Motorola Radius SP50 2-way radio battery eliminator

[dlgerard]

I recently bought a older race car setup with four good Motorola Radius SP50 2-way radios at a very good price. [radios, chargers, good batteries, antenna, PTT, head sets, etc.]

I would like to wire the SP50 radio that goes into the race car, so that it operates off of the race car's master 12V on/off switch, rather than having to turn the radio on and off separately.

Can anyone provide any information on a Motorola Radius SP50 2-way radio battery eliminator? I see a lot of battery eliminators on the market, but none specifically reference the SP50. Is there one that will replace the SP50 battery or ....?

Thanks...

DG

[FatBoy]

I could not find one specificslly for the SP50, but you have a couple of options:

One option would be some sort of drop in vehicle charger (have a battery in the radio for emergency power)
OR
acquire a 12v to 7.5-8v dc-to-dc converter and wire it directly to the radio.

Something to note, the charging cups use 12v from the wall transformer. Good luck, TT.

[HLA]

that radio is one of the lowest tier radios motorola offers but your best bet will be to just use a battery. Another thing is I don't think that radio will do narrow band so it's probablly why somebody got rid of it?

[WB6DGN]

Can anyone provide any information on a Motorola Radius SP50 2-way radio battery eliminator?

I don't know about aftermarket suppliers but Motorola didn't make one. Even the programming setup is a modified drop-in charger with extra contact(s) for the data line. If you can't find an aftermarket supplier, you're on your own; you'll have to improvise. A word of warning from my own experience trying that. I tried to make my own mobile charger for a Jedi radio I had out of a spare drop-in charger base and a cigarette lighter cable I made to interface with it. The first time I tried to use it, the circuitry in the charger cup was trashed by spikes from the car's charging circuit. I neglected (actually forgot) to put some transient protection on the cable between the cigarette lighter plug and the charging cup and the first spikes encountered destroyed the charger (fortunately not the radio, though). So...if you pull a "Tom" and don't do it right, you risk losing the radio. Just a word to the wise.
As for narrow band, as I recall, there was a narrow band version of the SP-50. Seems to me the last two digits in the model number were "00" (numbers) for the narrow band radio. Probably more information on that in the Model Specific section or, maybe, on the Repeater-Builder TIP pages. Pretty sure the wideband radios were NOT field convertable, though.
Tom

[RadioSouth]

Agree, I have had many SP50's and acc's. and never saw an eliminator OEM. Doesn't seem to be the type of radio to lend itself to an adapter, it has an internal battery. The eliminators made either slide on the bottom or clip on the back in place of the battery. Looking at a GP300 eliminator which also operates at 7.5v seems to have all it's electronics in the oversized lighter plug might lend itself to do the job with making as access hole thru the battery lid and attaching the leads to battery contacts. Also mentioned was the intention to connect to vehicle master 12v switch, don't know if race cars have a accessory line cause you don't want a radio being powered on during the running of a starter which has enough spikes to fry many electronics.

[com501]

Two issues:

The radio will be illegal to operate in the USA on commercial/public safety frequencies in 90 days.

Second, you might want to check with the inspection folks for your race car, as wiring to the electrical might have some requirements a portable unit doesn't need to worry about.

[RadioSouth]

Maybe, these were available in 25 or 12.5 spacing. 7th and 8th digits 20= 25 khz spacing 00= 12.5

But yeah, the end is close for the 25 Khz radios.

[com501]

12.5kc SP50s are about as rare as a 16 channel Mostar.