Noise cancellers for HF

[MrWeetabix]

Hello all, I have recently got set back up at a new QTH after several years in the Radio wilderness.

Despite now living some 420ft higher than my last riverside location I have a very high noise floor across the HF band. I was wondering if anyone has had any experience of Noise Cancellers and how they found they worked for them?

I have been looking at videos of the MFJ and WIMO devices primarily. I was wanting to get back into Digimodes using my Signalink USB adapter which connects using the 13-pin DIN connection on my Kenwood 570. I know that the WIMO needs to have a TX cable connected to the radio to bypass itself on TX as it does not auto detect and that this also connects using the DIN connection on the radio. The MFJ also has this cable connection option but also has the detection built in (though oddly MFJ Dont recommend you use it?!?!).

Obviously the auto TX Detection would be ideal so I can still use my signalink, so I am really looking for feedback from anyone who has used either device, and/or used them with datamodes and how you achieved that with any success. I am also open to other suggestions for Noise Cancelling options.

Thanks in advance

Craig

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[ch25]

Based on my and my friends experience it's wasted time and money.
If you can't get rid of local noise sources best solution is to find someone countryside you set RSP1A connected to internet, RX antenna and listen remote and TX from your QTH.
Chris

[MrWeetabix]

Thanks for the prompt response.

I haven't had time to see if I can eliminate any of it yet. I will do the usual of battery-running and turn off the main breaker, then work from there, but I am concerned that its not coming from my property.

I would love to run a remote radio from
Some idilic far-flung countryside locale but thats sadly beyond my means at present.

73 de Craig

[Buick Mackane]

I Had one a while back but wasn't impressed with it. Although i didn't really experiment with the noise antenna which apparently is the key to getting good results, Even if you did get results with it you still have the added problem of switching it out of circuit on TX, Too much faffing about in my opinion,

Have you tried to find the source of the noise ? That might yield better results than wasting time messing with a QRM Eliminator

A good way to trace noise is a portable radio tuned to a quiet spot on the AM BC Band, How much noise we talking about weety ?

[MrWeetabix]

I literally completed the install late on Tuesday night and have not had any real time since to eliminate easy sources.

I was just considering the worst case scenario and what I might to enjoy the hobby again, or at least the HF portion of it.

The noise floor is roughly 5-7 on most of the HF band. Slightly higher from 40m down over if anything and that was testing at around midnight

[Buick Mackane]

I literally completed the install late on Tuesday night and have not had any real time since to eliminate easy sources.

I was just considering the worst case scenario and what I might to enjoy the hobby again, or at least the HF portion of it.

The noise floor is roughly 5-7 on most of the HF band. Slightly higher from 40m down over if anything and that was testing at around midnight

Is that all ? These days thats classed as normal, I Think it has to be around that level before ofcom will investigate, Which is another option, But they don't install faith in me personally

[MrWeetabix]

I had OFCOM involved in PLT at the last QTH and I recall them being quite helpful really to be fair.

It doesnt sound like PLT though I can hear hints of it on 11m at times.

Between looking after a new baby and other household duties its took me the best part of 5 days to get it all up and sorted so needless to say I was a little disappointed at how poor it was when completed

[Buick Mackane]

I had OFCOM involved in PLT at the last QTH and I recall them being quite helpful really to be fair.

It doesnt sound like PLT though I can hear hints of it on 11m at times.

Between looking after a new baby and other household duties its took me the best part of 5 days to get it all up and sorted so needless to say I was a little disappointed at how poor it was when completed

That's just the way of it now craig, We live in a more electrically noisy polluted world due to crapo inported gadgets etc, If you go down the route of a QRM Eliminator forget the ones you posted pics of they're daft money, Kits are available for a fraction of the cost.

Turning your pre-amp off on the lower bands should help a bit

[MrWeetabix]

I’ve never been a fan of pre-amps. I dont think they work very well IMHO.

Well hopefully when I get a run at it I can make it usable, or close enough at least!

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[Buick Mackane]

Keep us posted

[MrWeetabix]

I wonder if eBay sell ‘Neighbour Cancellers’

[PeterA]

If doing the battery and mains off test shows improvement, a good addition would be a mains filter with surge protection.

You can make one to cover 1.8 to 30MHz easy enough...

https://gm3sek.com/2019/10/11/clean-up-your-shack-2019/

Or

buy one...

Tacima CS947 6 Way UK Mains Conditioner Surge Protection Interference Filter

These are popular with the audio lot.

[MrWeetabix]

Cheers for the tip. Could be a cheaper option to try

[PeterA]

Cheers for the tip. Could be a cheaper option to try

No problem.

To be honest having something like the Tacima CS947 or just a simple surge protection strip between all your radio gear and the mains to help protect it is a no brainer!

[Auldgeek]

If you can grab some recorded audio of your QRM and post it, there might be someone who recognises it. Best to record it in AM. There's a IO group dedicated to discussing QRM if you can be bothered joining. There's a few very knowledgeable guys on there.

https://groups.io/g/UKQRM


I have an earlier Wimo along with another assembled kit version I purchased on eBay that I think came from Poland. I've also tried the MFJ version. All of them are mediocre in what they were built for. Trick is to make sure your rx antenna hears the QRM as well as your main antenna, otherwise the phasing doesn't work, as you can't generate the noise null easily.
Regarding the ground requirement on TX, you should be able to get that from the socket marked remote that controls a linear amp.