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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
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.
(7 Sep '22) - Thank you to KK6PGA, WA6ZVE, WA2QB, KH6PXM, AH6BS, K6CES, W6ACC and KN6KBS for their recent donations.
(4 Jan '24) - KFS outage:  Both KFS WebSDRs were offline for several hours due to power disruptions at the receive site related to ongoing electrical work.
   - It appears that several rapid-fire power interruptions caused operating system corruption of both KFS WebSDR servers, requiring a site visit to diagnose and correct.
   - There have also been occasional, brief Internet outages that are believed to be a result of ongoing, widespread network issues occuring across the Western U.S. over the past few weeks and have been particularly severe in the Bay area.

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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.

Clicking a band below will switch to the secondary KFS WebSDR server

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.

?      compact view


? devpk dev_avg dev_pkavg freq???