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Old 04-10-2007, 02:23 PM   #1
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Default Lost Laps

Just wondering if anyone else may have this problem and if they have a fix for it.

I'm running a TC car (6 cell) with a futaba servo, spectrum micro rxr, LRP Q2 speed control (speedmind cap and diode), and two fans and a personal transponder. Since I have gone to this setup I have had lost lap issues.

I have tried component substitution as well as even different personal transponders, as well as putting it in different locations. I've tried different socket locations on the rxr and have changed tap in locations for the fans and have even run without them and still have the same problem. Now this also is a very intermittant problem, some times just one occurance in a heat but has been up to several in a single heat.

I've heard some people say it could be the micro rxr and others say the speedo. I'm thinking the rxr is a passive unit as far as the voltage goes, so are there any issues with the BEC of a LRP Q2 that may effect a personal transponder? And short from sending it back is there a fix?

Anyone?
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Old 04-10-2007, 02:29 PM   #2
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I had the exact same issue. There is an issue with the QC2 and any Spektrum Rx. You need the power cap Spektrum makes that plugs into the reciever. It saves a small amount of voltage so that the personal transponder doesn't lose voltage. Believe me, it works!
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Old 04-10-2007, 02:36 PM   #3
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If there was a track change and the loop is right after a corner where it calls for hard accelleration, it could be bringing the voltage down to just below the point the xponder needs to run at. The BEC voltage of the QC series is lower than most at around 4.8 to 5 volts. It wouldn't take much to pull that down on a hard accelleration. Running the spektrum cap as mentioned could help.

The loop line itself could be causing problems, too. This was a problem at our track where some people were missing once in a while. Then durning the regionals, the loop completely went flat. After a ton of troubleshooting we replaced just the loop antenna that goes over the track and everything was cool from that point on.
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Old 04-10-2007, 03:12 PM   #4
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Q2 BEC isn't strong enough. I have the same problems with my Q2 2 years ago and it's a well know 'problem'. You only have to search a little bit and you will find a lot more drivers with the same problem.
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Old 04-10-2007, 03:45 PM   #5
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Its a very common problem when using a Pt and the QC2, i've hardwired my PT to the battery tabs on the speedo and not had a problem since.
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Old 04-10-2007, 03:59 PM   #6
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Do you know if that power cap is similar to the one Novak used to sell with the older speed controls that where used for 4 cell?
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Old 04-10-2007, 04:03 PM   #7
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I was thinking of the hardwiring of the PT as well, but was a little leary of the overvoltage of a 6 cell pack, not knowing how much voltage a pt can handle. When you did this how many cells where you running?
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Old 04-10-2007, 04:23 PM   #8
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I actually made my own when I ran that setup...and yes I used a Novak power cap.
Quote:
Originally Posted by Johnny Wishbone
Do you know if that power cap is similar to the one Novak used to sell with the older speed controls that where used for 4 cell?
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Old 04-10-2007, 04:34 PM   #9
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A capacitor may not always cure the problems. If you're hard wiring a PT you should read the AMB manual and follow the instructions.

We manufacture an improved personal transponder the 'i-PT' which cures all power related problems such as those with the LRP weak BEC etc. We also make our 'Bug Booster' which can be fitted to a PT and has the same booster circuitry as the i-PT.

i-PT info is here: http://www.rctech.net/forum/showthre...ght=Booster%3A
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