Friday, July 29, 2016

First VEFF activity planned - VEFF-0158 on Aug 1

After meeting up with family, we are now on Manitoulin Island. There are 3 VEFF reserves on the island. One is near to where I am staying: VEFF-0158 Blue Jay Creek Provincial Park. 

Today I went over to check the area out. It is difficult to reach over off-road tracks and will require me to walk the last bit - as the track stays on the edge of the reserve.

After a few km's of gravel road, the last bit is even more off-road.

I counted on this though and bought a car battery from Canadian Tyre on my way to the island. Now I only need to find a proper tree for the antennas and some shadow. 

The weekend we will be spending enjoying a native's festival. If all goes well my first activation will take place on Monday Aug 1 from around 20h UTC.

Tuesday, July 12, 2016

Looking forward to VEFF

In 1,5 weeks I will be travelling to VE for the first time. I will be visiting my brother in Toronto and then travel around Ontario for 2 weeks with my family.

Discussing the various VEFF locations Dave VA3RJ (VEFF coordinator) decided to update the Ontario reference list and he helped me find a large number of provincial parks along my route.

After contacting several agencies (border police, customs, airline) it seems I am OK with bringing my radio. I am not comfortable with taking LiPo batteries as I expect I will run into problems checking them in. So I will have to either buy a power source in VE or use the car (which means I can only operate from a park if I can get in by car).

Checking the propagation forecasts it will be challenge to work EU with only 100w and a wire antenna. I hope I will attract some (new?) NA chasers as well.

There are VEFF locations near all the stops I have planned. However, there is a lot more to do and see and my travelling companions will not be particularly enthusiastic if I am away all the time. So I will have to see when I have the opportunity to go /P. 

If I have internet access I will post my plans to Twitter and the WWFF facebook page

Saturday, May 28, 2016

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 :)

Tuesday, May 24, 2016

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 a long as possible but with minimum weight. The good news is that there are a lot of other crazy hobbyistes 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 (3v-4,2v) cells (between 3V - discharged and 4.2V - fully charged).
  • LiFePOo4 batteries consist of a set of 3,2V calles (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.

Wednesday, March 30, 2016

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

Saturday, June 27, 2015

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...

Saturday, April 11, 2015

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.