----- Original Message -----
Sent: Thursday, April 11, 2002 11:28
AM
Subject: LF: E-field probe antenna versus
receiving loop.
Has someone tried the E-field probe vertical whip with high
impedance fet preamplifier, comparing it to a classic multiwire receiving
loop, here in 136 Khz?
I would like to made an E-field probe for use here at home
when in summer season the LF transmitting vertical in down, and i dont want to
put another loop on the roof ( i have now a magloop 4 meters dia for low band,
and a little one only 1 meters dia for 40 to 12 meters band hi
hi).
Thankyou and 73 de
IK2DED Giulio Scaroni
I never used anything else!
My receiving antenna for LF is a 4-meter vertical
whip.
Immediately below the whip is a box containing a bandpass
filter and an antenna amplifier.
The bandpass filter is a double LC filter, slightly
overcoupled, - loaded Q about 40; coupling
is capacitive bottom coupling (which gives a better
attenuation on the high flank of the
passband).
My amplifier is a Cascode Amplifier employing two
junction fets (P8000-devices, J310s could
probably do the job). The amplifier drain current is approx.
18 mA.
The double bandpass filter and the high amplifier drain
current make sure that I have no
problems at all with cross- or intermodulation from
the large european long wave broadcast
stations!
I hope this info might be of help to you.
= 73 de OZ8NJ
Niels+
