My KRX3 arrived yesterday and after about 4 hours of work It was fitted into my K3. For those of you that don’t already know The KRX3 adds a second receiver of equal specification to the primary receiver to the K3
Generally sub receivers are useful to help find out where the dx station is listening in the pileup, to search for multipliers whilst ‘running’ in a contest or to monitor a second band.
The K3 with the KRX3 fitted has another ‘neat trick’ up it’s sleeve. If the KRX3 is configured with the same filters in at least some of the slots as the primary receiver it can be used for Dual antenna diversity reception. In this mode the Sub RX tracks the tuning of the main RX. I have been using diversity reception for a number of years for tropical band broadcast Dxing with my Racal RA-3702 however the K3 is the first amateur transceiver I have used that is actually capable of doing diversity reception well.
Icom’s Flagship 7800 fails miserably in diversity on two counts. Firstly the main and Sub RX have a small but constant frequency offset making it very tiring to listen to, secondly the tuning of the main and sub receivers cannot track.
On the Elecraft k3 tuning tracks both receivers (when linked) RIT also applies to both receivers making the k3 very easy to use in diversity mode.
Diversity holds a lot of promise for weak signal DXing where using 2 separate antennas can help reduce the impact of fading, QRM and noise
Diversity is also very useful for enhancing the ability to pull individual calls out of large pileups
K3 30M Diversity is a 5 minute audio clip of the K3 in Diversity mode. For a better idea of how useful this is listen with headphones on.
here is the YR2TOP beacon on a noisy 160m with K9AY loops on the left and a beverage on the Right
filter bandwidth is 150hz this time
Here is a clip of an SSB pileup on 20m Here too diversity reception helps to separate the callers