Brian Machesney wrote: > > I was just reading about the differing levels of success that people have > with "active noise cancelling" units. It occurred to me that one should be > able to achieve the same kinds of results using the second RX and separate > antenna in the K3 - with the addition of control over the phase (delay) of > the arriving signal. >
I believe it should be possible also since the K3 and KRX3 are virtually identical (as required for diversity). Any gain difference could be compensated using the separate RF Gain controls, but phase differences would require some sort of control knob, which is in short supply on the K3 front panel. It's simple to do this with an external unit like the MFJ-1025 which is the way I'm heading. DXE also has a much more expensive unit (NCC-1) but the 1025 can be modified to make it similar (except for strong signal performance). I've done all the W8JI modifications below (excluding the filter modifications) and I also added impedance converters for the two inputs. For some reason both inputs on my 1025 show input impedance on 160m of ~160 ohms, so I added 2:1 transformer inputs to get ~80 ohms on both parallel F-connector inputs (another mod). I'll be using two identical Beverages staggered ~1/4 wl and spaced ~1/8 wl apart, each matched to 75 ohms. I was concerned about possible reflection issues if the Beverages saw 150 ohms looking back into the 1025. http://www.w8ji.com/mfj-1025_1026.htm Once the crops are out of the field where I plan to install this I'll try to report back on how it's working. 73, Bill -- View this message in context: http://n2.nabble.com/K3-new-feature-idea-question-tp3977080p3980098.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
