w6csn’s outdoor amateur radio

You’d be safe to guess that Mt. Davidson would have been my first SOTA activation seeing as it’s the closest SOTA summit to my home QTH. However, it actually took me a little while to get around to heading up W6/NC-423.

Today was the day! I dropped my hiking buddy off at work at 8 AM then drove up Market Street, over Portola Drive and wound my way around Mt. Davidson, finding easy parking on Dalewood Way near Lansdale Ave.

From the trailhead near the bus stop, it a short and easy hike up to the activation zone. On this route you reach the east end of the summit, opposite the large cross, which is a well known landmark.

Except for the occasional exercise enthusiast, I had the place to myself this morning. Not wanting to lug the fiberglass mast up the hill, I deployed the Gabil Radio tripod and loading coil, using a 3 meter collapsible whip antenna. This is an easy setup and not too much of a compromise on 20 meters.

While I can do a lot of back and forth the get the loading coil set just right for a good match, I find it easier just to get the coil close enough and touch it up with a tuner for a low SWR reading.

I sent a spot via Sotamāt and started calling CQ SOTA on 14.058 using the QCX-Mini. My first call was from JG0AWE from Nagano City, Japan. This was followed quickly by several more stateside calls and I was able to gather the four QSOs needed within a span of five minutes.

I continued working stations and chasing some Summit-to-Summit contacts for another half hour. It was at that point I noticed that I failed to throw the switch to the “Operate” position on the ZM-2 tuner. This whole time I had been operating in “Tune” mode with the 50 ohm absorptive bridge in circuit! It was almost like using a dummy load for an antenna!

Later, at home, I measured this tuner configuration with this radio using an actual 50 ohm load instead of an antenna and found that I was most likely operating with an effective power to the antenna of only 300 milliwatts!

Despite this extremely low power I was able, using CW, to complete the activation with no difficulty. This is a testament to the effectiveness of the CW mode, and not so much this operators skill.

After logging 10 contacts, I called it quits, packed up the station and headed back down for some breakfast. Next time I’ll try to remember to set the switch correctly after tuning up, but I make no promises. I’m guessing pretty much everybody that has a ZM-2 has at one point or other forgot to switch into “operate” mode, It was bound to happen.