Diversity reception with two linked K3s
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Diversity reception with two linked K3s
 
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It is possible to link two K3s together through the serial ports and
synchronize their tuning using N8LP's LP-Bridge, a free program available from his telepostinc.com website. I now have both my K3s lock-tuned together for rx diversity experiments. After setting the second K3's baud rate to 4800 with the K3 utility to match LP-Bridge, I connected it to LP-Bridge's "output com port #1" and pointed that port to match the physical com port the second K3 was connected to. I have two serial ports on this machine, with the other port servicing the "Master" K3. The second K3 follows the first K3's bandswitching/tuning when I tune with the buttons/knob. It also acts as a tuned slave to WU2X's PowerSDR connected to LP-Bridge (see below) , so PowerSDR can be "master" to both K3s. Tuning reaction time is sightly delayed - maybe 200-300 ms. Trying to tune the second K3 manually does not have any effect on either PowerSDR or the master K3, but it is immediately reset back to the master's freq. Since LP-Bridge does not relay the mode/filter commands to the output port, I have to set these manually on the second K3. N8LP tells me that this may be changed in some future version of LP-Bridge. I note there is a few Hz difference in the beat note between them on stations - I will get them aligned together more closely later. I use headphones with each radio in one earpiece, so I may not be bothered by minor differences. Much is yet to be learned. I am also using WU2X's PowerSDR as a panadaptor (google LP-Pan panadaptor) in this setup, and have gotten used to actually tuning my master K3 with it - both in "click-tune" mode and conventional mousewheel fine tuning. The second K3 tracks the master perfectly when I tune them with PowerSDR. NOTE - the panadaptor is not required to link the two K3s - only LP-Bridge is required. I have several antennas, so look forward to some Rx diversity experiments with this setup. I do not plan any transmit until I can verify safe RF levels on the other K3 or a method of disconnecting its antenna during tx. Currently using LP-Bridge V0.9.82, WU2X PowrSDR V0.92, K3 FW Rev 2.38 Jerry W4UK _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Diversity reception with two linked K3s
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FYI, Ham Radio Deluxe includes a "synchroniser" that allows you to slave any number of rigs off a master rig. You run one instance of HRD for each rig and just invoke the synchroniser. 73, Barry N1EU |
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Sounds like a $2500 solution to a $599.95 problem (i.e. a KRX3). And when you're done it actually isn't True Diversity unless both synthesizers are phase-locked (i.e. no beating of frequency or phase). I often hear rapid shifting of DX signals in Diversity mode (left-right-left) which I think would be a problem if the two RXs weren't phase-locked. 73, Bill |
Re: Diversity reception with two linked K3s
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From what I have read in years past, I agree locking the two
together could probably be useful. I don't know enough about it yet to be sure of this, though - having each radio in a separate earphone may be all one needs unless beam-forming is a goal. In time we will see how the subreceiver is locked to the main and then we should be able to duplicate the KRX3 performance. One step at a time. In the meantime, I have enjoying the several hours I have spent listening. I now have the two reference oscillators in agreement so I don't get the beat I heard earlier. Using one vertical antenna and one horizontal last night I observed polarity differences on 75 M. Also some sort of spatial effects on 30 M. It is definitely not a $2500 solution to a $600 problem - it is actually a zero-cost second receiver solution for the guy who bought two K3s for contesting and sees the second one just sitting there when not contesting... Jerry W4UK At 08:31 AM 11/22/2008, Bill W4ZV wrote: >Barry N1EU wrote: > > > > > > > > Jerry Flanders wrote: > >> > >> It is possible to link two K3s together through the serial ports and > >> synchronize their tuning using N8LP's LP-Bridge, a free program > >> available from his telepostinc.com website. > >> > > FYI, Ham Radio Deluxe includes a "synchroniser" that allows you to slave > > any number of rigs off a master rig. You run one instance of HRD for each > > rig and just invoke the synchroniser. > > > > 73, > > Barry N1EU > > > > > >Sounds like a $2500 solution to a $599.95 problem (i.e. a KRX3). And when >you're done it actually isn't True Diversity unless both synthesizers are >phase-locked (i.e. no beating of frequency or phase). I often hear rapid >shifting of DX signals in Diversity mode (left-right-left) which I think >would be a problem if the two RXs weren't phase-locked. > >73, Bill > >-- >View this message in context: >http://n2.nabble.com/Diversity-reception-with-two-linked-K3s-tp1564004p1565475.html >Sent from the Elecraft mailing list archive at Nabble.com. > >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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