Personal Transponder Mounting

If you are serious about doing some racing, sooner or later you’ll want to invest in a personal transponder. Having a personal transponder avoids the need to run the handout transponder back and forth, before and after each race. In addition, if you know your receiver pack is fully charged, you'll know your transponder should be working. When the handout transponders are on and off the charging base frequently, you often don’t feel comfortable about how well they’re charged for each race.

When I first started using a personal transponder, I had some signal related issues. Some of this was attributed to the fact we were also working out some of the bugs in the new scoring system at the local track where I was testing my transponder. However, it was obvious that the transponder’s reliability was questionable inside of the stock receiver box due to the weaker signal strength. After all, you don’t want to worry about whether the lap was actually registered or not as you pass the start/finish line. Mounting the transponder on top of the box was somewhat better, but still didn’t provide a strong enough signal for me to be comfortable with. So I started contemplating another idea for mounting the unit.

The trick to properly mounting the transponder, and getting a good strong signal, is to understand how it works. The transponder emits a cone shaped signal from its bottom. The peak of the signal’s cone, allow the scoring loop to see exactly when your transponder crosses the line. Anything in the cone’s path has the capability of disrupting the shape or strength of this cone, which may cause scoring issues. This is also the reason the AMB states that the transponder should be installed as close to horizonal, and unobstructed, as possible. In my case, I had particular issues with the stock composite receiver box blocking the signal and causing about a third of my laps to be missed.

The best course of action to help work through this and get a good signal is to have your local track check your transponder’s signal strength as you go across the scoring loop. Keep in mind that this signal strength will vary from track to track, depending upon the depth of the loop and whether or not conduit is used when it’s in the ground. I would recommend you check the transponder’s strength with track officials at any track you are unfamiliar with.

In the end, I opted to utilize the empty spot left by my change to a single steering servo setup. I took some scrap lexan, and placed a couple of holes in it, which allowed me to use some small zip ties to secure the transponder to the lexan. Then I used a couple more zip ties to fasten the lexan to the Revo’s chassis. This allows a nice, open, and unrestricted signal from the transponder to the ground. At the same time, the lexan also helps to protect the transponder from debris.