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Old June 12th 04, 03:13 PM
RHF
 
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= = = "Dale Parfitt" wrote in message
= = = ...
"RHF" wrote in message
m...
SARA,

The Icom IC-R75 (r-75) has two 'built-in' Pre-Amplifiers.

SO... WHY ? Complicate things with another outboard Pre-Amplifier ?


Although I don't own an R-75, I would think the preamps are as they are in
my IC-756 PRO- that is , they are 50 Ohms input ( or there abouts).
Thus, not suitable for the hi end Z of a short whip (capacitive probe)- they
shunt the vast majority of the sig to ground.
Don't confuse preamps with the active stages in an active antenna- their
primary purpose is to act as an impedance transformer, gain is secondary.

Dale W4OP


DP,

In my 'original' Reply - I then when on to say:

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"Two InDoor [Hidden] SWL Antenna Ideas" for the Icom IC-R75 (R-75).
INDOOR= http://groups.yahoo.com/group/Shortw...na/message/209
Note - Instead of the Push-Pins 'small' Cup-Hooks can be use.

PRE-SELECTOR: A small 'passive' Antenna Pre-Selector like the
MFJ-956 can be used with one of these InDoor [Hidden] SWL Antennas
and the Icom IC-R75 (R-75). The MFJ-956 is a very small box.
MFJ= http://www.mfjenterprises.com/produc...prodid=MFJ-956
The MFJ-956 greatly improves reception from 150 kHz to 30 MHz;
especially below 2 MHz.
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1. Use a basic 'home-made' Wire Antenna Element for an InDoor
Antenna with the Icom ICR75 (R-75) Receiver.

2. Couple the Indoor Antenna with a Pre-Selector to the Icom
IC-R75 (R-75) Receiver's LO-Z 50 Ohm SO-239 Antenna Input Jack.

3. Then use one of the two Pre-Amplifiers that are 'built-into'
the Icom ICR75 (R-75) Receiver as needed.

iane ~ RHF

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