We've run across this with two different AMB personal transponders.

They will miss 3-4 laps in a 50 lap event ?????

Mounted on a fibreglass pan chassis with a square hole cut it chassis so the transponder has a clear view of the track.

Wire under carpet so the distance is less than 1/2 inch above loop.

4 cell car and have tryed in two different reciever ports.

After buying second one seemed to fix problem for a few weeks, now back again ,,,,,hate to buy a 3rd.

Havn't sent back to AMB yet.

Thanks for any input :thumbsup:

take it off the chassis and try that

Now that just bad luck or a bad reciever! I would change the reciever then the speed control first before buying another PT. It might also be the servo, I've seen servos do crazy thing you would never think a servo would cause. I would try them in another car. The BEC maybe going bad on the SC.

Also if the track is using J-Lap it shows PT strength, maybe get the race director to take a look.

I don't recall the signal strength # but they seem plenty strong and then there's no hit ?

How bout wireing that sucker dirrectly to the pos and neg battery leads ??

You'd bypass the bec and reciever .

I've been seeing some of the carpet guys mounting theirs on top of the servo?

Yea that would work. You could get a adapter lead and try that. Doesn't eliminate the servo, but should show if the reciever and SC is good or bad.

I don't think there is a bad place to mount these thing, they have that strong of a signal.

I was told to mount the transponder so that the bottom center
of the transponder is not blocked by any graphite or metal chassis.

This can effect singal strength in faster cars.

I had my pt mounted i my radio box of my 1/8 offroad buggy and it worked well, even in a 30 minute main event.

Our Oval track www.carolinarc.com (http://www.carolinarc.com/) was completely rebuilt in 06 and we laid some high quality wire down as a loop before the black stuff was poured. It works very well with the pts running at the track no matter the chassis material.

Jim Duffle
Carolina RC Complex

Does anyone run a 5 cell reciever pack ?

I hate to carry the weight

ran mine in my savage on top of all the radio gear, that is about 6 or 7 inches above the wire that was in the dirt, at least an inch or so there.

On carpet you have static buildup that tends to mess with the electronics in these cars,it really has nothing to do with signal strength.If there was a problem with signal strength everybody would be having problems.I know humpty was suggesting to place a ground strap from the crossbrace to the floor to help eliminate this problem.

Is the loop close to a corner.
it maybe the servo as you go into or out of the corner
with your car turned on and off the ground hit thorttle and steering
at the same time, do this steering in both directions
watch the light on the PT
if it dims the servo is pulling to much power away from the PT
most of the time if its carpet static the car will jump sideways
or glitch.
good luck !!

A month ago I had a problem with my PT missing laps after having worked fine the week before. I looked at everything closely and noticed the plug that goes in the receiver looked a little "strange" (don't know how else to describe it). I replaced the connectors and plug with new ones (required a crimp tool for the connectors) and it has worked fine ever since.

So the general sensus here is leaning away from problems with the PT unit itself ?? :confused:

What I think I'm going to try for next week is to run the neg wire from PT to the neg battery wire on SC and splice the pos. from PT into the SC switch wire so I'm actually bypassing the reciever and SC .

If that fixes it then I'll probably just leave it that way :wave:

A guy at our track blew up his GT7 one week so I let him use an old Tempest I had as a spare. His PT missed laps throughout the day when his Brother had used the same PT the week before without any problems. He swithed to another ESC the next week and the problems were gone again. :confused:

Sounds like some of these BEC circuits just aren't up to par to run a good servo and power the reciever and PT at the same time. :confused:

If you were running a pan car where you solder your batterys in every run I'd suggest to bypass the reciever and solder your PT right to the pos and neg wires.

I won't know untill next week if this fixes the problem but at least it'll have plenty of amps.

The problem is most likely with the BEC circuit in the RX or the ESC. The problem with the PT's and 4-cell is that under load, the RX output voltage to the Pt can drop below it's operational threshold. This is especially true with 4-cell Mod and 19t but can happen if you are running a high amp draw stocker too. You can wire a rx pack and use it to power the PT, be careful wiring the PT to the battery directly, as the PT would be subject to an unregulated power source. (the esc and bec regulate the power thru the RX).

I would notice a lot more issues with PT in the electric classes and especially 4-cell than I did with offroad where the PT was powered directly from a dedicated RX pack.

You must remember that these PT's were designed in Europe where 4-cell racing for the most part doesn't exist. They are either 6-cell offroad or 6-cell TC, not much oval stuff using 4-cell. So the voltage issue wasn't an issue during design.

You really seemed to answer your own question. 2 transponders in the same car with the same trouble, i'd bet it isn't the transponders. Try the 2 you have in another car before you go thru the trouble of rewiring stuff.We've run across this with two different AMB personal transponders.

They will miss 3-4 laps in a 50 lap event ?????

Mounted on a fibreglass pan chassis with a square hole cut it chassis so the transponder has a clear view of the track.

Wire under carpet so the distance is less than 1/2 inch above loop.

4 cell car and have tryed in two different reciever ports.

After buying second one seemed to fix problem for a few weeks, now back again ,,,,,hate to buy a 3rd.

Havn't sent back to AMB yet.

Thanks for any input :thumbsup:

try a receiver pack the weight is minimal i personally have ran one ever since i started running 4cell mod4 years ago and now run one every time i race

I'm anxious to try this at the track ,,, but after looking over the wiring and double checking everything ,, I found that the transponder light would dim ever so slightly when cycling the servo.

I changed the servo out and the dimming went away,,, hmmm ,,, maybe a bad servo motor ???

Try mounting it away from everything. Like up front or off to the right. I had the same problem. It was mounted next to the reciever and would miss laps every so often. I mounted up past the servo and it went away.
Hope this helps,
Fireball

I believe the mounting had something to do with it also as it was mounted below the servo.
I moved it ahead to the front of the chassis and had no problems this week :thumbsup: