Great news: first place in PACC

Today I received incredible news. Together with two friends I secured the first place in the Dutch ham radio contest PACC using the special call PA55A.

We - PD7YY, PG8M and myself (aka YNOMY DX Group) - entered the contest for the third time. With good preparation, dedication, lots of fun and some suffering (freezing our hands off in rain and wind) we scored the highest amount of QSOs and multipliers of all single tx contestants.

I am really pleased we managed to pull this off with the minimal means we used - a temporary stations with wire antennas on a desolate campsite.

This goes to show that state of the art equipment is not the key differentiator.

Nice :)

Power sources for portable operation

When you start to go out on portable activities, you are confronted with the question what power source you should use. In this post I will share the choices I made working barefoot. 

The reason to share this info now is that I am in the middle of constructing something for my new mobile amplifier.. but more on that in a future post.

Introducing the challenge
The challenge depends on your operating conditions. Suppose that you are not going to work QRP and you will not be in or near your car. This is the situation I faced when I started activating special locations like nature reserves and castles.

Working with a 100W set, the power source you are looking for needs to supply you with approx 16A @13v, for as long as possible but with minimum weight. The good news is that there are a lot of other crazy hobbyists out there that face the same challenge. You will find them when you search for "RC" - remote controlled cars, planes, helicopters and more recently drones.

Working barefoot: LiPo and LiFePO4
These people have turned to LiPo (Lithium Polymer) and LiFePO4 (Lithium Iron Phosphate) batteries for their power.  LiPo and LiFePO4 have the best power to weight ratio of the power sources I compared. 

Although both are Lithium based, there are some differences between the two:

• LiPo batteries consist of a set of 3.6V cells (between 3V - discharged and 4.2V - fully charged).
• LiFePOo4 batteries consist of a set of 3,2V cells (between 2,8V - discharged and 3,6V - fully charged). 
• LiFePO4 batteries have a higher number of recharge cycles (approx. twice the number of LiPo recharge cycles)
• LiFePO4 batteries are intended for high power applications. They exhibit a more constant discharge voltage and are considered to offer better safety than other Lithium-based batteries.
• LiPo batteries are relatively cheaper and lighter (relatively = at the same capacity)

With this list in mind I initially chose to go for LiFePO4 batteries. The biggest I could find were 9.7Ah, capable of delivering 10C (meaning that the peak current is 10x the capacity). With a weight of around 1kg, they fit my requirements well.

After 3 years of working with these batteries I have found that the capacity has deteriorated to the point that it starts to annoy me. I can barely run an activity of 2h on two batteries.
When adding a new battery to my collection, I chose a LiPo this time. The main reason to choose this battery over a new LiFePO4 is that I found them in larger capacity (16Ah).

LiPo and LiFePO4 sizing
When you are going to select your battery you need to understand one more thing: a code with #S#P. This tells you the amount of cells the battery has in series and in parallel. The amount of cells in parallel is not that interesting, as it is the given design for the capacity you are buying (and that number is clearly defined in mAh). The amount of cells in series is more interesting as it tells you what voltage range the battery will operate in. There is of course not one voltage for a battery. It varies along its discharge curve. The good news is that the discharge curve is rather flat.

Discharge curve for a LiFePO4 battery (@ different currents)

Discharge curve for a LiPo battery (@ different currents)

Your radio is most probably happy to take 12-14V. With a LiFePo4 you should therefore go for a 4S version. The voltage of this battery varies between 14,4V (full) and 11,2V (discharged) - most of the time around 12,8V.

If you decide to go for a LiPo battery, then you can either go for 3S (voltage between 9-12,6V) or 4S (voltage between 12-16,8V). Looking at the discharge curve, you will find that with a 3S battery you will quickly drop to a voltage where your radio might not operate anymore or with less output. I used this with my FT-817 and it is a workable solution. At a higher current draw with my FT-857 I found that the battery was unusable too soon. I therefore decided to go for a 4S version. 

LiPo voltage conversion
If you have chosen a LiFePO4, you are ready to go out and activate whatever place you want to. If you went for the LiPo S4 you have one more challenge to go: your set probably won't like the 16.8V of your fully charged battery. So how do you bring this voltage to an acceptable range?

I chose a buck (step down) converter to do the job. You can find them on ebay rather cheaply (imo) as complete modules with adjustable output voltage. I only added a few capacitors and now have a steady 13V LiPo battery with 16Ah capacity.

DC-DC voltage step down conversion

LiPo and LiFePO4 connectors
One other thing to look at are the connectors of the battery. They come in different shapes. Most commonly used are the XT60 and the bullet connectors. The latter are used on higher capacity batteries.
I decided to standardise on one type of connectors - in my case the bullet connectors (as you can see from the buck convertor). So I have made conversion cables to go from different types of connectors (XT60, banana plugs, car cigarette lighter) to bullet connectors.

That is about it regarding power sources for portable operation. In a future post I will zoom in on working with an amplifier while working portable.

PACC 2016 with YNOMY

Studies have taken a lot of my spare time the last 12 months, so there is not a lot of radio news to share. I did however participate in PACC 2016 contest with the YNOMY crew.

We participated with the special call PA55A from the same camping ground we used in 2015. That year we finished second and were comfortably warm during the contest (as opposed to our first attempt in 2014) - good reasons to go back to the friendly camping owners. Although they look at us warily when they see us struggling setting up all those wires in rain and wind, we are most welcome to use their grounds.

The setup we used was comparable to 2015 with separate wire antenna's for 160m, 80m and 40m - using three fiberglass poles - and a hexbeam for 20m, 15m and 10m. We used one radio and a small solid state amplifier that gave us about 300w peak on most bands.

Another thing that was comparable to last year and the year before was the weather. It was cold, windy with some rain and snow. The pictures below give you an impression of the state the field was in.

It does look like we did well. We learnt our lessons from our attempts in 2014 and 2015. The preliminary results (from the log robot) place us in #1. Not bad at all. Now we have to keep our fingers crossed that we did not make any major mistakes. Last year we had very few errors. So let's hope the contest turns out to be comparable to last year on this level as well.

Muddy field - probably good for the reflection of waves though....

In the end everything was covered in mud - not just the shoes

Second place in PACC contest

Today the PACC results were published in the Dutch ham magazine Elektron. It turns out that we (YNOMY dx group) managed to secure second place in the multi operator single TX category only a few contacts away from the first place.

As this was our second serious attempt in this contest (or for that matter any contest) I am really pleased with the results.

The fact that we work from a temporary location where we build up our complete station from the ground with simple means just for the contest weekend makes this result even more pleasing.

We have set ourselves a real challenge for next year...

Celebrating 70 years of freedom with Special Event Stations

Within the YNOMY DX Group an idea was born at the beginning of this year to place special attention on this year's WW2 liberation celebrations as we have been living in peace here now for 70 years. 

70 years ago the allied forces liberated The Netherlands from Nazi rule, ending the second world war five years after it started. The southern part of The Netherlands was liberated in the autumn of 1944, while the northern part was only liberated in the spring of 1945.

On May 4, 1945 the German forces formally capitulated to the British Field Marshall Montgomery. The capitulation was effective the next day.

We therefore celebrate the end of WW2 for the whole of the country on May 5 every year ("bevrijdingsdag").

We were thinking of activating a range of special calls during the month of May with a group of operators. The range P*45FREE (PA-PH) was chosen after some debate. We also planned a group activity in the middle of the month with a special group call PA45FREEDOM.

We asked around and were able to organise a team of 9 operators that were supportive of the idea and willing to play a role in it by applying for and activating one of the special calls. The team consists of PA1WBU, PA3BAS, PA3FYG, PB7Z, PD7YY, PE1BVQ, PE4BAS, PG8M and myself.  

So we are moving from an idea to a whole range of special event stations that will be active during the month of May 2015.

In the mean time we have designed a special QSL card and are in the process of designing an award. This electronic award can be obtained free of charge when an OM or SWL has collected 45 points. Each P*45FREE counts for 9 points and the PA45FREEDOM call counts for 18 points towards the award.

Hope you will have a chance to work several of our stations.

PACC results visualised

For me data makes (far more) sense once it is visualised. So I spent some time with our PACC log data to transform it into pictures.

The easiest way of course is by totaling numbers of QSO per time slot, band and / or mode. You can display this in all sorts of nice graphs.

There is another way to do it, and it is one I really like: showing the actual QSOs mapped on the planet earth. This took quite some time as the N1MM logger we used during the contest does not log / retrieve the location of the station worked. Using HRD LogBook as intermediate I retrieved this data from QRZ.com.

Now with some minimal programming I was able to show the contacts plotted on the globe per time slot, per band and per mode. I made several maps with different segmentations of the data.

I liked this animation I made best - it shows our progress over time (with 1 hour increments). The colors of the data points represent the bands and the shape represents the mode used.

PACC 2015 - experiences of the YNOMY crew

Cross-posted from the YNOMY blog site
YNOMY is a team of 3 active OMs from around Arnhem - PD7YY, PG8M & PH0NO

Pre-contest preparation

We prepared ourselves a bit better than last year (which already was a lot better than the first year). We got ourselves a nice temporary special call PE55E and we constructed and tested a number of different wire antennas well before the contest (last year M was still working on the 160m antenna a few hours into the contest).

Pre-contest modeling of our wire antennas

M had arranged a proper location at a camping ground near to where he lives and - importantly for this contest - in our province of Gelderland. The place definitely was an upgrade of the cold and windy hut we were in last year. It even featured WiFi so we had online cluster info in N1MM.

Our shack during PACC 2015

M started the installation of the antenna park together with his station manager on Friday. They installed the three main poles - 12m, 18m and 12m high - that were holding the wire dipoles for 160m (supported by all three poles), 80m (inverted v from the center pole) and 40m (inverted v from the nearest pole).

Low band wire antennas

We tested this setup before (more info in this post). Modelling showed this setup results in more gain on 160m and less gain on 40m than last year. As we would be running 3 to 4 times the power of last year on the low bands we weren't too focused on getting the maximum gain though.

Final preparations 

Saturday morning NO and YY arrived to complete the contest station,  adding an end fed for 20m, a hex beam for 20-15-10m and a yagi for 10m. As NO had to leave Sunday morning before the end of the contest - taking the hex and the yagi - we set up an extra 5/8 vertical for 15m we built and tested just 2 weeks before the contest.

Our beams: portable hexbeam and home brew 3 element yagi

When we finished setting up the station we had 7 antennas at our disposal - quite an impressive set-up for a temporary station. We were running 300-400 watts PEP into them via an icom 756P3 hooked up to a pc running N1MM.

Contest operation

We manned the station for 24h by sleeping in shifts. The camping provided us with two extra sleeping places conveniently located outside the noisy shack.
M was our CW operator while YY and NO took care of the phone contacts.

M on CW logging in N1MM with YY following the proceedings closely

As the weather was much friendlier than last year we had no calamities (as blogged about in this post). All went rather smoothly. Conditions on the high bands seemed a bit better than we remembered from last year. We will have to compare our logs to see how this worked out.

A better preparation allowed us to operate with minimal switching times between operators. We used our experiences from last year to choose the right band and mode at the right time and we had more power at our disposal on the low bands (300-400w as opposed to 100w last year).

This has resulted in far more contacts and more multipliers than last year. We logged approx. 800 contacts last year during our first real try in this contest and came in 6th place. This year we set our goal at 1000 QSOs and surpassed that by a considerable margin.

We will add more information about our results once we have taken the time to run our log through the PACC log robot and compare our results in more detail with the results of last year (numbers, multipliers, dx per band).