At a former employer we used the EMCO 6502 with integral amplifier and
rechargeable battery pack. It worked quite well.
See http://www.emctest.com/productpage.cfm?model=6502&producttype=Antennas
I don't remember ever running the battery down in a day's testing. Of
course, we didn't run it all day long.
I have an EMCO 6511 (1 KHz - 5 MHz)
http://www.emctest.com/productpage.cfm?model=6511&producttype=Antennas ,
an old ALR-25M for both of which I have the only the "usual" antenna
factors, and an even older Empire LP-105 for which I have not even general
antenna factors. The 6511 is not bandswitching, the ALR-25 is for its 10
kc - 30 mc range, and the LP-105 from .15 -30 mc. Bandswitching networks
complicate antenna factors.
The signal pickup of a loop antenna depends on its area and the incident
H-field, as you know, and the calibration charts usually add a 51.5 dB
free-space factor for equivalent E-field. This can be seen in the curves
for passive loops such as the EMCO 6511 above and the EMCO 6512 at
http://www.emctest.com/productpage.cfm?model=6512&producttype=Antennas
A loop antenna properly built to the same dimensions and number of turns
will necessarily have substantially the same antenna factors. This suggests
that we might build our own and get reasonably accurate readings even
without lab calibration.
I would also use a rod antenna to measure the incident E-field, and not
rely on the FCC's assumption of free-space conditions.
Cortland
> [Original Message]
> From: Hare,Ed, W1RFI <w1rfi@arrl.org>
> To: <rfi@contesting.com>
> Date: 2/11/2004 1:02:55 PM
> Subject: [RFI] EMC active loop antennas
>
> Do any of you have experience with any particular active HF loop antennas
calibrated for EMC measurements? If so, if you have any recommendations for
an economical choice, please let me know on this list or by private email.
I want something reasonably small, but sensitive.
>
> Ed Hare, W1RFI
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