HFGCS Intermittent tone/beep

[CaptJSparrow68]

I'm monitoring the 11.175 frequency for HFGCS.  I am hearing an intermittent beep/tone on the frequency here near Mount Hood, Oregon.  Is anyone else hearing it too?  If so, when did it start doing that? 

Happy monitoring!!


-- CaptJSparrow68

Equipment used:

Yaesu FT-DX10
MFJ-1984MP 66FT End-Fed antenna 35 FT above the ground @1100 FT ASL NE to SW
Tripplite 35 amp Power Supply

[~SIGINT~]

I have recently been observing an increase of "chirps" across a segment of the 11 MHz band. For me, they sound like chirps (short burst transmissions) but I guess depending on where your dial is set, these could be producing some beeps / tones.

These have been there for a while, come and go, but recently appear to be more frequent in nature than usual. I am not sure what they are. They do transmit in sync with each other (multi-channel) and I have seen them elsewhere like centred around 15 MHz.

Here is what they look like on a waterfall display.

[CaptJSparrow68]

Hi ~SIGINT~,

Thank you for the reply and the info.  I appreciate it.  With the way things are right now, there are all sorts of strange signals on the radio.

73,

CaptJSparrow68

[~SIGINT~]

I am now hearing that beeping sound on 11175 at 01:23 UTC 20 OCT 2023. It is kind of that same type of beep you get when someone is recording a telephone conversation etc ... It is weak but readable with no consistent pattern.

RSPduo | Wellbrook loop antenna

[~SIGINT~]

This morning around 12:45 UTC 20 OCT 2023 those mysterious burst transmissions were very active for several hours. One was centred on 11175 which produced the aforementioned tones and beeps.

You can also see the trace from a sweeper starting at the bottom of the band and moving its way up.