why do truck drivers

Noperz --- 4x the received signal strength. Power at the xmtr is a matrix of volts AND amps, so +3dB *power* is a doubling of output *power*; +6dB at the TX is 4x the power, and +10dB at the TX is a 10-fold increase -- in power. However, at the receiver, the S-meter is looking at just volts in the AGC (or i.f. amp, or similar). Ignoring current in the receive circuit, it'll take twice the voltage to move the S-meter movement (for the same current, which isn't measured; it's part of the circuit, of course).
S-meter circuits are typically logarithmic, and the standardized voltage for incoming signals to show S-9 varies with the manufacturer, so the "standard" ......well, it ain't. For AM gear, it's *usually* either 50 uV or 100 uV, so unless you're using the same receiver & antenna & such to compare incoming signals from 2 or more xmtrs, any readings from multiple receivers are gonna be suspect.

I've got one of my boatanchors (albeit a very high end one) calibrated for 50 uV per the tuning specs, and I usually use it for "greater than" or "less than" comparisons of folks' radios on the air. When it really matters, though, there's no real substitute for a properly calibrated spectrum analyzer.

In the interest of full disclosure, I've been a ham 55 years now (got my Extra when one needed to send & copy 20 words per minute in Morse), a CBer 51 years, and a commercial licensed tech (originally 1st Phone w/ship radar and 2nd Radiotelegraph; now a GROL for Land Mobile) for 42 years. There's a place for all RF, as long as it's generated cleanly.


Did I answer the question, of did my having waxed philosophic just make it worse?
73

 

After reading all that the first thingthat came to mind was "scratching my head" WHAT!!

 

I can get an extra 's' unit out of this............

 

Handlebar is correct in his statement. Notice his statement " However, at the receiver, the S-meter is looking at just volts in the AGC (or i.f. amp, or similar)." He was NOT talking about the input voltage at the receiver.

leon
kc0iv

 

I don't know why so many truckers get their radios to sound so bad and think it sounds good.

Ham radios sound so much better and can get out much further and have thousands of frequencies to choose from.

Then again, if too many truckers get on the ham bands, they would start swearing and singing and using roger beeps and bring their bad cb habits to the ham bands. The good thing is that the FCC actually enforces the rules on ham bands and have vigilantes who use direction finding eqpt to find you. The fines are big.

We should get a "trucker calling frequency" though for each band.

 

Do you really believe that truckers are the only one who can't behave on the air.....if so i totally disagree with you!

Don't get me wrong truckers are capable of the worst but i have heard my share of ham doing stupids stuff on the air.

 

Because every time they ask some tone deaf goober comes back with: "sounds good!"

 

All you have to do is get on 75 meters.

leon
kc0iv