Discussion in 'General Technical Questions and Answers' started by KR6AUL, Nov 7, 2018.
Does the Mfj-1026 Noise Canceller 1 5-30mhz work? Anyone have experience with one?
Yes, I've used one and have also used the Timewave and DX Engineering versions. They all work, the DXEE NCC series is the primo version with a lot more adjustability but they all work. But they do require a decent noise sensing antenna, they work best against a single point noise source and they require re-adjustment every time you encounter a new noise source or QSY up or down band (or change bands).
If you've got a single nearby noise source like a neighbor's plasma TV they can definitely work but if you have several or many distributed noise sources such as in a typical urban environment then they're not great. And they do require tweaking as you move around the band or encounter new new sources you want to null out which gets tedious real fast.
If at all possible it's really best to tame noise at the source which might require a careful audit of home noise (turn off all breakers, power the rig off a battery or off the single active circuit, if the noise decreases then turn breakers back on one at a time till you narrow down the noise source) and perhaps a careful search for neighborhood noise generators (noisy power line insulators, noisy battery chargers, TVs, electric fences, etc.) and then work with neighbors or utilities to tame those noise sources. And of course a good antenna up high and in the clear can help tremendously both in terms of getting farther away from local noise sources and increasing signal strength for desired signals as it's S/N in the end that matters so anything you can do to increase S or decrease N or ideally both helps a ton.
Close, an ANC4 (Timewave) and a homebrew one from about 1994. Experience was about the same as K7TRF. Took a few sense antenna schemes, and adjustments were touch . My application was for just one frequency (with the HB one) so readjusting wasn't that critical. No, I just couldn't find the source. The ANC4 was more recent, with more noisy freqs and I reached the point where I just avoided those. The noises finally went away by themselves.
Be patient, they do work.
Agreed . . .
I borrowed a MFJ-1026 to try out . . . it's great on a single source of noise . . . you can completely phase it out.
But sadly most noise comes from multiple sources . . . and any of the Phasing units won't reduce it at all. So I gave it back to the shop.
However, as I saw one very cheap, I did later buy a secondhand MFJ-1025. It uses the same PCB as the 1026, so I copied their pre-amp circuit and so convertwd it to a 1026.
Although I rarely use it as a Noise Phaser, I DO use it as the Pre-Amp and Tx switching for my 160m Receiving Loop !
And by the way, even the one with the pre-amp would NEVER pick up enoughg of the Noise Source on the whip Antenna . . . if anything, you need quite a big antenna (at least 50ft of wire), especially on 160 & 80m.
Well I ordered it so I guess we will wait and see. I think I found the source of the noise but it is just the highest noise. Seeing as I live near the downtown area, I am sure there is noise coming from everywhere. Trying everything I can to at least reduce some of it.
I live in urban Las Vegas, 1963 neighborhood. I have used the canceller quite a bit, since I picked it up. $4.99 at Goodwill. It's always inline with my SDR. Comes in handy.
Would I buy one at full price? Probably not, even after using it for a while. But, it does help when needed.
I also have worked with neighbors to quiet down their homes. THAT really gets results.
Worth every penny. I use it all the time to both cancel noise and phase two receive antennas together. I also use it as an antenna mixer, where I can use primarily my Loop on Ground antenna (connected as the sense antenna), but then mix in however much if the main antenna I need to capture weaker signals.
I modified mine with additional capacitance to increase the phase cancellation angle, and I added a relay to short circuit the sense antenna when transmitting. Otherwise RF can blow out the little protection bulb inside the unit depending on what power level you are running and how close your transmitting antenna is to the sense antenna.
The main relay in the 1026, like any relay, doesn’t like hot switching of RF. Mine failed, but I called MFJ and then mailed me a replacement for free.
The secret is that the second antenna has to hear only the noise, not the signal. So, if it is a specific noise like your drill charger, you can run a coax near it with a small pickup loop to hear it. I moded mine to receive am broadcasts to cancel a local station. It was +40 without the antenna even connected. The 1026 completely cancelled it out; about 100 db or so.
Yes, that would be the ideal arrangement . . . but almost impossible to achieve in practice, unless the noise is coming from something inside your own house ! (in which case why not get rid of it, or at least turn it off?)
No, nor would I ! (mine was a quarter of the New price) . . . it just doesn't do enough in most real-world noise situations.
As others have said, the BEST thing to do is try and identify the noise sources, and come to an arrangement with the neighbours (like buy them a new Charger . . . or even a new TV, like one Local to me did!)
Yep, I did the same thing.
It didn't help reduce my dominant noise source, which is my neighbor's roof-top grid-tie solar system. The RFI from it comes from a wide subtended angle. It is as though the noise seems to come from multiple sources, all a different distance away from the main receiving antenna. You can null out one at a time, but that leaves the others...