Constant tone on 27.265 LSB

Could it be something electronic on your truck, I know my radio gets super noisey when ever I plug my phone in to charge

 

You shouldn't need to scan. Channel 38 LSB is the common calling frequency.

For reference: http://fldx.org/site/11m-call-frequencies-and-operating.php

http://www.delta-alfa.com/27-385-profile/

 

Sounds like you've got a "birdie" going there.
"birdie: A false or spurious signal in a receiver inadvertently produced by the receiver’s circuitry."
http://www.dxing.com/radterms.htm#balun:
That particular frequency produced some birdies in some older Radio Shack crap.

 

That's not a constant tone, it sounds like nothing is wrong with the radio. Rather someone keyingnup a mic to test something like swr.

To all that don't know how a radio works, when you turn on ssb from am, there is a change in what appears to be the sensitivity of the radio and a drop in noise, this happens when there is a narrowing of the if strip - it goes from wide to narrow to get one half of the am signal - and the addition of a signal inside the radio to decode the ssb signal so you can understand it. This sometimes allows you to hear weak and other wise hidden signal on the channel.

So this signal, only on lsb is as I assume off frequency and weak. The reason you hear it on lsb is because the center frequency of the carrier is lower than it should be, and because you also don't hear it on am or USB is because it is weak.

 

That tone is coming from a componet or device that is in close proximity to the antenna.

It is modulated on the same frequently you are tuned to. LSB check. 26? You said it is quiet on all other channels? The scanner has isolated the frequency. now you must find the source of that frequency by turning off the all accessories using the internal circuitry on the truck.

Turn the engine off tune to channel 26. Do you still hear the tone? It could be a data transmission from the engine ECM to the Trucks internal diagnostic UI. (user interface)

Typically tablet & cell phones operate at different a frequency range, so they shouldn't be suspect unless the have Bluetooth and then that is unlikely.

I think it has more to do with the on board electronics.