LF: G3XIZ's ERP on 9kHz (2uW)

To:	[email protected], Chris Osborn <[email protected]>, Eddie <[email protected]>, M0JXM Dennis <[email protected]>, Pete <[email protected]>, James Cowburn <[email protected]>
Subject:	LF: G3XIZ's ERP on 9kHz (2uW)
From:	Roger Lapthorn <[email protected]>
Date:	Sun, 6 Mar 2011 14:03:23 +0000
Dkim-signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:date:message-id:subject:from:to :content-type; bh=fih6J4bDi/TOkU1yTJvyBzYXkF9xF/otx0Na+df8gTU=; b=dEPxiNw4upftTk7SE+BweHtQqcqgRsyAfsFbVIfushWYudBp/mgikz7bTCOwQ5XGdx XtU69rpW5w7KZBTOxbGGrjezt/WRPSDodtVp7yw18tWpSg7f9iJIcGHCK6ah6tkS5Qhu 48dtKFb4emuHFFs3OYvafBUgTpM52FIZpqIYY=
Domainkey-signature:	a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=FeJbLiPDW/nQadj95I6oS9HzuYIEguqXTrXSxaY46/TVIxsTf/jL2d2rSTAk1Xcul+ cquwym1cFbSJ6Ja1oMnvvSw0nUjpwTRQiTshxGslZ2LOUh10GR0f9bVulKk7qrEzBXpx uMDCfkNGWfVjt5mKy1Lcb0BP+7kLYakL3U5X0=
Domainkey-status:	good (testing)
Reply-to:	[email protected]
Sender:	[email protected]

Today I did a quick calculation of Chris G3XIZ's ERP on 9kHz based on information he has provided. I appreciate the accuracy is not great.

Parameters

Antenna type: Marconi with 10m vertical and 40m horizontal
Power: 100W RF out of the PA
Antenna current: 0.18A

Rr (Radiation resistance) = 160 x pi^2 x Heff^2 /lambda^2 . For simplicity, I have assume Heff is 5m. It might be a little better than this, but not much at this wavelength.

So, Rr = (160 x 9.9 x 25) / (33000 x 33000) = 39600/1089 x 10E-6 = 36.36 uOhms

ERP (for a Marconi) = 1.8 x I^2 x Rr = 1.8 x 0.0324 x 36.36 x 10E-6

Therefore G3XIZ's ERP = 2.1 uW

Clearly there are errors and uncertainties, but this gives an order of magnitude. Hope this is correct (I make lots of mistakes with sums) and of interest.

73s
Roger G3XBM

--
g3xbm-qrp.blogspot.com/
www.g3xbm.co.uk
www.youtube.com/user/g3xbm
G3XBM GQRP 1678 ISWL G11088

<Prev in Thread]	Current Thread	[Next in Thread>
LF: G3XIZ's ERP on 9kHz (2uW), Roger Lapthorn <=

Previous by Date:	Re: LF: Sub 9kHz antenna tests., Gary - G4WGT
Next by Date:	Re: LF: VO1NA 06-03.jpg, James Moritz
Previous by Thread:	VLF: Long carriers on 8970, Markus Vester
Next by Thread:	Re: LF: VO1NA 06-03.jpg, James Moritz
Indexes:	[Date] [Thread] [Top] [All Lists]