UV 5R broke my car radio...

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Orbit_Uranus

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I was sitting in my car listening to 90.7 FM radio station, and when pressed the PTT button on my UV 5R radio in the 140Mhz range it would cause the car radio to lose reception of the radio station. It does not do this in the 70cm bands, only the 2m bands. So I got the handheld closer to my car radio to just see what would happen to test it again and see if it was doing what i thought it was doing, and my car radio turned off totally. Now the car radio won't even power on! I have not had a chance to check the fuses in car yet as I was out on my lunch break at work.

Anyone ever see / hear of something like this happening? Why would a broadcast in the 2m bands effect my car radio, and how could the 4 watts from my HT have made the car radio blow a fuse?

Thanks :)
 

902

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This could really be anything at this point.

Yes, your HT transmits enough radio frequency energy to desensitize radio stations under certain conditions. It might even have enough energy to get into the radio and upset a microprocessor or memory device, or maybe even induce a voltage somewhere and pop an internal fuse.

You're doing good by checking the obvious first. Beyond that, it's whatever you feel comfortable with. The worst you can do is break it... but it's that way already, so the best you can do is fix it and learn while doing.
 

WB4CS

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Basic, general, RF Theory 101: Transmitting RF very close ("So I got the handheld closer to my car radio to just see what would happen") to a receiver is never a good idea.

I agree with the post above, you probably overloaded the receiver of your car stereo. Time to go shopping for a new stereo.
 

elk2370bruce

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You overloaded the frontend of the radio......
Yup. Bad experiment. Predictable outcome. Expensive mistake. The UV 5R is blameless.
 
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Orbit_Uranus

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Yup. Bad experiment. Predictable outcome. Expensive mistake. The UV 5R is blameless.

not expensive, it was a radio player i took out of a car from the u pull it junk yard, 5 bucks ...the replacement will also be :)

Learned something new so I guess i won't be doing that again....:) Thanks for the replies.

Overloading the front end of the radio, not sure what that means but it does not even power on anymore, so maybe I overloaded the front middle and back ends .....

If i can figure out how to edit my 1st post i will change the topic to 'I broke my radio with my UV 5R'
 
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robertmac

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spurious images which the Baofengs are well known for?
 

KB0VWG

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I have run mobile radios in my truck and car and never had an issue and sometimes that's at 50 watts output on vhf and 35 watts on uhf.
kb0vwg
wqoi992
 

rescuecomm

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I have run mobile radios in my truck and car and never had an issue and sometimes that's at 50 watts output on vhf and 35 watts on uhf.
I do too but never with the antenna inside the car directly near the face of the stereo.

Bob
 

Darth_vader

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Yeah, probably overloaded the car radio's RF frontend and burned it out. 136.050 and 158.725 are the 1.5th and 1.75th harmonics of 90.7, which the 140 MHz band is in between. Whichever specific frequency you were transmitting on must have been harmonically close enough that your car radio couldn't handle it.

Were you using the 5R with an external (i.e. mag-mount) aerial situated on the opposite end of the car from the stereo aerial or transmitting off a rubber ducky/whip in the cab?

"Not sure what 'overloading the front end of the radio' means but it does not even power on anymore, so maybe I overloaded the front middle and back ends."

Read: https://en.wikipedia.org/wiki/RF_front_end

Basically it's the part of the radio that takes the incoming signal as it's picked up at the antenna, filters the signal on the selected frequency from the others around it and converts it to a lower-frequency signal the rest of the receiver can handle. "Overloading" basically means giving it too much RF energy, at too high a power level than it can handle. This is the same reason the audio in a stereo receiver radio, or the picture on a TV set, can become "scratchy" and distorted if used with an antenna amplifier that's set too high.

Let's just say that without it, the radio would be deaf as a stone.
 
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WA0CBW

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Did you ever check the fuse to see if it was bad? I can see where you may have overloaded the front end of the radio causing it to be less sensitive (deaf) but to cause it to not turn on seems a little strange. Burning out the front end would normally not prevent the radio from turning on. It might cause the front end transistor to let out the magic smoke but I don't think it would prevent the radio from turning on.
BB
 

N4KVE

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I find this story amazing because I use a 100 watt MCS2000 UHF radio in my car, with a 5db gain antenna which sits less than a foot from the AM-FM antenna & have never had a problem. Some of my transmissions can last 20 seconds, & while both antennas are 12" apart, no damage has occured. Just strange.
 
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It's not that strange MOONBOOTS,
Plenty of stories out there about guys running amps on their cbs cooking other motorists radio's when sitting right next to them in traffic or something. You don't see it on UHF, however once I get 60 miles away from the broadcast transmitter on FM even running 5W through a quarter wave vhf antenna sitting over the 3rd row of my trailblazer (AM/FM antenna is in the traditional location) will desense the receiver as long as I have the radio keyed. 20 miles from the transmitter, I can transmit 75W and you'd never notice the desense.

Sent from my ME173X using Tapatalk
 

Kirk

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When I was a kid I had a 13" Sony Trinitron tube television that would pop a cap and die whenever I transmitted with a 4w UHF HT within a few feet of it. It got to where I kept a bag of spare capacitors on hand for repairs. The TV wouldn't blow up if it was powered off, so I suspect I was causing some kind of inductance issue. Over time I got better at remembering to turn off the tv before transmitting.
 

ControlNode

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That radio may still be good, but may have to disconnect for power for a while. I have radios to that, not from me using a transmitter, maybe someone near me was, but they still acted dead but no fuses were blown. I removed them opened them to see if I could find anything obvious inside blown and all looked good. Hook it back up and it works again. My logic is something in the memory or something got corrupted and the united need a full discharge to reset and work again. Worth a try at least, its free.
 

W9BU

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Note that RF energy from any radio transmitter has the ability to damage nearby receivers. This problem is not unique to any particular brand or model of radio, either on the transmitting or receiving side of the equation.
 
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