Home-Base: High Noise Level

Hi everybody I have a serious problem, RF, I have 9 pound of the stuff all day a and it only drops at around 11 o'clock at night, I have turned all the electrics off in the house at the mains, still 9 pounds,I then connected to a charged car battery but still there,I am using at the moment a himalaya5/8 antenna,I can transmit and be heard really well but when they return the contact I can't hear half of them,this is doing my head in,how can I stop all this RF or at least drop it down.Help.

I notice the same in my building. Don't think its electrical, more related to the actual brickwork picking it up.
Maybe copper rods into the soil might help.
If i go outside car to car noise drops from 7 to 1

Hi Bev, I came across this last night. Some of it is way above what I understand,  but there some links and ideas that may help.
73's
Nik

http://www.m0nwk.co.uk/mains-electricity-filter-for-emc-noise-reduction/

Thankyou mr tang and nik70uk for your help on this matter, now I have a project to keep me busy for a while, will let you know the results later. Many thanks,CT3574-ww692!

Hi Bev,

You're going to get loads of ideas, some simple, some a bit more complicated.
(I'm going to waffle now, bear with me, these are my own experiences...)


In my own quest to sort out interference I nearly went nuts, figured most of it was down to my neighbours and luckily calmed down before I started doing anything stupid

Years ago everyone complained we were interfering with their TV reception etc. due to our CB radio antics.
"Must be you.... You've got that stinking big aerial up!", they'd say...
Nowadays it's us on the brunt end of interference with just about every electronic device kicking out spurious radio signals

You've done the basic tests, (switching off electrics etc.), and still have the problem.
You can go mobile and get away from the interference or even move to an out of the way location, but Diss is hardly a metropolis area is it?


Most of my noise was coming through the mains wiring - even when you switch off the electrics it's still coming through, an RF "sniffer" or simple AM/MW radio proves that. But, if you had a communications receiver you'll see that most, (not all, the "new" and WARC bands etc.), are actually free from interference. That's because the power companies had to start filtering that hash out! Unfortunately CB frequencies aren't catered for.....although you will find mid-band/EU/CEPT is actually less affected.

So, a mains filter might help but I didn't find much of an improvement.


Ground rods......
Hmmm, unless you know what you're doing I personally wouldn't start mucking about with them. You could make your antenna a fantastically efficient lightning rod, your mains protection unable to function, (think street grounds and neutral bond looping), and even pick up noise from the ground!

QRM eliminators....
You can buy them, (usually expensive), or make them. I'm lucky I was able to make one. What a PITA that thing was!
Some people claimed to have good luck with them, most example videos show them to be great, (usually heavily doctored to get you to buy their product), but what a pain. You fiddle, tune, change 'noise' antennas and on it goes. Get one frequency clear and the moment you QSY you have to fiddle with the damn thing again! Yep, not the 'magic' solution.

Working with your neighbours.....
Yeah, good luck with that one. They don't care about your radio 'hobby', they won't let you start fiddling with RF chokes on their TVs etc. and it won't take long before they swing it back around to you and blame your CB for their Wi-Fi dropping out 'sometimes'. 
Heck, I've even heard people blame CB for making their 12 year old, 300,000 mile washing machine play up!!
I have a neighbour with a spangly solar panel roof...damn thing could transmit across the cosmos to other intelligent life...do you think they care about my radio? Ha, not one flipping bit!


Not sounding good is it? .....bear with....


Antennas....
It's well known that different antennas have different noise responses, by design or their efficiency increasing your signal AND noise floor. You'll get differences of opinion on types of antennas, manufacturers and makes, loops, end feds, deltas, on and on it goes. Most of us get stuck in that quest for the 'holy grail's of antennas...and why not? For most of us it's flipping fun and we grow the proverbial 'antenna farm'. If that's for you, sure, give it a go.


OK, pause, pant, deep breath...we're getting somewhere.

This so far is what I went through. Not much fun is it? So what did I do....

Turned my RF gain down and switched my noise blanker on!!!!!!!


No way?!! Yep, flipping worked and amazing we miss the simple stuff! If your RF gain is cranked all the way up, you're also pulling in all the crap. Got a weaker signal? Seems counter intuitive to turn the RF gain down doesn't it? But you'd be amazed how their signal suddenly jumps out at you. I won't go into technical nonsense but your radio often works better with that gain knocked slightly down.

Noise Blanker, (NB), Automatic Noise Limited, (ANL), or any other fancy thing a manufacturer calls it. These can be surprisingly effective but sometimes with a catch....on my own 40 year old Yaesu it's NB is fantastic, so long as I do the opposite of what I've just said and turn the RF gain all the way up! Again, technical nonsense explains it but if you 'boost' the noise the blanking circuits work better.

Flip...after all that I found a simple solution

I know, can't be true....but give it a go, would've saved me a lot of trouble if I'd had that little tip.

I went from S9 of hash on the triple 5 to S2 with that simple exercise. What a dumb f**** I am!


Anyway, (waffle over), keep at its there's bound to be more suggestions but worth trying simple stuff first.
(Like the 'clarify' control, not all of us are bang on frequency and that can often improve a DX contact).


Oh, before I go. A friend had similar issues....we tried everything....until I noticed the rusty old PL259 hanging out the bottom of his antenna. We changed that and amazingly his noise virtually disappeared! Like I said, the simple stuff

Let us all know how you get on.


All the very best to you,
Victor

Victor,

That was a very informative post you entered regarding reducing the RF gain then utilising the Noise Blanker, thanks.

Bovril

Hi Mike,

If my waffle could help even one person then I'm grateful  So thanks for the feedback, it is appreciated.

All the best,
Victor

Victor your "waffle " can be very interesting you carry on all you want.
I found the RFgain and NB to be the fix for me especially on my FT-450d not as good on my RCI-2950 but helps a lot.
I think people think the RFgain has to be up full or they might miss something but folks just try it you will still hear the station and it might not sound as strong but in reality if you think about it with the rf turned up full what is the loud noise you hear yes it's noise not the operator you want to contact.

works good, back it down till noise near gone and the voice pops out of it. Less irritating also when leaving it on standby.

Hi  
I had the same issue. 
Went through lots of ideas to cut the interference down and 
ended up with the same solution. 
RF Gain down a bit and use the NB/ANL and Hi cut. 
Not perfect but way better than before!🥳

Thanks for all the info victor, There is a lot of info there for new comers to C T cropped cheers mate.

No worries Bev,

I appreciate the feedback and thanks, so you're very welcome.

It seems my 'waffle' was appreciated or helped by more than just yourself and maybe read by and helped others without my even knowing. In which case, I thank you for posting on the forum. It all adds to the Charlie Tango experience


All the best,
Victor

Thanks for that nugget of information Victor, going to try the RF solution in the morning and see if it improves. Cheers.

Move the aerial as far away from houses inc your own as possible

Failing that take the foundation ham test easy to pass
then you have some clout if getting noise on ham bands get ofcom to sort it and
if by magic it will probably sort out the 11m noise as a side bonus and your neighbours cant do squat as you will be licenced to transmit on those bands and they wont be to interfere with them

There has been a lot more I've learned during the past two years or so since I last commented to this posting....

One of which is that the practice of turning down the RF gain is a lot more widely accepted than first thought. (Yet more still think it's nonsensical to diminish the 'capabilities' of their finely specified radios.)

The other would be 'Common Mode Currents'.


Yeah, that phrase might send shudders into some with even more having paid a pretty price for all the ferrite materials they lashed onto every bit of coax and connector systems they posses!

There's a bewilderingly vast array of subject material available online concerning such matters, some good, some, well, not quite so good and a lot fixated on the problems of transmitted RF reflected back in the shack more than anything else. (Not SWR, but the effects on the outside of the coax braid as the 'third conductor'.)

Not many however tend to mention the effects of mitigating noise on reception which is where some of the solutions to common mode current can come in handy.

On my own station the addition of a 1:1 'bisectional/bifilar' wound ferrite toroid made the most dramatic effect to my reception noise even though I have now switched to a balanced doublet or non-resonant dipole system. (That already decreased the noise by a huge amount compared to an end-fed antenna 'solution'.)

The following link to such an example (although a commercial establishment) does show you how you can construct such a device :-

https://www.hfkits.com/manual-common-mode-choke/


You can of course take the simpler and sometimes suggested example of wrapping around your coax to a suitable diameter and number of turns to also mitigate common mode. This is often suggested for end fed vertical antennas such as commonly used on CB radio. The awesome work done by Steve Hunt G3TXQ (now unfortunately SK) gives great examples of such contained within a chart found on his site here :-

http://www.karinya.net/g3txq/chokes/


A length of plastic soil-pipe can be a cheap source of material to wrap your coax around and again there are many examples which can be seen online.


The observed effects of reducing your reception noise by moving away from sources of such are well known with many believing that they can only operate with a remote or mobile station setup. Many more will see the effect of placing their home base antenna (as suggested) further away from their home having a positive effect.

The one thing to realise with such solutions is that sometimes it's just not possible or convenient to always run mobile and your house is often a great resource for a stable high platform to attach your antenna to.

You also have to take into account any additional coax losses you may face if extending such to place the antenna further away from the house, the losses not only occurring on your transmitted RF but also your reception. Pushing more Watts through may make up for the losses going out but won't alleviate the losses of signals coming in.

The simple calculator available below will allow you to calculate such losses through your antenna feed systems :-

https://www.qsl.net/co8tw/Coax_Calculator.htm


So in fact you could well be placing an inconvenient and more expensive RF Gain control in line with the losses from the extra coax. Except it also affects your RF going out unlike the RF gain 'twiddle'.


The sweeping statement that taking your Ham test is easy and that by doing so will immediately place certain 'authorities' responsible for your own hobby woes is quite unfounded.

Many people face difficulties with stress scenarios such as examinations or even meeting people whether in person or online and yet more have difficulties with conditions such as Dyslexia or even lack of literacy skills. This makes certain 'gatekeeping' exercises such as gaining an Amateur Radio licence quite impossible for some but thankfully access to other radio means is available to them such as CB or PMR radio.

The document that follows produced by the RSGB gives away some of the aspects of 'responsibility' when dealing with issues of interference even to your own station :-

http://rsgb.org/main/files/2019/09/EMC-Leaflet-4-Interference-to-Amateur-Radio-Reception-v1.0.pdf


The section entitled "What can I do to reduce the chances of experiencing RFI?" helpfully includes references to such solutions as common mode chokes. There is also mention that Ofcom's responsibilities lay in more pressing issues than the non-commercial hobby aspect of Amateur Radio.


Anyway, more of my intense waffling but performed in the usual manner of doing my very best to help others.

I think it may be worth it as I hadn't realised how many times people reference such postings and are still gaining helpful hints from them.


All the very best to you all and enjoy your radio,
Victor

yes keep up with the waffling Victor it is very informative for the rest of us mere mortals its brilliant 

I appreciate the sentiments there Lionel so thanks, but also let it be known that I am no more or less a 'mere mortal' than anyone else. I'm just sharing the fabulous work that others have done in the hope that it helps more of us enjoy our radios. The other aspect is just empathy shown to others so beyond just my own view of the world.

well im still getting used to the president mc kinley and enjoying it, there seems to be more people coming on channel all the time around here it was really busy on friday night so i hope it continues and i should  shortly be getting delivery of the silver rod so that should be getting me further afield 

Id rather run a longer bit of decent coax than turn the rf down 
Failing that as said id go mobile

Alan Pilot wrote:

Victor your "waffle " can be very interesting you carry on all you want.
I found the RFgain and NB to be the fix for me especially on my FT-450d not as good on my RCI-2950 but helps a lot.
I think people think the RFgain has to be up full or they might miss something but folks just try it you will still hear the station and it might not sound as strong but in reality if you think about it with the rf turned up full what is the loud noise you hear yes it's noise not the operator you want to contact.

It's a similar principle to another of my hobbies, metal detecting. Crank up the power and your signal is reflected back by the ground in high mineralisation, knock it back a few notches and the signals start coming in.

'Dismiss' others answers? No, simply another point of view that happens to be different from your own.

I'm sure that someone who happens to fail the Foundation examination for whatever reason will feel so very delighted at your mention of "the foundation is Easy to pass". Equally as less rewarding to someone who studied hard to pass also.

But there you go, we are after all very different people for very different reasons.

It's what makes the world the wonderful place it really is.


After all, aren't we just trying to help out our fellow radio enthusiasts?


A wider view than our very own often helps with such things.

Some people might find the test hard and some easy.
I see many people saying they "just passed" but i can only think of one member on here that owned up to failing and twice i think it was before the came back to say "i passed".
So we will never know how hard some find it we are all different and some learn better than others.
Anybody looking to take the test don't give up ask on here if you get stuck or if doing the Essex Han as Pete and hid gang.