New question on "Scanner Overload"

[JimboConn]

Would there be a way to test for damage of a hand held scanner?
When I didn't know what I was doing I tested out trying to pick up my HT transmission on a unifen scanner...I tested this by walking a few rooms down. The scanner picked up Zero transmission...I've posted here in the past about that issue...but when trouble shooting why the scanner on the same frequency picks no signal at all from the HT, this issue is still pressing, but lead to believe I was overloading the scanner.
Did I damage it? If I am picking up NOAA and local activity does that mean it's not damaged or may it be semi damaged?

 

[a417]

Would there be a way to test for damage of a hand held scanner?
When I didn't know what I was doing I tested out trying to pick up my HT transmission on a unifen scanner...I tested this by walking a few rooms down. The scanner picked up Zero transmission...I've posted here in the past about that issue...but when trouble shooting why the scanner on the same frequency picks no signal at all from the HT, this issue is still pressing, but lead to believe I was overloading the scanner.
Did I damage it? If I am picking up NOAA and local activity does that mean it's not damaged or may it be semi damaged?

Transmitting in the same room is not a good idea. If you have a giant flamethrower of a transmitter, or you have the antennas connected together - a couple of incidental transmissions in the same room is not likely to cause permanent damage.

To confirm, you are still picking up NOAA and local activity? If you are, you either have a programming issue on your HT, you don't have the scanner set correctly to recieve the HTs transmissions...or you are just overloading the front end and it's perfectly well within its right to sit there and do f**k-all.

 

[Whiskey3JMC]

Did I damage it? If I am picking up NOAA and local activity does that mean it's not damaged or may it be semi damaged?

What model Uniden? Were you able to reliably pick up "non-local", more distant stations from the same rooms using that scanner before but not now? No other programming changes to the radio? No buttons accidentally pressed? How does the scanner perform outdoors? What antenna are you using, got another antenna aside from stock? If it were totally fried then you likely wouldn't be able to pick up NOAA or strong nearby stations at all. Too little info to go by to come to an ultimate conclusion & everyone's RF environment is different

 

[nessnet]

Would there be a way to test for damage of a hand held scanner?
When I didn't know what I was doing I tested out trying to pick up my HT transmission on a unifen scanner...I tested this by walking a few rooms down. The scanner picked up Zero transmission...I've posted here in the past about that issue...but when trouble shooting why the scanner on the same frequency picks no signal at all from the HT, this issue is still pressing, but lead to believe I was overloading the scanner.
Did I damage it? If I am picking up NOAA and local activity does that mean it's not damaged or may it be semi damaged?

Jimbo - if the radio picks up other signals, you are fine.
"Overloading" the front end of a radio blows certain solid state components.
Components that are used to pick up everything, so if it works....

 

[tvengr]

If your radio is on a repeater and the scanner is tuned to the repeater output, it isn't unusual for the scanner to be overloaded and not hear the transmission. Set your scanner to the repeater input frequency and try it again from a distance.

 

[Ubbe]

Radio signals attenuate 30dB, one thousand times, at a one meter distance using 800MHz. 5 Watt equals 15 volts into 50 ohm so it's 15mV from another antenna with no gain. At 5 meters it will be less than 1mV.
150MHz equals 15dB attenuation that's only 50 times and 15 volts will be 300mV at one meter.
50Mhz attenuates only 6dB at one meter, 4 times, and the signal are 4 volts from the antenna.
With each doubling of the distance it adds 6dB in attenuation. So at 50MHz at 1/2 meter, holding a radio in one hand and scanner in the other, there will be close to no attenuation at all.

The bandpass filters in a scanner usually attenuates the signal to half and if it is monitoring a signal in another band it will attenuate at least a hundred times. Some scanners have a diode protection at its front end to clip any signals above 1,4 volt but others like a BC125AT do not.

The first amplification transistor in most of Unidens scanners, that sits after the bandpass filter, can handle a max signal of 500mV according to its specification. So in some cases, depending of frequency and transmit power and also distance and what frequency band the scanner are currently in, can blow the scanners front end when too close to a transmitter.

In many cases of overload damage the transistor doesn't stop working completely but just doesn't amplify as it should and the scanner has reduced sensitivity and usually have interference issues as well.

/Ubbe