[Elecraft] [K3] Diversity and CW?

[Gary Hinson]

> Does CW benefit from diversity reception? Can anyone relate any
> experiences with such improvement and some details on their setup
> including filters/settings?

Absolutely Jim!

Diversity helps on ALL MODES.  The main thing I notice is that it "fills in the dips", in other
words when a signal fades in QSB on the main antenna, it seems to not dip as far and may even come
up a little on the diversity receiver.  The net effect is that the signal appears to drifts
side-to-side from ear-to-ear rather than up-and-down into the noise.

I estimate diversity is worth a few very valuable dB on receive.  It helps most with those weak,
QSB-ridden DX signals wandering up and down at the band noise level.

Nothing special needed on the filters & settings - just turn diversity on - with one exception: for
best performance, the main and diversity RXs need matched filters.  Mismatch will apparently cause a
slow 'beat' and reduce the benefit.

The more important issue is to have sufficiently different antennas for main RX and diversity RX,
ideally with both spatial and polarization diversity.  I have been using my normal TX antennas for
the main RX, all about 100m from the shack on a remote switch, and a single 30m wire loop for
diversity RX, about 10m from the shack in the opposite direction.  The 30m loop works best on 30m,
of course, but helps to some extent on all other bands except 20m where it's too badly mismatched.
A full set of monoband diversity RX antennas would be lovely, and I guess a decent multiband
vertical would work OK too, but meanwhile the 30m loop does the job ... Or rather it did until a
storm broke the line, and I put up a 12m TX loop instead!  I miss diversity and plan to reinstate
the 30m loop, moving the 12m loop across to the TX end.

73
Gary  ZL2iFB