This is a WebSDR receiver, located in KO39DC (Väike-Maarja, Estonia). It is operated by ES4O from the TPT Radio Club. e-mail

The setup is rather experimental, and neither continuous service nor good performance are guaranteed. Comments into the chat-box are welcome!

Update 12.10.2017: Check out our ES4O multiband reverse beacon spotter at or

Update 06.11.2017: 2m/70cm band is mantainance, will be back soon.

Update 10.12.2017: The WebSDR server is now connected directly to the internet. You can see different client IP addresses at the users section.

Update 12.12.2017: Default waterfall settings have been changed: Speed -> fast, Size -> large and View -> weak signals

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Allow keyboard:
j k ← →: freq down/up (+shift/ctrl/alt faster)
u l c a f: USB, LSB, CW, AM, FM
z Z: center/zoom waterfall
g: enter frequency

Frequency: kHz

Or tune by clicking/dragging/scrollwheel on the frequency scale.

? kHz @ -6dB; ? kHz @ -60dB.
Or drag the passband edges on the frequency scale.
Waterfall view:
Or use scroll wheel and dragging on waterfall.

? dB; peak ? dB;
mute squelch autonotch
Signal strength plot:
Call of station that you hear:
Comments, if any:
Note: time, frequency, your name/call, and DXCC information are added automatically.
View the last 20 lines of the logbook, or the entire logbook (ctrl-click for new tab/window).

This WebSDR is currently being used by ? user(s) simultaneously:      compact view

This chatbox is intended to discuss the operation of the WebSDR.
The operators of this site disclaim any responsibility for text appearing in this chatbox.