Originally shared at StealthGTI.com in 2020; Photos last updated or added in 2025.
I had a long weekend commute on quiet highways from 2006-2009. Surfing the HF bands was a great way to help the drive pass. I was using a Yaesu ATAS-120A at the time. Performance-wise, it can be described as “adequate, but not great.” With my Yaesu FT-857D, tuning the ATAS was as simple as pressing a “TUNE” button… or what could be called an “EASY” button. 😉 I made some distant contacts with that antenna, even toward the bottom of the solar cycle. I took a break from HF when I was stationed closer to home; my interest in ham radio tended to come and go. Eventually, I decided that I wanted a better antenna. Some say the Scorpion SA-680 is the best mobile HF antenna money can buy. I decided to find out.
The Scorpion SA-680 comes standard in stainless steel. I paid extra for the “Black Widow,” which is powder coated in gloss black. Eventually, I ordered a clear coil cover so that I can display the inner workings of the coil while still having a black antenna. Each antenna is made to order. I got my antenna in about six weeks. It was packaged in a manner that would allow it to endure almost anything… VERY impressive. I ordered a capacity hat, too, which came in its own PVC pipe packaging. My setup is for part-time use; everything is easily removed when not in use. I had originally planned to mount my Scorpion on a roof rack. Setting up the rack isn’t necessarily fast, but it is easy enough to call “temporary.” Mounted on the roof rack, the SA-680 is obnoxiously tall, but still within the highway-legal limit of less than 13’6″ with the cap hat mounted (the whip would exceed max height allowances). However, I was unable to tune all of the bands.
In particular, 20m wasn’t even close to tuning. The match was terrible. That was most likely due to a lack of sufficient bonding between the rack and the body of the car. I tried straps to threaded points in the door jambs (see photos below), but they weren’t enough. I was unwilling to remove paint or make the mechanical modifications needed to improve my bonding. I’m a Volkswagen enthusiast first, followed by ham radio. Therefore, I abandoned roof rack mounting and moved to the hitch. I was also hitting too many tree limbs with the Scorpion on the roof rack!
The hitch is probably the least efficient place to mount an HF antenna; but it seems to be my best option. If you have a hitch, then you know that installing a ball mount is easy. My ball mounts are hollow and have internally threaded anti-rattle devices. Rather than a pin, I secure my mounts with a 1/2-inch bolt, capped with lock washers and a nut. It’s VERY sturdy and nearly impossible to wiggle loose without me noticing. I don’t think I can drive long enough between stops for the bolt to work its way out of the antenna mount. 🙂
This photo shows how I choked the feed line and control cables separately. The cables pass through the floor above the exhaust heat shield. I thought that bonding the antenna would be a challenge. Bonding straps are best kept short. However, there is no short path from the ball mount to the body of my car. I decided to use the hitch itself as a bonding point. It’s fastened to the body at nine points, seven of which are at the factory impact bar locations. Electrically, the hitch is certainly grounded… but would it make a good RF ground? The answer turned out to be YES. I concluded this by connecting a bonding strap to the hitch and then comparing noise floor levels with and without additional (and longer) bonding straps to body points farther under the car. The additional straps made no difference. I also bonded the doors, hood, and exhaust system. See photos below. Even better, see this article about my specific bonding journey.
Field Day was soon after my install. I operated for just an hour from a small peninsula in southeast Virginia and managed to make seven HF contacts. Six were on 20m, with the farthest being ~1000 miles away in Texas. I made a contact to North Carolina on 80m, which is a new band for me. So far, my most distant contact was to Slovenia, over 4500 miles (7200 km) away. I’m tempted to install a 500-watt amplifier since the Scorpion can accept full legal power (1500 watts). Perhaps that will give me just a tad more “punch” to be heard in the distance. But pulling an additional 80 amps through my car’s electrical system would possibly introduce a new set of challenges. These are all things I must consider before stuffing more electronics into this small car. [edit:] Ironically, “more electronics“ is exactly what I’ve done! [/edit]
I mentioned the capacity hat earlier. They’re also known as “caphats.” Caphats are physically shorter, but electrically longer than the standard 67″ whip. Caphats also increase radiation resistance and enable the antenna to operate with less coil exposed. Being electrically longer than the whip, mounting Scorpion’s caphat takes away 10-12m, but I can work those bands with my ATAS-120A. I eventually tried a larger, 35-inch, 8-spoke caphat by W8UZZ. I cannot claim to notice a significant improvement over the Scorpion caphat, but there’s something to be said for needing less coil to tune a band. The only drawbacks that I had noticed was the loss of 15m and additional wind loading at highway speeds. I tried for a long time to keep my speeds at 70 mph or slower. But I can’t stick to it! HAHA! I eventually returned to the Scorpion caphat since it’s easier to carry inside the car during hotel stays or when I enter parking structures.
All said, I think the Scorpion is a great antenna! Sure, I’m probably not maximizing its effectiveness the way I have it mounted, but I’m very pleased to have an HF antenna that’s easy to install and remove while giving me the option to add more power. It yields good performance on the HF bands while allowing me to remove and store it in just five minutes. See more info and an install demonstration in this video.
Presto Chango,
Scott
