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----- Original Message ----
From: Fraser <fraser.castle@...>
To: loopantennas@...
Sent: Sunday, May 13, 2007 4:09:03 PM
Subject: [loopantennas] Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?













--- In loopantennas@ yahoogroups. com, Paul Birke <nonlinear@. ..> wrote:

Hi Fraser and All

sorry scratch all that I just transmitted

the 10 dB is the antenna alone LOL

oh well

Paul

Hi Paul,



Thanks for the input.



The DX-One base unit has unusual calibrations on the attenuator.

Instead of just showing the inserted attenuation it shows the system

gain.



The +10dB position is a straight through connection and is described

as +10dB because the antenna head is stated as having a gain of 10

dB. The 0dB position on the base unit is actually an insertion of

10dB attenuation. Theoreticaly in this position the input to the

receiver splitter is the same as the signal strength at the antenna

elements without any gain. This does not take account of feeder

losses though.



The base unit is a work of art. It's a very solid affair and contains

a low noise 28 Volt d.c regulated power supply, a calibrated stepped

attenuator, A MW filter and a high quality splitter. I bought a

couple of extra base units from Lowe(UK) last year for ?20 each. They

are easy to convert to 12V output and work very well with any phantom

powered active antennas.



I will have to look out the X-Rays that I took of the Head unit

electronics as they may be of interest.



I note that the review that I refered to states that the DX-One

requires an excellent ground plane. I have the DX-One MKII and the

only groundplane requirement detailed in the instructions is for

static discharge purposes. The same is not true of my RFS DX-500

which requires an excellent groundplane to perform well.



Fraser














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