From: Claudio Pozzi <smtp01@email.it>
To: rsgb_lf_group@blacksheep.org
Date: Wed, 26 Dec 2007 13:41:46 +0100
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Subject: Re: LF: E-field probes.
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On Monday 24 December 2007 16:04, G0MRF@aol.com wrote:
> Seasons greetings all.
>
> Does anyone know if the e-field probe can be adatped to HF  frequencies?
>
> Some of you will know I am a member of Amsat and we have an opportunity
> where we could propose a single frequency 29MHz 'SSB' receiver on a 
> satellite. However, as we will not be allowed a large traditional antenna. 
> I wondered if I could propose an e-field probe for 29MHz.
>
> Is there any data / design information anywhere which may help make a
> decision?
>

I'm using an e-field antenna in HF, it's about 6 - 10 dB lossy versus an 1/2 
wave dipole. The probe is a beer can.

In the earth environment the emf developed at the e-field probe is referenced 
to the ground potential.

In open space the spacecraft body is the reference potential but you should 
consider the [(delta voltage) over (delta space)] as function of the electric 
field strength .

I think that the spacecraft to e-field_probe distance is very little, so the 
emf is also little.  May be that a "long tail" connected to space craft body 
may help.

Some references:
(1) Christof Rohner, "Antenna Basics", Rohde&Schwarz, 1999 (search WEB with 
GOOGLE)
(2) SCHWARZBECK MESS - ELEKTRONIK, "VAMP 9243 9 kHz - 30 MHz Low noise active 
monopole antenna", http://www.schwarzbeck.de/Datenblatt/m9243.pdf
(3) SCHWARZBECK MESS - ELEKTRONIK, "Calibration of Vertical Monopole Antennas 
(9kHz - 30 MHz)" (search WEB with GOOGLE)

73 de Claudio, ik2pii

-- 
Claudio Pozzi  -  Happy Linux User  -  http://www.qsl.net/ik2pii

 
 
 
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