QRO portable

Most of my QSOs I have made while out portable. At home I only have a simple antenna: a wire running from the attic window into the garden. Quite early on I found that to work interesting DX stations I had to have a better setup. At around the same time I discovered the WWFF and COTA/WCA programs. A portable journey had begun.

Why bother about the setup?
My radio time is rather limited. This is one of the reasons I want to make the most out of the trips I undertake. The other reason is that I like to give chasers all over the world a chance to collect references in the (worldwide) award programs I participate in as activator. 

Antennas
Trying many antennas and setups I moved from simple wire antennas via a home made cobweb to the folding hexbeam. That one still is my favourite DX antenna. I use that one if I have the time and know there is enough room to set it up. For low bands I use verticals, a c-pole (40m), delta loop (40m) and dipoles (center and end fed). 
For ease of deployment I have lately started using a linked dipole in inverted V configuration for 20-80m. I am quite pleased with the performance and the ease of changing bands.

Masts
With antennas you are faced with the next challenge: height. I started out with an extended Spieth mast (14m but very thin top) and Spiderbeam 12m mast. Fine for end fed's (vertical / sloping) or high band dipoles but once you get to 40m and below you want more height. So I moved to 18m and later even 26m Spiderbeam masts. The 18m version is the one I take out by default. I added some features to make it easy to deploy on your own in the field.

Power - applied and transmitted 
Last but not least there is the question of power. I moved to LiPo and LiFePO4 batteries for my radio's years ago. The capacity / weight ratio is unbeatable. With LiPo's you can run 100w for hours with little added weight.
Moving towards the solar minimum I was looking for a bit more TX power. I started with a cheap RM Italy amp and then moved to the Ameritron ALS500m. It provides a max output of 400w - which is exactly what you are allowed in PA.
I purchased a lead acid battery of 145Ah to power that amp - with the idea that this would allow full day operations (like when I am on expedition with my team YNOMY). However this has two downsides: the battery is *very* heavy and it only supplies 12v or even less under load. At that voltage the amp - designed for 14Vdc - is putting out probably something like 250w.
For a while I looked into voltage booster solutions but I did not manage to build something that was practical and reliable at the same time.

By the end of 2018 LiPo's had become far less expensive than when I started buying them and I had collected a few already (sunk costs). So I decided to see if I could power the amp with LiPo's. The big advantages being that the amp would run at the designed 14v with far less battery weight.

In preparation of the YNOMY GJFF expedition I built three extra batteries from individual LiPo cells I bought in China. During the expedition we have run the amp for two days on LiPo's and the radios on LiFePO4's, using the 145Ah lead acid battery as recharging unit. This worked brilliantly.

HobbyKing 16Ah LiPo, DIY 20Ah LiPo and DIY 20Ah LiFePO4

The capacity required to run the amp for a given period of time depends on a number of variables, like the mode used and how much you transmit during that time. A couple of portable activities have learnt me that I need one LiPo battery (16/20Ah) per 90 minutes of SSB activity. 
In GJ we had four 16/20Ah LiPo's and when we drained one, we recharged it from the Lead acid battery (using a balanced charger). In the end we never drained all batteries as we had a recharged battery ready when we drained the next.

Note that with the Ameritron amp you can choose two approaches. The standard power leads consist of 4 wires (2+ and 2-). This means you can attach two LiPo's and run them in parallel. This is a way to extend your operation without needing to switch batteries in between. I chose a different approach. I left the original (longer) leads and added a short extra power lead (fused). The wires are just long enough to rest the battery on top of the amp.

[update 2020: I built a 5 cell in serial LiFePO4 battery for the amp]

Beware of low voltage
It is important to keep an eye on the voltage level of your batteries if you intend to use them more than once. You can buy battery alarms that monitor each cell in the battery. They will give off an alarm you cannot miss (think of fire alarms in your house) once a cell reaches a set minimum. I recommend you always have an alarm attached while using a LiPo / LiFePO4 battery.
For LiPo's in general 3.2v is used as a safe lower limit per cell. I think it is conservative and in this particular case too conservative as the current drain is high. This means that the cells will show a voltage dip from which they will bounce back a bit once you disconnect the battery. I therefore use 3v as the cell minimum for the LiPo's.
The LiFePO4 cells can go a lot lower. I set the alarm for 2.5v per cell - still quite conservative.

This setup is effective. Apart from direct experience (hardly scientific) I do once in a while get a chance to compare my results with other stations out in the field on the same day. As PAFF and COTA-PA coordinator I receive a lot of /P activity reports and logs. 99% of the time I was not out myself but the times I was, there was bound to be someone else out as well. In those cases the difference shows both in QSO rates as well as in distance covered.
This setup is also bulky. Last time I had to walk quite a distance in the sun with the radio, the 18m mast, the amp, batteries, antennas, chair, food and drink, and it was killing. Transport-wise there are still a few improvements I can and plan to make.

Lots of heavy stuff!

Projects - 18m pole set-up improvements

I use a variety of antennas and poles/masts when /P. The 12m HD Spiderbeam is the most compact one I have and is easy to set up in the field without any supporting structures. The bigger ones I normally attach to the car one way or another or to any suitable construction I can find around the place I am going to be active from. My favourite and most versatile antenna pole is the Spiderbeam 18 HD fiberglass pole. I use it almost every /P activity. Preparing for a tour through LX I decided to implement some improvements that make the pole even more portable.

Guying the 18m Spiderbeam pole
I have twice set up the 18m HD Spiderbeam pole on my own using an ingenious structure with all the 6 guy lines extending while I pushed out the segments. That took quite a bit of time so I looked for another option. When I set up the pole using the car or a supporting structure I find that I do not use any of the supplied guy lines - so it should be possible to find a much simpler configuration to set up this pole in the field.

I decided to try and set it up with only the lower segment guyed. That would allow me to simply set up the pole while it is still collapsed and then push out the segments without worrying about any other guying arrangement.

Borrowing from the idea behind the clamps Spiderbeam supplies for keeping the segments extended, I bought a hose clamp and applied rubber lint that I crimped in place. I cut some of the rubber away so I could add three rings. So now I have a permanent feature on my Spiderbeam pole: fixed guy rings. 

Securing the base
You also need the bottom part to stay put. Before I would use a large peg with some soft (insulation) material around it. I would just position the pole over this peg. However I have found this is not a very solid construction - e.g. it does not allow you to keep the pole standing while it is still collapsed. With the set up I just came up with, I need the collapsed pole to stay upright while I attach the lower guy lines. So I replaced the peg with this:

The center hole fits around the pole while the other holes can hold pegs that secure this little box in its place. Trying it in the field it turned out to work well - the Spiderbeam pole kept upright while I attached the lower guys.

With these two changes I can set up the pole in no time without needing any supporting structure, like so:

I used this a couple of hours with the pole extended 18m holding an efhw wire. Granted, it was not very windy that day. I will have to see if this is strong enough in higher winds.

Practical segment clamps
One last adjustment I made to the configuration is a replacement of the clamps that hold the segments in place when extended. The default clamps provided by Spiderbeam require a spanner or wrench to open and close. That is inconvenient and so I really did not use them often. I either extended the segments to the point that they stuck (with the risk that the antenna would collapse during a QSO) or I would use duct tape (that is quick to apply but not so easy to take off). 

So I bought clamps that have butterfly tightening tabs. I added rubber strip on the inside that I crimped on the clamps to protect the pole (like with the original clamps). I tried them and they work well.

Project - DIY aluminium push up mast

Working portable a lot I was looking for a set up that could help me work the DX that I could mostly copy on my vertical end fed wire antennas but that I had a hard time working - especially in a pile-up situation.

I bought the CB yagi first and changed that into a 4 element 10m yagi. Later I bought the folding hexbeam. Both are very nice antennas to work DX.
Of course I could not put these antennas up with the fiberglass poles I use for the end fed wires.

So I set out to find a portable mast that was sturdy enough to set up without guying (under low wind conditions) and could reach at least 10m high.
This turned out to be a challenge. There is not much out there that is strong enough to set up without extensive guying or it is outrageously expensive.

DIY decision
After a while I decided to build a mast myself from aluminium tubes. I could not find the right material around where I live. The challenge is that you need a nice series of diameters with 1-2mm in between the sections. The other challenge is that you do not want to buy 6 meters of each section (which is the default "industry length"). Luckily it turned out there is a webshop for aluminium stuff in The Netherlands that stocks almost all diameters and sells custom lengths.
 
Dimensions
What would be the dimensions to choose if you want a sturdy but still portable mast?
After some experimentation I decided to go for the following series (diameter x thickness in mm): 70x2 - 65x2 - 60x2 - 55x2,5 - 48x2 - 42x2 - 35x2,5

The widest tube is 2 meters long - running up to 2,4 meters length for the last tube. I did this to make sure they collapse together nicely with each narrower tube sticking out the previous one.

Okay. So far, so good.
 
Clamping
Now how do you clamp the tubes together when you want to extend the mast?
For this I used my angle grinder to grind slits into the top of each section. In the most narrow tube I used 4 slits (the gap between the 42 and 35 is larger), for the other sections I used 2 slits. Note: be sure to carefully file the metal afterwards or you will find that the tubes "stick" when you want to extend the mast.

Tube clamps - right one is the new and more durable version

Over this upper part of each section I slid a heavy duty tube clamp. I started using a version I found in a boat shop but they are made of stainless steel. As this is slightly softer the threads of the bolt used to open and tighten the clamp tend to damage quickly. Now I am using a different kind that seem to be more durable (see the picture above).

The end result: mast of 7 aluminium tubes with 6 cable clamps (5 old types, 1 new type)

Proof of the pudding

How does it work in practice?
Well, the mast is a fully manual operation version :)
Extending the tubes can be hard work, especially under windy conditions. In those conditions the mast tends to bend putting a force sideways on the tube you want to extend. This increases the friction.
The best way to extend the mast is to make sure you position yourself on top of anything practical that brings you on a height where the top of the mast is just above your waist. That way you can extend the mast  

Does it need guying?
In conditions of low winds the mast can be extended completely without guying. It needs to be on a level surface though.
When the wind is somewhat stronger I do not extend the last section and still use the mast without guying. At some point it will need guying, either to compensate for not setting the mast perfectly upright or for windy conditions. For this I added a simple and low cost guy ring out of PVC (as can be seen in the picture). It does what it needs to do: act as an attachment point for the guy wires and stay in place while the mast rotates.

I have been using this mast now for more than a year and I am happy with it. When I set it up, I secure it at the base (I built a mast foot from wood that attaches to the wheel of my car) and at the roof of the car (again using a wood construction) I am still considering changing the base I use. I will write about that one another time.

PH0NO goes vlogging

Setting up my /P station for CQWW this weekend I made some movies to give you an impression of what setting up that station entails. 

This one shows you how I set up my hexbeam. It is up on the mast (around 12m/40ft high) in 20 minutes.