Thanks for the info Ed, quite appreciated. And, similar to what Lyn has stated, I have had mixed results using a Timewave ANC-4 on 6M. When the noise source was S7 from one direction about 2 miles away, I was able to use a low 3 el vert noise yagi to reduce it to S1-2. But when the noise was radiating from the powerlines right in front of my house with a broad azimuth, I could not do too well.
73, Chet, N8RA -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Lyn Norstad Sent: Saturday, April 16, 2022 5:12 PM To: 'Ed Cole' <[email protected]>; [email protected] Cc: [email protected] Subject: Re: [Elecraft] Using MFJ-1026 Noise Canceller on 6m-eme Interesting setup, Ed. I've used the MFJ-1026 in the past, but found that satisfactory (i.e.: meaningful) results were hard to come by when used in the recommended manner. Please keep us posted on your tests. 73 Lyn, WØLEN -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ed Cole Sent: Friday, April 15, 2022 8:32 PM To: [email protected] Cc: [email protected] Subject: [Elecraft] Using MFJ-1026 Noise Canceller on 6m-eme Diagram of final configuration: http://www.kl7uw.com/6M_NOISE_CANCEL.jpg This a basic phasing unit to reduce band noise on HF bands. But first I tried it on 6m where no null was achieved. Next I configured to use the 1st IF output of my dual-Rx Elecraft K3 running in Diversity mode which phase-locks both Rx to the main VFO. That involved using an outboard SDR to detect the 8.215 MHz IF signal and supply audio to my computer. Sensitivity was too low on the second Rx so required opening/inspecting cables inside the radio. I found the synth coax not seated well to the second Rx. Re-seating the connector fixed that. But I still had too low an audio level from the 8-MHz SDR to drive wsjt-x. A bit of research found the proper dialog box to adjust mic gain. Apparently the K3 line output is much higher than the SDR audio (LP-Pan2). Original design involved using an external preamp for the 6m noise antenna (3-element yagi) but I found I had adequate gain using the MFJ internal preamp set to gain=2 (out of 10). To add additional RF protection to the MFJ, I added a coax relay to disconnect the aux input of the MFJ. It does have a TR control line to give protection to the main Rx line, but none to the aux Rx input. My main Rx is fed by a preamp at the tower located behind a TR relay. I adjusted audio levels for main and aux inputs so wsjt-x read 36 on the audio bar meter for each. With both inputs it read 40. Placing the K3 into diversity mode I could null about 6-dB (reading dropped to 32/34. No idea if this is enough noise reduction for 6m where I regularly see S5 pointing NE toward MR, Pointing SE local noise often drops to S2/S3. One s-unit is 6-dB. Next is to test with actual eme signals. 73, Ed - KL7UW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
