If you set up noise antennas properly, any of these devices can work for you. That’s the essence of my QRM Eliminator Wrap-up.
Sadly, all good things come to an end. It’s time for me to return my borrowed NCC-1 and MFJ-1026 to their rightful owners. Thanks VE6KK and VE6AGR, respectively. Also, time for me to provide a QRM Eliminator Wrap-up.
Our tests showed that the DX Engineering NCC-1 is a marvel for both reducing local RFI and phasing multiple antennas. I found everything about this unit smooth, precise and lab-instrument quality. As expected for the $850 price, I guess. If you ever have a chance to grab one of these used at a flea market (remember them?) give it serious thought.
At the other end of the price spectrum, my RA0SMS X-Phase actually worked pretty well, especially as a $21 kit. Although somewhat prone to IMD with a wideband antenna, careful adjustment of the antenna attenuation controls sorts this problem in many situations. Phase adjustment is a bit limited and not very symmetrical, though, and there is not really any gain for a noise probe. However, if you have the right antennas, you will find this unit performs okay for RFI reduction, surprisingly well in a few case. Worth a try.
JPS got this whole thing started with the ANC-4 back in 1995 which is when I got mine. Thanks to Timewave for keeping it going. Although lacking gain control for the main antenna, it does a great job reducing local RFI. Phase control is a bit touchy (as are all except NCC-1) but results are repeatable and noise null is sufficient for noticeable improvement.
MFJ introduced its MFJ-1026 (and 1025 without preamplifier) soon after. I found its performance comparable to the ANC-4. Unfortunately, performance is limited to HF due to hard-wired high pass filter. From what I have read, though, build quality varies with the MFJ, so if you are buying one used check it out first.
QRM Eliminator Wrap-up Closing Remarks
You can read additional notes about how these units performed in my previous articles. Suffice it to say, they all work for noise reduction but only the NCC-1 does a good job at serious receive antenna phasing.
As discussed many times, the critical factor for RFI reduction with these boxes is the antenna setup, particularly using noise probes to pick up RFI rather than desired signals. It’s really all just math, whether done analog or digital with a two channel coherent receiver.
My conclusions for QRM eliminator wrap-up? First, get the noise antennas right for your specific requirements. Second, use diversity reception if you can. You can do more with I/Q data at baseband than with any analog box. Third, try any of these devices if you want to enjoy HF reception again on a city lot.