My first SOTA activation

Today I activated my first summit. I think this aspect of amateur radio is going to be addictive!

The summit I chose to activate was Mt Ainslie in Canberra. I chose this as it isn’t too far from where I am staying as I would be relying on leg power to get there. Also, being close to the CBD I figured there would be a fair chance of making some contacts. Bearing in mind that four are needed for the activation to count, I didn’t want to waste a Sunday without results.

I needn’t have worried.

I started out by posting an entry on the SOTA web page announcing my intentions and the time I anticipated commencing operations.

The gear I would be taking included my Elecraft KX1, Buddistick antenna, headphones and a length of RG58 coax. I also packed in my Yaesu FT-250 for 2m work and my Jingtong for 70cm. All this fitted nicely into my backpack, but I would need to carry my camera tripod, upon which I mount the Buddistick, by hand as it wouldn’t fit into the backpack. A bottle of water and some lunch completed my kit.

I set out at 8:35am local time and after about 35 minutes arrived at the turn off to Mt Ainslie.

Now for the hard part - uphill all the way.

Now for the hard part – uphill all the way.

I arrived at my destination one hour fifteen minutes after leaving my QTH. That was some walk! Climbing to the summit took the best part of 45 minutes and was very tiring; I had to stop and rest no less than three times.

Once at the summit I located a nice quiet spot out of the way of people and set up my gear. It took a fair while to tune the Buddistick but I eventually achieved an SWR on 40m of 1.7:1, and 1.9:1 on 20m. Power levels were 1.5W for both bands as I had chosen to load six alkaline AA cells into the KX1.

I found this large rock to sit on during the activation.

I found this large rock to sit on during the activation.

At the advertised time I put out a CQ full of enthusiasm, but this soon began to fade as nobody replied. I tried both HF frequencies without luck, then tried the VHF and UHF frequencies, both of which were dead quiet.

Then the calls started.

For the next two hours I fielded calls from as far away as Victoria (VK3-land) which was most gratifying.

I was interested to note that of the eight stations I worked, only the first five were at 1.5W. The batteries faded pretty fast after that with 1W being all I could squeeze out of the rig. By the time I had made my 8th contact, battery power was down to 0.7W, which was too low for me to operate the rig’s internal ATU.

VHF and UHF saw no activity at all, so all that was left was for me to dismantle my station, pack up and begin the long walk back home.

As soon as I had cooled down, I fired up my computer and logged the contacts into the SOTA database. Mt Ainslie (VK1/AC-40), which is situated at grid square QF44NR, is worth 1 point, so I am on my way to Mountain Goat status!

Saving SLA batteries

One of the issues I face as a 100% QRP operator is looking after my battery power, especially while operating portable. SLA batteries don’t come cheap.

I read about a neat little piece of gear called the battery saver in Silicone Chip magazine back in September 2013 and finally got a chance to purchase the kit and build it over the Christmas holidays.

The kit went together nicely in no time at all, thanks to the small parts count. The settings are adjustable, depending on your requirements. Basically this is to set the cut out voltage that suits your particular type of battery. Mine being 12V SLAs I set it to cut out at 11.5V.

I then mounted the small PCB in a rather large metal enclosure, the only one I had handy at the time.

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It seems to work rather well. But now I need to purchase a new 12V SLA battery as the ones I am using are a bit long in the tooth and shut down frequently.

The only problem I have encountered is that the 1M Ohm trimpot doesn’t adjust the until it clicks as mentioned in the article. Mine turns and turns and turns … I also found it very difficult to get Mosfet Q1 to turn off and on.

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2014 Winter UHF/VHF Field Day

This weekend I packed up my portable gear, checked off my check list and headed out to the summit of Mt Coot-tha (grid square QG62LM) to participate in the annual Winter VHF/UHF Field Day.

My intention was not to chase any of the awards but merely to try out my new portable station that consists of an FT-817, and a 2m quarter wave ground plane antenna. The rig would be powered by a 2 a/h battery.

I found an unoccupied BBQ area, parked the car and set up my station. I would be concentrating on working SSB on the 2m band only. Power output would be 5 Watts.

 

My gear set up on the BBQ bench.

My gear set up on the BBQ bench. Note the antenna on a short pole.

I also had with me an Wouxun 2m/70cm hand held and a Yaesu FT-250 hand held (both FM units) just in case.

I spent two hours operating and made 11 contacts, so it was a case of mission accomplished.

The battery did well; to start with there was just on 13v and on completing there was 11.86v.

The battery did well; to start with there was just on 13v and on completing there was 11.86v.

Next time I will take along an antenna that will allow me to work the 70cm and 6m bands as well.

A stand for my FT-817

One of the drawbacks of the ubiquitous Yaesu FT-817 is that when it is sitting on the bench ready for use, it’s so difficult to read the display. This is because it is on the leading edge and not the top of the rig as is common with trial-type designs.

So to see what others had done to rectify this situation, I took to the internet and ran a search. I soon come up with the web page of Alex, KR1ST and read about how he turned an old DVD case into a stand for his FT-817. Check his page out here: http://www.kr1st.com/ft817stand.htm

I followed his instructions to the letter and ended up with a fine business stand for my FT-817.

The old plastic case, once I had cut it as instructed.

The old plastic case, once I had cut it as instructed.

Then it was time to put it together and try it out.

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The proof of the pudding is in the eating, as the old saying goes. Time to put the radio onto the stand.

Fits perfectly, as if it were made to measure.

Fits perfectly, as if it were made to measure.

A view from the operating position.

Now the view of the display is just perfect.

Now the view of the display is just perfect.

Reverse polarity protection

Now that I am a 100% QRP station, I rely more on battery power than ever before. Sure, I do have power supplies but I tend not to use them, preferring to make use of renewable energy whenever possible.

This brought into focus the importance of reverse polarity protection because the last thing I’d want, especially during the hurly-burly of setting up in the field, is to connect up the power the wrong way round and destroy my rig.

The first thought I  had was to insert a diode into the positive line of the battery feed line, but on second thoughts, quickly discarded that idea. You see, suffering a drop of around 0.7V simply because of the diode doesn’t make sense, especially seeing I’d only have around 12V at my disposal.

Better to make use of a Schottky diode, but then again, even though the voltage drop would be far smaller, when you’re dealing with QRP you want to squeeze out as much voltage from your battery and be able to have it at your disposal as you can. OK, Schottky’s have only a 0.3V drop, but I wanted to do still better.

This meant I’d have to think about using a FET.

I asked Jan, VK4EBP, if he had a spare that I could use as I didn’t have any in my junk box. He said he did and supplied me with three FQP27PO6’s.

The idea is to chose a FET with a SDS On Resistance of around 0.07V or better, and a maximum gate-source voltage well above the typical voltage I’d anticipate using. These are rated at around 25V, which would do me fine. Their drain source voltage is also around 60V, so I had a starter.

Next I had to draw a quick circuit diagram so I wouldn’t make a mistake and fry my rig. I had to remember that as I would be using a P-Type FET it would be inserted into the positive line, not the negative.

My quick drawing of what I needed to construct.

My quick drawing of what I needed to construct.

I decided to solder the FET onto a piece of vero board, to which I’d also solder the wires. The idea was to have something rigid so that the contraption wouldn’t fall apart in the field.

Rough and ready, but it'll do the job.

Rough and ready, but it’ll do the job.

I used a rotary tool to grind away the copper trace where necessary. I prepared enough vero board to make two units as well.

Next, it was simple a case of soldering the FET and the wires into place.

Soldering done and waiting for the insulation tape to seal.

Soldering done and waiting for the insulation tape to seal.

I then sealed the board with some insulation tape.

Now came crunch time. I connected the cable up to a power supply in the right order and measured the output voltage at the plug with a DMM. Perfect.

Voltage reading as expected. So far so good.

Voltage reading as expected. So far so good.

Now for the moment of truth. I reversed the leads to the power supply so that the black (negative) lead was connected to the red (positive) terminal on the power supply and the red lead to the negative terminal.

When the DC voltage is reversed, the gate is pulled LOW relative to its source, and the FET turns off.

When the DC voltage is reversed, the gate is pulled LOW relative to its source, and the FET turns off.

All working as intended. I now have a good reverse polarity protection that has a minimal voltage drop across the protection device.

John Moyle Field Day 2014

One of the aims of the John Moyle Field Day is to test your ability or readiness for portable operations. This is an even I like to take part in as it not only allows me to prepare for remote operations, it also guarantees contacts.

This year as always, I prepared my kit, made a check list and ensured I had thought of everything. My mode of operation would once again by CW only on the HF bands. My rig of choice was my Elecraft KX1 and my antenna my new Buddistick. My location would be up on Mt Coot-tha, which is not very far from my QTH.

This year I took the added precaution on including a few backup options, and boy was I glad I did. These included a long wire antenna, extra batteries and a multi-tool.

When I reached to top of Mt Coot-tha, I found an unattended BBQ area off the side of the road near the Channel 9 TV studios. Perfect. There was a nice table and bench seat provided too.

I unpacked my gear and started by assembling the Buddistick antenna. Bugger, I had left the all-important antenna mast and stand at home in my haste to get going. And worse still, it had the mounting plate still attached so I couldn’t make use of the small tripod that came with the Buddistick.

Thank goodness for the long wire antenna. I proceeded to cast the end of it up over a high branch of a nearby tree but the weight at the end of it twirled around the branch a few times causing the thing to become stuck. I wasn’t able to pull on it and raise the wire antenna up into the tree. There was now nothing for it but to cut the line loose and try again. Second time around was more successful.

The stand I made to keep the counterpoise off the ground.

The stand I made to keep the counterpoise off the ground.

The rest of the station deployed easily enough and I was able to get a 1.3:1 SWR reading using the new inbuilt antenna tuning unit in the KX1 on the 40m band. No such luck on 20m; 7:1 was the lowest I could obtain and there was no time to fiddle with reducing the length of the wire. I needed to make contacts and score points.

My operating conditions.

My operating conditions.

In total I operated for three hours and chalked up eight QSOs, mostly with VK2 stations. So considering I was only putting out a tad over two watts, I was more than satisfied. Oh, the new paddle worked fine too, even though I found it to flex a little too much for my liking on the enclosure, resulting in some errors in sending. But all in all, I was satisfied.

Listening for signals.

Listening for signals.

Now to wait for the results. At least I have learnt the lesson about being prepared and taking contingencies into account.