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Welcome to the version 3 upgrade of the KFS WebSDR, located six miles south of Half Moon Bay, California USA. This facility is maintained by Craig, W6DRZ, e-mail To read about the new features of this upgrade, click here. A complete technical description, operating tips, updated propagation information, and a donation opportunity can all be found on the ABOUT page. More information on the worldwide WebSDR project can be found on

An outstanding alternate system in the Western USA is Northern Utah WebSDR, North of Salt Lake City.
Also, check out W7RNA Phoenix WebSDR in Arizona; and AI6VN Maui WebSDR in Hawaii.
For HF reception from the East coast, use either NA5B WebSDR in Washington, DC. or Home of K3FEF & W3TKP in Pennsylvania.

(27 Mar '21) The KFS Radio Club has been issued the callsign W6KFS.
(6 Oct '21) Separate Kiwi receivers are now available on all four TCI antennas. Use this Landing Page for access.
(30 Mar '22) The new upgraded version of the KFS WebSDR is on the air. Please use the new domain for future access. Questions and comments? Please email Craig.
(21 July '22) Users of the CatSync program may find that it can't parse the 1 Hz tuning display resolution on this WebSDR: Add "?10hz" to the URL to force display of 10 Hz tuning, as in "". More URL-based commands may be found here.
(27 July '22) Users of Firefox now need to press the "Firefox/Mozilla Audio Start" button as of version 103:  For more information, go to the Firefox Audio Fix page.
(7 Sep '22) Thank you to KK6PGA, WA6ZVE, WA2QB, KH6PXM, AH6BS, K6CES, W6ACC and KN6KBS for their recent donations.
(13 Dec '22) Computer replaced! The server for the WebSDR was swapped in its entirety with new hardware to resolve the issue of USB ports failing on the plug-in cards. The only difference that you (the user) should see is that the 15 meter receiver is working again! Using the old server and spare parts, a second server (link) covering 160, 12 and the top of 10 meters was brought online.
(22 March '23) Several Internet outages caused KFS to be inaccessible for several hours today. Upgrades to the Internet connection are expected to occur in the next few months.

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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
m: mute/unmute audio
s: toggle squelch

Frequency: kHz    VFO:  ?  
Enter frequency above, or tune by clicking/dragging/scrollwheel on the frequency scale. freq???
Mode:  ?      
Use the = kHz button to snap to the nearest kHz.

Memories are stored as cookies on your computer, not on the server.

?:   ? kHz @ -6dB; ? kHz @ -60dB.  Default BW in bold.
 USB CW RX: Check box, or put  ?usbcw  in the URL for USB CW reception.
  CW uses a center frequency of 750 Hz and LSB by default.

PassBand Tuning (PBT):
Use buttons to select BW/mode or drag passband edges on frequency scale. PBT/IF Shift by Weert Websdr.
Call of station that you hear:
Comments, if any:
Time, frequency, your name/call, and DXCC information are added automatically.
View the last 20 lines of the logbook, or the entire logbook (opens new tab/window).

? dBm  Peak ? dBm  ?
 S-meter squelch:        
Mute Squelch Notch1
Notch2 High Boost
 DSP Noise Reduction:
More info about Noise Reduction, Notch2 & High Boost here

Audio buffering:
  More buffering may help with drop-outs or slow/jittery connections.
  Vari-Notch (Hz):   Off

   CW Peak (Hz):   Off    Ref. Tone

Gain control:   
RF AGC Alt AGC Manual
Try "Alt AGC" for better AM reception, particularly with QSB.

devpk dev_avg dev_pkavg   

Audio channel: Left Both Right

Sig. strength plot:
Waterfall view:
Or use scroll wheel & dragging on waterfall.

Toggle "Hide labels" if labels are missing.

There are currently ? user(s) on this WebSDR:      compact view

Actual CPU utilization percentage is 1/4th of the value shown above.

? devpk dev_avg dev_pkavg freq???