GordonFreeman

iTrader: (2)

Alot of us were getting Radio hits Sunday. As I recall some people were noticing it at a specific spot on the track. Was it near the lap counting system? If so, is it possible that it is causing some interferrence?

I know at the flying field in Verona somebody (maybe AMA related) did some sort of testing for "stray signals" or something and found that there were certain channels that were being interferred with. Does anybody know if we could get the same type of testing done at the MARCCA building?

Ron Anderson

The Verona flying field is near an area called by radio guys as "intermit alley", and is a known RF hotbed. Due to the proximity of a number of very large RF emitters and other lower powered, but significant emitters hanging from their towers and the surrounding area, signals are being summed and differentiated all over the place. I had an old "Craig" car radio in the early 80's and when I got near Ch15's tower it would receive all sorts of stuff. Taxi, ambulance, the works.

I have seen the chart at the Verona site. I believe that although well intentioned, it is not "proof" that there are problems, or is a scientific study. The data appears to have been collected by checking with the affected pilots sometime after the incident and plotting the location and frequency. Because of the nature of the data, and the fact that I have seen many folks have visual tracking problems in the areas affected, I do not believe the chart to be an accurate representation of the condition at Verona.

At the Dome, also in "intermit alley", there are 15 or so guys and gals on 15 different frequencies, sometimes all flying at once in a small area. The incidence of "shootdowns" is fairly low and is mainly caused by using a single conversion receiver in that environment, or somebody leaving their transmitter on. 99% of the crashes are pilot induced or mid-air.

On to your interference problem. As I understand it, you race in a metal building, so unless there has been some additional RF sources installed inside the building, you can pretty much discount outside interference. Timing system? Has it caused problems before? Has any one added anything new? Is every one following the procedure of shutting off their transmitter after they are done? Is there one user who was affected more than others? Badly (rf) shunted brush motor? Has anyone tried charting the trends?

GordonFreeman

iTrader: (2)

The drivers stand and computer arrangement is different than last year, I think. I computer is closer to the track, the track is close to the stand.

I know quite a few people were getting hits right by the front of the drivers stand. Could be all the transmitters, could be something else.

I think with my own situation I have a weak (borderline) Rx or Tx in the car. I would literally have no control of my car, for seconds, minutes. Until this one guy turns off his transmitter, (We both have the XSR synthesized) then my car is fine. How do we tell who's equpment is bad here?

Is there a device that can just sit there and record frequency power and (width, messy signal?) And is there a way to see who, if anybody, has messy radios?

Matt M.

iTrader: (26)

i think that a sabatour has a few radios on and is under your drivers stand......that must be it...

Ron Anderson

This seems significant. Are you on adjacent channels? Same channel ( by accident of course)? Since it appears you can change frequencies, how about setting them further apart? A bad RX on your car can be a culprit, or his TX. Hard to tell without putting his TX on a spectrum scope. Is your RX a single conversion? If so, try a double conversion.

Having a number of radios in close proximity is always a bad thing, but often can't be helped in a close setting like racing.

Computer equipment if not properly shielded can radiate RF over a wide range of frequencies. Computers should be grounded and all cables to and from should be shielded. Most home/office computers are poorly shielded and are a class "B" computing device, which means that if they cause interference, they are the ones that must be shut down in a conflict.

Measuring the spectrum quality of transmitters is a bit beyond 99.99% of all hobby stores. The device you are looking for is a spectrum scope. It will tell frequency and show the modulated envelope. Expensive.

FIRE RIDER

iTrader: (1)

1. the track last year was right next to teh stand(touching it)

2.could be stray signals

3. if its an am radio its the metal in the building that is causing it.(thats why i got a new radio)

4. bad electronics/ or low batterys.