thank you ........and is this comparison half-wave antenna vertical or
horizontal ? Are there limits about how far away is the 'notional
measuring' position .
It seems we can radiate more power on 136 than I thought ;-) 1.6 times in
fact.
Bryan
----- Original Message -----
From: "Rik Strobbe" <[email protected]>
To: <[email protected]>
Sent: 06 October 2006 21:33
Subject: Re: LF: Re: erp ierp VY1JA
Hello Bryan,
ERP, EIRP, EMRP ... It's just a matter of what reference antenna you take
ERP is the power which would be required to be fed to an 1/2 WAVE
DIPOLE antenna
to achieve the same field strength at the same distance as is generated by
the antenna under discussion in the centre of its main lobe FEEDING 1
WATT INTO THE ANTENNA.
EIRP: as above but replace 1/2 WAVE DIPOLE by ISOTROPIC
EMRP: as above but replace 1/2 WAVE DIPOLE by VERTICAL MONOPOLE
73, Rik ON7YD
Quoting captbrian <[email protected]>:
> Gentlemen,
>
> I have long been fully familiar with 'isotropic antenna ' and 'Effective
> Radiated Power.' ......indeed I hope no-one can get a transmitting licence
> without such knowledge but.........
>
> ERP is the power which would be required to be fed to an isotropic antenna
> to achieve the same field strength at the same distance as is generated by
> the antenna under discussion in the centre of its main lobe.
>
> for example: an antenna with a gain of 10db fed with one watt of power
has
> an ERP of 10 watts.
>
> However "Effective_ Isotropic_ Radiated Power" is ..........what ?
>
> Bryan
>
>
> ----- Original Message -----
> From: "John Andrews" <[email protected]>
> To: <[email protected]>
> Sent: 06 October 2006 11:33
> Subject: Re: LF: Re: erp ierp VY1JA
>
>
>> Bryan,
>>
>> As others have pointed out, the "I" is for isotropic, a theoretical
>> radiator that sends the same signal in all directions. A 3-D model of
>> the radiation pattern would be a sphere. The far field of a dipole has
>> no signal off the ends, and hence has gain in the favoured direction (at
>> right angles to the dipole). The 3-D model would be a donut (without
>> chocolate frosting).
>>
>> John A.
>>
>> captbrian wrote:
>> > What is I in IERP ?
>>
>>
>
>
>
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