5th SOTA Activation, S2S and QCX

That was my 5th SOTA (Summits on the Air) activation, this one is called Pedra do Sino (PY1/RJ-001) located in the city of Teresopolis, Rio de Janeiro, Brazil. I used a simple and cheap dipole “inverted V” wire antenna suspended by a 6 meter fishing rod. As I am always used to carry my daypack (5 Kg) with all needed items for one-day hiking (2 bottles of water, food, clothing, batteries, etc), walking a total distance of 22 Km in 6 hours to a big and beautiful 2,278 meters high summit. It’s not an easy hiking. My friend PY1II (Douglas, SOTA enthusiastic ) made a video of my summit operation, where I tell that 21MHz QCX-Mini is not a commercial option yet because it hasn’t been thoroughly tested, but I made a workaround (aka “gambiarra” in portuguese) resized the LPF toroids and mosfets and it worked perfectly.

I built the QCX-Mini specifically for SOTA activations this time in 21 MHz band, even if this was not totally tested by developers yet. I did a very detailed building by analyzing and matching lots of BS-170 mosfet transistors and fine tuning the toroid inductors from LPF (yes, I had to remove 1 turn and squeeze/spread spirals) and all other transformers, using a signal generator and scope trying to find the specific -3 dB fc point cut-off frequency.

Surprisingly I got very good results, reaching 5.1 watts at 11V x 600mA power supplying, much better than expected!

That was my first smoke test with new transceiver, in a nice QRM-free location. The proof that it’s working properly is the results…

In the first 30 minutes of activation, I made QSOs with Switzerland (9400 Km), Czech Republic (9900 Km), France (8500 Km), US (10600 Km), Argentina (1700 Km), Germany (9500 Km), Spain (8400 Km) and Brazil.

Sometimes it is very hard to hear other distant stations, but as SOTA hams are sharing the same thoughts, they are very patient to re-transmit and try, try again (AGN, AGN), and I understood all callsigns.

I also got a very interesting Summit-to-Summit contact with another SOTA Activator in Germany (DL6GCA/P), my real first S2S QSO! That was really amazing!

That was an amazing hiking, and successful DX contacts, really fun SOTA day!