ERP versus range

[marcossaad]

Hi guys,

Shouldn´t manufactures be obey to advertise ERP instead of this range b.s. ?
At least in the manuals...

Thank you,

 

[DaveNF2G]

Neither specification is meaningful except as advertising hype. ERP and range are totally dependent on the way the radio is installed.

 

[marcossaad]

Agree but a least it is something you can compare.

 

[WB4CS]

Hi guys,

Shouldn´t manufactures be obey to advertise ERP instead of this range b.s. ?
At least in the manuals...

Thank you,

Your message isn't specific to what service (GMRS/FRS) you're talking about. If it's an FRS radio, no matter the advertised "range" on the FRS (non shared) channels power output is limited to 500mW.

Now if you're talking GMRS that depends on the type of radio you're using. If it's a hybrid FRS/GMRS handheld, on the GMRS channels the radio will probably be between the range of 2-5 watts but with a mobile radio that could be as high as 50 watts.

On the handheld hybrid radios, there's really no need to advertise the power output since that A) it's legally set at a certain power level, and B) the general public buying the bubble pack radios would not know what a watt is or how it contributes to radio propagation. Hell, most of the general public doesn't even get the GMRS license before using those channels. So, they manufactures use a very poor "range" level that is only obtainable in nonexistent environments or requires a repeater (which most/all hybrid handhelds aren't able to use.)

I realize that didn't really answer your question, I think I was more on a rant than anything else
This appears to be your first post, so welcome to RR!

 

[marcossaad]

Thank you.
It´s my first post.

 

[prcguy]

Aah, but when you have two different 500mw radios, one with a 1" long loaded antenna that has maybe -4dBi gain and another radio has a 6" long full 1/4 whip with maybe -0dBi gain, the latter radio will have 4dB more ERP with the same 500mw. ERP would be a useful spec for radios with permanently attached antennas.
prcguy

Your message isn't specific to what service (GMRS/FRS) you're talking about. If it's an FRS radio, no matter the advertised "range" on the FRS (non shared) channels power output is limited to 500mW.

 

[WB4CS]

Aah, but when you have two different 500mw radios, one with a 1" long loaded antenna that has maybe -4dBi gain and another radio has a 6" long full 1/4 whip with maybe -0dBi gain, the latter radio will have 4dB more ERP with the same 500mw. ERP would be a useful spec for radios with permanently attached antennas.
prcguy

Ahh, good point, I missed that. Thanks for pointing that out.
I went over the FRS rules again and it does specify a limit of 500mw ERP and not PEP(according to the trusty Wikipedia.)

 

[kennyloatman]

I really believe the OP is talking about the bubble packs that advertise 25 to 35 mile range when everyone knows that under normal operating conditions your lucky to get a couple miles.

 

[marcossaad]

Indeed.
Of course the antenna does matter but it is still comparable and is gain could be aslo advertised, among with the ERP.
What doesn´t make ANY sense is the 25 to 35 mile ....

Tks,

 

[W2NJS]

Simply put, ERP has nothing to do with the radio. Rather, it is generated by the antenna which is connected to the radio. Therefore, in advertising a radio the ERP is totally irrelevant..

 

[kennyloatman]

Simply put, ERP has nothing to do with the radio. Rather, it is generated by the antenna which is connected to the radio. Therefore, in advertising a radio the ERP is totally irrelevant..

Ok, taking your theory in consideration, the antenna that comes in the bubble pack with the radio does not perform as advertised. If I bought a car that advertised that it did 200 MPH, but only if you put a bigger engine in it, That's a little misleading.