After my building of a colinear antenna for 2m, it was time to try it out, and what better than a SOTA activation. I picked three summits that were close to each other, and where it was possible to get into Melbourne on 2m, but only one of these summits, Federation Range VK3/VN-003 had anything that was close to line of sight.
Mt Mitchell VK3/VN-012
After getting my gear together early on Friday morning, I headed out (about an hour late) up to Mt Mitchell. There is a well made gravel road that leads up to close to the summit. The main 2WD road skirts the edge of the activation zone, getting about 5m into it. So, it is best to park the car a little down from a junction NE of the summit with a 4WD track. This track is mostly in the activation zone and passes over the summit to the north and then the west. Being 2m, I wanted to be at the summit itself to get good takeoffs in most directions, especially south and west. Approaching from the north west meant summitting.
The vegetation is recovering from the 2009 bushfires. The fire here was intense and killed nearly all the trees. Regrowth is currently about 2m high and is not too bad to get through. There are also rock areas about 10m across to make things a little easier. I found one of these close to the highest point and set up here to operate.
I was wondering how the colinear would go with electrical shorts, and it was no surprise to find that a short had developed when I set it up. Thus began a process of taking down the squid pole and checking the various connections. One thing that I have noticed is that because I used RG58/U – to obtain a shorter antenna – with a stranded centre conductor, the setup is far more susceptible to shorts. When I did the soldering, I did not have the best light. I am going to have to resolder the connections and ensure all strands of the centre conductor are captured by the solder. As it is, there are free strands that make their way where they are not supposed to.
After about 20 minutes of stuffing around, I managed to get a short free colinear. I was running way behind time, so I did not bother getting a VNA readout of the colinear. It has acceptable SWR over the whole 2m band, but it could be optimised as it looks like the centre point is at the top end of the band. This means the positioning of the choke on the input cable could be pushed out a little.
The colinear worked well. I was able to make a contact with Peter VK3PF down in Gippsland, even though there are quite a lot of hills causing obstruction over the path of well over 100km. Clearly this thing has some gain. The only comparison that I made was into VK3REC, an EMDRC repeater. The 1/4 wave on the HT could break the repeater. The RX was scratchy, so you had to move around a little. The Colinear had it well over 5 and 9 plus (I guess 20dB). So I need to fix up the shorting problem to get this baby on the air more often.
I was present at the activation area for about an hour, but with the stuffing around to locate the short in the colinear, I only operated for a little less than half an hour. I headed back to the car, grabbed some quick lunch at Buxton and headed for Sugerloaf saddle underneath Sugerloaf peak in the Cathedral Ranges State Park.
Sugerloaf Peak VK3/VN-011
I have been to this summit twice before. The first was many years ago, when I was not very experienced in overnight walking. We (my wife and I plus some friends but I cannot remember now who they were) camped at Farmyard, about 3 km to the north. We planned to head down to Sugerloaf Peak and return to Farmyard. It was overcast and foggy. We never made it to Sugerloaf due to a few spots on the “track” that were very exposed on the rock.
My second attempt was as part of a warm up for a 16 day walk in SW Tasmania. I was walking with a guy to train him up physically for the Tasmanian walk. He is an experienced rock climber. There is a path that goes up the side of Sugerloaf Peak that he said would be graded 3. He said it is much harder when carrying a full pack. Nonetheless we went up. I would have never have gone up without him, but he clearly knew what to do. Foot here, press against that, move other foot there, etc. I just did what I was told and he made it look easy. I, of course, had no idea of what to do. The tables were turned a few weeks later in SW Tasmania, where luckly I knew what to do out of the group that went down.
So for this my third visit, I headed up the “less hard” track, which still has lots of open, exposed rock. It would be tricky when wet, but in dry conditions, just take good footwear, and don’t look down too much.
Also, since the fires, there has been an upgrade of facilities at Sugerloaf saddle. There is a nice shelter there now which could fit more people than would ever likely be there at one time, ever.
I made the summit in good time. Check the colinear cable – no electrical shorts. Looking good. Raise colinear – shorts! Try as I might for the next 45 minutes, I could not find the short. Do I raise the end fed on 40m, or get out the 1/4 wave. This is supposed to be the hardest summit of the day, will the 1/4 wave on 2m even make it into Melbourne? Turns out it did without too much trouble. I did not get any contacts on FM, but SSB saved the day.
I should make mention of the BHI NEDSP1061-KBD noise reduction module here. I have one of these installed in my FT-817, and in my FT-897 as well. It does make SSB easier to listen to, but it can also improve readability where the signal is on the limit. It helped two of my QSOs today, pulling what would have been R3 to R4, and R4 to arm chair copy. If something is R1, it won’t help it, but if it is R2, it can pull it to R3 and you’ll get the QSO that you would otherwise would have not.
Sugerloaf peak is the most scenic of the summits of the day, so here are some pics.
Notice the drop off to the right on the pic above (click it for a better view).
Federation Range VK3/VN-003
Time for the final summit of the day, Federation Range to the north of Lake Mountain. I headed up to the ski resort and parked in the main car park. This place is D E A D during summer. I headed up the XC ski trails heading north and after about 30 minutes made it to the top. The activation zone is fairly large, but again, 2m makes you want to operate from the highest ground. This time I did not bother to attempt to operate the colinear. I simply plugged the 1/4 wave into a Wouxun KG-UVD1P and started up. I made two contacts on FM, but then things were slowing down. Time to plug in the FT-817 and I got 5 more contacts on SSB. Even Peter VK3PF got a look in. The path to his QTH is not clear, but there is much less in the way than at Sugerloaf Peak. I still think that if the colinear was able to be operated there, he would have got that summit in his log.
The activation here was short as I wanted to try and be out of the resort area by 6:30pm. In the end it was closer to 6:40 when I was back on the Marysville Woods Point rd, but it seemed not to matter. It was an interesting day for 3 summits and 20 SOTA points, all on 2m. It would have not been possible without SSB, but I need to get this colinear working! Even though its first adventure did not quite work out, I think this antenna has already shown its promise and with a little corrective surgery, need not be a pain in the rear end!
One little side note: I took up some 18650 cells, but in the end the internal battery on the FT-817 was able to last through all three activations. It was getting a little tired in the end, and if I had wanted to keep going, I would have needed to plug in the external power. It lasted about 1 hour 30 minutes of operating, but that included quite a bit of FM at 5 watts, which is going to hit it harder than CW or SSB at full FT-817 power.
EDIT: There were a few shorting possibilities in the colinear. I used some unused RG6 insulation to provide a shunt on the joins to provide greater structural integrity. The BNC connector itself had developed a short! I have a good crimping tool, but these are the hazards with working with stranded centre conductor coax.