Lemons Radio Tech (Page 3 of 5)

With our midlands we just secured the charging cradle with the 12v power adapter in the car. Dropped the radio in and secured that down.  So when the car has power the radio is charging and when the car power is off the radio runs off of the battery.

I've used a set of secondhand Motorola Radius SP50's at various racetracks for over a decade.  They're set up for 2 different selectable 45x mhz frequencies.

Radiuses of various models and ages are super popular for circle-track racing, and you can often find complete used sets on eBay with several handsets, multiple chargers, PTT gear, a couple spotters headsets, etc., for a pretty reasonable price.  The factory claims a 12 hour battery life with a 90% standby duty cycle, but I don't think I ever saw better than half of that out of the ones I used.  At Lemons events it would mean 1 or 2 radio swaps per day or wiring up a charging station in the car. 

I usually rigged up the PTT button on the shaft of the shift lever, so to avoid wires getting wrapped and pinched around the steering wheel.  I used to use a "stubby" roof-mounted antenna, which seemed to work pretty well.  At larger tracks there are still dead spots, though, where pit & car can't communicate. 

Getting a helmet-mounted mic for 2-way comm seems to be a pretty big hurdle for most Lemons drivers, though, so the last several teams I've been running with are radio-less.

Newer to Lemons and only raced at NJMP, but in May we just used cell phones with $10 headphones/mic.  It worked great, with minimal issues.  We typically made a conference call in case we lost a phone.  On occasion the driver inadvertently hung up while getting in the car, so our backup plan was to wave a team shirt when they went through pit road.  Last year we used hand held radios that were secured in the car.  Communication was choppy and very frustrating.     For us, the $10 spent on cell headsets worked out fine especially compared to spending hundreds on radio systems.

Yes, a battery eliminator replaces the battery and runs directly off the car. You lose car power and you will also lose radio power.

For at least the third time, the wires ripped out of my push-to-talk button.
I am using the ones from Sampson (SRC), which are supposed to be
pretty good, but they are absolutely non-repairable.   Does anyone have
any suggestions for really rugged PTT switches?   The problem is
that someone always seems to get hung up on the cord and yanks it
out of the button assembly.

If not totally rugged, I would settle for ones that can be taken apart and
repaired.

I have repaired a lot of PTTs.

I made a wireless one for our car.

I can't speak to this directly because I don't have those particular radios, but it looks like they're just rebadged Baofeng UV-5R's.

This website has some good information about programming Baofeng's:  http://www.miklor.com/uv5r/

I have a couple of the Baofeng UV-82's, which I imagine are fairly similar from a programming standpoint.  The instructions on that website were able to guide me through programming mine.

I would suggest doing memory reset before beginning, just to clear out any of the channels that come pre-programmed from the factory.

I use GMRS frequencies.  You can get an FCC license for GMRS easily.  Programming frequencies outside FRS/GMRS is risky unless you have a commercial license or Ham radio license.

With the proper license you can transmit over GMRS frequencies with up to 50W (large fixed stations).  Typical handhelds like this are limited to 5W, which is above the output of the UV-5R (4W), so it's fine to use on GMRS.  You're still supposed to be licensed...the FCC put forward a proposal in 2010 to remove the licensing requirement on all GMRS frequencies, but there wasn't enough push behind it to make it a priority in government, so it stalled.  The FCC seems completely uninterested in going after people using GRMS without a license, but YMMV.

Per the regulations, channels 1-7 are shared between FRS and GMRS and require a license if transmitting at over 1/2W, 1/2W and under they're license free.  Channels 8-14 are FRS only, license free, 1/2W max.  Channels 15-22 are GMRS only, and technically require a license, but in practice that regulation does not seem to be enforced.

Interesting. Everything I had seen was that the UV-5Rs weren't allowed on GRMS at all,  but maybe they meant without a license. Thanks for the correction. We just bought a couple of the UV-5R radios and I've been trying to figure out which license I need to be getting just to be safe. Guess it's that one.

This chart of FRS/GMRS frequencies and power limitations may be helpful:

http://wiki.radioreference.com/index.ph … nnel_chart