Mt Ritchie, Strickland and Donna Buang 2014

Hi all,

After what was then my recent trip to the snow, it was time to pick up a few more bonus points on two summits that I had done before, and pick up a new extra summit.

Mt Ritchie VK3/VC-003

This summit is one that I’ve activated a few times before. There is about a 6.5km walk from the nearest road access on the Acheron Way. Using Road 15 up to the saddle, then Road 10 to the north, the terrain climbs up to the summit.

Conditions were quite fine today. Previous activations have been far more cold and windy. Pick the right day here, and it could be under 20cm of snow.

Activating at Mt Ritchie

Activating at Mt Ritchie

As seen in the picture (if you click on it and zoom in), activation again was using the random wire (notice the counterpoise wires on the ground) with the KX1. Notice the branch, which I stuck into the ground to support the wire near the rig.

It is generally pretty easy to get day time activations on 40m CW away these days, even if you can’t spot. Some chasers must leave their rigs on 7.032 and listen to that first CQ call.

Mt Strickland VK3/VN-030

Mt Strickland is to the north of Mt Rtichie, but track access from Ritchie involves entering the restricted catchment area. Instead I headed back to the car, proceeded north along the Acheron Way and used Feiglins Rd. This is a good quality gravel 2wd road. It is used by logging trucks. Taking the left fork shortly after leaving the Acheron Way, it winds its way up to the ridge. Turn left and it proceeds into the activation zone.

Activating at Mt Strickland

Activating at Mt Strickland

Activation was the usual “random wire” with the KX1. Complete station almost in your pocket – apart from the squid pole, but that only weighs 300g.

It is interesting these days that I am taking the 4.7m squid pole even on activations where I am not expecting an off-track scrub bash. Guess the 7m pole is in semi retirement these days, although if I want to get out the 2m colinear, it needs the bigger squid pole to host it.

Mt Donna Buang VK3/VC-002

The final summit of the day was Mt Donna Buang. Access is on sealed rds, coming up from Warbuton. I was coming from Mt Strickland, so I was on the unsealed Acheron Way. The road is sealed on the Acheron Way to the Mt Donna Buang turnoff. The road from the turnoff to the summit is also sealed. While conditions were good today, if there is snow on Mt Donna Buang, it is a good idea to either use a 4wd or a 2wd with chains – even though you do not legally need them. The grader they use to keep the road clear cannot keep up if it is even moderately snowing.

With the 4.7m squid pole, I rarely need to use anything to secure the pole in vegetation, even 20/30cm of ground coverage is generally enough. with the bigger squid pole, it generally needs something to be secured on. At Donna Buang, I activated in the grassy area between the lookout tower and the shelter. There were a few people wondering around, some wondering what I was up to. My CW is not strong enough yet to be able to send while talking to someone with me at the same time, so there were a few gaps between overs.

Activation again was the “random wire” and the KX1. The random wire is not fantastic for DX, but it can bring in occasional contacts on 20, so it was nice to get back into the EU, even with just a 4.7m squid pole. I had far more success with a vertical. Maybe one day I’ll do a few more vertical antenna based activations.

Conditions were still fine on the summit, but I was keen to get home after six contacts and no more answers to CQ calls, and so that was it for the day.

Regards, Wayne VK3WAM

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4 Summits in the Yarra Ranges

Hi all,

With all the fast and furious SOTA action going on in recent weeks, it was time to get out and clock up a few more points, lest I eventually lose my VK SOTA activator lead, but hang on, SOTA’s not supposed to be competitive, right?

Mt Richie and Mt Donna Buang form a summit pair that are quite easy to do in a day, and that’s what I did last year. This year the plan was to add two extra summits onto the day, Mt Bride and Britannia Ridge. I had not activated those last two before, but plenty of others have.

Mt Richie VK3/VC-003

This summit is accessible by a series of management vehicular tracks. There is a gate for Road 15 at Acheron Way. The large bolted concrete barrier is to stop the public driving up, but foot access is ok. The track log below shows the route.

GPS tracklog plot of Mt Richie access

Mt RIchie tracklog

The junction between road 10 and 15 is at the most southerly point on the tracklog. Turn left, and it’s about 5km walking from this point. The route involves over 500m of climbing, but it never feels too bad on the way.

I first put up the vertical, but I need to do a bit of soldering on the feedpoint as the connection was poor. The base of the loading coil seemed disconnected, I am going to have to look into this. No action on 12m with a poorly functioning antenna.

Lucky the end fed was in the bag. I took down the vertical and put up the end fed and worked a series of VK1,2 and 5 stations. Good reports. It would seem at this stage in winter in the hour or so after sunrise, sometimes there can be a large skip zone on 40m. Bernard VK3AMB reported hearing me very weakly, must have been ground wave over a 45km distance. I did not bring the 2m colinear for this summit.

My phone struggles to take photos in cold conditions, so no activation photos from here.

Mt Donna Buang VK3/VC-002

It’s next off to Mt Donna Buang with the walk back to the car and then the drive up to the summit. The last car park before the gate is 40m vertical down from the summit, so I parked here. Looks a little strange with other members of the public parking at the summit itself, but it ensures my final access is non motorised. I set up near the lookout tower with the 2m colinear and the end fed both on the squid pole at the same time.

2m colinear and half wave end fed on the 7m squid pole at Mt Donna Buang near the lookout tower

Operating at Mt Donna Buang

The only implication of this set up with a 2m coax run from the feedpoint to the radio is the need to move about 5m when I want to move from 2m to 40m. Aside from that, it worked well. I used the Wouxun HT on 2m FM, and the FT-817 on 2m SSB and 40m.

Mt Bride VK3/VC-009

Mt Bride was my third summit of the day. With things running nicely to schedule, I decided to activate both on 2m and 40m at this summit. I used Mt Bride Rd off Old Warburton Rd. A road branches off to the left just under 2km from the summit. It’s a bit rough, but I got the Prius up without any real difficulty. I parked the car at the crest of this road and found the walking track branching off a little further along.

GPX tracklog screenshot of Mt Bride access

Tracklog to access Mt Bride

Someone had recently rode a dirt bike up here. Might have been “fun” with some of the low hanging branches!

I activated on the track as it was well in the activation zone, perhaps less than 5 vertical metres from the highest point.

Activating using a squid pole on the track near Mt Bride summit

Activating at Mt Bride

I again mounted both the colinear and the end fed on the squid pole. It’s working well. I was unable to get the full four contacts on 2m, but there was the usual pile on 40.

Britannia Ridge VK3/VC-011

Conditions up to this point had been quite sunny, but the clouds started rolling in. It was time to get this last activation in place. I accessed it by continuing to drive along Mt Bride Track until reaching the base of a track that goes up a spur towards the summit. Mt Bride Track is fine in a 2wd. The track going up the summit would need a much more capable vehicle. It’s about 200m down and 1300m away from the summit, so it is not a long walk.

GPX tracklog screenshot of Britannia Ridge access

Tracklog to Britannia Ridge

I headed up to where the track levelled off before going off track up to the summit. I did not look too closely at the map, but the track perhaps does not quite get in the activation zone. My way back down to the track was quite more open. Look to leave the track about 50m before it levels out at the top.

My operating site was quite cramped, and for this reason I did not put up the colinear and the end fed at the same time. I commenced operating on 2m. I did some coordination on VK3REC as I had no mobile signal. I worked 2 stations on 2m FM, and Bernard VK3AMB put out a call to see if anyone else was around and perhaps SSB might be a go. I tried getting Marshall VK3MRG, but I could just hear him and there would be little chance he could hear me on 5 watts. Just after pulling down the colinear, another station announced on the repeater that they had my signal booming into them, but they could hear nothing on the 2m 1/4 wave. Bernard himself could hear nothing on the 1/4 wave, but 57 on the colinear. It certainly makes a difference.

I put up the end fed and worked the usual pile on 40. Interesting that 40 was still open locally late in the day after being closed even an hour after sunrise on Mt Richie.

With that, packed up and got back to the car just a little after sunrise. A nice productive 30 point day, and the uniques count was expanded by 2.

73, Regards, Wayne VK3WAM
South west of the summit

Improving the backpackable vertical antenna

My SOTA activations on HF use a vertical antenna which is all home brew. I decided on using a vertical because:

  • I wanted an antenna that could be used anywhere, whether there were lots of trees or not.
  • It needed to be able to be disassembled into segments no longer than 75cm in length so they could be put into a backpack. Some SOTA summits need significant off-track walking to access, and carrying a large 1m or more item outside the backpack – including being strapped on – was not a great solution for those situations.
  • I wanted something with a low angle of radiation to work SOTA DX. Perhaps this would be at the cost of working local stations, but if the antenna was efficient enough I should still be able to work local, but get the DX as well.

Bunnings sell cyclical al in 10mm, 12mm and 16mm segments – and larger. By using the workshop at my radio club, I have cut these to size.

State of play in June

In June, I had a 6 summit activation long weekend in the Grampians. The final activation was at VK3/VW-007 Near Baroka Lookout. Allen, VK3HRA joined me for the second half of my activation. I was working 20m DX on CW while he worked 40m SSB. Some stations he worked had also worked me earlier on 40m, so I was very interested in his signal reports, which were generally about 2 points higher than mine. It’s not a contest about who has the best antenna, but when conditions are poor, a better antenna could be the difference between a successful activation or not, so it was time to do some work.

Allen was using a Buddistick with one radial. Now some get into the counterpoise vs radial wording thing, but at the end of the day it is about providing some kind of ground to minimise ground losses with a vertical. Now both our antennas were short for 40m, but mine was less short. I also had eight radials! So why the poor performance? His antenna was loaded, mine was unloaded. Answer: Rather than relying on an ATU to match the antenna because because of the short capacitive reactance, I needed a loading coil. Time to make one.

The Loading Coil

I like working multiple bands, and putting a loading coil on the antenna could restrict me to one band, and this would not do. The loading coil needed to be tapped, so I could bypass it, also select tapping points suitable for various bands. With 8 segments, the antenna is 6m long – longer than a 1/4 wave on 20, but short on 30 or lower. I used an online inductance calculator at Hamwaves, designing it on 50mm PVC pipe with a flat piece of aluminium to allow it to be screwed onto the antenna at one of the coupling points. I had already made up a piece of wood about 100mm long with two M8 screws at either end, so this was perfect to mount the coil. The coil would be long enough to have enough turns to resonant the antenna on 80m, as well as making tapping points lower down to resonant the antenna on 30 and 40.

My plan was to put the coil between segments 2 and 3 on the vertical, about 1.5m up from the feedpoint. On the net, and in NEC2 modelling I had done, having the loading coil up as much as possible is better, but it needed to be low enough that I could physically access it to change bands without needing to lower the antenna. I would still use an ATU, but this would be more about matching the resistance, rather than having to deal with all the reactance as well. A short antenna has a feedpoint resistance well below 50 ohms – even 1/4 wave is about 36 ohms, and shorter is lower. As the ground plane is improved, this resistance is lower than otherwise, leading to greater mismatch – but this is good because the missing resistance is missing ground losses. The job of the ATU is to match for this mismatch, but the losses across the ATU would be small.

First use in anger VK3/VC-003 Mt Richie

Now with my new loading coil, it was time to get it into action. Mt Richie was the first activation, with Mt Donna Buang VK3/VC-002 later in the day. Reports on 40m were a good two to three s points up on the usual, with many stations reporting that I had a good signal, rather than the usual “I’m digging you out of the noise”. So it looks like I’m better in the game. I could also tell during the setup that when I tapped the coil on 40m at a suitable tapping point – the radio was hearing a lot more signals. Loading a short antenna certainly seems the go.

One impact of the loading coil was that I could not use the antenna with 8 segments. The loading coil added enough weight that the antenna, despite 2 sets of guy ropes, could not stay up. I had to use the antenna with only 7 segments – 5.25m high from the feedpoint.

The Bunnings 10mm segments were just too weak and I needed something stronger. I had used 16mm segments for something else, but I was not that happy with how ridged it was either. I made up two 16mm steel segments with some 10mm aluminium tubing inside for the M8 threads. The 10mm tubing was held in place by a 6mm nut and bolt about 10cm up from the coupling. This has worked well in my experience, and makes the couplings stronger than other parts of the antenna. This approach would allow me to have a drop in replacement for the bottom 2 75cm segments on the vertical, and should get me back to an 8 segment antenna with the loading coil.

Rubicon forest triple activations

A few weeks after Mt Richie and Mt Donna Buang, I was activating three summits, Mt Bullfight VK3/VN-002, Pyramid Hill VK3/VN-005 and Bill Head VK3/VN-004. Conditions were poor on 40m to say the least, with a large skip zone during the day and attenuation on hops on 40 during the day high. If it was not for the loading coil, I would have not got away with the points from the three summits that day – as described in by blog post. I might not even got a single contact on some of those summits.

By now, I had used the stronger steel segments down the bottom of the vertical, and these had made the antenna structurally sound. There was no buckling anywhere lower on the antenna, which was the reason it used to fall over.

While conditions were poor, and a few days later, Peter VK3PF only got two contacts from VK3/VT-003, underlying the challenge, it made me think that things are still not quite right.

Further improvements

I had always not put the ATU actually on the feedpoint, but somewhere on the ground nearby. This was because the antenna would not be able to bear the weight of the ATU – it does not weigh much, but I was always struggling with the structural integrity of the antenna. My two steel segments seemed to have resolved that problem, so now I have begun to think it is time to put the ATU directly at the feedpoint.

When I first started doing portable activations with this antenna last year, I first had a 10m run of coax from the ATU to the feedpoint, with the radio near the ATU. It is convenient, but performance was terrible. I then had a short, 1m bit of coax from the feedpoint to the ATU, and then a longer run to the radio. This worked better. It does not significantly matter how long the run is from the radio to the ATU. It is all about what is between the ATU and the feedpoint and coax here is bad.

So I built up some homemade twin line from enamelled 1mm wire I had available. The run was 4 metres long. It was this length because another vertical I had been using has a feed point 1.5m off the ground. Even with my 8 segment vertical with a feed point 30cm off the ground, the 4 metres of twin line worked much better than 1 metre of coax. There was nothing wrong with the coax – I could use it quite happily between the radio and the ATU!

Still, the antenna is unbalanced and so is the tuner, and twin line is a balanced transmission line, so running an unbalanced signal down it must not be good. I built two Guntella 1:4 baluns, one to go at the tuner, and the other at the feedpoint. This further improved things – there was evidence before of RF at the radio, and these baluns removed it, also my RX was much better – further evidence of common mode currents before. One time I forgot a balun, and using the setup without them was certainly worse than what I was used to.

Reading W2FMI Jerry Sevick’s Transmission Line Transformers made me think that I still have not got this thing quite right. The Loading Coil gets rid of capacitive reactance, but it can not be said that there is 50 ohms on one side of the balun and 200 ohms on the other. This would mean that the losses of 0.05db that I had measured using a network analyser on these baluns would not be the case because of these mismatches. Over the Gippstech weekend, I did some Keith Roget activations at 100 watts in Morwell National Park and Tarra-Bulga National Park. The baluns got warm. Not hot, but the hotter one had it’s temperature raised about 20 degrees. This tells me that the loss is much greater than 0.05db, more like about 2 to 3db. There are two of these baluns, so there is 4 to 6db of signal improvement waiting to be taken.

So my current plan of attack is to do the following:

  • Put the ATU directly on the feedpoint of the antenna, now that the steel segments have removed the instability problems. Get rid of the twin line and the two baluns. The ATU is unbalanced, feeding an unbalanced antenna.
  • There will be some common mode currents reintroduced because the baluns are gone, and we do not want these. We certainly do not want them anywhere near the radio, but across the ATU is not such a big deal. So a 10 turn on 50mm PVC pipe Ugly Balun with coax – which is really a 1:1 unun will do the trick.

This Ugly Balun will get rid of the common mode currents that run on the outside of the shield, but because it is made of coax, the inner conductor and the inner surface of the shield are unaffected. There will be enough reactance on the Ugly Balun to block common mode currents even at 80m, but not too many turns to not work at 10m. Being on the radio side of the ATU – but right next to the ATU, means that the RF inside is going along a matched transmission line with low SWR, so the loss of this Ugly Balun should be very low.

That’s the plan, we’ll see how it goes at the next activation.

Regards, Wayne VK3WAM