Strange RF problems

jim · Post by **jim** » Wed Jan 16, 2002 11:48 am

After spending two and a half hours today trying to figure out why a cell phone powers up when you key the VHF radio, I was wondering....
what is the strangest, most bizarre RF intrusion problem all of you have ever experienced?

This particular case had a BK VHF radio with a 120 watt PA. The department had orange pylon cones on the trunk the hit the PL259 connector on the PA and pulled the coax slightly out of the connector. This caused two problems from the RF finding another path:

1. It burned up the cell phone low profile antenna.

2. The VHF radio's coax runs near the 8 conductor cable leading to the front of the car to the handset. The coax was touching this cable in one spot and burned through! This explains the phone turning itself on.

Don't ask how the phone's LP antenna burned up though. I haven't figured that one out yet, but everything works as it should.

I know the lowband Maratrac throwing a 2001 Crown Vic belt sure takes this!

Nand · Post by **Nand** » Wed Jan 16, 2002 1:29 pm

mike38015 · Post by **mike38015** » Wed Jan 16, 2002 7:25 pm

I remember back a number of years ago while using a 110 watt low band (47.xx) Mitrek I was picking up a friend and while parked in front his house talking on the radio I discovered I was opening and closing his garage door whenever I transmitted.

It was kind of fun seeing how many garage doors I could open whenever I drove through neighborhoods when I happened to be transmitting.

Post by **HumHead** » Wed Jan 16, 2002 8:23 pm

We used to use the high power Syntor XX VHF radios in our ambulances to:

1) Turn on motion sensing flood lights
2) Set off car alarms

Oh yeah- with a 5w HT, almost any "touch lamp" becomes remote control. Also used to come in handy for ending one of my former college apartmentmate's multi-hour cordless phone marathons when one of us needed to make a call

[ This Message was edited by: HumHead on 2002-01-16 23:36 ]

radioEd · Post by **radioEd** » Wed Jan 16, 2002 8:27 pm

Same here! We light up the homes motion sensor flood lights with just a HT & 5 watts!
cheap lights!

Anyone set off any car "air-bags" yet?

[ This Message was edited by: radioEd on 2002-01-16 23:30 ]

Glendale Radio · Post by **Glendale Radio** » Wed Jan 16, 2002 8:34 pm

Put Me Down For One Chevy Cavaler Air Bag At 25 Watts!
Glen

PCSAR4x4652 · Post by **PCSAR4x4652** » Wed Jan 16, 2002 8:47 pm

I've done all the ones listed above except the airbag. Used to screw with my upstairs nieghbor and set off his car alarm with my 10 meter roger beep over and over till he disabled it each night. Figure this one out ... When I key up on my 10 meter rig at 10 watts, my 110 watt VHF trunk mounted A9 headed Spectra reboots like you just turned it on.

_________________
Todd Freeman
Pierce Co Sheriff Dept. SAR

[ This Message was edited by: PCSAR4x4652 on 2002-01-16 23:49 ]

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Wed Jan 16, 2002 8:51 pm

It just so happens I had a webpage from GM in my favorites having to do with Mobile Radio installation. Check it out: http://service.gm.com/techlineinfo/radio.html

Perhaps it could provide some advise on how NOT to set off another airbag.

_________________
73
KC8RYW

[ This Message was edited by: KC8RYW on 2002-01-16 23:53 ]

Monty · Post by **Monty** » Wed Jan 16, 2002 9:30 pm

Hi:

Fair warning to all !!

Use Caution when transmitting around a
Computer with a Cell Phone. The Digtal
Nokia likes to corrupt Hardrives, and
System Bios's if you are close.

Good way to make Enemies !!

Sad to see there is no effect on Slot Machines in las Vegas though !!

Monty

EC-7 · Post by **EC-7** » Wed Jan 16, 2002 9:50 pm

My 11 meter rig used to tur on/off/dim the touch lights in my house and my neighbor's houses. I've set off car alarms, lit up the floresent lights in my kitchen, shrunk the screen size on my brother's tv, turned off my computer monitor, erased all messages on the awnsering machine, sounding a nice buzz through alarm clocks and more. Keep in mind that this was with a "RCI-2950", 250 watt amp and a "Antron 99" on my roof. My mobile had a "Uniden President HR-2510" and a 300 watt amp on CB freq's. (Yes, I know it was illegal, I don't get on CB anymore.) Now I just set off car alarms with the BASS from my car sterio system pumping 900+ watts. Ahh the good old days...

captainkirksdog · Post by **captainkirksdog** » Wed Jan 16, 2002 10:13 pm

Back in the 60's my dad and I set off dynamite charges at a road construction site with a 1000 watt linear on our CB. Blasting caps were way too sensitive, back then. Don't think we killed anybody...<CKD>

10-95 · Post by **10-95** » Wed Jan 16, 2002 11:09 pm

I would agree with the others who say it's the RF, it's probably freaking out the controller in the cell phone. Reminds me of the time I worked at a radio station in the early 80's, they still used turntables back then, we had the nice Technics SL series, and once while on the air I keyed up my HT600 and the turntable pitch control went nuts!! Springsteen sounded like the chipmunks, I had a lot of fun with that trick , while a buddy of mine was on the air one night I did that about three or four times during his shift from the next room, he was a nervous wreck after he got off the air!!

10-95

Post by Pj » Thu Jan 17, 2002 2:26 am

I forgot what radio it was, (either CB, HAM or X9000), and I THINK it was my old 89 chev corsica, but I was transmitting one day, and noticed smoke coming from the windshield heater... After dekeying, it stopped.

After that, never saw it smoke again...hmmmm

jim · Post by **jim** » Thu Jan 17, 2002 5:15 am

I've experienced all of the above, except for the airbag. That one may take the award.
Here's a few more:

1. a Texas Star DX-1600 watt PA on 11 meters in a tri-axle dump. The mirror mount antenna couldnt handle the power while tuning and the end of the antenna "popped" and turned into a 1" diameter ball of blue corona spark that modulated. When you'd talk or whistle, you'd hear it in the "glowing blue ball of RF"

2. A 600 watt amp on 11 meters in a 82 VW Scirocco would would disengage the logic controlled fuel pump relay and shut the car down.

3. 79 Dodge truck: a 110 watt 33Mhz Mitrek would cause the truck to stall. This was solved by making the ignition pickup leads into a twisted pair and installing a ferrite bead. Wierd thing was, it only did it on 33.80 and no other.

4. My neighbor that lives two doors down was installing a stereo in his car and had a pair of 3-way 6x9" speakers laying on the roof of the car- nothing at all connected to them. My voice was coming out of them! We were running 10 meters and the local truckers were interfering, so I tuned up the Henry 2KD amp and drove it with a JB12 modulator and went to town on channel 19. If you're not familiar with this amp, it's 220 powered and will do about 1700W on SSB. Being the speaker was actuall three speakers in one unit, one speaker was inducing the voltage from my RF and one of the others was reproducing the sound from the voltage.

Bizzare.

jim · Post by **jim** » Thu Jan 17, 2002 5:17 am

Now, does anyone remember their first 100+ watt RF burn? I DO!!

radiofreak · Post by **radiofreak** » Thu Jan 17, 2002 5:21 am

I have seen 2 different RF adventures lately. The first one is from a company that uses 110watt Maratracs (42Mhz) in there Ford Explorers due to off road work. After mounting several with the antenna all the way at the rear where they wanted them the problem arose. Every time the radio would key, the rear wiper would make a swipe across the back glass. Found out the motor was computer controlled. The other is from a company that uses 110watt Maratracs (160Mhz) and one Ford F150 had a problem with the engine shutting down at highway speeds when keyed. After hours orf searching we found a computer control module behind the glovebox. We wrapped it in tinfoil and the problem went away, so much for factory shielding.

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Thu Jan 17, 2002 9:29 pm

On 2002-01-17 02:09, 10-95 wrote:
Reminds me of the time I worked at a radio station in the early 80's, they still used turntables back then, we had the nice Technics SL series, and once while on the air I keyed up my HT600 and the turntable pitch control went nuts!! Springsteen sounded like the chipmunks, I had a lot of fun with that trick , while a buddy of mine was on the air one night I did that about three or four times during his shift from the next room, he was a nervous wreck after he got off the air!!

10-95

What band was it? How much power did it have?

I'm curious; that could be a fun trick to try on a serious club-type DJ.

Just kidding, i think?

cracked · Post by **cracked** » Fri Jan 18, 2002 12:06 pm

On 2002-01-16 16:29, Nand wrote:
Well, I'm not the man I used to be. And I blame RF for it. And if you look at some of the older HAM operators you will likely agree.
Nand.

what exactly did RF do to your manliness? as a young guy starting a carrer as an RF tech, should i be concerned? all the older hams i've seen just seem like pretty typical older guys...

radioEd · Post by **radioEd** » Fri Jan 18, 2002 12:14 pm

[/quote]

what exactly did RF do to your manliness? as a young guy starting a carrer as an RF tech, should i be concerned? all the older hams i've seen just seem like pretty typical older guys...
[/quote]
We get gray hairs faster! And less hair period! you feel ok talking on a cell phone 2 hours+ a day! does wonders on the neruo system. (but cell phone makers/dealers ect.) will say No! no cancer!

cracked · Post by **cracked** » Fri Jan 18, 2002 1:09 pm

We get gray hairs faster! And less hair period! you feel ok talking on a cell phone 2 hours+ a day! does wonders on the neruo system. (but cell phone makers/dealers ect.) will say No! no cancer!

shrug. that whole cancer from cell phones etc issue is just a little silly. maybe the older RF guys complaining about loss of manhood need to hang up the soldering iron once in a while and go for a jog.

as for some RF oddities: take your 5W portable and wave the antenna around the case of your home phone. it'll usually start dialing tones, numbers stored in memories, flashing...

next time one of those megawatt rap-blasting buttheads pulls up next to you at a light, key your VHF or UHF (experiment on both bands) radio, amped way up, and listen to his "system" buzz and pop. usually works better if he's listening to the radio and not playing a tape/CD.

[ This Message was edited by: cracked on 2002-01-18 16:10 ]

[ This Message was edited by: cracked on 2002-01-18 16:47 ]

willbartlett · Post by **willbartlett** » Fri Jan 18, 2002 2:05 pm

I had this really self centered upstairs neighbor a few years back, and he loved to listen to whatever bass heavy top 40 crap was popular with no consideration for us poor 6-inch-thick-no-insulation-in-the-floor downstairs housemates. So I decided to hook my 50 mhz 80 watt kenwood low band radio up to a spare 6 meter radiator from a beam I had stored in the basement. That didn't stop him, but the running around trying to figure out what happened to the backstreet boys sure eased the pain. I took great pains to make sure my neighbors didn't suffer any interference from the various Ham antennas on my roof, to the end of runnung a ground cable up the air shaft to the roof. Oh well, It isn't always so sweet, but it was nice.

jim · Post by **jim** » Fri Jan 18, 2002 2:40 pm

I just remembered another one from a few years ago...how could I forget this!

Next time you're in a self-serve high quarter operated carwash, quickly key up your high powered rig and watch the quarter counter. My 10 meter rig used to put 25 cents on the clock each time the mic was keyed. One time, I did it in a bay that was too close to the equipment room and set off the alarm. They since installed cameras due to vandalism, so no more free car washes.
I discovered this by talking on SSB while on the way to wash my Jeep. I noticed that on several mornings there was something like 7 minutes on the clock when I pulled in the bay. I'd usually sit there for a moment and sign off. It took me about 4 times of this happening to finally figure out that the "person before me" didn't really leave this time on the clock, but my RF was racking up the time (:

I had the cleanest Jeep in town for almost 2 years.

radioEd · Post by **radioEd** » Fri Jan 18, 2002 3:27 pm

shrug. that whole cancer from cell phones etc issue is just a little silly. maybe the older RF guys complaining about loss of manhood need to hang up the soldering iron once in a while and go for a jog.
[/quote]
Nope Cell phone cancer ain't silly! Drop by a local college & try to have a chat with a "health-care-physicist" you may be surprised! Not to stray from the Radio subject! Alot of people in an X-Ray room, behind, the lead glass, or wearing a lead apron, Or standing next to the x-ray tech. while he pushes the button & zaps "whoever" is getting an x-ray. Think your safe from exposure? Some! Those lead walls, lead impregnated glass, lead aprons...just SLOW x-ray exposure down! It will find ya!

[ This Message was edited by: radioEd on 2002-01-18 18:29 ]

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Fri Jan 18, 2002 3:50 pm

I was considering wearing lead-lined under-shorts to protect my "guys." However, the thought of exposing my "guys" to Lead scared me, too. Both RF and Lead can cause bad things to happen. What is a guy to do?

captainkirksdog · Post by **captainkirksdog** » Fri Jan 18, 2002 4:08 pm

Here's another RF problem I remember when I was in junior high. I lived in St. Pete, Florida, at the time, and our school gym had a metal roof. Once in a while, Miessner Marine Salvage, on marine VHF, could be heard coming from the ceiling. It wasn't the speakers. We found that out one day when it boomed so loud everyone had to leave the building. Apparently, the high salt concentration in the air had corroded the metal roof to the point it acted like a diode detector. The school grounded the roof and the problem went away. *CKD*

601 · Post by **601** » Fri Jan 18, 2002 4:58 pm

I was talking to a friend on my VHF 45 watt MCX1000 at an intersection, when I noticed that everytime I key up, it shut off the green traffic light! Only does it on those new LED ones.....

Post by **vcaruso** » Fri Jan 18, 2002 6:14 pm

I noticed the same thing with the traffic lights but with our 100 watt low bands.

radioEd · Post by **radioEd** » Fri Jan 18, 2002 6:30 pm

Still have that radio? want to sell it? I can have Lunch here at a Light

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Fri Jan 18, 2002 8:03 pm

On 2002-01-18 19:08, captainkirksdog wrote:
Here's another RF problem I remember when I was in junior high. I lived in St. Pete, Florida, at the time, and our school gym had a metal roof. Once in a while, Miessner Marine Salvage, on marine VHF, could be heard coming from the ceiling. It wasn't the speakers. We found that out one day when it boomed so loud everyone had to leave the building. Apparently, the high salt concentration in the air had corroded the metal roof to the point it acted like a diode detector. The school grounded the roof and the problem went away. *CKD*

Humm. I wonder if Miessner Marine Salvage was using the maximum legal Marine VHF power of 25 Watts? I suspect they were using a bit more...

57Shasta · Post by **57Shasta** » Sat Jan 19, 2002 8:47 am

I had a police dept I did work for that had a key-card system for the doors. They figured out that by holding the uhf portable close to the reader and keying, they could open the door. Saved them from digging in their pockets for a card.
I went in one day to pick up items for repair and sure enough there was a portable with the complaint written on it "WILL NOT OPEN DOOR".

radioEd · Post by **radioEd** » Sat Jan 19, 2002 11:42 am

I gota try a withdraw in front of an ATM. Cause it could backfire & shortchange me?

jim · Post by **jim** » Sat Jan 19, 2002 1:28 pm

...or it will take take a picture of you after activating the internal tamper alarm!

radioEd · Post by **radioEd** » Sat Jan 19, 2002 2:15 pm

Yea! I know Jim, but it was a passing thought. maybe if someone in front of me is getting cash. And someone calls on the radio??? Na ! I skip the idea! (with my luck I'll ask for $300. & only $100 will come out? I could stop the process)............it may backfire?

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Sat Jan 19, 2002 4:00 pm

On 2002-01-19 11:47, 57Shasta wrote:
I had a police dept I did work for that had a key-card system for the doors. They figured out that by holding the uhf portable close to the reader and keying, they could open the door. Saved them from digging in their pockets for a card.
I went in one day to pick up items for repair and sure enough there was a portable with the complaint written on it "WILL NOT OPEN DOOR".

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Mon Jan 21, 2002 9:23 pm

Speaking of "adding credit" to coin machines, has anyone done any studies on the effects of RF on casino slot machines?

Likewise, did anyone see that MacGyver where he took the HT-220, with the really long telescoping-type antenna, keyed up next to the candy machine, and got a free bag of M&M's? Yeah, MacGyver saved the world from evil, and had a bite to eat, too. Or was that salt-water in the coin slot of the Coke machine? I can't remember.

radioEd · Post by **radioEd** » Mon Jan 21, 2002 10:27 pm

On 2002-01-22 00:23, KC8RYW wrote:
Speaking of "adding credit" to coin machines, has anyone done any studies on the effects of RF on casino slot machines?

I would not advise you mess around with any RF device in a casino! Thats another way missing person reports stem from! at least out west (still) Theres a guy I know (20 yrs ago. from Stanton, MI Montcalm county, went to vegas..never came back?????)

EM-01 · Post by **EM-01** » Tue Jun 18, 2002 1:55 pm

My Most interesting Experience was when I was a Police Officer and installed a 175 watt bilinier to my CB. When I transmitted my voice would come out of my Siren Speaker for all the World to Hear.

And these days if I am playing a cassette tape in my truck stereo and I transmit on my X9000 (100 watt) I get the chipmunks.

Too Much Fun

mancow · Post by **mancow** » Tue Jun 18, 2002 3:17 pm

Well it's not exactly accidental I guess

I was in a high school electronics class my senior year. A guy at the other table insisted on dominating the stereo receiver and listened to nothing but country (not exactly my style).

Me and A buddy got an idea one day. We took an old dial type RF generator an took apart an old portable tape player. We hooked the speaker lead into the modulation input and put a set of rabbit ears on the RF out lines.

We set the unit under our work bench out of sight. Every time he would tune it to that damn country station we would just tune over him and play what we wanted. It worked incredibly well. He finally got so pissed trying to figure out how the station changed when he left the room he gave up all together. He wasn't real bright anyway. Most of the time he passed the hours putting components in all the powerstrip outlets and hit the power. A hell of a fireworks show until the instructor showed up and went ape S***!!

mancow

Will · Post by **Will** » Tue Jun 18, 2002 11:53 pm

He graduated, and now instead of putting componets in the AC plug strip, he IS programming your radio at a socalled "Dealer".

Hightower · Post by **Hightower** » Wed Jun 19, 2002 1:31 am

Don't get your hopes up on the slot-machine thing. I watched Cyber-Crime on TechTV a while back about slot-machines and the way people try to rip them off. All machines that go into service are first tested with a variable-controlled "stun-gun". The special Stun Gun is designed to vary the voltage, frequency, amps etc. They shock the machine for hours. The next test is the RF test. They stick the slot machine in a RF proof room, and direct a directoinal yagi beam at the slot-machine and bombard it with the whole RF spectrum with varying power levels, AM/FM/SSB/Digital etc to make sure the machine doesn't jam up or give you more money than it should. ......would be nice tho......

Also if you got a 10/11M radio and PA (something 350watts or larger), you can get free car washes, and get to vacume your cars for free at most carwashes. Just position your radio's antenna close to the coin box, and whistle on SSB (USB or LSB) - walla. Hehhehehehehe, I had a nice clean car for years!

Have Phun!

USPSS · Post by **USPSS** » Wed Jun 19, 2002 6:38 am

In the later 70's while I was serving our country in Omaha, NE, I reserved with a local police dept. We had DUMONT radio's 39mhz (Remeber those) and if you saw a 6v Volkswagon you could key the radio and turn the bug off, we drove around looking for cute women in them so we could shut off the car and get out to help them (that's what we said) got many a date that way.

MO_TRASHER · Post by **MO_TRASHER** » Wed Jun 19, 2002 9:01 am

I find it quite interesting that slot machines would be designed to be RF Proof, and yet, you get poor quality shielding and worse in cars, trucks, and "high-end" two way radio equipment. Guess it's all about the $$$$.

I remember a Merc Benz that would downshift and turn on the wipers when keyed. Lowband of course.
Olds Cierra's that the rear window defrost indicators would glow. Also Lowband.
I had an ambulance that had such a bad problem with the placement of the antenna & lightbar, when you'd key, the siren went on, indicators in the cab electronics were flashing, and if you held the mic just right, you'd get one nasty RF burn. You guessed it, LOWBAND!!!

jim · Post by **jim** » Wed Jun 19, 2002 1:09 pm

Sounds like another weekend-warrior installing a lowband and not grounding anything and checking VSWR.

I had a VW Scirocco that would shut off the fuel pump relay with a 600W 10M rig. It was a logic controlled relay. The problem was a linear grounded to the dash brace. It was electrically grounded, but RF still managed to get everywhere else.

EKS · Post by **EKS** » Wed Jun 19, 2002 8:20 pm

My vhf Visar disconnects all the phones in the house when keyed.

I set off a bank alarm one night during a hail storm. 2 meters, 50 watts in the drive through lane will do that.

cranbiz · Post by **cranbiz** » Thu Jun 20, 2002 4:16 am

My HT1000 and all of our FD officers MTS2000's reboot our dispatch Macintosh when keyed within 30 feet of the dispatch office, however we can key up the trucks MCS2000 radio's in the bay (same distances) and not cause any problems. Go figure.

R F Burns · Post by **R F Burns** » Thu Jun 20, 2002 4:58 am

This is kinda benign, but when I worked overnights on a TV news crew and meal break came up, my partner and I would eat at a certain diner that had Seeburg table-top jukebox remotes. Needless to say that whenever we wanted to dine to music, just a click of the MX-350 would result in as many tunes as key-ups.

- RF Burns <-- yep... been bitten a few times

larrybl · Post by **larrybl** » Thu Jun 20, 2002 9:12 am

I was reading the rf stories link, and remembered back to my military days..... I was the operator of a Troposcatter microwave relay terminal. 4.5 to 5.0 GHz and would push 1500W, there were two stacks of equipment. I was on a mountan top in Korea, and only using one stack for operation. I decided to try an experiment with the other stack. we placed our C-rations (sorta like caned food) in a circle on the ground, and cracked the lids, then placed the end of a wave guide poinedd towards the cans, about 12" away, fired up the B-stack, and started cranking up the power. Had to watch the reflect (it would shut down at 100W). Output was around 500W W/ 90 or so reflect. In a few minuets, hot food!

I could talk about the blue haylo also. Used to run a AN-GRC-106

Post by **alex** » Thu Jun 20, 2002 11:59 am

Keying up on VHF at my local Mc'ds in the drive through, you can turn off the LCD touch screens. I haven't played with the order takers that much, but I discovered it after trying to page my friends radio while in the drive through. Very amusing.

I also have noticed that the Apple LCD Displays will turn off randomly when subjected to VHF RF, esp from a Saber.

However, the sony monitor I have here on my desk doesn't even blink when I key the UHF Portable on my desk.

-Alex

April · Post by **April** » Thu Jun 20, 2002 12:22 pm

I used to have a problem when entering the Wharehouse Video store, my P50 UHF would set off the rental Video tape detector at the door and I was not transmitting! It was just on my belt not bothering anyone.
I once baught a pair of jeans and the clerk could not get the theft detector gadget off the pants. She gave me a discount and I went home and cut the dector off the pants, took it appart to see what was inside, sort of a oscilator coil, transistor and a diode. I put the circuit, minius the housing, in my jacket pocket and went merrily along--- triping dectors off at some clothing stores that had a simmular system.

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