EA2/BI-033 Sollube SOTA activation

Yesterday I made a short afternoon activation of Sollube Mt. (SOTA Ref. EA2/BI-033) near Bermeo, at the biscaine coastline. This is a drive-in summit, full of comm towers, where the RFI mainly, but not only, on VHF and UHF bands, are huge. 

My goal on this activation was to test some portable equipment recently arrived to my station or being there for long time but not being used before. In this particular case, the targets were my new Xiegu X6100 portable rig, and the JPC-12 antenna, and how they would work together. Also we wanted to check how the new FT8 android apps work in order to use them as a compact SOTA digital station. So I carried all the wires and connectors needed to do so.

Sollube, EA2/BI-033

When arriving to the summit around 15:30 local time, the weather was sunny and temperature about 23ºC, with no wind. One of the tests I wanted to do was checking whether the antenna could be able to manage a medium wind without using any kind of help -say 3 rope winds- but this could not be be made under these conditions.

The antenna

Once all items out of the rucksack, first thing to mount was the JPC-12 antenna. This antenna can be found on a number of well known chinese stores, as at USA and EU radio gear commerces as well. It consists in a metallic pike, 4 aluminum tubes, an adjustable coil and a telescopic wipe. All together makes a 4.2 m high vertical multiband antenna, working from 7 to 50 MHz bands to up to 100w output. When stored back in its bag (already provided),  its length is only 33 cm, weighting about 1.4 Kg. It also brings 10 radials of very thin wire (computer flat ribbon wire type) working at ground level.

JPC-12 antenna

Obviously, being supported by a pike, you need a specific kind of terrain, making it difficult to install on rocky or sandy ones. Probably on these cases, some paracord winds tied under the middle coil might be used to secure it. I think the supplied pike is a bit short for the height of the antenna. The builders could use the bag size to implement a 33cm pike instead the actual 25cm one, making it a bit safer at least.

All the parts use the same M10 screw mounting, so it's very easy to tie all them together, being it quite intuitive and fast. The mounting order is: ground pike, feed point (PL-259 type), 4 aluminum rods, adjustable coil and finally the telescopic (2.4m) rod. Don't forget (as I did) to connect the gound wires between the pike and the bottom side of the feeder before going on. The parts cannot be mounted on a wrong way due to male-female connections, but they can be mounted on a wrong order. Be careful on this, I have already read on the net that some people have mounted the adjustment coil on the base, just after the feeding part. On the other hand, this one have a rugged surface, very useful while sticking the pike to the ground.

The user manual (also included) tells to deploy at least 3 radials, but being at ground level and no tuned, I chose to install all of them. To do this you must take apart all the thin wires that come joint as a ribbon, and then distribute them evenly around the antenna.

Once the antenna installed, my intention was to adjust it on the different bands using the nanoVNA which I previously had calibrated at home. No way. Due to the strong RF signals at the summit, the readings were continously changing, showing random weird values. Same thing has already happened to me on several similar RF seriously polluted summits. Fortunately, the X6100 has an option of SWR check which later provided me with at last a rough measure of the behaviour of the antenna.

So that I did. Install and connect all kind of items to the transceiver, that is: microphone, battery (5200 mAh Lipo 3S 11.7v), cw iambic keyer, usb C cable and BNC antenna connector. For this I used a short 2m RG-174 male PL-259 to male BNC with a small choke on the radio side, trying to avoid RF signals on the usb connection to the phone (and it worked!)

Once the Xiegu turned on, the first thing to remark was that the display. It was easily seen, despite the sun light (my phone was not so good on this when taking the photos). I adjusted the antenna to the proposed point of the coil for the 20 m band (it has two marks, for 20 and 40m bands), change the rig to the SWR check mode and run it. I had to change only one turn (making the virtual length of the antenna longer) to have it at 1.3:1 ratio over all the 20 band. Actually, the minimum span of the X6100 check is 1 MHz, so I could see the SWR value from 13.9 to 14.9 MHz. 

More fine adjustment can be done by shortening slightly the telescopic rod, but in this case, it was not necessary. I was really surprised by the width of the working range, being a "short" antenna, loaded with a coil, at least compared with my previous experiences with other similar (but quite shorter) antennas. Almost the same happened on 30 and 40m bands, the adjustments being easy, wide, and accurate. I guess it can be due -at least partially- to ground losses caused by a basic radials system. 

In summary, the antena is well mechanized, strong, and easy and quick to be installed and adjusted, provided you have some way to check the SWR ratio on the chosen frequency. No need to use an ATU, so that is less weight you must carry to the summit. It performed well  on the 20/30/40m bands, having at sight that a quite strong CME was on, and the conditions were not the best. It could be appropiated particularly on small summits, where a pole supporting and EFHW or CF dipole could not be installed. OTOH, the 1.4 Kg weight and the size of its bag is not small and could determine the size of the rucksack needed.

The rig

As previously said, the first thing was the display. Even under strong sun light it was easily visible, a good point. The ability to check the SWR was also very useful. However, the use of the different options are not the most intuitive. Basic items -like power output adjustment, keyer speed, or RIT- are kind of hidden among other features not so commonly used. It would also be prefereable other kind of setting the freq stepping, for example, by pushing the main VFO knob. Better if you learn all these at home, before going onto work at the summit!

The waterfall is pretty, and capable of being adjusted on amplitude (other bigger and more expensive rigs cannot), but not particulary useful while SOTA activating, as usually you are going to stay on a fixed frequency, but it always can give you an idea of the band activity or conditions.

The noise reduction was not useful at all. Even on the lowest levels, the behaviour is extremely aggresive, making the signals weird and hard to be copied. Some firmware work have to be made in order to improve it seriously.

By this moment I had operated mainly on CW, but I also used SSB to check the clarity and readiness of my signals. The controls given were not the best, and I found the PTT switch of the mike a bit soft, not making a clear on-off, but overall it was not so bad.

Although the X6100 has its internal battery, the maximum power available when you use it is only 5w. In order to have up to 10-12 w (band depending) the use of an external power supply is a must. But be aware that any source giving more that 10-11 volts will cause a sensible heating of the equipment. So, LiPo 11.7 volts 3S batteries are strongly recommended. As an alternative, some kind of heat sinks attached to it can be used (There are some raspberry ones that can be easily adapted)

FT8 Android Apps

Although FT8 is not my preferred mode at all, this is quickly becoming one of the most used modes, and the needing of carrying some kind of computer (tablet PC, raspberry, etc) has refrained its use on portable scenaries. 

Now we have at least two android apps making possible its use with some rigs and a simple smartphone, that you probably are already carrying during your SOTA activations for using it as GPS tracker, for self-spotting, S2S QSOs and so. These are:

FT8 Radio (at 9.99$)

FT8CN by BG7YOZ, and freely available on Github

They both work with a number of rigs -using a bluetooth connection or via an USB OTG cable, like IC-705, Xiegu X6100, Lab599 TX-500, QDX, uBITX, etc. They all have an internal audio card, but it can be also used by means of an external USB audio card

Working procedures and interface are not similar to the usual WSJT-X way, and each one has its own particularities. I found FT8CN more adequated to my needs as activator as I am normally more interested on calling CQ and less on answering calls.With this one it is easier to find clear frequencies to call -using its own waterfall- and to keep your transmission freq fixed. In my POV, it also manages better the QSO interchange, but this is a matter of taste.

They are both in a developing state and must be still refined regarding to its operation procedures but the two give you a way to work this mode without carrying any suplementary equipment. 

Any further question? Please let me know, and thanks for reading, 73!