Such a relay is a workable solution.
BUT be aware that the K3 KEYOUT only provides a ground. The relay coil
must be connected to a voltage source. Since you are also using an
amplifier on the KEYOUT line, you will have to carefully match the
voltage of the relay and its voltage supply with the voltage provided in
the amplifier - if you do not, there will be current flow between the
amplifier and your relay's power source.
That current flow can be prevented by the use of a series diode in each
leg of the "Y". If the diodes are used, there is not as great a need
for matching the voltages.
So things are a bit more involved than just using a "Y" cable.
73,
Don W3FPR
On 1/28/2020 5:31 PM, Conrad PA5Y wrote:
If you want to be absolutely certain you could add an external relay driven
from the key output. If you use this port to key you PA then you can just use a
Y splitter. There are hundreds of suitable relays on eBay. Configure so that on
TX the sub RX is terminated with 50 ohms. Typically relays such as Dow Key 401
series will give well over 100dB isolation on HF through 6m, they say 85dB but
it's a lot more on all the ones I have measured.
For example
https://www.ebay.com/itm/Dow-Key-401-175-RF-Microwave-Switch-15V-SMA-NSN-5985-01-320-1388/143186092545
Regards
Conrad PA5Y
-----Original Message-----
From: [email protected] <[email protected]> On
Behalf Of VernonJ
Sent: 28 January 2020 20:28
To: [email protected]
Subject: [Elecraft] Dual Receivers 2 different antennas Diversity receive
My K3S has Main and Sub receivers. I would like to use Diversity receive with
the Main using the transmit antenna, and my Sub using a small receive loop.
Is there sufficient isolation on the Receive Only antenna connection to protect
the Sub? Antennas are 60 feet apart, and I intend to run 500 watts at some
point. If I need additional isolation and protection, how would I do this?
Thanks.
--
Sent from: http://elecraft.365791.n2.nabble.com/
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