[Elecraft] Re: K3 KRX3 - BNC or KAT3?

[wayne burdick]

Tony, N2TK wrote:

 > Is it recommended to hook up the BNC connector on the back to
 > the KRX3 or to use the second SO-239 on the K3 or does it make any
 > difference?

Hi Tony,

If you have a KAT3, you can optionally use the non-transmit KAT3 
antenna (which might be ANT1 or ANT2 at any given time) as the sub 
receiver's secondary antenna source. If not, you'll need to use the BNC 
jack.

The BNC jack is recommended anyway, and an appropriate cable is 
supplied with the KRX3 module. It's the way we set up factory-built 
K3s. It's more flexible, because you can connect a receive-only antenna 
for use with the sub receiver that is well-isolated from your transmit 
antennas. (Physical and electrical isolation for a receive antenna is 
good practice in general.)

If you don't have a special RX antenna for use with the sub receiver, 
but you do have two antennas connected (to ANT1 and ANT2), the KAT3 
non-transmit antenna might be a better choice.

This selection has no impact on *shared* use of the main antenna by the 
sub receiver. You can do that in any case.


 > Most of the time I will be using the same antenna for both
 > receivers.

That's the "shared" case.


 > When the K3 has the capability of having the two
 > receivers on two different bands I would like to monitor another
 > band with a second antenna. An example would
 > be to monitor 6M. Figured I could use the second SO-239 for this.

Either the KAT3 non-transmit antenna or the BNC jack would work. If you 
use the KAT3 non-transmit antenna, be sure to keep the antennas on ANT1 
and ANT2 very well isolated so the sub receiver's carrier-operated 
relay doesn't get triggered when you transmit.


 > I assume that when I am listening to both receivers on the same band
 > that if I am using the receive antenna input the receive antenna
 > will go to both receivers. Is this correct?

Yes.

73,
Wayne
N6KR