Successful QRM / RFI (Radio Frequency Interference) Tracing!

No video

Successful QRM / RFI (Radio Frequency Interference) Tracing!

Рет қаралды 18,169

Күн бұрын

A pre-planned local area power outage gave me a rare opportunity to experience my local HF noise levels without local interference. Even though this outage only covered a few roads around my house and a limited number of properties, the impact was incredible! I heard New Zealand for the first time from home 😀 It also highlighted a significant amount of QRM, particularly a strong 70KHz repeating signal across all the HF bands.
In this video filmed on New Year's Eve, I build a simple non-resonant RFI/QRM loop antenna and use it to track down the location of the interference. Despite looking rather odd wandering around the local area looking as though I was detecting bats or something, it was good fun and in these times of social distancing, caught the interest of local passers-by with whom I chatted and explained what I was up to 😀. All were intrigued and one had even heard of RAYNET!
My thanks to The Radio Amateur Society of Australia Inc. for the antenna design.
Here is the link to the previous area power cut video: • A Rare Local Area Powe...
And this is my previous house power off tests: • Reducing Electrical In...
And also, here's the link to the follow-on video where I finally solve the QRM problem!: • I Found & Eliminated M...
This is one of many amateur/ham radio related videos on my channel. Please feel free to browse 👀, like 👍🏻 and subscribe 🔔, remembering to hit the bell so you’re notified of new videos as soon as they're published and you don't miss out.
0:00 Introduction
0:43 Antenna Design
1:40 Antenna Build
10:25 Backpack and Power Needs
12:53 Initial Tests
13:21 Direction Finding
16:38 Closure
Thanks.
Ian.

Пікірлер: 143

@timg5tm941 3 жыл бұрын

Superb video

@ianxfs 3 жыл бұрын

Thanks Tim! Nearly sorted 🤞🏻

@SocialistDistancing 3 жыл бұрын

Very interesting.

@ianxfs 3 жыл бұрын

Thanks!

@bashcoder 3 жыл бұрын

This is just great. Can't wait for the next one!

@ianxfs 3 жыл бұрын

Fingers crossed 🤞🏻

@stewpot3971 3 жыл бұрын

Interesting video...I have a similar problem on 40m... looking forward to the conclusion. Good luck and 73!

@ianxfs 3 жыл бұрын

Fingers crossed 🤞🏻

@Foxsoup 3 жыл бұрын

That’s fantastic! Very clear results there and an easy build. I look forward to hearing how you get on with it. All the best and keep up the excellent work!

@ianxfs 3 жыл бұрын

Thanks!

@spanners73 3 жыл бұрын

Great upload Ian... looking forward to the next installment 👍

@ianxfs 3 жыл бұрын

Thanks Paul!

@vwtyp53i 3 жыл бұрын

Very nice video thanks 73 from Austria

@ianxfs 3 жыл бұрын

Thanks! Check out the follow up video and hello Austria 🇦🇹 😀

@memorgan1 3 жыл бұрын

Excellent, thanks for posting this. Something I need to do I think.

@ianxfs 3 жыл бұрын

Thanks Mark!

@Scotscan 3 жыл бұрын

Very interesting build - probably the easier part of the project. I imagine part 2 will be trickier! I hope your neighbours are cooperative.

@ianxfs 3 жыл бұрын

Thanks! Yes, fingers crossed! 🤞🏻

@gbamck 3 жыл бұрын

Fantastic sleuthing, Ian! Very interested in the source and looking forward to your update. Let's hope the door-knocking yields welcome 'reception' 😉

@ianxfs 3 жыл бұрын

Indeed Mick! So far, so good 👍🏻

@TheNoCodeTech 3 жыл бұрын

Yes, thank you. I will be building one of those.

@ianxfs 3 жыл бұрын

Thanks! There’s now a follow-up video to this one too 👍🏻

@Jamesblaxland 3 жыл бұрын

Great Video Ian - Fingers crossed they are cooperative and you get this solved.

@ianxfs 3 жыл бұрын

Thanks James! 🤞🏻

@ronheron4179 3 жыл бұрын

I’ve made a loop too, after watching the success you had using yours. I’ve yet to try it out in the field but tests are promising

@ianxfs 3 жыл бұрын

Good one Ron! Hope it works for you 👍🏻

@lee2e0wyk60 3 жыл бұрын

Definately a worthwhile exercise & pleased you found the problem. I shall be doing the same with hopefully the same result. Great video, thanks for taking the time to make & share.

@ianxfs 3 жыл бұрын

Thanks Lee! And good luck with your own exploits 👍🏻

@M0RSF 3 жыл бұрын

Excellent loop build there Ian, and in the cold too. Very interesting video and hope you get the noise problem sorted. All the best for the New Year. 73 Chris M0RSF

@ianxfs 3 жыл бұрын

Thanks Chris! Yes, all the best 🥳

@kevinmatthews2620 3 жыл бұрын

Superb video as usual there Ian :)

@ianxfs 3 жыл бұрын

Thanks Kevin!

@chazrw2chz290 3 жыл бұрын

Good work. Hope the neighbors are helpful.

@ianxfs 3 жыл бұрын

Fingers crossed Chaz!

@NICKGAR7 3 жыл бұрын

Interesting stuff. Thx Ian. I’ll watch n listen with interest. Next video: digging up the power cables in the road ;-)

@ianxfs 3 жыл бұрын

Ha ha, yes 😁

@mplmpl7780 3 жыл бұрын

Love it excellent video

@ianxfs 3 жыл бұрын

Thanks!

@OldSal-d8h 2 жыл бұрын

Enjoyed the video. Having the same issue when using a ground loop. Good luck and happy and healthy new year! Cheers de N9NY

@ianxfs 2 жыл бұрын

Great and thanks! There’s a follow-up video to this one too if you haven’t see it already 😀 Merry Christmas 🎄

@VK4KK 3 жыл бұрын

Great video Ian. Good luck with everything and keep up the good work. And I hope that lockdown is really helping to get the UK back on track. 73 from Brisbane in QLD Kevin, VK4KK

@ianxfs 3 жыл бұрын

Thanks Kevin and Happy New Year! Yes, fingers crossed 2021 will be loads better than 2020 🤞🏻

@chrisbartlett6022 3 жыл бұрын

Verrrrrry innnnteresting :-)

@ianxfs 3 жыл бұрын

Fingers crossed Chris 🤞🏻

@brentjohnson6654 3 жыл бұрын

Great video. That loop antenna looks easy enough to make.

@ianxfs 3 жыл бұрын

Thanks, and yes Brent. Simple to make and I was really pleased that it actually worked 😀

@jollyfinequality9865 3 жыл бұрын

Really enjoyable to watch Ian. Inspiring. On top of a noise floor of S9+10db I have a solid noise of S9+50db which typically sits around 7.170Mhz. Tonight it seems to be at 7.106Mhz. I have more enjoyment with a mobile station. Thanks for putting the video together. Look forward to the next chapter. 73 2E0JFQ

@ianxfs 3 жыл бұрын

Thanks! Hopefully sorted soon 🤞🏻

@andycallaghan5028 3 жыл бұрын

I know what I’m building with that scrap bit of RG213 tomorrow! Thanks 👍

@ianxfs 3 жыл бұрын

Good one Andy! Have fun 😁

@markg6jvy135 3 жыл бұрын

HNY Ian 👍👏👏

@ianxfs 3 жыл бұрын

Same to you Mark 🥳

@pete1927 3 жыл бұрын

great video, it's amazing what distance it can go, so much for Chinese compliance and CE marking :-) the items are covered with regulatory marks LOL.

@ianxfs 3 жыл бұрын

Yes, frightening Pete isn’t it!

@whitefordpipeshandmadebymi7238 3 жыл бұрын

Excellent as I have intentional QRM from a local so called ham ...73 de ve3hip from Welland Ontario Canada 🇨🇦

@ianxfs 3 жыл бұрын

Hope you get sorted soon!

@ZL1BQDRoly 3 жыл бұрын

Great going Ian, reminds me of the "fox hunt" days. .....cheers

@ianxfs 3 жыл бұрын

Thanks Roly 👍🏻

@mike-M0MSN 3 жыл бұрын

Nice Video

@ianxfs 3 жыл бұрын

Thanks Mike! No kitchens were hurt in the making of this video 😁

@fivestar2227 Жыл бұрын

Im waiting for the video where we build a discrete portable EMP gun to silence those pesky rfi emitters.

@ianxfs Жыл бұрын

Indeed!

@MauriatOttolink 3 жыл бұрын

Use a blob of glue or a heat-shrink sleeve! That forest of spikes on 80m looks to me suspiciously like solar panel stuff. (Not viewed it to the end yet!)

@ianxfs 3 жыл бұрын

Ok thanks. Watch part 2 😀

@micedwards4037 3 жыл бұрын

Good luck on finding the problem

@ianxfs 3 жыл бұрын

Thanks Mic!

@kevinkc3onohelijeepworld953 3 жыл бұрын

Great piece of kit you have there. Fighting rfi issue myself. It’s coming from a am tower 640 am is coming out on the 1.920 MHz so written two email to am station in hopes that they can fix their 3rd harmonic. KC3ONO

@ianxfs 3 жыл бұрын

Thanks Kevin and good luck with that 👍🏻

@James_Bowie 3 жыл бұрын

Haha, a cliffhanger. Good work, mate. I love DF, but you sure picked a big rig to lug around. I have an FT-60, attenuator and small Yagi for that.

@ianxfs 3 жыл бұрын

Ha yes James! Not the most portable “handheld” I’ll agree 😁 Battery just died as I finished....

@James_Bowie 3 жыл бұрын

@@ianxfs FT-60 has 108-137 MHz aircraft band (receive only) which is great for tracking power line type noise.

@paulsharp5473 Жыл бұрын

I have some local interference pop up. It’s not there all the time but it’s S9 and it’s North West of me I only get it when my HF beam is pointing that way. So I’m going to make this and track it down.

@ianxfs Жыл бұрын

Good luck Paul! Hope you sort it 👍🏻

@SuburbanDXing 3 жыл бұрын

I am with @Bash Coder...I am looking forward to the conclusion of this. Great video, Ian...thanks for posting it...73! de WX0V

@ianxfs 3 жыл бұрын

Thanks!

@r188ops8 3 жыл бұрын

Great stuff Ian!! Once you’ve finished there can you pop over to Aycliffe? 🤣🤣. On a positive note, I spoke to the OFCOM engineer just before Xmas and with the log and wav files I’ve sent them, they’re coming out next week hopefully.....fingers crossed for positive results. The noise sounds exactly the same as mine here, 40/80/160 are a nightmare 🤷🏼‍♂️....looking forward to the next video.....Paul 👍🏻

@ianxfs 3 жыл бұрын

Good one Paul! Hope we both get sorted soon 👍🏻

@garymustoe2524 3 жыл бұрын

I have the same problem, noise is off the scale in all bands! The neighbour has had broadband fitted in his man shed and has run electricity into it also . It's impossible to operate . I'm now moving my station into my car and going mobile .

@ianxfs 3 жыл бұрын

That doesn’t sound good. Hopefully you’ll enjoy your mobile ops. Good luck!

@RFeye 2 жыл бұрын

This simple loop design can be vastly improved sensitivity wise, if you short the braid to the centre conductor of the coax at the end of the coax where you don't connect the centre conductor to the centre pin of the PL259 connector. Try both the original design and then the shorted design and you will notice the improvement in both received level and sharpness of the peak/null obtained.

@ianxfs 2 жыл бұрын

Thanks!

@MAV8865 3 жыл бұрын

Ian - VERY! useful looking forward to the next one, Can I ask you something what happens if the interference was coming from a sub-station can you get the local power company out to fix it? thanks again Ian.

@ianxfs 3 жыл бұрын

Hi Martin, yes I guess you can submit a report of evidence and take it from there on the basis there’s something at fault. Fingers crossed I can suss this one 🤞🏻

@VK5IR 2 жыл бұрын

Great video! Am I correct is assuming you simply reduced the RF gain or added attenuation as you got close to the noise to DF it?

@ianxfs 2 жыл бұрын

Hi. There’s a follow-up video to this one which is worth watching for the whole track, trace, eliminate story. I didn’t touch the rf gain, but used a “sniffer” for close in work 👍🏻

@sean2607 3 жыл бұрын

Excellent video Ian, really interesting. I think I know the property that you've pinpointed, is it the old Doctors Surgery? Also, how many times did you get stopped and asked what you were upto by inquisitive people?!

@ianxfs 3 жыл бұрын

Ha yes Sean, well spotted! Yes, I bumped into 4-5 people. All interested in what I was doing. One had even heard of Raynet 😀 Hopefully sort the QRM soon 👍🏻

@sean2607 3 жыл бұрын

@@ianxfs Brilliant. Certainly looking forward to the next video to see the outcome. M7MGX.

@jquintana7097 Жыл бұрын

Hi Ian awesome video. Would this loop work on 40mtrs as well?

@ianxfs Жыл бұрын

Thanks. Yes it should. It just depends upon the strength of the QRM and how close. Good luck 👍🏻

@Steve_Wardley_G6JEF 3 жыл бұрын

Great bit of detective work there Ian. I just had a bit of a chuckle to myself thinking....... Is this going to lead him back to his own QTH. Definitely going to try that loop myself. Did I miss it or was there a particular band you were on ?

@ianxfs 3 жыл бұрын

Ha yes, Stephen! I was sure it wasn’t me, but you never know! I’d tee’d up all my neighbours too with a lengthy note through their doors explaining what’s what and they were keen to do power-down tests etc. Sod’s Law this house isn’t on my small estate...watch this space! I was on 15m, but works on all bands 👍🏻

@zaperfan 2 жыл бұрын

You Should the regulators Ofcom how it's done

@ianxfs 2 жыл бұрын

Ha ha yes! With pay 💰😁

@fatboymotorsport 3 жыл бұрын

Great video Ian how critical are the dimensions, I see you were testing on 15m, my QRM is worse on 10m so would like the loop to work best there, thanks,

@ianxfs 3 жыл бұрын

Hi and thanks. It’s a non-resonant loop so it should work fine on 10m. I used it on 80 as well. Good luck 👍🏻

@plazi4 3 жыл бұрын

Hello there. Is it 900 mm before the chop or after the chop? Many thanks. Awesome vid.

@ianxfs 3 жыл бұрын

Hello! Cut 900mm of coax and then attach your plugs 👍🏻

@ianxfs 3 жыл бұрын

The 20mm bared-off section is at the top. So 10mm either side of the 450mm middle 😀

@2e0ggjrobin31 3 жыл бұрын

I have the same qrm. 68 - 70kHz spacing across all bands 👀 for your next installment

@ianxfs 3 жыл бұрын

Thanks Robin! Looking forward to getting it sorted 👍🏻

@MauriatOttolink 3 жыл бұрын

2E0GGJ That 68/70 khz spacing is identical to mine except that yours is a bit wider. I have traced mine, unarguably to a Roof Solar Panel installation. It seems that it is likely harmonics from the Installation Inverter. If it goes off after dark, that's a good indicator. Panels can cause QRN but more wide band. Listen to one spike on AM wide band and check for a pulsed sound.

@philstrons 2 жыл бұрын

Why did you use a cable length of 900mm? Does that correspond to a frequency of interest?

@ianxfs 2 жыл бұрын

Hi Philip. It’s a non-resonant length as per the original design by the Australian Radio Society.

@TonesElectronics 3 жыл бұрын

At the end of the video, they look like electric gates ? Is that the problem

@ianxfs 3 жыл бұрын

I first wondered that at the time, but it definitely seems to be coming from the house/area beyond. Watch this space!

@iaradtech1 3 жыл бұрын

Great video. I am making the same antenna and will use it with my FT 891 and battery that I use for Parks on the Air to see if I can track down my RF noise at my QTH. How did you put line on the map to triangulate? Did you use Google Maps some how?

@ianxfs 3 жыл бұрын

Thanks Kyle. I just used Google Earth and use the ruler option to draw lines. That was just for the video though. In reality you’ll either be able to remember or just sketch your area on a piece of paper and record your result lines on there. Good luck 👍🏻

@ianxfs 3 жыл бұрын

ps. Watch the follow-up video if you haven’t already 👍🏻

@DonzLockz Жыл бұрын

We're you listening on 70KHz with this loop?

@ianxfs Жыл бұрын

Hi, no I was on 15m.

@GM6DX 3 жыл бұрын

Nice loop seen this on the VK QRM website. Just wondering when you are using the loop does the noise increase when the edge of the loop is facing the source - or does it go quiet when the edge is facing the source?

@ianxfs 3 жыл бұрын

Yes, that’s the one 👍🏻 The null is face-on and side-on (edge) increases the signal. Both help with the direction finding 😀

@GM6DX 3 жыл бұрын

Thats great have seen a few and was unsure on how this particular loop worked. Did you notice which edge/ side of the loop was better the side which had the centre of the so239 connected or the side whixh didnt?

@ianxfs 3 жыл бұрын

No difference.

@aaronlynch139 2 жыл бұрын

G'day Ian Unless I missed it, you didn't mention what frequency you were using with the loop? Did you move up bands, or stay on one band? I tracked a leaking insulator on a 33kv line 8kms away a couple of years back, but that meant moving up the bands, starting at 40m then up through harmonics, 20, 10, then 6ish. I knew when I was hearing the noise on 70cm, I must have been standing awful close to the source. Then I physically heard it buzzing overhead. It was horrendous at home on 40m...'switch of the radio' type stuff. I have a local switchmode sweeping noise like yours locally this time. Different approach, so I am finding your video useful. Interested to know what freq you used with your loop to do your hunt. Also, were you using IPO or preamp on the 991? 73 Aaron VK2ON

@ianxfs 2 жыл бұрын

Hi Aaron. That insulator you tracked sounded horrendous. I stayed on 15m. I can’t recall if that was by chance when I turned the rig on. It will have been amp1, but just adjust the rig so you can pick up the QRM as once you’ve got a signal you’re off on the hunt. If it was mega-strong then I suppose you could attenuate to help with direction, but guessing the source won’t be that bad? I’m sure further down the comments someone previously suggested a different method of terminating the loop for greater sensitivity if you need it….good luck 👍🏻

@aaronlynch139 2 жыл бұрын

Thanks for the prompt reply Ian. I have a loop antenna here....a small wire within a bigger hoola hoop with a break and capacitor at the top, but I am very impressed with your little loop. Looks a nice simple solution worthy of an hour to knock up. I think the 991 was a very good radio to do this with. Beautiful receiver, so you certainly through some good equipment at the problem. Well done again, and thanks for sharing your experience. 73 Aaron

@andycampbell5416 3 жыл бұрын

hi would your loop antenna work to find inerference on 27mhz? cheers

@ianxfs 3 жыл бұрын

I think so Andy. I used it on 3.6 & 21MHz. As long as the source is strong enough and/or you can get close enough, you’ll pick it up I reckon. Costs buttons, so nothing to lose 👍🏻 Good luck 🤞🏻ps. See the follow-up video 😀

@andycampbell5416 3 жыл бұрын

@@ianxfs hi, cheers for answer bud` oh im suffering with a blanket QRM across all of my transmit modes,,, every frequency is wiped out with a S8 of hash!!!!!! AM is just a buzzzzzzzzz ,,,,,gota find it

@franciscolopez3229 Жыл бұрын

Can these dimensions be used on 27MHz. as well?

@ianxfs Жыл бұрын

Yes Francisco. It just depends on the strength of the QRM and whether you’re close enough to be able to track it down. Anyone trying will need to walk around their neighbourhood to hopefully pick up a signal. Good luck 👍🏻

@franciscolopez3229 Жыл бұрын

@@ianxfs That is very nice to know sir. The reason I asked is because I am having the same problem with static QRM from where I am at here in the Philippines both on 11 and 10 meter bands. Thank you so much for your reply, I really appreciate it. Always be safe and 73's.

@trialen 2 жыл бұрын

What frequency/mode do you use for the receiver?

@ianxfs 2 жыл бұрын

Hi, I was using sideband and mainly 15m. Works well on AM and other bands too.

@trialen 2 жыл бұрын

@@ianxfs Thanks. I've got a similar problem, S9 noise, repeating every 70kHz or so. Got an electric car charging point in the village, which is horrendously noisy and may be the culprit.

@ianxfs 2 жыл бұрын

@@trialen Good Luck! If you haven't seen it already, there's a follow-up video to this one.

@autoadjuster 3 жыл бұрын

What frequency did you use to listen for the RFI?

@ianxfs 3 жыл бұрын

Hi Philip. I used both 21MHz in the loop video and 3.7MHz in the elimination video. The loop seems to work across HF. There’s some stills in the second video that I used in the first so you’ll see the rig with 21MHz showing. I didn’t feel like I could film much in the second video as it was at the chap’s house. I did ask when I used the wand as I explained I hadn’t used it before and wanted to see if it worked and it would help others too😀

@autoadjuster 3 жыл бұрын

@@ianxfs Thanks for the updated info, my friend is getting RFI onto the input of his repeater. It occurs mostly after rain. It sounds like electrical arcing, it's sometimes so bad people with a weak signal cant get in.

@ianxfs 3 жыл бұрын

@@autoadjuster Ah right Philip. Hope he can sort it 👍🏻

@wd8dsb 3 жыл бұрын

Hi Ian, thanks for the nice video. The antenna design you used is definitely the easiest shielded loop to construct and works well on higher frequencies but I recently did extensive tests of it versus what I consider the traditional shielded loop design (where the free end of the coax shield and center conductor connect to the shield near the feedpoint) and the traditional shielded loop works much much better as you go lower in frequency compared with the design you used. From 15 MHz and up the design you used works really well, but as you go below 15 MHz the traditional loop is really a better choice as it has more gain. The design you built is really deaf down in the AM broadcast band as an example. At 7 MHz the traditional shielded loop has 17 dB more gain than the design you used, and down at 1.4 MHz the traditional shielded loop has 28 dB more gain. I've had discussions with The Radio Amateur Society of Australia about how deaf their design is as you go lower in frequency, and they agree that it works best when used from 10 MHz and up. Just FYI and 73, Don (wd8dsb)

@ianxfs 3 жыл бұрын

Brilliant explanation and additional information. Thanks Don!

@ianxfs Жыл бұрын

Hi again Don. I made the revised loop you suggested and used it successfully (new video). Thanks for the tip! 73 Ian.