I am a shortwave listener. I have battled S9 noise on all frequencies below 10 mhz for some time. Most of it is caused by my new build house central central heating and hot water system. Having used a similar noise canceller years ago at another location, I was confident this new noise canceller would give some improvement. It does work very well, you have to experiment with all combinations of settings for each band, I also found a longer local sensing aerial worked better for 80 metres, wrapping part of the sensing antenna around the incoming main aerial coax cable seemed to help on lower bands. I have put chokes on the coax to my wellbrook loop antenna, chokes on power supply cabled, this noise canceller made the biggest difference , well worth it.

Great video! Thanks for the clear demonstration of how to use it.

Thank you Mike, Great demo. I just ordered one 73 M0HDX

It does work if you use the right aux/noise antenna, the telescopic whip is useless. You must experiment with different antennas combination. I have an MFJ, can't live without it.

I got one of these a few months ago. It works better at higher HF freqs. When set to null on 10M, I could hear stations that I couldn't hear at all with it turned off. If you're interested, try to make sure it has the built in VOX. On ebay most of them don't have this feature. The seller I bought mine from isn't carrying them right now because of the Ukrainian/Russian war since he is in the Ukraine.

It basically works like noise-canceling headphones. It samples near field noise and turns phase 180 degrees. I would not call it attenuation as it is selective. Probably if your receiving antenna would be much better you would have an attenuation effect. That needs further testing. What I'm interesting in too is how it will react on near field radiostation like radio amateur next street or so.

Hi Mike, Thanks for your videos I really have enjoyed watching them. This reminded me of the time I first discovered this unit I blew the input cap by reverse polarity. My eliminator does not have a label warning of no PTT no RX so I will be adding two warning labels today. the unit was recoverable with a quick change of the blown capacitor, so all was not lost from this little wonder. thanks again and will look for you on the bands down here in Derby 73's. 2e0tcu.

Hi Mike, I have the MFJ version which I've done some experimenting with. I had very mixed results to be honest. My personal experience is that it was absolutely fantastic for narrowband QRM on spot frequencies but it was pretty hopeless on wideband QRM (such as VDSL or other broadband interference) which covers the whole band. I did however find having to keep tuning it every time that I changed frequency/band to be a bit of a pain. There's no doubt about it, they do work & they have their applications but it's not a silver bullet. Unfortunately it didn't quite give the results that I was hoping for in my case (where I have very high noise across the entire band on 40m & 80m). Having said that, there are a lot of cases where I can see it being a great addition to a station. To cut a long story short, it's a few months after experimenting with it & I don't currently have it connected!

Nice one Mike

I think the crucial bit here is as you switch the unit in and out of circuit, yes you can see the amplitude drop but the signal content of your scope seems to drop by the same amount. Is the signal to noise ration actually improving ? Interesting and something I have thought about. Do you still use the item 6 months on or is it on a shelf ?

Wow . Nice . Ty

You R Great

Hi Mike, I have 2 of these things but not yet tried either of them out yet. I've seen many videos about them, including 1 that was using one of these in conjunction with an MFJ audio stage external noise eliminator. However, I forgot to save the vidio and cant remember who made the video. What I do remember is the the combination worked very well, as he demonstrated each device separately, and then combi ned, during which the results were superb combined.. Kind Regards , Ray. M0RAY.

Tengo uno de los que se venden en kits y me funciona rebaja el ruido de la señal y rescata al operador, no me arrepiento de haberlo comprado, montarlo y usarlo, desde el. 2020, saludos Mikel

I have an old FT 840. I use one of these with a BHI 1031 audio DSP box and both transform the operating experience. I set mine with gain 2 to max - no attenuation of the signal. My antenna is a 2m band colinea vertical on a 5m pole. I have HV power cables (pylons) less than 100m from me. Once matched, i get a 2 s point reduction in noise on the 40m band with no signal attenuation. For £50, that is a good return. I am still experimenting with antennas - there may be more to come. The bhi unit clears up the rest. I did have an Icom 7410. My FT840, Eliminator and bhi unit blows the wheels of it.

Good video, I have these issues at my qth as well. I'm actually looking for tips on attenuating USB noise from those cheap SDR dongles.

Nice video, thanks Mike! Expensive radios may have several good filters as some commented here. On the other hand that's why they are expensive. If the receiver of a radio is sensitive enough, then indeed this eliminator works by offsetting down the signal level such that receiver "cannot pick up" noise even on a broader bandwidth. Although S/N ratio is not improved (if not decreased), the noise is attenuated away at the antenna port. As shown, the combination of eliminator+radio with good receiver works fine in practice (and is indeed cost efficient if radio is cheap). And human's perception effectively reacts on audibly absent cracking noise rather than on poorer S/N and lower audio volume. I think it would be interesting to test following: 1) What about testing this eliminator with radio having the receiver which is, say, few times less sensitive? I am pretty sure you will find radios when this eliminator will not perform well. 2) Also would be interesting to see how it performs at 70cm and 2m bands, say with handheld radios. 3) Experimenting with automatic or manual squelch may lead to surprising results drastically limiting eliminator's application.

Awesome! Thank you so much - terrific demonstration and (critically) rotating the controls to show the effects of what we would be doing ourselves - extremely helpful! thanks so much for doing this. I too, am sold on the concept. Just need to have the 2nd antenna preferrentially pickup (and counter) the noise - like favoring polarization or orientation... then it's a slam dunk, eh? How'd you get that cool callsign? 🙂 Best to you- RN AJ6IR

Congratulations for the video! Can you advise PTT cable details ? Thanks

Do you put this between the ATU and the antenna and what happens when you tune and then TX

Do I put it before the antenna tuner or after? I've read both...

Used one of these for over 30 years although mine is RF sensing so doesn't need a PTT switch, by reducing the noise floor presented to your RX input it certainly makes for cleaner reception of signals, experimenting with the noise antenna is also interesting, the better it picks up the interference the more effective it is. - Mark

Do you use stock aux antenna ?

how to use on ic-706mkii for PTT input?

Hi Mike have you tried an external antenna outside? I put up a short piece of wire and fed with crap coax and definitely noticed a difference between the whip antenna and the external 1 73 Gm4zji Chris

Hi, Mike. Congrats on the video! Would it be possible from you to share the link were you bought that product? I can`t find any place were it`s sold like your version with the PWR/TX LED`s on the front panel... all the versions I found don`t have those LED`s, I wonder if they are old versions??? Cheers! 73`s

I'm still trying to track down the source of QRM generated from some device in my Hymer motorhome. I have found a fuse, which when removed, stops the noise, so now I just have to find what circuit that fuse is protecting.

Hi Mike, where did you order from also is for the flex ptt using ppt tulip plug on the back of the flex and straight to qrm eliminator?

Surely turning down the rf will reduce the noise?

Congratulations on the video. Your device has 2 gain and one phase knobs. Others have 2 phase knobs and a gain knob. Can you tell what the difference is? Thanks

Hi these boxes seem to vary slightly, do you have the link on ebay where you ordered yours, if its still active , best regards

Eficient in 14mhz ,21mhz up ???

S/N ratio is key. Everyone is 5/9 anyway 🤣

Hi, maybe I've missing the part, but when transmit with radio how much power can handle the bypass with ptt? I've my beloved Icom 781 that still put 130 watt in some band ... 73 de IZ3QVB Alex

Hi Mike, I'm not convinced, but I am prepared to be. Could you not achieve the same result using the RF gain and or filters? available with your software or in my case on my transceiver? From the comments already posted I think I will be in the minority. 73 and thanks for the videos, enjoy them all.

Turning the RF gain down does the same thing

Those are not required......If you just use your radio filters you will get the same or better results.