No Idea What This Is

[Matt_B]

Can anybody hear the tones on 27185/27186 right now? Hearing various tones under CB chatter into the Western PA SDR.  Assuming it's just some jackass playing around?

For reference, here's a recording of said tones. 

https://drive.google.com/open?id=1H8g-bzI_xcrqt5zhEtq5Mgz5LJcVp95L

[Josh]

That's just mixing from all the am carriers that are off freq coming in from skipland.

[R4002]

27185, or 27.185 MHz CB channel 19 - is one of the busiest frequencies in all of the HF spectrum.  Even with some moderate propagation enhancement you can get a lot of carriers on frequency at once.  For most CB users, their radios are never aligned as far as frequency goes outside of work done at the factory or if the tech doing the "peak and tune" actually does an alignment...so you'll often have carriers 400-500 Hz off center frequency, resulting in annoying heterodyne (or "het") squeals and tones when multiple carriers on heard at once.

So if you have a signal on 27185.0 kHz and another signal on 27185.5 kHz (500 Hz off center frequency) at the same time, you'll hear a 500 Hz tone (the difference between the two signals).  Add multiple signals on top of each other and you have a real mess of tones and interference during favorable propagation conditions on 11 meters.

[N2NXZ]

27185, or 27.185 MHz CB channel 19 - is one of the busiest frequencies in all of the HF spectrum.

Do you really mean all of the HF spectrum or just 26.965 - 27.405 ?
Stop in to 14.074 USB or 10.136 USB...maybe 7.074 and 3.573 ...all USB mode
Jim