Filtering & Noise Reduction for your Ham Shack (with Ferrites!)
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- Опубликовано: 13 сен 2024
- Potentially cut your QRM local mains utility power noise down with some ferrites. This is the way I did it but your mileage may vary! Callum.
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Hi Callum , good video and advice, have installed inline choke (2s removed)ring mains socket,then on seperate 20a feed socket from Dist board (dont worry i am a retired elec eng )added a TV Cath Ray tube def ring (knew i would have a use for it one day! wife calls it junk!) 12turns 2.5mm 3 core ,good up to 7mhz .But as the cables run together there is crossover ,so installed clip on s (31 mat)on meter side of dist board (4 on ph +N) 4 (Largest) on Earth bundle (- 1 s point) noise level now nearly as good as running station on batteries.. Its like adding radials to a vertical contstrained only by budget 73 s .
Hiya John.. Well it turns out I don't have any mains RFI but your advice sounds great!
I have no idea what you just said. Could you make a disagram or a video?
@@mrtechie6810 Hi sri not able to make vids ,have enuff issues setting up N1MM logger for rtty contests hi...have installed seperate 2.5mm to station via Old CRT Deflection ring(philips colour tv 1980)
wrapped 2.5mm 3core thru ring 12 times
then also added inline large torriod 31material to radios socket outlet..
this cut my noise level by 2s points
I've had good success with my ferrites. Dropped noise floor 2 S units in some situations, but even a few dB can be mighty useful in working those weak signal contacts you really wanted to make....
Good tip!
FWIW I made a copy of the GM3SEK filter but without using the clip on ferrites (but using the correct mix) it made a significant improvement to noise levels. I was able to just unplug the radio to swap from "filtered" to "unfiltered" at best about 2 S-points drop. 3 turns on those cores is not really enough for the lower HF bands, you can get 6 or 7 easily if you strip the sheath off the cable. The 12v distribution is good advice, some of the wall warts are a nightmare for noise.
Yes good point. However, in my case, there's no change going between batteries and mains...
@@DXCommanderHQ well that is a valid point! A friend found similar with his station (no difference between battery and mains) so no amount of common mode filtering is likely to change his either.
Switching from your mains to a battery will only reduce the noise if the noise is coming from something associated with your your mains that isn't RF based. An item such as a wall wart produces interference via RF so even with a battery if your radio is close enough it will pick it up.
I'm happy you employ Metrics... 👌
Nice video. It would be great to see a comparison of receiver noise with and without the ferrite sponge ;-)
Of interest.. And in my case, there's no difference! Woops.
Hi ,well i found about 2s points noise reduction using the large clip on , 31 mat ,from"amateur goodies"
on Top Band (rfi locally was S6 on HF Doublet 50M 10M High openwire fed via Balun+ ATU no earth )
made comparisons by running FTDX10 on mains PSU/ battery operation ...
There are lots ofWebsites run by Radio Amateurs like Callun and GM3SEK , but for whats its worth-
I stripped the outer insulation from a 13A extension cable ,then using a drill ,twisted cable (PH.N.E) about 1 turn in 50mm , 12turns via ferritte clip on placed in plastic wiring box, load tested on a 3kw heater for an hour (safety temp check, noted fuse was warmer than cable )
My view is that rfi noise from mains is passed via the metal body of the Linear PSU to the negative supply to radio,(not safe to remove the Earth conection and difficult to modify PSU ?)
Hope you checked the correct polarity and earth on those sockets Callum. I don't think you doing your own electrics are legal.... not here anyway. Stay safe, I like your video's! 😉⚡️⚡️⚡️
Completely legal if it's a plug top.
@@DXCommanderHQ I've found many Chineseium power strips and such are wired incorrectly - polarity.
Thank you for sharing .
If the coax cable was placed through a steel flexi tube or copper pipe the ferrite filtering noise reduction wouldn't of been required & sadly ferrites do very little in terms of noise reduction , though ferrite is indeed mainly effective within DC power supplies , for future cable replacement or addition steel square galvanized box trunking cable management can be used , it's ideal shielding from 50Hz , & SMPS supply noise ,the box trunking will require an earth grounding to slug down any exterior electromagnetic noise within the radio room area.
Ferrites can be sort of used as an addition ,though ferrites are normally used to help reduce spikes but anything to help reduce noise , though the steel trunking would work without doubt & would provide positive results without fail , this method will work beyond question , but it is more expense .
If the material cost is a factor there is a cheaper alternative for those at home for example , as in 25X16 sticky back PVC trunking , prior to placing the coax into the trunking place silver foil first neatly into the trunking cavity & then place the coax in to the trunking cavity & fold both sides of the foil over the coax , it's not as good as the steel trunking or copper tubes , silver foil would also be tricky to earth too , but it would still be far more effective then ferrites nevertheless , the aim would be ideally isolate in flexi steel from antenna right up to the back of the radio , you'll bless the day & won't look back rest assured .
I find it fascinating on those that spend huge amounts on radios & yet have exposed coax cables , interesting .
Yes, you have said that before on another video I thin,
Kindly explain RF grounding -- for uppers storeys? Seems it shouldn't work on HF....
@@mrtechie6810 Hello @mrtechie6810
That's a good question , the grounding in terms of radio transceiver operation from multi story properties will essentially depend on the condition of the electrical system of the property .
The earthing requirements on a property, external earth loop impedance (Ze) should be 0.8 Ohm for TN-S system & 0.35 Ohm for a TN-C system ,these measurements are considered satisfactory by the NICEIC & other electrical safety bodies , however on aged electrical installations the (Ze) readings can be higher , to measure the (Ze) your particular flat you would need to carry out the (Ze) test by a qualified electrician .
If the (Ze) measurement is satisfactory this will provide a sufficient grounding to the radio & antenna .
If you are using a 13.8V DC power supply within the property technically the black negative output conductor from the power supply should relate to earth in effect the radio & indeed the antenna is grounded to earth .
For mobile or portable radio transmission a ground electrode stake should be used .
I hope that the above has been of some help to you .
Hi Mr. Callum, Well I finally found you again.. That is Good.. ♠W.G.
Welcome back!
Would have been good to see the difference in quality of the power lines on a oscilloscope before and after
Indeed. But I only copied folks who actually did that, I just did the installation :)
are those "ring" circuits? You guys wire the house in ring circuits? no direct home runs to the service maine panel? I am amzed that works! wow!!! PS your videos rock! I am saving up for ur antnna! hopefully soon!
All the sockets on the walls are MOSTLY rings, yes. Actually with an apporpriate breaker, you are allowed a single run. I'm not an expert on rules.. So I plumbed into the 32A breaker system via a plug-top (at 230V). Still working great.
Great video, as always but where are those related links you mentioned you'd put in the notes? Thanks again..
Good point! I can't remember - drop me an email and I'll figure it out sorry!
Hello - I rarely comment on peoples RUclips offerings.
You seem very helpful to a lot of people.
May I suggest - When you are connecting your 6mm metal rod to the flexible (what ever it was), A good interface, that may grip both pieces very well could be shrink tube.. I know, not a biggy, right? Have a goodday VK5AMJ
In the radio shack is it better to use ferrites in the power cables that go to the radios of should have them on the antenna cable ?
It all depends on what problem you are trying to solve.. Both is belt-and-braces.. Honestly, that would take a chapter in a book.. Sorry to be so short.
Can you provide the link to where i can get these exact Ferrites that you are using in this video. Thanks
Try Farnell.. They come up fast on a search.. "BIG FERRITE CORE"
I wouldn't have put it on a plug top I would have hard wired it straight into the socket and all those extensions on a spur I wouldn't trust them would have used patrices and sockets fed from your trunking loop in loop out
It's been like this for 4-months now. No hot spots. Also, the landlord is responsible for the electric. Had I wanted to do that, he would have HAD to book his industrial engineer.. (and the cost) Can't be bothered!
Where did you get those ferrites I got some similar but lost that order They were from digikey but I'll be darned If I can find duplicated in short I didn't order enough
OK, lots of suppliers in UK including Farnell.
Palomar in US carries some big ones.
great topic! you’re 20amp at 220v ?
No.. I can pull 32A from this socket BUT the rating on the fuse is 13A.. So basically 20A on voice peaks :)
@@DXCommanderHQ You need to speak louder then 😀
Nice video. Is there a reason for looping through the ferrites individually, or would looping through both at once yield similar results?
Similar results I believe.
How much noise reduction did you get compared to dirty mains in s points
I don't really know.. Once it's in - you have no idea because you can't easily switch it in and out... I was "told" to do this by a good friend - so I did..! LOL
You have 220V AC as wall sockey power?
Yes, in the UK we have only 220/240V sockets. There is no 120V.
WOW where SPECIFICALLY can I purchase these Monster Ferrites? Make and Model #? Mix#? I Wish we had PROPER PLUGS AND SOCKETS like in the UK. 73 DE W8LV BILL
Oh heck, I can't remember.. I think it's this one uk.rs-online.com/web/p/ferrite-sleeves/4669164
Try Palomar in US. Just picked some up
Bait & switch. Common Chinese tactic.😂. "Here's your T240....oh, wait. Our bad!" Ancient Chinese secret (if you know, you know).
😋😋
*.. GOOD THIS **#FERRITES** (ONLY "COST" 50 cents !! FOR A "BIG ONE" ..) OR **#WHAT** "YOU" SAY ?? THE "COST" IS ... !!!*
*I DID "NOT" HEAR "IT" ...*
Neither did I.. Best to write in a way that I can understand if that's OK.. Thanks.
Sketchy as #uck. Please NO ONE drill or screw through multiple socket outlets like that. You don't know if you are touching or have damaged the bus bars inside. The screws now protruding on the front could kill you.
Putting the flex through the ferrites creates a common mode choke. Good for interference suppression on mains cables.
Mr DXCommander please stick to antenna advice...
😬😬😬😁😁😁
You are talking bollocks. If you look at the back of most of these sockets, you can see where the inserts in the tooling for the front holes. Most times they blank them off and leave a keyhole. Just drill them out. It's fully insulated. Next time, be more respectful in your style.
@@DXCommanderHQ Well sad and so true.
Excellent idea and beyond that, awesome dog. KI7YWO