What kind of range (in miles) can I expect with a 12dBi 2.4GHz yagi and a 1 watt amp?

The antenna and amplifer are both good quality; so is my LMR-300 coaxial cable (about 30 feet of it). I've listed some specs below:

Yagi: (from Netgate.com)

Max. Gain: 13 dBi (+/- 0.5 dB)

Min. Gain over band: 12 dBi +/- 0.5 dB)

Frequency: 2.4 - 2.5 GHz

VSWR: < 1.5:1 between 2400-2450 MHz

< 2.0:1 between 2450-2500 MHz

Feed power handling: 10 W

Azimuth Beamwidth: 44° (+/- 2°)

Elevation Beamwidth: 48° (+/- 2°)

Input impedance: 50 ohms (nominal)

Input connector: integrated 20cm RG58 pigtail with N Female connector

Polarization: Linear vertical and horizontal

Dimensions (L x W x H): 95mm x 400mm x 40mm

Amplifier: (from Hyperlinktech.com)

Frequency: 2400 - 2500MHz

Max Input Power: 100mW (20dBm)

Transmit Power: 1 watt (30dBm)

Receive Gain: 17dB nom.


I'm also quite aware of the legalities for private use, however I am a licensed professional doing range testing for rural ISP clients... that's my story and I'm sticking to it.

1 Answer

  • 1 decade ago
    Favorite Answer

    I hate to say this but if you are in the US you are over the LEGAL FCC LIMIT (even lower in UK and most of Europe) with this setup. 36db max based on what you say 30db (1watt amp) + 12db(antenna) = 42db - line loss which is not much at 30 feet of cable === ILLEGAL power.

    Once you modify a Part 15 device, such as by using a non-approved antenna you modify its RF characteristics which change important details such as how much Effective Radiated Power (ERP) which is limited to 4W in the US

    30db=1watt 33=2watts 36=4watts. Each 3db is double the ERP.

    However. your range is limited by "LINE of Site" so if you can "see" the other end you can reach it. As long as no obsticles are in the way this is good for MILES and MILES.. we have used much less power and 19 db for up to 20 miles. See this article for a 125mile link -- no amps.


    Have fun and stay out of jail drop the power some! Power isn't going to get through obstacles! DO NOT GET IN FRONT OF THIS THING it is MICROWAVE and at that level will indeed begin to cook you. (Many Microwave ovens are on 2.4 gig just for information).

    Just noticed your a "Licensed Professional" why ask the question -- your supposed to KNOW THIS STUFF!

    I am just an Extra Class HAM (who can run power on 2.4) and WISP owner and I know it..

    If you really want range you wont use a YAGI -- not enough directionality! Oh and don't forget the OTHER end of your connection needs to be able to reach you too!

    Source(s): FCC and many years of Ham Radio
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