NVIS Trials in the Elaho Valley

Event Date: 
Saturday July 24, 2010
Last modified: 
Thursday, July 10, 2014 - 19:54

I (Eric) have been using VHF in the hills for many years now. It has proven to be a reliable tool but there are many places further into the hills that even Ham repeaters do not reach. To handle this region I wanted to setup a go kit with HF gear in it and be ready to communicate from anywhere in South-western BC to home. To accomplish this I needed to purchase a new portable HF radio and build an OCF dipole antenna. I already had the mast sections to raise the antenna to around 12 feet so it shouldn’t be too much work to finish off the kit.
I have an Icom IC-7000 at home and really like the radio so I purchased a second one for my kit. I then picked up an 4:1 balum and some decent flexible antenna wire for the dipole. I decided to build the antenna for 80 meters and then cut it to work on 40. I assembled the antenna and Ralph came over with his analyzer and we checked out the SWR, after tweeking the height a bit we were happy that we could use it without a tuner on both 80 & 40 meters.
Our first field trial was into the Silver-Hope valley were we had a decent amount of mountain bertween me and home but still had VHF coverage to arrange the test. Ethan and I set out on July 3rd to try it out. We set up on the Sowerby FSR with the antenna broadside to White Rock. Unfortunately we were unable to reach White Rock though we did make a contact in Oregon. This was disappointing and did not look encouraging for our main test in the Elaho.
During the following week Deme did some modeling of the antenna and determined that we would need to cut it down to 40 meters for it to work as an NVIS antenna on that band. This had been my original plan and being shorter and easier to work with I didn’t hesitate to cut it down. Once cut Ralph came by a second time to help tune it. This time we struggled to get the SWR down to a usable level and ended up raising the centre point a few feet to make a slight inverted V. This got the SWR down a bit but I was still concerned about the high levels.
Well the 17th was now upon us and Geoff and set out for the far end of the Elaho FSR. It took us around 4 hours to get there. We set up the now shorted antenna, this time the end was pointed towards Shite Rock. It took us around 20 minutes to set up the kit. Once ready I checked the SWR with the built in mini SWR scope and found the site to be really quite good – much better than my back yard. It seems the drier ground was better for this configuration. We were ready ahead of our 12:30 scheduled contact so I checked around for some other stations on the band but it was quite empty. 
At 12:30 I put out a few calls and could just discern a faint voice in the noise but it was not clear enough to understand. Our next attempt was at 1pm and when I put out a call then I heard some voices a bit stronger and Stuart sent some CW which came through quite well. By 1:10 the signals had strengthened and I was able to chat with Carolyn from home and then Ralph followed by Stuart. So it was a great adventure and worked well from around 1:15 on. After chatting for a while we packed the kit up and went on to explore the area, it having been 5 years since our last visit. I plan to do another test from north of Hope in August.