Putting together a link dipole for SOTA…

Here is my take on the Linked Dipole antenna which has proven popular for SOTA work…

For some upcoming activations, I needed to put together a linked 20-30-40 M dipole as an alternative antenna to the EFHW I had built for my first activation on Mt Lofty.

While thes antennas work well, I felt that those using a linked dipole were putting out a slightly better signal, hence my interest…

Thes linked dipole antennas are available to buy if that’s your thing but I much prefer to make my own…I have been hoarding stuff in my “Junk Box” for years so I had just about everything I needed, except the centre support. For this, I decided to cut one out of some scrap plastic I had kept. This plastic is thin, about 2mm thick but quite stiff, although it has a nice flex if put under stress. I came from a promotional “point of sale” tray that fitted under a printer from my work place. I have dozens of the bloody things! It proved easy to cut with a good pair of sharp scissors, and was easily shaped with my leatherman tool knife blade. Conveniently, it had a nice lip bent over past 90 degrees, perfect for mounting the BNC connector…

Dipole centre cut from scrap plastic with BNC connector and Balun mounted.

Dipole centre cut from scrap plastic with BNC connector and Balun mounted.

Although perhaps not really necessary at QRP levels, I decided to fit a choke balun at the feed point to keep any rf from flowing on the outside of the coax. I used a Jaycar CAT. No. L-1238 Toroid as I had some on hand, and wound about 8 turns of some excess RG-316 and soldered one end to the BNC connector while the other ends of the coax were crimped to each dipole wire…

Centre insulator on the Squid pole ready to raise up

Centre insulator on the Squid pole ready to raise up

For the dipole links I used automotive spade lugs, as I had some on hand…other ideas would be power pole type connectors or even bullet style connectors, whatever you think is a fair thing! I crimp mine, and use Aluminox paste in the joint to provide longevity. The insulators are actually from the packaging holding my youngest lads last Nerf Gun firmly to the cardboard! I live by the motto, “never throw anything out!” – here it came in handy…

Dipole Link, I used automotive spade lugs and the insulators are left over bits of plastic from Xmas toy packaging!

Dipole Link, I used automotive spade lugs and the insulators are left over bits of plastic from Xmas toy packaging!

I have mounted a bit of PVC pipe in the front yard so that I can slip my 9M Squid pole over it and quickly raise it for operating or testing out a new antenna. I used this to gear effect today, and starting on 20m, I was able to trim the dipole lengths and add the next sections in a relatively short time. I was also very fussy with the tuning, and trimmed each band to 1:1.2 or better. This lets the FT-817 develop full power into the antenna on each band – important when operating at 5watts QRP, every milliwatt counts!

Testing the link Dipole

Testing the link Dipole

I got to try out the linked Dipole during my latest Sota activation, and it seemed to worked well on the 3 bands it was designed for. Due to the very strong winds I was only able to get around 70 degrees of angle between each leg, where as I like 100 degrees or better as I believe there is some cancellation of the TX signal below this angle…

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Squid pole bending in the wind…

Success!

So there you have it, much more satifying than buying a ready made unit, cheaper as well, I think I’ll probably end up keeping the EFHW in the kit as its only one piece of wire, and I bet that it would be relatively straight forward to make a linked version of one of those as well.

Thats the beauty of this hobbly, you can experiment at will and build stuff to your heart’s content, or if your time poor then there are usually plenty of companies the affer what you want and are very willing to take your money!

See you on a summit!

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Oh, Bugger!

Hi all just a quick update to my blog to let you all know that on Tuesday Morning of last week, I suffered a serious Heart Attack. I am currently in the Flinders Medical Centre in their Cardiac Care Unit receiving the best of care, after having a Stent put in. There was only the one blockage.
Consequently, my planned Activator intentions for the foreseeable future will be somewhat curtailed! I.e cancelled!!! You will still hear me chasing!!!

A gentle reminder to all to visit your GP regularly for a. health check at least annually!!!

The Baofeng UV5R – getting going on APRS

One of the motivations for getting one of these el(dirt)cheapo Baofeng handhelds was to investigate if I could make a small (tiny) APRS tracker for use on longish trips in the work vehicle. Several years ago, I had purchased a TinyTrak3 from Byonics for another project. This is a tiny PCB that employs a PIC microcontroller to encode position data from a NMEA compliant GPS and transmit it via a 2m radio, be it a hand held or mobile rig. The fact that you can now pretty much see all of the activity for APRS on a smartphone or tablet at aprs.fi pretty well eliminates the need to view APRS info on an external device that is hard wired to the tracker like say a Garmin GPS unit, and being limited to that units maps and features. The detail and info on a smartphone these days is amazing! as long as your APRS position is gated to the Internet via a digipeater then you’re good to go! this could also be used on a SOTA summit, spewing APRS data as you ascend your next peak in search of Goat glory!

The TinyTrak (TT) has evolved since the TT3 I obtained, and there are quite a few different kinds now. Alternatively, the OpenTracker is a similar concept and will also do the trick.

The whole thing came together pretty easy. In my case, I used a older a Garmin GPS 16 unit to supply the GPS data to the TT, but any serial GPS that outputs NMEA-0183 compatible $GPRMC or $GPGGA sentence data will be ok. The TT is very configurable in terms of supply voltage and GPS voltage, all jumper selectable. I would imagine that just about any serial output GPS could be hacked into service with the TT.

Interfacing to the Radio was relatively straight forward, as the Baofeng UV5R uses the same sockets on the side of the rig for Mic/speaker/PTT as many Kenwood H/H rigs. The Byonics website has a lot of excellent info on cables to and from the TT to your radio for those wishing to wire up something for themselves, or those less savvy could simply cheat and buy the cable!

My goal is to have the complete APRS tracker fit in to a kids lunchbox/tupperware style container that just needs an antenna and GPS connected and power to be ready to go. The unit could then be quickly deployed in a mobile situation or taken along on a SOTA summit.

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Cooltong Conservation Park

VK5 Parks Award – Cooltong CP

WX – Fine, 17 degrees C.

Antenna – EFHW for 40M

Rig – FT817ND

Today’s Terrific weather saw me and my oldest lad Josh head out in to the scrub to activate the Cooltong Conservation park, for the VK5 Parks award. (Josh needs to get his hours up on his “L” plates so he was keen to be my chauffeur!) . Access is via Santos Rd, off the Sturt Highway, a few km’s out  from Berri towards Renmark past the Gun Club.

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Cooltong CP entrance…

This is a dune and Mallee scrub park, some 3700 Hectares and is home to many wonderful species of birds and animals. It’s not that far from my home and Josh had us there in about 20 minutes. The road is quite good for a few Km into the park where it starts to deteriorate somewhat but all in all it’s quite serviceable, especially if you have a 4WD or a capable SUV. In summer I would imagine that it would be passable to most vehicles but the recent heavy rains had still left the road boggy in sections with water still in the many ruts.

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cruising in the scrub…

After finding a good spot I set up the squid pole and the End Fed Half Wave antenna with the FT817ND and started calling CQ…I use the iPad for SOTA goat alerts and many other tasks…I log the calls in a paper notebook!

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The EFHW ready to go…

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The trusty FT817ND safe and snug in its Crumpler bag…

I was rewarded quickly with several stations, including a few out on SOTA summits – Nice!…the sun on my back was delicious!!!

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Yours truly on the mic…

The following stations made it in to my log…VK5BJE John, VK3MNZ Don, VK5KX Peter, VK5FMID Brian, VK3AFW Ron on VK3/VW-009, VK5AIM Steve, VK5KBJ Barry, VK5FTCT John, VK3XY Derek, VK3ZPF Peter, VK5KC David, VK3MRG/P Marshall on VK3/VN-027, VK5LY Larry, VK3ANL Nick,VK2UH Andrew, VK5FTTC Rod and VK3UBY Colin.

I ran in to a few issues…1. 40 M with the introduction of SOTA is now VERY busy with stations all over the central bit of the band – finding a spot to call CQ  can be a challenge!!! 2. Morons tuning up over the top of other stations…3. Even bigger Morons calling CQ on a very obvious “in use” frequency. One particular VK2 F-call was displaying all the qualities of getting his foundation licence from a cereal box!!! 4. Splattering stations…some were so bad they were being heard many KCs away…and yes my noise blanker and preamp were OFF!!!

Still bags of fun though, and always nice to pick up a few SOTA summits as part of the deal. Might have to look at operating up higher to escape the hordes around 7.085 – 7.110 Mhz

I also think I’ll try a dipole next time just to see if it’s any vast improvement over the EFHW. Although the EFHW works a treat, it seem those running a dipole get a bit stronger reports over all…either that or make a better effort at getting the far end of the  top section higher or actually running the EFHW as an inverted “V” instead of an “L”

I’m thinking I might be getting some cancellation of radiation if the angle off the “L” bit of the wire is less than 90 degrees at the top of the squid pole (see the 3rd Photo)…something to experiment with!!!

See you in the next Park or Summit!!!

Cheap Chinese Handhelds…so what are they really like?

What if I told you…that you could get a dual band handheld transceiver for LESS than AU $40 DELIVERED to your door? Not a cheap nasty POS but a well made, high featured unit with a drop in charger, good capacity battery and a hands free mic/earphone all thrown in for that price as well? Horse Hacky! No! Enter the BAOFENG UV-5R…

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The Baofeng UV-5R – Good looking, well built…

Hang on, you say, 40 bucks?!!? Yep, you’d better believe it…Ok, “if it sounds to good to be true then it probably is” is a pretty good rule of Internet shopping these days, but if you’re prepared to bend just a little from what you perceive to be normal operating in the world of Ikensu HandHelds then one of these things may just fit the bill as a viable alternative or as a back up unit…even if you lost it or broke it, you’re only down $40′ not the hundreds you probably paid for your current handie…Oh, it’s got torch! gotta have a torch…

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$38 AUD delivered…

So what it like?…Have you ever held or even owned a modern Yaesu hand held like a VX3/5/6/7R series? an FT60? Then this thing has the build quality and feel of one of those units…it’s that good. I was completely thrown by this, and I spent a fair bit of time nit-picking over the construction. 10 out of 10 for that. The display is bright and clear, it’s easy to read and the backlight colors are pleasant to look at without burning your retinas! They are colour coded as well, light purple for operations, blue when RXing a signal and orange for TX!!! for $40. It’s dual band and out of the box it will tx from 136-174 MHz on its VHF band and from 400-480mhz at UHF…

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The unit is small and lightweight, but fits the hand well and oozes quality…

It’s honestly easier to tell you what it doesn’t have…It’s not waterproof! No inbuilt TNC…No inbuilt GPS, nor facility to plug one in…No dual RX different or same bands at once…no 23cm capability, no airband AM RX…no am band or short wave!!! It’s a $40 radio! It will however give you all the basic features you need to access a repeater like DTMF and CTCSS. It also includes a dedicated FM radio band which works very well indeed…

What’s in the Box?…what you see here is pretty much it. I had already attached the nice strong belt clip…the battery for my unit was charged and ready to go out of the box…the main knob turns the unit on and adjusts the volume ( think your first transistor radio) it’s audio I found very good, there’s plenty of it and its clean and articulate, handy for a hearing aid wearer like me. I wasn’t expecting that! PTT has a positive click feel and the keypad keys are close in, but still useable…remember, it’s $40!!! If you wanted to get a better antenna than the duck provided then eBay will serve you well, either that or get an adaptor so you can use one of the several hand held antennas that you’ve collected in your shack!

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Comes with everything to get you on the air…

Yes but is it easy to use?…absolutely! it’s actually much easier to use than my Alinco DJ-G7…all the buttons are clearly labeled and anyone familiar with the concept of a set mode ala Icom or Yaesu will have no problems operating it or changing settings. The only different concept is how a repeater is programmed in to a memory channel as a RX and TX frequency. once you get your head around that then it’s quite easy to add a repeater. The rig gets good on air audio reports and seems every bit as sensitive as my other “big brand” HandHelds, and their stock antennas. Plugging it in to a roof mounted 1/4 wave didn’t seem to overload it.

The manual that comes with it…is perhaps the worst I’ve come across with any bit of ham gear I’ve bought, but hey, as I’ve said a few times..$40!!! The saving grace is that there is a couple of free software apps available on the Internet to program the rig. You MUST order a USB programming cable when you buy one of these, it will be we’ll worth it! I used “CHIRP”, and had the Unit programmed with all my usual repeaters and simplex stuff within minutes. Very “Handy”! There are also lots of YouTube videos on programming these things…google is your friend! Importantly, the CHIRP software will allow you to program the unit for Amateur Band Tx only, so you can keep the ACMA happy…

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Liz thought it was great as well…especially since it was only $38!!! (another Radio?)

At the end of the day…it all comes down to what you want your handheld to do for you…if you want APRS and/or lots of bells and whistles then you might do better elsewhere. But if you just need a sturdy unit to take on your travels then one of these cheap Chinese handies might just do. I’d probably still take my waterproof VX6R out to a SOTA summit on a rain/wet activation, but this rig will come with me when it’s not!

SOTA VK5/SE-005 Mt Lofty

Date: 08/06/2013 – 09/06/2013

Time 23:20 – 01:00 UTC

Weather: Overcast. Forecast Fine 18 . Activation Temp. on Summit 9 Deg C

On Sunday the 9th of June (local), I successfully activated Mt Lofty, SE-005 for my very first SOTA summit…

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The view from VK5/SE-005…

This was a going to be a lot of fun! After leaving my accommodation nice and early for a breakfast stop,  (Think ridiculous clown and a big yellow “M”) a leisurely drive up the South Eastern Freeway had me in the summit carpark with plenty of time to walk out and back into the activation zone before finding a place to set up and be out of the way of the hordes of people flocking to this place!

Mt Lofty has a very nice, well patronised Cafe right at the summit that is a Mecca for the Lycra/ Gym  Junkie types of all shapes and sizes, from dusk ’till dawn. It’s busy. REAL busy! Cyclists ride from near and far to it, and Fitness freaks traverse up the very popular but steep walking trail from Waterfall Gully some 7.5 Km away. Walking in and out of the activation zone the required distance just about killed me! Must work on the fitness Andrew!!!

There was no way I was going to set up near the cafe, so I chose a spot just to the north/north-east of the car park, just off of one of the many cycling/walking tracks…

The operating position at VK5/SE-005 Mt Lofty...

The operating position at VK5/SE-005 Mt Lofty…

This seemed as good a place as any, so I set up the trusty End Fed Half Wave for 40M inverted L style on the 9 M squid pole and occy strapped it to the trunk of some foliage and ran the top part out to a high branch out of harms way. WX wise I was protected from any wind but I didn’t have to worry as it was actually not bad, 9 degrees. I was lucky!

My FT817ND in its Crumpler "Haven" bag...

My FT817ND in its Crumpler “Haven” bag…

Firing up on 7.090 Mhz, I hit the airwaves at 23:28 UTC and Paul,VK5PAS/P came up from in the Pt Clinton Conservation Park, on his way to activating some SOTA and Parks on Eyre Peninsular was the first to answer my CQ call. I was then immediately spotted by VK2JI on the SOTA goat and the stations came thick and fast. It was evident that I had a problem though, as soon as I dropped the PTT, an awful switch mode noise came over the frequency at S9 for a few seconds then disappeared, enough to momentarily block out the stations calling. I soon realised that my new u-beaut DC DC converter for dropping the LiPo battery voltage down was a dismal failure in its current form! I had seen Andrew VK1NAM, using one on his activations in his photo’s so I decided to try one, but it looks like it might have to go in a metal enclosure with some bypass caps…

After disconnecting it I hurried back to the waiting pileup and worked VK3PF, VK1MDC, VK3JM and VK2UH before Marshall VK3MRG/P called me from VK3/VN-017 for my first S2S! Grinning uncontrollably, I continued with VK2JI, VK3CAT, VK3TCX, VK3MCD, VK3PI and Allen,VK3HRA/P called from VK3/VN-012, for S2S number #2. Rick, VK4KRX/5 wanted a contact for the VK Shires Contest and I happily obliged…Things then quieted down so I took a short break and checked the gear and had a drink and a bite to eat before starting again after the UTC rollover…

I self spotted on SOTA Goat and was instantly welcomed by VK5PAS, VK3PF, VK3TCX, VK2UH, VK3DET, VK3AMB, VK3PI, VK3MRG/P on VN-017, VK1MDC,VK5UG, VK5LY, VK3BYD, VK5EMI, VK5FMID, VK3HRA/P on VN-012, VK5NRG, VK3GHZ,VK3KAN/P and VK2JI…This site is also part of the Cleland Conservation Park so I was able to qualify this park for several stations chasing the VK5 National and Conservation Parks award

After things went quiet again I packed up the HF station and tried 146.500FM. I called CQ and  listened for a while after self spotting on the SOTA Goat but the front end of the handheld I was using was pretty much swamped by RF and I didn’t hear anyone!

I finished around 1:30 UTC and headed into the previously mentioned Cafe and intergrated with the fit looking by rewarded myself with one of these…

Mmmm...coffee!

Mmmm…Coffee!

All in all a great morning, a lot of fun and I learnt that I’ll need to equip myself a bit better in the back pack department and get some proper walking/hiking shoes if I’m going to do many more activations… As I knew Mt Lofty would be busy people wise, I left the VHF Yagi at home, but it will definitely come with me on the next summit!

Murray River National Park

Besides SOTA, I have also become interested in the VK5 National & Conservation Parks Award promoted and run by the Adelaide Hills Amateur Radio Society.

I had heard Paul, VK5PAS, out and about activating some of the conservation Parks near his home in the Adelaide hills, indeed, even on his way back from a SOTA summit! The boy is keen!

After a bit of reseach, it seems that there are quite a few National and Conservation Parks near my home QTH. As it turns out, I actually have a lovely view over the Kataraptko section of the Murray River National Park from my front door!

Armed with this knowledge, I packed up the X-Trail with my portable gear and headed out late Sunday morning, with the intention of going into Kataraptko to put it on the air…However, I got about 1 km in on the access road and after facing the opposite direction to where I should be going I decided that perhaps going in here might not be such a good idea after all…heavy rain the previous Thursday and Friday had made it pretty hard going on the mainly clay based “road”. Time for Plan B!

Plan “B” was to head to the Lyrup Flats section of the Murray River National Park, just north of the Lyrup Ferry, a few km from Berri.

Lyrup Flats

Welcome sign…

The access road in here seems better maintained and was no problem for the vehicle and pretty soon I was on the air, making contacts from Black Box campground. I set up the trusty the End Fed Half Wave and the FT817ND…

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The Squidpole lashed up to a tree…

Portable setup

The ‘817, and the EFHW match box…

I worked a good number of stations, including VK5PAS Paul, VK3AFW Ron, VK5BJE John, VK5FMID Brian, VK3XBC Duncan, VK3KAB/P Kevin, VK5HCF Col, VK7NWT Scott, VK2UH Andrew, VK3JM Fred, VK3AMB Bernard, VK2ZRD Rod, VK3ZPF/P Peter, VK5KC David, VK3HRA Allen, VK7FEET Warren, VK3ANL Nick, VK5NRG Roy, VK5FAKV Shaun, VK3KCD/M Peter, VK3BJA Brenton, VK3KIS Andrew (on his 2watt QRP rig he built himself from Drew Diamond circuits), VK5DX Gary and VK3PI/P  Mark, for the last contact before I had to pack up for the afternoon. I was copying most stations at 59 or better, conditions seemed quite good.

The 5000mA LiPo battery I used worked well, not even breaking a sweat for the entire 2+ hours I was on the air. I’m very impressed with it’s performance so far. I have a switch mode voltage regulator coming from ebay to drop the 15+ Volts fully charged to 13.8v, more on that when it arrives. All in all a successful activation. The next park I’ll be doing is the Cooltong Conservation Park. (actually just across the Sturt Highway from Lyrup)