[Elecraft] In praise of the sub Rx & Diversity

[Victor Rosenthal 4X6GP]

Almost the only time I don't use diversity is when I need the 
subreceiver for split pileup operations (and often it's enough just to 
watch the P3, so even then I use it). It can make a huge difference.
My antennas are only about 15m apart, but one is a dipole and the other 
a (vertically polarized) Pixel Loop.
The loop has a relay that disconnects it when I transmit so there's no 
danger to the subreceiver.

73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
http://www.qsl.net/k2vco/
On 29 Oct 2017 02:11, lmarion wrote:
> I have been trying along time to get buyers to go for it and get the sub 
> rx for its many pluses.  One that is kind of not obvious is the 
> diversity receive. I knew about it from my years of working on FAA 
> radars, and military search RADARs maintained by the FAA. All search 
> radars from way back have diversity RX, because it will find those small 
> target weak reflections. And some specialized diversity receive is being 
> developed for those dog gone drones.  I have not measured the 
> sensitivity of the K3s, but there are weak stations that are not heard 
> when not in diversity. A friend in the city of Spokane can adjust the 
> phase between his antennas and null out some strong RFI completely!
> 
> Leroy AB7CE
> 
> -----Original Message----- From: Bill Johnson
> Sent: Thursday, October 26, 2017 7:56 PM
> To: Gary at ka1j.com ; elecraft at mailman.qth.net
> Subject: Re: [Elecraft] In praise of the sub Rx & Diversity
> 
> I use diversity on 20 meters with a vertical SteppIr and a loop.  Both 
> are separated about 150'. What a difference.  Amazing.  Makes a huge 
> difference with stations fading in and out and near the noise level.  I 
> can work them with the Loop, but the vertical is so helpful when receiving.
> 
> 73,
> Bill
> K9YEQ
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Gary Smith
> Sent: Tuesday, October 24, 2017 10:38 PM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] In praise of the sub Rx & Diversity
> 
> When I bought the k3 in 09 I went all out and bought most of the 
> accessories to go with it. One of these was the sub Rx and a full 
> matching set of crystals for it. As upgrades happened I did them all and 
> wasn't using the Sub Rx in diversity so much but, the advantage of the 
> Sub Rx was always there with flexibility I take for granted.
> 
> So I upgrade to the K3s and migrated the sub Rx to it as well. I just 
> don't think of diversity much but that was one of the reasons I bought 
> the Sub Rx in the first place. With the 3 dB loss going to Diversity, I 
> just listened more with the main receiver and let it go from there.
> 
> So today I'm working a ve7 on 10M and the band is going out. I can hear 
> him but it's at that marginal iffy point, I was missing characters in 
> his CW. I have a HI-Z triangular & a circle 8 pair of Rx antennas. The 
> Circle 8 rocks on the low bands, has a filter to cut out above 40M but 
> the triangular has no such filter and I often hear better on it than on 
> the the roof mounted tribander. So for fun, I used diversity and the 
> triangular on the sub,
> 160 sloper for the Tx antenna & Voilà, I heard him so much better, 
> finished the Q and that reminded me of the real advantage of diversity 
> and why it is an asset.
> 
> So now it's tonight, I see 3C0L is still on the air at around 3AM their 
> time, on 20M. They're heading home today and the low band antenna is 
> packed up already.
> What troupers to still be in the game at this point. But I digress... So 
> here they are, I don't have a good antenna for 20M, have to use the 160M 
> antenna or tribander.
> RFI from the neighbors makes the tribander useless so I hear them on the 
> sloper and can hear them on the Hi-Z Triangular a bit better but much 
> QSB so remembering the success with the VE7 earlier I go Diversity & all 
> of a sudden, solid Q5 copy, no QSB and I snagged them on 20 CW.
> 
> Diversity really made the difference. I bought the K3s because it had 
> such excellent specs, nothing else to me came close, save for 1-2 radios 
> that in 09 were hot and cost more than a new car. And they weren't any 
> better in practicality than the K3 was. I bought the Sub Rx for the 
> diversity and now today, while the K3s is itself stellar in all the 
> right ways, it is an a better product with the Sub Rx.
> I'm really honored to have such an
> incredibly capable radio.
> 
> Just sayin'
> 
> 73,
> 
> Gary
> KA1J