Beyond Line of Sight

I have covered team comms extensively. Team comms are basically line of sight. What does the Guerrilla do once you are beyond LOS?

Thats where HF comes in. Not just ANY HF frequency but specific frequencies and specific style of antenna. NVIS antenna setup is mandatory for this type of radio operations.

Below are multiple articles on NVIS. Keypounder has forgotten more than I will ever know. My simple minded explanation is an dipole antenna cut for your frequency in the 40-160 meter range suspended at a low elevation. 10′ or so. It sends a signal straight up and then about straight down in a approximate 500 mile range from the transmitting station. See the pics below.

NVIS techniques – Part one

NVIS techniques, Part 2

NVIS techniques, Part 3

In the ham radio most radio operators are only worried about making contacts. Very few are worried about making a DIRECT contact. That’s because it’s alot easier to make A contact over a DIRECT contact.

The problem with any radio testing is that it takes two people normally. Not just two people but two people with a General Ham license. Two LIKE minded General license people…. yeah not that easy to find.

Thats where the digital program JS8CALL comes in. The great thing about JS8CALL is we can leave it running at the house on our specific frequency with AUTO-REPLY on and it will answer us if it hears us. This feature also comes in handy if we can’t man the radio during a specific call window time. The Guerrilla team can leave a message in headquarters JS8CALL inbox.

I used two different radios during my testing of direct contact. I used my Icom 706MKII running 30 watts for one day of testing and the XIEGU X6100 running 10 watts for the remainder of the testing. I only used 40 meters for my NVIS testing. All but one of the testing attempts were during the day.

The day I ran the Icom 706MKII I was using an end fed antenna from the QRP GUYS that I built.

This is the Icom 706MKII setup below. I was also using the Microsoft Surface Pro 2 to run JS8CALL. I was about 11 miles away from the home station with the end fed antenna at about 8ft off the ground. There is a 9000ft mountain between my location and the home station. I was able to make contact with the home station and leave a message in the inbox.

The rest of the testing was with the XIEGU X6100 at 10 watts and a 40 meter dipole antenna.

The location in the picture below was 25 miles away from the home location. There were no trees or anything to string up my antenna so I had to do the best with what I had. I laid the antenna on top of the sage brush in the area. I sent a HB on JS8CALL and got a reply from the home station. This time just for fun I turned the power all the way down to the lowest setting on the X6100. I was still able to get a reply from the home station.

The next test I tried was was 20 miles away down in the river bottom of the Green River. There are two mountains between my location and the home station. I laid the dipole on top of a fence that was at the park. Sent a HB on JS8CALL and got a response from the house.

The last test I did I was 15 miles from the home station. Still had the mountain in between me and the home station. I strung the antenna up in some Juniper trees about 4ft high. I was able to make contact this time as well.

While doing this testing someone had mentioned that it was probably ground wave propagation. I needed to see if that was true so I went to the location down on the Green River where I had made contact during the day and put the station back up in the same location on the fence but at night. I had zero luck getting my home station. That showed me it was actually NVIS during the day and not ground wave. I checked PSKREPORTER.INFO that night and seen my signal from that test had been heard across the US to the east coast. The 40 meter band seems to go long in the evening.

So what does all this mean for the Guerrilla?

It means that you can still have semi-reliable comms beyond LOS. I say semi because HF is definitely not 100% reliable as anyone who is an HF operator can attest. You don’t need to have a repeater on top the mountain between you and your home station. You can use an HF radio with an dipole at a low elevation to get your signal over the mountain or beyond distances of your VHF/UHF comms. Also using JS8CALL as you mode of communication you don’t necessarily need someone at the radio at all times to copy a message. As long as you know the home station heard you the G team can leave a message in the home stations inbox for them to read when they return.

I will be teaching this and more in my HF Operations Class May 29th. Cost is $150 for the day. I suppy everything. If you are interested email me at johny1time@protonmail.com