4 meter WEBSDR in Hertfordshire covering the London area

This WebSDR is using a RTL Dongle receiver into a Raspberry Pi4, the vertical antenna is a Sirio CX-4-68 4M
the horizontal antenna is a 4 meter Halo, QRA located IO91TP.
It is operated by M0XVT and G3VHH, for more information e-mail G3vhh@yahoo.co.uk
More information about the WebSDR project can be found on http://www.websdr.org.

Note: The latest Chrome update has once again broken WEBSDR sound plus
tuning with the mouse wheel no longer works with latest Chrome and Microsoft Edge see workaround

Note: 6th June 2021 The Halo antenna has been placed outside any reports would be welcome.

New audio features - Notch, HB, DSP NR - developed by the folks at the Northern Utah WebSDR, for more info visit http://www.sdrutah.org/info/dspnr.html
You may find that when using the DSP feature you get audio drop out try using Firefox, the speed of your PC may be an issue.

Have a look at our 2 meter WEBSDR http://www.sdr.codedv.com:8092.

Note: Unless your browser supports HTML5 audio, you need both Java and JavaScript enabled for this page to work properly.
If you don't hear anything, probably Java is disabled or its version is too old (i.e., pre-1.4.2).

It seems you are using a mobile device; click here to switch to the mobile version of this site.
It seems Java is not installed or disabled on your computer. You need to install and/or enable it for this website to work properly.
Since Java version 7u51, Java needs to be enabled separately for each website; see http://websdr.org/java.html for instructions.
Your browser does not seem to support HTML5 WebAudio; please try a recent version of Firefox, Chrome, Opera or Safari; or switch to Java.

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

Waterfall view: Display Speed: Display Size: View:
Or use scroll wheel and dragging on waterfall.



Button + / -
* * *
* *

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


? kHz @ -6dB; ? kHz @ -60dB.
Or drag the passband edges on the frequency scale.

av: ? dBm  pk: ? dBm
mute squelch Notch1
Notch2 High Boost
DSP Noise Reduction:
Signal strength plot:

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.

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).