How Far Should a Radio TX be from a stereo or computer?

[Unidener]

I know transmitters can cause problems in cars. I remember years ago on my VHF HF when I would transmit it would cut off cruse control. Yesterday my GMRS radio wiped out all of my saved channels on my Pioneer stereo. And Yes I was on the handheld antenna not an external....wonder if that would have prevented the problem.
I'm just concerned since I'm setting up my computer room as my radio shack....

Thanks for any suggestions other than wrapping everything in aluminum foil....I've already done that

 

[DeeEx]

Modern-ish name brand gear (post-1995 or so) has never given me any issues on any band.

I had a vintage GE 110W VHF mobile in my shack once, the transmitter seemed wide as a barn, but it never bothered anything else.

Install some ferrite chokes if it gives peace of mind.

Avoid 11m “export” radios with modulation limiters clipped.

 

[Unidener]

It's just odd that it wiped out my stereo programming for the channels that were stored.....that's why I concerned about my other gear and my computer.

But I have seen shacks with many transmitters and computers....just wanted to know if there was some suggestions! My electronic knowledge is lacking but can you suggest a particular size or is it just a see what works?

Thanks for the reply!

 

[merlin]

100 watt on 2 meter, antenna 6 foot from PC, worst so far is kills the USB mouse. the fix, disconnect/reconnect.
Still, that 100 watts wreaks havock with all my electronics. 4 watts UHF takes out my TV at 10 foot.
Get the antanna up on the roof, it has little/no effect.
Put ferrite toroid chokes at your speakers, outputs, inputs, and power should save your channels.

https://www.aliexpress.us/item/3256801219886564.html?aff_platform=true&aff_short_key=UneMJZVf&isdl=y&src=bing&pdp_npi=3%40dis%21USD%211.10%211.10%21%21%212.81%21%21%40%2112000030882325490%21ppc%21%21&albch=shopping&acnt=135095331&isdl=y&albcp=373871275&albag=1308419064071836&slnk=&trgt=pla-4585375812965762&plac=&crea=81776241344382&netw=o&device=c&mtctp=e&utm_source=Bing&utm_medium=shopping&utm_campaign=PA_Bing_US_PC_customlabel1&utm_content=customlabel1%3D7&utm_term=clamp%20on%20ferrite%20chokes&msclkid=922412a774a61a0d2c0b748a83566c80&gatewayAdapt=glo2usa

 

[Unidener]

I have several and I just ordered an assortment....thanks for the help!

 

[AB5ID]

Put ferrite toroid chokes at your speakers, outputs, inputs, and power should save your channels.

That's a great price! Any idea of the frequency coverage range for the ferrite pieces?

 

[merlin]

That's a great price! Any idea of the frequency coverage range for the ferrite pieces?

They are awful broad. Never swept any so don't know any specs. they are OK for line type noise through SMPS wall warts and such.
Probably a bit better for strong RF fields .
I think the 'fair-rite' web site has some technical specs for theirs.
Standard toroids are often used for blocking common mode on coax, so they can get awful high in upper frequencies.
Of those I have found, they can get pricy.

 

[sempai]

i would have assumed it was power related because usually when my car stereo is reset that's the culprit. i have a corner of my house that is where wifi goes to die and that corner usually has a radio nearby if i'm sitting in that chair >< i should learn to use the spetrum analyzer in the Mayhem firmware for Portapack.

 

[merlin]

Far enough not to cause interferance.

 

[N4KVE]

Years ago I had a UHF 100 watt MCS2000 in my car. Once while transmitting I set off the burglar alarm on the car next to me. Other than that, there’s never been ill effects from the hi power radio.

 

[RFI-EMI-GUY]

I once lived in a studio apartment that had been created by dividing a larger apartment. Turns out the power and phone(*) circuits were shared. The neighbor liked to play the stereo at a very high volume and had poor taste in music. I found "by accident" that if I wrapped my lamp cord around the antenna of a VHF portable that their stereo would create a terrible distorted buzz. Thus I trained them to run the volume at a much lower level.

(*) I found phone calls on my bill to a city where I knew nobody. I called the most called number and it was a girlfriend of the guy. He just plugged in a phone and started calling for free on my line.

 

[spongella]

Evertime I key up the mike on my ham xcrvr the touch sensitive lamps throughout the house toggle on and off. Hilarious.

 

[prcguy]

Every computer or stereo setup will be different and will react to RF fields differently. I worked in a satellite broadcast facility and found the security guard hand helds would glitch a very critical computer responsible for on air programming and they were prohibited from using their radios in that particular room. After some equipment upgrades years later and testing with my multiband hand heads I found it impossible to glitch anything with 5w radios inside the racks right up against the equipment and cables.

 

[davidgcet]

years ago we installed a 25w uhf m100( i said it was years ago) in the scale room at a grain facility. the antenna was outside but because this room as on the second floor only maybe 15 feet away from the controller's desk where they could see the trucks thru a large window. they would key up and the entire scale system would freeze up so hard they had to power cycle it. we ended up having to both move the stinger antenna and turn the radio down to 5 watts to stop it. the antenna had been there for years, they got a new radio and repeater which is what we were installing. old radio was a 25w on a simplex uhf channel so basically it was the new freq that caused the issue.

 

[KevinC]

Since we're going down memory lane...

Middle of nowhere, pulled up to first gate at the tower site, right next to it was a different property gate with a wireless opener. Keyed up on VHF trunked system (40w radio with quarter wave antenna) and the other gate opened.

Working on low-band base at a temp construction site (100w micor). Toyota truck with engine running parked under the antenna, keyed up base, Toyota engine revved way up, jumped into reverse and went flying across parking lot crashing into receptionists brand new Chevy truck. If I hadn't seen this I would have never believed it.

Installed antenna for 800 MVP on a trunk groove bracket on the front drivers side on a Datsun something. Keyed up MVP and the wipers came on.

Keyed up APX7000 on a TDMA TG on a 800 system while about 3' from a GFCI outlet. Outlet started chattering like crazy.

So you never can tell how electronics will react.

 

[Unidener]

Far enough not to cause interferance.

If I had an external antenna.....wonder if that would make a difference? Got one will test it out!

Thanks!

Evertime I key up the mike on my ham xcrvr the touch sensitive lamps throughout the house toggle on and off. Hilarious.

With almost all light/fans on wifi switches.....this out to be good

 

[Unidener]

Every computer or stereo setup will be different and will react to RF fields differently. I worked in a satellite broadcast facility and found the security guard hand helds would glitch a very critical computer responsible for on air programming and they were prohibited from using their radios in that particular room. After some equipment upgrades years later and testing with my multiband hand heads I found it impossible to glitch anything with 5w radios inside the racks right up against the equipment and cables.

Woooooppppsssssyyyyy

 

[paulears]

If I use a VHF marine handheld, my computer loses the programming dongle and goes bing bong. My UHF radios make the Mac screen flicker, One higher powered radio can knock out my router and I lose the internet.

Back in the early 80s, the local Philips TV plant had a department who removed expensive protection from production TVs to save a few pennies on each one - they'd remove a filter, test, remove something else and repeat until the TV played up. They'd then measure the field strength and see if it still met the specs. Essentially the job was to interfere with them till some something happened. What the something is we don't know.

 

[RFI-EMI-GUY]

Every computer or stereo setup will be different and will react to RF fields differently. I worked in a satellite broadcast facility and found the security guard hand helds would glitch a very critical computer responsible for on air programming and they were prohibited from using their radios in that particular room. After some equipment upgrades years later and testing with my multiband hand heads I found it impossible to glitch anything with 5w radios inside the racks right up against the equipment and cables.

When I was involved in one of the first Smartnet systems, the analog microwave system, 6 GHz, 2 GHz Starpoint, Starplex etc; would go nuts if a 3 watt 800 MHz STX was keyed up in the radio sites. It created a lot of alarms and crashed the SpectraTac voters. We had some big red vinyl stickers made up that said Do Not Use Portable Radio Transmitters on site or some such wording. I have one of those signs here somewhere. I don't know if the factory microwave guys ever solved that. It was hard to test that on a live system.

 

[paulears]

Back in the Cold War days, I had a little side job looking after the comms between a number of bunkers serving the civil defence department. Messages about bombs, fallout directions so the county headquarters could arrange food, move people from fallout, that kind of thing, and we had some antennas on Police masts, as the biggest bunker was underneath one of the Police stations in the centre of the county. We had 100W out on UHF and VHF, and it worked pretty well linking the towns to the main centre. The Police radio transmitters got swapped out in the rack room, and as we used the emergency system one Sunday a month, nobody saw an issue. Until our practice bomb drop messages started coming out of the Police system which caused some confusion. Nothing to do with RF - we were thinking all kinds of clever solutions, and discovered we had used an apparently unused empty audio patch bay, as an easy solution to get A into B - what we didn't realise was it was also rear connected into the the Police system - hence why the 'interference' was so good, quality wise. Embarrassing! It was supposed to have been a secret.