Generally, a club rechargeable has multiple advantages in my mind, one being there is hope they help stop people walking away with them if they are no use to anyone but a club, also people here have nitro cars with sealed receiver boxes and/or receivers in balloons etc, making use of a plug in harder.

But more than anything, just ease of use for a club, and hopefully to retain something people won't want to keep, because I see all sort of issues with leading out personals, and basically never getting them back again, with them being real easy to sell.

That makes perfect sense. I've left the track with one of them still in my car, many years ago when we still used them.

I envision using an existing personal transponder, adding a single NiCad cell with a boost switching power supply, and putting it all in a single enclosure, with a charging connector exposed. (Using a single NiCad cell means that there will be no concern about cell balancing or discharging the cell all the way.)

Do you have the ability to put all of the components into a sealed box? All we need to create is the boost supply, and this is easy.

I have completed a PCB layout for the transponder. Now I just need to spend the $100 or so required to have a small quantity made!

I included a calculation for carrier frequency in the spreadsheet I made to reduce the pulse train data from the four AMB and two MRT transponders I have available. The result was a minimum of 4.9726 MHz, and a maximum of 4.9994 MHz, for a spread of about 0.54%. That's a wider range than I would expect from crystals unless they are extremely cheap, so I'll assume that resonators are used instead. I've been using Abracon AB308 crystals that have 50 PPM accuracy, which is overkill, but they're also small, cheap, and easy to mount and solder.

Thats good news.
Any chance of selling off the pcb boards only?
This would eliminate any hassle of dealing with the fcc and leaving it down to the end user who would be constructing a "hobby electronic project" at that point correct?
I have built hundreds of diy guitar pedals this way (pre fab pcb or scratch from vero board).
Heck...a pcb with schematic and parts list...Count me in.

You can count me in too if you decide to do something along those lines

Your location leads me to believe it's a certain Esc/motor mfg

+1 I would totally assemble my own from a kit. It'd be fun!

There's a fine line when it comes to meeting FCC regulations. Components for digital devices (like a computer motherboard) can get by without testing because emissions of the the final result (a computer in a box) are largely a function of the enclosure, wiring, other active components, RF suppression components (like ferrites), and care in assembly. Offering a kit steps over the line because it leaves no choices to the final user; one can reasonably expect that the device will be constructed using all of the provided components (which is the whole point of a kit!), so the kit must meet the regulations.

Even selling just PC boards is a can of worms, because the PC board is mostly responsible for the emissions of the finished device.

We would probably be on the safe side of the line if only the microprocessor were sold, leaving the rest of the construction of the device up to the end user. The FCC permits individuals to construct up to five devices of any given type for their own personal use, as long as they use "good construction practices" (a rather vague requirement, and which I am only paraphrasing).

The best possible scenario is for us to find a fellow racer who has access to the equipment necessary to determine compliance. I'd guess that there is at least one racer out there that works for a company that has the equipment, and might be able to do the testing gratis, or at least at a substantially reduced cost. If anyone knows of such an individual, please say so!

Me too! Fun stuff. Analog equipment (like many guitar pedals) have no FCC restrictions because they don't contain high-speed digital circuitry.

On an unrelated note, it's good to know of other musically-inclined people who are also involved with RC. I've designed many electronic devices for music. An internet search will reveal some of them. If you're interested, you can see more here:
http://s1191.photobucket.com/albums/z467/howardcano/
http://s1191.photobucket.com/albums/...ctronic_Drums/
http://s1191.photobucket.com/albums/...g_Synthesizer/

The company I referred to is not in the U.S.

I've never been to Castle Creations, although I live about five minutes from their old location, and about ten minutes from their new location. I also have had no contact with them regarding any type of lap counting equipment. I'm not sure that lap counting equipment would fit in with their current focus, which is probably not the racing market. Racers make up a small minority of the RC market in general.

But if I pursue both the transponder and decoder designs, I'll certainly consider them as a possible manufacturer.

What are your plans for transponder conflicts?

For my own personal use, I'll simply make a bunch with the same number as one of my AMB transponders.

The final goal would be to create programs for any arbitrary ID number. I don't know the data format, so I can't presently create any particular number, but this may not be necessary, and it's probably unimportant as long as I can create different numbers for each transponder. Assuming AMB were to issue all possible seven-digit numbers, then there would be a 1-in-9999999 chance of conflict. That's close enough to zero for me.

I've included a jumper on the PCB to use for selecting different ID numbers. This is not currently supported in the code, but it is quite simple to do so. At the moment, I have no need of this feature.

I am a huge Rush fan... You can imagine I am drooling over those midi converted pedals.
I would link up some of my finished pedals...but it would be like showing Michelangelo my crayon drawing...
Sorry...OT
I am impressed.

RCTech user "Payalneg" has asked about the integrated circuits I am using for the present design, and some of you might be interested in this information.

The microprocessor is from Microchip's PIC12F family. They are neat devices, and very compact (only eight pins!), but there is nothing "magic" about them; other microprocessors would also serve the purpose. I just happen to have some (and a programmer for them) laying around from other projects.

The other IC is a CMOS logic gate used for the 5 MHz oscillator and as a driver for the tank circuit, since the PIC12F output current capability is too low.

Please don't think that way! We all have our own strengths and weaknesses, but good ideas can come from anywhere. Musicians tend to be a very laid-back and appreciative group, and I'm sure many would love to see your creations posted on one of the appropriate boards. Here's an example of one for bass pedals:

http://www.talkbass.com/forum/f36/ba...c-club-781414/

There are probably several for effects pedals also.

By the way, I too am a fan of progressive rock!