHz.

After testing and adjusting the antenna at home, I rolled up the wire and its guy ropes, ready for deployment on the hill.

How did it work?

Quite well.  There was a very strong sporadic E propagation in the first few hours of operation from the hill, giving excellent reports from VK5 and VK4.  This was very encouraging and I made steady progress in my log, handing out contest numbers to those who wanted them and giving others the SOTA summit code.

I later set up my standard linked dipole and was able to compare the quad loop with the dipole.  In some directions the dipole received and transmitted stronger signals than the quad, consistent with the orientation of both antennas.

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I did find that during the afternoon, signals from Japan were more consistent on the quad than on the dipole.

As for my unique callsigns score, I did make enough contacts to add 28 new uniques.  I had hoped for more, but conditions were just not good enough for contacts into the USA and that was a factor.  Still, the antenna experiment was fun and worth doing.

VK1DA

Activating Bowning Hill during the CQ WW DX contest (CW section) 

I hoped this activation would allow me to add some new unique callsigns to my stations worked list for the 10m part of the 6m/10m challenge.  I used three new pieces of equipment for this activation.

First, the antenna.  I thought my inverted Vee dipole could be improved upon for long distance contacts (DX), so I cut a quarter wave vertical with 4 radials as a trial antenna.  It seemed to work very well and I heard and worked stations in Japan and the USA without much difficulty despite using 5 watts from the FT817.

The base of the main vertical element was at about 1.5m above ground, with the radials sloping down to ground level but insulated off the ground by small lengths of hootchie cord.  The main radiator element was taped to the squid pole.  It was actually the lower half of the 20m vertical I have used for several activations on that band.  I simply cut it at half its length, then crimped a set of  spade lugs onto each half.   Thus, a linked vertical.  I should probably do the same for the radials.

Signals from some of the Japanese and US stations were indicating s9 on the strength meter of the 817.  What I found was that it was necessary to call the louder stations, sometimes several times, to make contacts. I did have a “run” of about 5 contacts on 28.052 where I called cq for about 15 to 20 minutes at one stage.  But to really attract attention you need a big signal and mine certainly wasn’t big.

The second new piece of equipment was a sun shelter, kindly bought for me by my wife, who worried that I would get badly burned sitting in the sun on hilltops.

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And the third new item for this activation was the guying kit that Adan VK1FJAW made for me, complete with 3D printed guying ring that sits right on the top of the first segment of the Haverford 7m squid pole.  With guys about 2m in length, the pole was as stable as if it was tied to a fence or a steel stake.  I’m very pleased with that one, Adan!

After working about 25 stations on 10m CW I decided to take a break from the pressure of the contest speed (about 22 wpm in my case but some of them were running somewhat faster).  I pulled down the squid pole to put up the usual linked dipole set to 40m.  Then I found I was almost the only SOTA portable on the air, apart from Greg VK1AI who I could barely hear.  The parks weekend was in full flight, with a dozen or more portables workable at various locations around NSW, Victoria and South Australia.

After the break on 40m ssb I decided to have a final listen on 10m and after removing the 40m dipole and feedline, I made a few more contacts on 10m CW.

 

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Final 10m cw contact count was only 28.  More power and an even better antenna next time!

 

ANZAC centenary special event station VK100ANZAC

The centenary of the ill fated landing at Gallipoli in 1915 was a well publicised event in Australia, with many special events occurring both in Australia and in Turkey.  ANZAC day commemorates a military disaster in 1915 in which thousands of Australian and New Zealand soldiers died attempting to invade Turkey but were repelled by the Turks at a great cost to both sides. Oddly enough the nature of the conflict has seemed to generate long lasting mutual respect on both sides.  

The amateur radio community participated in the event by running various special event operations. In Canberra it took the form of a broadcast at dawn featuring various dignitaries from the military and the Wireless Institute of Australia. 

A corresponding special event station was set up by the Turkish amateur radio association near Gallipoli.    

The Canberra Region Amateur Radio club  supported the WIA event by setting up a field station on Mt Ainslie directly above the Australian War Memorial.  After the broadcasts were completed the station went into general contact mode and was kept on the air until about 3pm when the antennas and equipment were packed away. A lot of interest was shown by the regulars on 40m and some who are not heard often.  

My interest in this event, apart from contributing to the clubs operation, was to provide SOTA operators with a contact with the special call sign from the SOTA summit. To be compliant with the SOTA rules I used my normal SOTA equipment powered by a LiFePO  battery. The 40m antenna was a wire dipole supported by a mast and a tree. 

After the main station was packed away in the afternoon I set up my usual SOTA station to continue making contacts as vk100anzac on 20m. 

Some photos here show my setup in the club tent on 40m in the morning.    The IC703 is using the 4200 maH battery on the nearest edge of the table.  The key being used in this pic is a Brown Bros BTL, 1965 vintage.  Photos by Min Sun, used with permission. 

 


VK1DA sends some code while Fred VK3DAC observes and listens to the message sent.   

The other HF operating positions are on the right.  Dale VK1DSH is seated at the right hand end of the table, Raoul VK1FIVE is standing on the far left.  Roger VK2ZRH is on the far right explaining an aspect of his 10 GHZ station which he used earlier in the day to make a contact with Dale VK1DSH.  I don’t have the name of the person standing next to Roger, I will add his name when I know it.  

 

The 20m operation was housed in a small dome tent and there wasn’t much light to take photos as it was almost dark when I set that up.  I took some photos by torch light and the camera was the iphone 5.  This was later in the operation when I was trying the 706 to see if the higher power made much difference. 

 

  

On 20m I made 43 contacts using the IC703.  I did have the IC706 available but I wasn’t sure the battery would last the distance if I used the higher current required by that radio.  I did call Mike 2E0YYY in the UK  using the IC706  on 50 and 100 watts just to see how well he heard its signal, well after the propagation faded somewhat.  He gave me a signal report about the same as how I was receiving him.  

Overall I thought national and international interest in the special event station was pretty good.  Thanks to all those who patiently waited for the traffic to clear and make their calls.