Help wanted / RFI problems

Hi guys,

Since a couple of days I'm using a new radio. It's the President Lincoln ll Plus. I'm very happy with it but there is an issue and I'm sure it has nothing to do with the radio itself. It's picking up a lot of continuous RFI noise all over the 10, 11 and 12m band (S7 on SSB / S5 on FM).

I'm using a Solarcon (Antron) A99 and it always served me well on my former rig. The Lincoln however receives much better, but unfortunately that also goes for this RFI...

I already excluded the 'in-home factors' and I know for sure by now that it's picked up by the aerial. I'm pretty sure it's being caused by the solar panels across the street, which are only 250 feet away from the Antron, so I want to replace my aerial for another one which doesn't pick up these kinds of RFI that much. I'm bound to restrictions when it comes to length and I really want a fiberglass one because I'm living close to the coastline with high and salty winds.

That's why I'm thinking of erecting a Sirio Gainmaster 1/2 wave (the 5/8 version is too long for my QTH). I like this particular antenna because it's center-fed and therefore completely in phase, acting like a dipole. I saw plenty of reviews of the 5/8, but does anyone have some experience with the 1/2 wave version??  

Looking forward to your comments!

Cheers & 73's from The Netherlands  

I doubt simply changing from one vertical to another will get rid of the noise, I'm afraid, because it is omnidirectional. But you might find a "QRM eliminator" or phasing box helps.

26TC62 wrote:

I doubt simply changing from one vertical to another will get rid of the noise, I'm afraid, because it is omnidirectional. But you might find a "QRM eliminator" or phasing box helps.

Maybe, maybe not. For as far as I know, the Antron is known for picking up lots of statics. Besides that it's a groundplane, while the Sirio is -technically speaking- a center-fed dipole.

I've been browsing the internet for filters and/or info that could take care of this problem. So far no luck...

Gert 19CT006 wrote:

I've been browsing the internet for filters and/or info that could take care of this problem. So far no luck...

MFJ 1026 noise canceller or similar. What it is is a unit that has a receive antenna for receiving the local noise. It then feeds that signal into the signal from your antenna 180 degrees out of phase which cancels out the noise.

Hi. Gert.

The MFj 1026 that Stu mentions is V.good. I used 1 for 6mths till
local rfi got to much they are pricey £200. Also have u considered
a Horizontal? I used a Sirio SD 27 with good results it'll tune 10-15
with a good Atu (MFj) it has v.good bandwidth. Good Dx. 73s Mike

I went from a 5/8 silver rod getting around s7 to s9 to a 5/8 skip master the 2011 shorter version and i only get around s3 now.
Don't know if the extra 5ft pole i put under it made it better but that was all i did.

Hi Conor, Mike and Alan, thnx for the input!

Yep, two days ago I saw the MFJ on the internet (amongst others). I'm convinced it works very well, but there is a problem however. It needs an additional aerial to pick up the noise, so the device will be able to put it in counter phase. I really don't have a possibility to set one up. I live in an apartment building on the ground floor and I'm happy they've let me get away with this set up and I'm not intending to push my luck. The Antron is on the flat roof, mounted on a heavy duty tile stand at about 40 feet (13m) heigth. I'm using something like 96 feet (29m) of coax, which is guided through a rain pipe. Erecting a horizontal aerial is also not possible unfortunately...

I'm aware of the fact that the MFJ has an antenna of it's own, but I really think it won't be able to pick up the noise properly because it will be too far away from the source, or could I be wrong on this?

Oh yeah, before I forget: I don't think those solar panels are the problem by the way. The noise is also there at night, so it must be another source. It sounds like ordinary white noise with a small 'rattle'. The coax is also not the problem because I use Aircell 7, which is VERY well shielded.

Therefore I'm considering replacing the Antron. It has to be a light weight antenna (like the Gainmaster HW) since it's on a tile stand as I mentioned. I know that the Antron picks up more static than other aerials. But will this solve the problem?? It could also be the case that it will only increase the probs since the Gainmaster has better reception. The question remains: is it atmospherical static or RFI caused by electronics? I really don't know...

I'm sorry for possible typo's. After all I'm Dutch right?

I'll attach some pics of my QTH and aerial set up.

Hi. Gert.
Since seeing your pic.& checking your spec's. Is your p/supply a switch mode? also the Amp. could u move it further away from
the rig? Have fitted ferrite rings to p/s & amp supplies? In the diagram is the rain pipe metal or composite? Check your p/supply
to mobile phones/laptops are off. Also ask neighbours if they have
any switch modes or LEDs. Finally how about a T2LT ? Alot of Ops
in UK use them with good results or a Delta Loop? 73's Mike.

Hi Mike, thnx for your thoughts!

I already excluded all 'in-home factors'. I disconnected everything and did a set up with only the radio and power supply, nothing else. I also switched off all electronical stuff in the house. No result...

The rain pipe is PVC and there haven't been any changes in the environment that I know of. Besides that; this setup has been established 8 years ago and I never experienced any trouble. I was off air for a couple of months and last week I came back with a new radio (President Lincoln ll Plus) and trouble started. First I thought it was the radio itself giving me problems, but when I hooked on my old radio's, the noise was there as well.

Good thing that you mentioned the power supply by the way. Yes, it's indeed a switching one, so he was a suspect! But I hooked my radio to a non-switching power supply and there was no difference.

I'm totally convinced that my aerial is picking up this noise.

Cheers & 73's

Could you try a car battery as power just to see if it is coming through the mains supply.
Just a thought.

Gert 19CT006 wrote:

Hi Conor, Mike and Alan, thnx for the input!

Yep, two days ago I saw the MFJ on the internet (amongst others). I'm convinced it works very well, but there is a problem however. It needs an additional aerial to pick up the noise, so the device will be able to put it in counter phase. I really don't have a possibility to set one up.

The MFJ ones come with a small telescopic antenna that screws into the top of the unit. You can use an external antenna instead and it only needs to be a small one, you don't need to put up anything like a full size one so even something just a couple of metres long would work fine, you could even use one of those mini magmount CB antennas.

Alan Pilot wrote:

Could you try a car battery as power just to see if it is coming through the mains supply.
Just a thought.

Hi Alan. It can't possibly be the power supply. Like I said, I hooked up the radio to my former one which I've used for many years without probs. Besides that: I unscrewed the PL259 from the radio, which is standing next to the power supply; S 0... Since it's so close by to the radio, there should have been some interference right?

Hi Conor. I know it has an antenna of it's own, but I'm really wondering if it will be able to pick up the noise, since my Antron is (very) far away from my shack. The telescopic antenna will be inside the shack (which is a desk in my living room by the way) so I find it hard to believe it will be able to pick up the RFI well enough to put it in counter phase, but I could be wrong on that. Anyway, it's impossible to drag down a second coax for an auxillary aerial on the roof.

I also understood that the MFJ can only handle 100 watts. Usually I'm running standard power (55w), but sometimes I'd like to insert my amp. By doing that I would blow the MFJ to heaven and back I guess...

There's also another device on the market, which is designed by a Russian amateur. It goes by the name of QRM Eliminator X-Phase. I've been reading several reviews of it and it seems to work very well. The only thing is that I'm not sure how much RF power it can take. Any thoughts?

No idea about the QRM Eliminator but it works on the same principle as the MFJ unit and needs a receive antenna.

Northern Crusader wrote:

No idea about the QRM Eliminator but it works on the same principle as the MFJ unit and needs a receive antenna.

Yep, they all do... You know, I've been thinking; if I place the eliminator between the radio and the amp instead of 'at the end of the chain', the device will only take the original radio RF power. In that case I don't have to worry about blowing it up...

Another problem is that I don't have a PTT input on my Lincoln ll Plus. I'm not sure if the VOX of the eliminator will work properly on SSB.

OK, regarding the solar as a likely cause....stupid question, but does the noise go at night when the panels aren't active and the connected inverters power themselves off? If not, it isn't the solar!

(Unless they have batteries running the inverters, of course, but worth asking them)

Re the MFJ unit. I have one, and they are only really great for notching out noise....if the noise is across the whole band, or bands, they won't do much.

Also, they NEED an external antenna, and it needs to pick the the same noise, ideally to the same level, as your normal antenna. The whip they come with is useless....unless the noise is inside your house, and close to it...which it isn't, as you've checked.

If you do get one, make sure you use the T/R socket on the back to control TX switching, and don't trust the RF sensing....

Hi Jeff, thnx for your comment.

The RFI / EMI still goes on in the middle of the night. Therefore I already ruled out the solar panels. But is it really true those eliminators don't work properly when the noise is broad banded? I mean: it's a matter of putting it in counter phase, regardless the bandwidth, right? Or am I seeing things wrong? Could be the case, since I don't have much experience with those devices...

I'm planning to use the T/R socket indeed, because I really don't trust the RF sensing. My radio is a President Lincoln ll Plus, which doesn't have one, but I will manage to create an inlet bus on my desk mike, since my radio is new and still has warranty.

I was planning to use a mobile 5/8 whip on the ground floor (where my QTH is) as an aux antenna. I'm not sure if it's able to pick up the right amount of QRM, but there's only one way to find out: I will hook it on my radio and check the S-level of the noise. Ofcourse there's always the option to adjust it, using the gain control.

Hi Gert,

My experience with them is just that you can deal with specific noise, but if the noise is such that it’s wideband, you simply can’t dial it out. YMMV, of course, but the better YouTube reviews (VK7HH, N4lQ channels, etc.) seem to agree to some extent.

With regards aux antennas.....is your main antenna a vertical? If so, and they both see the noise source at roughly the same level, you’ll be fine, as you can adjust the preamp and sensitivity for each, obviously...but a vertical vs loop or horizontal, will not only have you 16-20dB down to begin with, but often picks up different noise via different polarisation to begin with.

Hi again Jeff,

My antenna is an A99, so they're both vertical. We have some restrictions over here concerning heights etc., that's why I'm using this one. Not the best aerial, but still VERY manageable. Intercontinental contacts have never been a problem...

Today I did some testing with the reference antenna, which is an old Skipmaster 5/8 mobile whip. It works and it works well! When the QRM on my Antron was kicking in with S 7, it came in through the whip with S 4, so that's more than enough to combine both signals and to put them in counterphase. So far so good...

The noise is widebanded indeed, but still I'm willing to give it a try. The QRM eliminator X-Phase is offered on eBay for something like 75 dollars, including shipping, so that's not a big deal.

The only thing I'm running into is connecting it to my Lincoln ll Plus. It doesn't have an amp inlet bus and I certainly don't intend to rely on the internal RF sense relay of the eliminator. Besides that, it would only work on AM/FM, but SSB will give problems I think.

That's why I was thinking of creating a mini jack socket on my desk mike. Do you think it would be wise to connect it to the PTT switch of the mike? After all it's just a matter of making contact between those two wires, so the eliminator will be bypassed when it's in TX mode (PTT button pressed in).

Hope to hear from you and thanks in advance!

EDIT: Oh yeah, before I forget; I have a VERY strong suspicion against the elevator installation of my apartment building! My Antron is only a few yards away from the shaft. Today I did lots of try-out set ups with the reference antenna and they were all pointing in that direction.

The MFJ is pretty good, though you can get these things *MUCH* cheaper.  Just search for X-Phase QRM Eliminator on ebay.  They're available as a kit for about £20.

You can also get a cheap SDR (software defined radio) which will allow you to visualise the radio spectrum - say from 26-30MHz - and this can help you to find the source of the noise.

If you can get a noise antenna close to the noise source (it just has to be a piece of wire or even a wire loop) then you're much more likely to be able to null it out.

I did fear that my neighbour's solar panels would be a problem but when the contractor was installing them I gave him some ferrite rings to wrap around the input and output from the inverter which is usually the cause of the problem. He said "oh, yeah, those things come with the kit but we don't usually install them because it's extra work". Ever wonder why solar panels cause problems? It's because of the lazy chimpanzees who install them.

I used a A99 for many years and only recently changed it to a Vector 4k but my A99 never gave me any noise issues in the 7 years i owned it.I was advised to use a "air choke" which was 6/7 tightly wound coils of the coax around the scaffold pole it was attached to just below the antenna.
I have no idea if i was going to get rfi or any other noise issues as i never tried it without but i always had S0-1 of noise across 11m on FM/AM/SSB but i did get more noise on my newer Mass dx5k rig than my Yaesu/Kenwood or Superstar 360 so i did suspect my Mass was far more susceptible to noise..Good luck sorting it out..

Sam