Return-Path: Received: (qmail 28261 invoked from network); 30 Jun 1999 04:49:40 +0100 Received: from magnet.plus.net.uk (HELO magnet.force9.net) (195.166.128.26) by guiness.force9.net with SMTP; 30 Jun 1999 04:49:40 +0100 Received: (qmail 20498 invoked from network); 30 Jun 1999 03:50:22 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnet.plus.net.uk with SMTP; 30 Jun 1999 03:50:22 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 10yKQf-0001fr-00 for rsgb_lf_group-outgoing@blacksheep.org; Sun, 27 Jun 1999 20:17:25 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from smtp-out1.bellatlantic.net ([199.45.39.156]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 10yKQe-0001fm-00 for rsgb_lf_group@blacksheep.org; Sun, 27 Jun 1999 20:17:24 +0100 Received: from bellatlantic.net (client-151-200-120-12.bellatlantic.net [151.200.120.12]) by smtp-out1.bellatlantic.net (8.9.1/8.9.1) with ESMTP id PAA26612; Sun, 27 Jun 1999 15:15:39 -0400 (EDT) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <37767785.FA5629BC@bellatlantic.net> Date: Sun, 27 Jun 1999 15:12:06 -0400 From: "Andre' Kesteloot" X-Mailer: Mozilla 4.02 [en]C-DIAL (WinNT; U) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Field strength measurement. References: <001e01bec01f$ebc79f80$46218cd4@default> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Sender: Alan Melia wrote: > [...] > The field strength is given by > e= (18.85*N*E*(r)^2)/X*d^3 > where N is the number of turns on the exciter coil > E is the sig-gen voltage in mV > r is radius of the exciter coil; in cm > d is the distance between the exciter coil and loop aerial in > metres > X is the reactance of the exciter coil > and e is in uV/metre > There is not a lot more than that in the text but I am willing to send a > photocopy to anyone who wants it. Interestingly, Terman and Pettit also wrote "Electronics Measurements" (McGraw-Hill 1952) and , on pp. 400-410 developed the above theme, giving more details and sketches of various methods used in receiver measurements.Quoting from page 403: If the self-resonant frequency of the signal-generator loop is very high compared with the operating frequency, so that capacitive currents are negligible, then the field strength produced by the signal generator loop is E = [47.15 * N * d^2 * I] / D^3 where E = equivalent electric field strength in volts per meter at center of receiver loop, N =number of turns in signal-generator loop, d = diameter of signal-generator loop in meters I = Current in signal-generator loop, in amperes, D = distance from center of signal-generator loop to periphery of receiver loop. unquote I, too would be willing to supply photocopies to anyone interested 73 Andre' N4ICK