RFI help please

Can anyone help with ideas on how to deal with RFI when using 2m?
Whenever I key up and no matter the power level, it sets the house smoke alarm off.
I don't have the ideal setup with my antenna being in my loft but I really have no option to move it outside.
Doesn't happen on 4,10 or 11metres.

Hiya Tam,

What antenna are you running? Is it the HamKing you mention in your profile? If so how have you got that hooked up in your attic?

I know, questioning a question but anyone would need to know a bit more info to help you out.

If it helps any I know that some people have had problems with typical J-Pole type antennas, straight dipoles are easier to build (and tune!) and my own efforts with a VHF EDZ extended double zepp saw me having to add a WD2U Maxwell choke (several clip on ferrites at the antenna end of the coax) to alleviate issues. Yep, I also set off the smoke detectors....and that was with a typical Baofeng walkie!

Nowadays I run a typical commercial white stick collinear along with some decent coax and not only do I not cause any interference but suddenly found out that there are a lot more repeaters in my range than I thought possible! (Different rigs now too, the Baofeng being long gone.)

You could try moving the location of your antenna with respect to the smoke detector but I'll tell you the tale that I had to move my old EDZ closer to it rather than further away to stop setting it off.

It's not all straight forward this radio stuff is it? Especially if you have to make do with what you've got. (Like making your own antenna setups which although fun can also be frustrating.)

That's where the oft suggested ideas of simply purchasing a solution comes to the fore. Even a small white-stick would only cost you about £40 or so (plus coax) and can be easily hung in the loft space. I have a copy of the much bigger (and more gain) type installed in my loft space which just fits and bags me 10 or more repeaters but at least six or seven of them in total comfort. I can happily chat to an old friend whilst he's mobile across several counties now and don't believe installing it outside would give much improvement.

Sometimes a small splash of cash can make things much simpler.  


I hope you get sorted out there Tam.

All the best,
Victor

I hit the bedside touch lamps smoke detectors where ok.
Had a longer coax than i needed so wound it like a dirty balun and it worked for me.

Victor wrote:

Hiya Tam,

What antenna are you running? Is it the HamKing you mention in your profile? If so how have you got that hooked up in your attic?

I know, questioning a question but anyone would need to know a bit more info to help you out.

If it helps any I know that some people have had problems with typical J-Pole type antennas, straight dipoles are easier to build (and tune!) and my own efforts with a VHF EDZ extended double zepp saw me having to add a WD2U Maxwell choke (several clip on ferrites at the antenna end of the coax) to alleviate issues. Yep, I also set off the smoke detectors....and that was with a typical Baofeng walkie!

Nowadays I run a typical commercial white stick collinear along with some decent coax and not only do I not cause any interference but suddenly found out that there are a lot more repeaters in my range than I thought possible! (Different rigs now too, the Baofeng being long gone.)

You could try moving the location of your antenna with respect to the smoke detector but I'll tell you the tale that I had to move my old EDZ closer to it rather than further away to stop setting it off.

It's not all straight forward this radio stuff is it? Especially if you have to make do with what you've got. (Like making your own antenna setups which although fun can also be frustrating.)

That's where the oft suggested ideas of simply purchasing a solution comes to the fore. Even a small white-stick would only cost you about £40 or so (plus coax) and can be easily hung in the loft space. I have a copy of the much bigger (and more gain) type installed in my loft space which just fits and bags me 10 or more repeaters but at least six or seven of them in total comfort. I can happily chat to an old friend whilst he's mobile across several counties now and don't believe installing it outside would give much improvement.

Sometimes a small splash of cash can make things much simpler.  


I hope you get sorted out there Tam.

All the best,
Victor

Hi Victor,
Yes it is the Hamking on a mag base on sheets of metal, happy to buy this white stick you talk of if it improves my range which, is not too bad with the hamking. Can you advise the sticks you mean and I will look them up? As you know I am stuck with my loft as an outdoor antenna is a no no. My loft has the Hamking, a P5000 for 11m, a wire dipole for 10m and an Ampro whip thing for 4m  . I am toying with the idea of getting a decent rig that covers most bands and thought of using it with 1 antenna and an ATU but I have no idea if that is even an option. Anyway, I suppose I can disconnect the alarm when using 2m meantime. 

Alan Pilot wrote:

I hit the bedside touch lamps smoke detectors where ok.
Had a longer coax than i needed so wound it like a dirty balun and it worked for me.

That is worth a try-Thanks.

TamGlasgow wrote:

Can anyone help with ideas on how to deal with RFI when using 2m?
Whenever I key up and no matter the power level, it sets the house smoke alarm off.
I don't have the ideal setup with my antenna being in my loft but I really have no option to move it outside.
Doesn't happen on 4,10 or 11metres.

Hope you don't set off the neighbours smoke alarms on 2m or else you will get a lot of vocal QRM


Have you thought about adding Ferrites to the coax, psu power leads and if the smoke alarm is mains powered, then slip one around the mains supply cable as close to the alarm as you can get.

Come to think of it, on my 11m CB rigs, Yaesu 8900 and Yaesu 8000 set off my bedside light (a touch activated one) whenever I key up but never cause any neighbour issues luckily.

It's a pain if I'm in the bedroom/shack as when you key up the light comes on the lowest setting, key up again and the brightness goes to medium level, key up again and the light is on full power (40 watt bulb), key up again and you are in darkness !

Often thought about changing it but it was a present from my daughter many many moons ago so its one of those things that you can never get rid of.

Telstar wrote:

TamGlasgow wrote:

Can anyone help with ideas on how to deal with RFI when using 2m?
Whenever I key up and no matter the power level, it sets the house smoke alarm off.
I don't have the ideal setup with my antenna being in my loft but I really have no option to move it outside.
Doesn't happen on 4,10 or 11metres.

Hope you don't set off the neighbours smoke alarms on 2m or else you will get a lot of vocal QRM


Have you thought about adding Ferrites to the coax, psu power leads and if the smoke alarm is mains powered, then slip one around the mains supply cable as close to the alarm as you can get.

I dont think I set off anyone else's   I haven't heard anything but then again my hearing is shot . Will look at the ferrite and put them on everything I can think of. I just bought a more modern alarm so going to swap them out to see if it helps. Cheers

My apologies Tam, I mean items such as the 'diamond' X30, X50 etc. but remembering there other manufacturers of these fine antennas too. (White fibreglass collinear VHF/UHF antennas.)

(I won't get into the debates regards so called 'copies' etc. but let's just say I didn't pay through the nose for mine. )

Loads have already made suggestions that you can try out but I personally wish I'd gone down the route of buying a 'white stick' much earlier....it's fantastic to hear so many repeaters.

Victor wrote:

My apologies Tam, I mean items such as the 'diamond' X30, X50 etc. but remembering there other manufacturers of these fine antennas too. (White fibreglass collinear VHF/UHF antennas.)

(I won't get into the debates regards so called 'copies' etc. but let's just say I didn't pay through the nose for mine. )

Loads have already made suggestions that you can try out but I personally wish I'd gone down the route of buying a 'white stick' much earlier....it's fantastic to hear so many repeaters.

Thanks Victor, I will look at the other manufacturers too as I'm no slave to "Brands". Meanwhile, I have replaced the fire alarm and the new one isn't going off so we shall see. If I can put one of these "diamonds" in the loft then brilliant mate. Cheers

Victor wrote:

My apologies Tam, I mean items such as the 'diamond' X30, X50 etc. but remembering there other manufacturers of these fine antennas too. (White fibreglass collinear VHF/UHF antennas.)

(I won't get into the debates regards so called 'copies' etc. but let's just say I didn't pay through the nose for mine. )

Loads have already made suggestions that you can try out but I personally wish I'd gone down the route of buying a 'white stick' much earlier....it's fantastic to hear so many repeaters.

I have found the "Diamond" you speak of, can I get a pole, screw it to a joist and then install the antenna onto the pole? I'm away to measure what height I have in the loft.

Hi again Tam,

Glad you got the fire alarm sorted and hope that's your problems resolved for good.  

I've just been playing with my new antenna (SQBM500P MKII if you want to look it up and at 2.5m it just about fit my loft space upright) whilst chatting to my old Ham friend running mobile. As he crossed county lines we jumped repeaters to stay in contact so with me in Bedfordshire we chatted whilst he was in Cambrigeshire, Northamptonshire, then as we lost the Northamptonshire repeater at his end we switched to Hertfordshire before he finally got home in Buckinghamshire. Not too bad going with us splashing RF across the five counties on six repeaters!

(Could've been more if we were able to run a line from GB3PI but he was off in the opposite direction.)

As I said, I wished I'd gone down that antenna route sooner!

(I was running a little Leixen VV-898 at 10W throughout which is a surprisingly good rig.)

The antenna needed a volunteer to put up as I'm disabled but considering it's just taped to a rafter standing upright and proud to the attic peak it seems to be doing the job. Oh, went all 'snobby' with the coax too and it's running RG213 instead of my favourite fallback RG11.

Anyway Tam, something to think about if you want to extend your VHF/UHF coverage at all.

Got to shoot off now so catch you soon.

73,
Victor

 Thanks again Victor, will give that a look and see if it will fit. I will keep you guys updated and really appreciate all the help. Cheers

Victor
I have the same antenna and coax lol.
With mine the little bolt turned to dust so it has a wobble but still works spot on.

Hi Alan mate,

Worth knowing about that bolt issue (could probably replace with a stainless steel one) for anyone mounting such an antenna outdoors. Luckily I'm hoping mine will outlive me by being sheltered in the loft space. I'm sure many will have been caught out with the assembly procedure and not connected up that top section inner connection or hooked up some terrible coax with then less than stellar performance. (For anyone reading the assembly is the same as the X200.)

Does seem to be working out well and thoroughly impressed with the performance so far but was surprised the little Leixen performed the best out of all the 2m gear I've got! I'm just happy that I can chat to my old friend a lot easier as he travels around with his work.

Playing with antennas and building them was a lot of fun what with j-poles, dipoles, EDZ's, etc. but damn I wish I'd purchased such an item early on and enjoyed the performance.

Cheers Alan, great input on the forum as ever.

Good point there Victor about the middle connection.
I remember when i got mine about 5 years ago looking at it and thinking how.
Just slides out simples lol.
I must admit it does work well use it more than the yagi don't have to mess with the rotator and it is almost the same signal.

I found the same Alan mate!

I've built a 6 element 70cm Yagi as well as a 4 element 2m in the past but this vertical collinear is performing as well as (and sometimes better) than they ever did. Plus I don't have to 'armstrong' the antenna not having (or now needing) a rotator.

I've been scanning through the frequencies seeing what repeaters I can access and the list is getting longer so got to program them all up next. Looking forward to trying it all out with SSB especially with my old mate running mobile so he'll be stuck with vertical polarisation anyway. Bit of a tropo lift on this weekend too so might have a bit of fun playing with VHF/UHF.


Sorry to be blathering on your posting there Tam.

Victor wrote:

Sorry to be blathering on your posting there Tam.

Not at all mate! I am sooking in all this info .
I have bought the antenna you mentioned as I was up the loft this morning with my tape... 3m 20cm to the top.
Looking at pictures and I am probably missing the obvious but what is the small metal pole thing for?(At least I think it is metal) .
Another thing, is there much activity on SSB 2m? I only use a wee Retevis RT95 but if this antenna improves my lot, I would look to get some sort of multi-mode if it was worth it.

TamGlasgow wrote:

Looking at pictures and I am probably missing the obvious but what is the small metal pole thing for?(At least I think it is metal) .

It's ok, I found the X200 instructions which explains it.

I've had my Diamond X200 since March 2020, bought it along with my Yaesu FT8900 the day after I passed my Foundation exam. At first, installation was on a 3 meter pole mounted on a ex basketball net ground frame and then in 2021 a couple of friends mounted it on my house back wall on T & K brackets with RG213 coax. It works very well. I bought a local for sale Comet GP15 a while back which is a similar antenna but taller and is 70cms, 2m and 6m but as yet its still stacked up in my shed, must try assembling it and trying it out sometime and comparing it to the Diamond X200 on 70cms and 2m. the addition of 6m will be handy as my Yaesu FT8900 is a quad bander (70cms, 2m, 10m and 6m). I use a Hamking CR8900 quad band antenna for mobile use with the Yaesu.

The Diamond X200 is a genuine (not a knockoff) antenna and it works fantastic and the SWR is very low across both bands.

Telstar wrote:

I've had my Diamond X200 since March 2020, bought it along with my Yaesu FT8900 the day after I passed my Foundation exam. At first, installation was on a 3 meter pole mounted on a ex basketball net ground frame and then in 2021 a couple of friends mounted it on my house back wall on T & K brackets with RG213 coax. It works very well. I bought a local for sale Comet GP15 a while back which is a similar antenna but taller and is 70cms, 2m and 6m but as yet its still stacked up in my shed, must try assembling it and trying it out sometime and comparing it to the Diamond X200 on 70cms and 2m. the addition of 6m will be handy as my Yaesu FT8900 is a quad bander (70cms, 2m, 10m and 6m). I use a Hamking CR8900 quad band antenna for mobile use with the Yaesu.

The Diamond X200 is a genuine (not a knockoff) antenna and it works fantastic and the SWR is very low across both bands.

Brilliant, my aim is to get my antenna situation sorted for this 2/70, then I will sort out my 4m. My loft is a dogs dinner with different mags and dipole, looking to tidy it all up. 6m is on the cards too. I like the challenge though.

Hi Tam,

Sorry to only just have got back to you but have been indisposed for a little while.

Spent the morning playing VHF/UHF with my old friend and had great fun finally being able to transmit from home QTH to home QTH with him rather than working around through the repeaters. (Dirty big hill, or rather as big as they get in these flatlands which usually blocks our path.) We worked both simplex FM as well as a bit of SSB fun so was able to shove it all in the logs too.

(Not exactly DX but working inter-county when we were previously unable to was great.)

VHF SSB activity can be more fruitful than 70cm ever is but depends on what's going on. There's the SOTA guys (summit on the air) but a lot work FM as there's more chance of gaining a contact nowadays and also worth listening out for the first Tuesdays of the month for the 2m SSB RSGB contests. (There's a lot more gong on too so worth searching online.)

Also worth keeping an eye out for some Tropospheric propagation (a bit going on this weekend) as that can herald some surprising long distance contacts as well as opportunities at operating further flung repeaters :-

https://www.dxinfocentre.com/tropo_eur.html

Some constantly shout out on a repeater for a while then declare it dead forgetting that just because they're on air at that time it doesn't mean anyone else is. We have a lot of spectrum available to us nowadays which gives a lot of places for people to be operating so harder to coincidentally bump into.

Anyway, better leave it at that as someone's bound to pop in with the 'DX greatness' of bigger, better VHF/UHF equipment than we'll ever have.

It can all be rather a lot of fun Tam and I enjoy operating any type of radio wherever it is.

I look forward to doing a lot more 2m work especially now that my local repeater has moved site away from my backdoor as well as having the new antenna. (Could open it with a dummy load at 1/4W before!!)


You have fun there Tam and I wish you all the best with everything.

73,
Victor

A wee update!

Victor, I got the colinear up in the loft with RG213(By god that is stiff)  
What a difference! I had never heard some of the stations before so thank you for pointing me in that direction and i'm only using the Retevis RT95. Bonus....My smoke alarm doesn't go off now.
Will make more use of 2m also as there are so many idiots around here keying the mic and music playing on uk40.

Once I get bored again, I will move on and get my 4m setup sorted

That's wonderful news to hear there Tam and really glad that you're getting to enjoy some 2m action.  
(I've been very impressed with the 70cm performance too.)

I've set my little Leixen to scan several 'local' repeaters now as well as the calling channels on 2m/70cm and great to catch newly licensed operators as well as old hands. (The scan speed is relatively fast if you're not trying to scan the whole of the bands! )

Absolutely chuffed for you and wish you well with all of your radio pursuits.


All the best,
Victor