Further to discussions on the site I attach below a list showing the power of 50 or so two-way radios certified by the FCC over roughly the past three years. I have it as an excel spreadsheet but this site won’t accept that as an attachment.

Basically the list gives every FRS/GMRS radio submitted by Cobra, Midland and Motorola over that period. I hope it helps people when it comes to choosing radios .

I have had to hand-crank the data from the FCC site and I am sure there are some transcription errors, although not too many, I hope.

Columns 1 and 2 show the make and model. Column 3 is the ERP (Effective radiated power) on the highest GMRS setting the unit boasts. Column 4 is the ERP on the FRS setting. ERP is the signal strength that actually gets out of the antenna, which is what matters in terms of distance at which a signal could be picked up. Receiver sensitivity and a whole lot of other things will affect whether the signal is actually received, so it does not necessarily follow that the most powerful two-way radio pair will have the longest range. As ever, though, horsepower helps (or technically, tiny fractions of horsepower…)

As I got further into making this list, I got more and more puzzled by the data. Columns 5 and 6 reflect that puzzlement. I have a pair of Cobra LI6050WXs so I spent a bit more time looking at them along with their baby brothers the LI3950DXs, which look to me to have the same casing and antenna.

As well as giving the ERP, the FCC site gives a whole lot of other info, including how to set up the radios and some stuff on power consumption etc.

Looking first at the 6050s, the setup instructions (for technicians) say that the power at the output to the antenna should be 3 watts. This ties in with the power consumption of the final stage amplifier per the FCC, which is 5.18 watts. However the ERP (the power out of the antenna, in effect) is just0.372 watts.

The 3950s setup instructions say that power at the output to the antenna should be 2 watts. The 3950s seem to run a more efficient final stage: pwer consumption is 2.36 watts. But ERP on these is .492 watts.

So with the same antenna we have

6950s: 3 watts in, 0.372 watts out

3950s: 2 watts in, 0.492 watts out.

I’d expect the same aerial to give the same attenuation so what is going on? Also this is a crazy level of loss. Where is all that power going?

I also don’t understand it from the manufacturers’ point of view. There is no commercial advantage in building a more powerful (more expensive) final stage and ending up with a less powerful transmitter. Is there anyone out there in the industry that can give us a clue as to what is going on?

These are my personal ponderings. I hope the attached doc helps everyone in their 2-way radio choice.

Kakistoc

Make: motorola Model: t7100/t7200 GMRS Power: 1.559 FRS Power: 0.402

Make: motorola Model: CP200 GMRS Power: 4.6 FRS Power: 1

Make: Cobra Model: PR3850TX GMRS Power: 1.37 FRS Power: 0.134

Make: Cobra Model: LI6050WX GMRS Power: 0.372 FRS Power: 0.06 final amp stage 5.18 output to antenna 3.0W max

Make: Cobra Model: LI3950DX GMRS Power: 0.492 FRS Power: 0.12 final amp stage 2.36 output to antenna 2.0W max

Make: Cobra Model: PR165VP GMRS Power: 0.245 FRS Power: 0.218

Make: Cobra Model: PR250WX GMRS Power: 0.462 FRS Power: 0.398

Make: Cobra Model: PR990VP GMRS Power: 0.286 FRS Power: 0.233

Make: Cobra Model: PR4700WX GMRS Power: 1.16 FRS Power: 0.5

Make: Cobra Model: PR5050WX GMRS Power: 1.4 FRS Power: 0.5

Make: Cobra Model: PR150VP GMRS Power: 0.72 FRS Power: 0.5

Make: Cobra Model: PR3500DX GMRS Power: 1.2 FRS Power: 0.5

Make: Cobra Model: PR650WX GMRS Power: 1 FRS Power: 0.5

Make: Cobra Model: PR245 GMRS Power: 0.95 FRS Power: 0.5

Make: Cobra Model: LI4900WX GMRS Power: 0.5 FRS Power: 0.31

Make: Cobra Model: LI6550WX GMRS Power: 1 FRS Power: 0.5

Make: Cobra Model: MRHH425LI GMRS Power: 1.9 FRS Power: final amp stage 13.54 output to antenna

Make: Cobra Model: LI7000WX GMRS Power: 1.25 FRS Power: 0.5 final amp stage 6.29 output to antenna 5W max

Make: Midland Model: FG2 GMRS Power: 0.492 FRS Power: 0.41

Make: Midland Model: G220 GMRS Power: 1.3 FRS Power: 0.41

Make: Midland Model: FG1 GMRS Power: 0.54 FRS Power: 0.45

Make: Midland Model: G300 GMRS Power: quoted in DbM FRS Power:

Make: Midland Model: G9 GMRS Power: 1.4 FRS Power:

Make: Midland Model: M222P GMRS Power: 1.3 FRS Power: 0.5 final amp stage 2.7 output to antenna 2W max

Make: Midland Model: G225/G227 GMRS Power: 1.75 FRS Power: 0.41 final amp stage 3.6 output to antenna 1.8W max

Make: Midland Model: LXT314/317 GMRS Power: 0.665 FRS Power: 0.271 final amp stage 2.94

Make: Midland Model: GXT710/735/750 GMRS Power: 1.6369 FRS Power: 0.2447 final amp stage 3.78 output to antenna 3.2W max

Make: Midland Model: LX210/310/330/410/435 GMRS Power: 0.676 FRS Power: 0.307 final amp stage 2.46

Make: Midland Model: GXT700/771 GMRS Power: 1.6369 FRS Power: 0.2447 final amp stage 3.78

Make: Midland Model: GXT555 GMRS Power: 1.549 FRS Power: 0.198 final amp stage 9.66 output to antenna 4.5W max

Make: Midland Model: GXT800 GMRS Power: 1.6379 FRS Power: 0.2035 final amp stage 3.78

Make: Midland Model: XT511 GMRS Power: 1.0815 FRS Power: 0.2622 final amp stage 9.9 output to antenna 4W max

Make: Midland Model: GXT808/850/800 GMRS Power: 1.289 FRS Power: 0.215 this one is very informative

Make: RCA Model: 32350RC3 GMRS Power: 1.59 FRS Power: 0.37

Make: Giant Model: T9140 GMRS Power: 0.06 FRS Power: 0.05

Make: motorola Model: T9500 GMRS Power: 1.03 FRS Power: 0.11

Make: motorola Model: FV600 GMRS Power: FRS Power:

Make: motorola Model: FV225 GMRS Power: FRS Power: 0.14

Make: giant Model: T8260D GMRS Power: FRS Power:

Make: motorola Model: Model 525 GMRS Power: FRS Power: 0.15

Make: motorola Model: T6100 GMRS Power: 0.26 FRS Power: 0.23

Make: motorola Model: FV200 GMRS Power: 0.14 FRS Power: 0.13

Make: motorola Model: SX700 GMRS Power: 0.63 FRS Power: 0.17 per tune up info not test report

Make: motorola Model: FV500 GMRS Power: 0.28 FRS Power: 0.1

Make: motorola Model: T5000/5500 GMRS Power: 0.275 FRS Power: 0.265

Make: motorola Model: SX500 GMRS Power: 0.28 FRS Power: 0.2

Make: motorola Model: FV700/FV750 GMRS Power: 0.75 FRS Power: 0.17

Make: motorola Model: T6525 GMRS Power: FRS Power: 0.21

Make: motorola Model: SX700 GMRS Power: 0.63 FRS Power: 0.17

Make: motorola Model: L1010/R1010 GMRS Power: FRS Power: 0.25

Make: motorola Model: T6300 GMRS Power: FRS Power:

Make: motorola Model: T8500/8510/8530/8550 GMRS Power: 0.68 FRS Power: 0.26

Make: RCA Model: 32310RC3 GMRS Power: 0.63 FRS Power: 0.12

Make: motorola Model: T9580 GMRS Power: 0.75 FRS Power: 0.29

Make: Model: T3800/3400 GMRS Power: 0.09 FRS Power: 0.08

Make: Model: LA8270 GMRS Power: FRS Power: 0.1

Make: Model: L8230 GMRS Power: FRS Power: 0.14

Make: motorola Model: T8525 GMRS Power: FRS Power: 0.32

Make: Model: L3400 GMRS Power: FRS Power: 0.03

Make: Model: T2010 GMRS Power: 0.2 FRS Power: 0.21 yes, this way round