I have to conclude therefore that the answer to the original question / title of this thread - is It depends (on all kinds of factors which are effectively impossible to measure on a summit during a SOTA activation - and pretty difficult from the home QTH as well).
lets hope no official ever finds time in his lunch break to come by and ask us to PROVE that we are not emitting more than 15w EIRP!
Usually the burden of proof falls on the accuser ;).
PROVE that we are not emitting more than 15w EIRP!"
Who could?
There was a time when that was the case. Nowadays, Iām not so sure ā¦
73,
Walt (G3NYY)
The respected German national amateur radio magazine āFunk Amateurā in itās article about the 60 metre band becoming available in Germany (on page 161 of the February edition) tells itās readers that 15w EIRP is 15W PEP from the rig when using a half wave dipole antenna and assuming 2 dB of cable/connector losses.
Our discussions here concluded 2.5w at the rig, not 15w.
Not so well respected now then!
Hi Andy,
The writer and editor clearly donāt have a firm grasp on the physics. Not that that makes them bad people but an errata would be in order.
Ed, if you donāt believe the earlier well based posts you need to get an antenna modelling program and do the hard yards yourself. There are free versions of EZNEC available. Get one and go through the scenarios. It takes an afternoon if you are reasonably expert in these matters. As has been stated we do not operate in free space so formulae based on that give the wrong answer.
Garbage in, garbage out.
It always helps to read up on a subject and do some work before expressing an opinion.
Stick to 2.5 W and you will be fine. Run 5 W and you had better have your ducks in a row as otherwise you might exceed 15 W eirp. (No comments about how to phase the ducks please).
Most stations running 10 W will definitely exceed 15 W eirp. There is no miracle about to occur that will make 10 W or more Kosher if you have a 15 W eirp limit. No wait, thereās the Miracle Whip.
73
Ron
VK3AFW.
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Hi Ron I HAVE accepted the 2.5w guidance, which is why I have also sent an email to the magazine pointing out their error.
Ed
Hi Ed,
My apologies, I misunderstood.
Occasionally reputable publications do print something of poor quality (wrong) material but on something like this they should have had it vetted by someone āin the gameā. Good on you for pointing out their slip up.
73
Ron
VK3AFW
Reply from FunkAmateur:
Der YO9IRF im Thread hat insofen tendenziell Recht, als es durch Reflexion am Erdbodenuntre unter gĆ¼nstigsten Bedingungen bis zu 6 dB āground gainā geben kann.
FĆ¼r die BNetzA ist das aber nicht relevant, sondern es ist zulƤssig (und wird auch immer so gemacht, siehe Programm Watt, siehe Programm WattwƤchter von der BNetzA selber), mit dem theoretischen Freiraumgewinn zurechnen.
Also Dipol G = 2,14 dBi, um es ganz genau zusagen.
Real dĆ¼rften durch Kabelverluste, Steckerverluste, ein geschleiftes SWR-Meter, evtl. sogar Antennenumschalter usw. immer Pi mal Daumen 2,14 dB Verluste zusammenkommen.
Bleiben also 15 W PEP Senderausgangsleistung.
Genau so habe ich das gemeint.
Crude and short translation the regulator in Germany (BNetza) uses 2.14 dBi as the Isotropic gain of a dipole (not the ground gain of 6+Dbi), hence, with 2.14dB cable/connector losses 15w PEP from the rig will be under the 15w EIRP at the antenna.
Of course other countries might use different values for the Isotropic gain of a dipole. This really should be defined at an IARU level to be consistant.
Ed.
This kind of Admiral-Nelson-I-See-No-Ships attitude displayed by your regulator is not what is expected from German institutions were accuracy, quality and getting it right first time is the norm.
If this is how standards are moving then there maybe hope for the UK post-Brexit! 
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No, typical behaviour of a german authority, as it minimises work. 
How dare they copy the well established British way of ignoring problems.
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Actually I thought that process was originally Australian āSheāll be right, Mate!ā.
And other countries might use different values for the watt. For example, in Belgium it seems that
1 Belgian Watt = 10 conventional watts.
73,
Walt (G3NYY)
And it seems dBi is a new unit for attenuation. Does PTB know about this? Not mentioned on their web site.
Ed when the ānever made a mistake hereā guys are carrying on the appropriate expression for this is āThings are crook in Tallarookā.
73
Ron
VK3AFW