[Elecraft] KAT500 Signal Isolation between antenna ports

[Keith Onishi]

Hi Phil,

Thanks for the info. I read the product review.
I will try to find better combination of antenna connection to the ANT1/2/3 ports.
Local noise is very strong in my location, sometimes S7 to S9 in worst case. So bigger antenna picks up more noise. When my 14MHz quad is connected to ANT1, the noise from the 14MHz quad goes to TRX on selecting ANT2 or ANT3.
If the unselected ports went to ground level, we would have better isolation.

73 de JH3SIF, Keith


On 2014/01/19, at 1:23, Phil & Debbie Salas <dpsalas at tx.rr.com> wrote:

> Hi Keith – Take a look at the measured KAT500 isolation numbers in the “Product Reviews” section of my website at www.ad5x.com.  The isolation varies based on the ports chosen, and the frequency band.  As an example, the isolation on 20 meters has a worst-case value of 36dB between ports 2-3 (when 3 is selected), and a best case value of 65dB between ports 3-1 with port 1 selected.  You might want to select the antennas and ports to maximize isolation.  As an example, port 1-2 isolation is much worse than port 1-3 isolation.  So I put my 6-meter beam on port 2, and my two HF antennas on ports 1 and 3.
> 
> You can easily hear signals that are very far down from a desired signal.  Measurements made in my old telecom days indicated that you can usually hear tones as low as 90dB down!  And, of course, if the signal on the unselected antenna is hotter than on the selected antenna, things can sound worse.
> 
> Phil – AD5X
> 
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