Antenna Wattage Rating Question

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adachr44

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May 17, 2010
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Hello All,

Newbie ham here that is looking to put together their first mobile rig. I was concerned about the wattage rating of the antenna that I wanted to use. My radio would be putting out about 75W on 2 meters and the antenna that I was looking to use is rated for a max of 100W.

The gain of the antenna is approximately 2.15 dB....and this would raise the ERP above 100W. Does this matter? Will this factor damage my transceiver and or antenna? I just wanted to be sure before I keyed up and created an expensive puff of smoke :).

Thanks in advance for all your advice!


Chris
 

LtDoc

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Dec 4, 2006
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Oklahoma
Chris,
If your antenna is rated at 100 watts and you are putting less than that into it you should be just fine. That ERP isn't actual watts of power, the antenna still isn't going to be handling anymore than you put into it. That 'E' stands for 'effective', meaning the antenna effectively reshapes a typical radiation pattern, moves the radiated power from one direction/angle to another, so that it's just like you were using more power. It's just like a light bulb with reflectors around it. No more light is being emitted from that light bulb, but it'll seem like it's brighter because light was 'moved' from one place to another. Make sense?
- 'Doc
 

prcguy

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So Cal - Richardson, TX - Tewksbury, MA
The antenna would be rated for 100w delivered to the base of the antenna. With 75w feeding about 15ft of RG-58 coax the loss would be about .5dB so your 75w will only be about 66.8w at the antenna under these conditions.
prcguy


Hello All,

Newbie ham here that is looking to put together their first mobile rig. I was concerned about the wattage rating of the antenna that I wanted to use. My radio would be putting out about 75W on 2 meters and the antenna that I was looking to use is rated for a max of 100W.

The gain of the antenna is approximately 2.15 dB....and this would raise the ERP above 100W. Does this matter? Will this factor damage my transceiver and or antenna? I just wanted to be sure before I keyed up and created an expensive puff of smoke :).

Thanks in advance for all your advice!


Chris
 

adachr44

Newbie
Joined
May 17, 2010
Messages
4
Thanks...

Yes, I think that I got it now. I never thought about it like that before. Thanks again...
 
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