KP4MD's blog

As evidenced in the WSPR database, some US hams are transmitting on the default WSPR 60m dial frequency 5.2872 MHz which is outside FCC authorized 60m channels.

Some of the questionable 60m reports in the WSPR database appear to be uploads from stations with HF receivers that are not synchronized with the WSPR program frequency, such as in this listing

This Microsoft Excel (2000 or later) spreadsheet has added new enhancements to Mark Hughes GM4ISM's WSPR data download spreadsheet.
To use the spreadsheet, Instructions :- Fill in blue cells and click the cogs (click away from the blue cells first). The macro will retrieve and chart up to 2500 of the most recent spots that match your criteria directly from the online database.

2 meter WSPR spots span the 4061 km between N3IZN in California and KH6IMB in Hawaii today
Read the discussion on!topic/2-meter-wspr/4WaqFZTfYoQ

Charts of 80 meter and 40 meter WSPR Near Vertical Incidence Skywave (NVIS) spots SNR vs. distance
Clusters of spots in red were received during daylight hours. Those in blue during hours of darkness.
The antenna used was a thin wire 40 meter full wave horizontal loop at 6 meters above ground.

An RF-powered quadcopter supported antenna and findings of the VHF/UHF WSPR group will also be presented at the "Introduction to WSPR" session at 10:45 am on 11 October at the ARRL Pacificon Convention at the Marriott Santa Clara in Santa Clara, California.

I checked into the Northern California 432 SSB Net on 432.100 MHz at 1900 PST on Sunday night and also listened carefully as 1 kW net control station KG6HXI in Wilton CA swung her large Yagi antenna calling for check ins around the compass points. I heard some weak SSB signals at or below the noise level from the north and south SF bay area. This suggests that 432 MHz WSPR contacts are possible from Sacramento to those areas.

Here is an updated map of 144 MHz WSPR Study Stations and propagation paths.

Download the KML file from the page and open it in Google Earth
To view an elevation profile, right click on the propagation path and select "Show Elevation Profile"

Carol, KP4MD

Here is the current list for GPS reference locked 144 MHz WSPR stations on the Pacific coast of North America
144.490460 KC6KGE DM05gd - Taft, CA
144.490470 KI6STW CM97bk - Milpitas, CA
144.490480 WA6M CM88in - Timber Cove, CA
144.490490 K6PZB CM88nk - Graton, CA
144.490500 N6GN CM88ok - Santa Rosa, CA
144.490510 KP4MD CM98iq - Citrus Heights, CA
144.490520 WW6D CM88pl - Santa Rosa, CA

Detailed listing at

This modification to GM4ISM's Excel Spreadsheet polls real time WSPRnet data and estimates the signal path quality for various communication modes: WSPR, JT65, Olivia, PSK31, CW, RTTY and SSB. These charts show expected signal dB over threshold on these modes with user-defined transmitter powers and relative antenna gains. The values below threshold are in red, above 6 dB in green and intermediate in yellow.

Here are a few points to consider in resolving the issue of ARISS voice operations in the 2 meter WSPR frequency segment outside of IARU Region 1:

  1. WSPR activity has occurred on 2 meters since the inception of WSPR and will continue into the future. Joe Taylor K1JT mentions 2 meter WSPR activity in the Pacific Northwest as early as April 2008 when the WSPR program was first released.
  2. The G4ILO WSPR page documents 144.490 MHz as the preferred 2 meter WSPR frequency in 2008.
  3. In the IARU Region 1 band plan, 94 nations (a majority of IARU member societies) have concurred on 144.4905 MHz (144.489 MHz dial) as the designated world-wide WSPR frequency on 2 meters. 2 meter frequency allocations in Region 1 are much more constrained than elsewhere as their band encompasses only 144-146 MHz. Therefore Regions 2 and 3 should follow the lead of Region 1 rather than expect Region 1 to change its established band plan.
  4. Although IARU Region 2 (the Americas) currently lacks a VHF band plan, this is an agenda item for the IARU Region 2 General Assembly scheduled for September 2013. A good case may be made for 2 meter WSPR activity in Region 2 to continue in the current WSPR frequency segment of 144.4905 MHz.
  5. Since June of this year, WSPRnet statistics would indicate that 2 meter WSPR network activity has grown to account for probably over 99% of the current regular worldwide activity on 144.4905 MHz.

NEW - Points to consider in resolving the issue of ARISS voice operations in the 2 meter WSPR frequency segment outside of IARU Region 1:

Worldwide 2 meter WSPR activity on 144.4905 MHz has increased over 100 fold in the last 6 months, with operations currently primarily in North America, Europe and Australia. This has increased the potential for mutual interference with the ARISS uplink frequency of 144.49 MHz in IARU Regions 2 and 3. ARISS uses 145.20 MHz for the voice uplink in Region 1.

We have been advised that there is no concern for interference with scheduled event and school voice contacts as ARISS conducts these activities on alternate unpublished uplink frequencies. The ISS team members may use the 144.49 MHz ARISS voice uplink frequency only sporadically for recreational contacts.

AMSAT is interested in this matter, and Frank Bauer, KA3HDO, has related the difficulty with which ARISS coordinated its current frequencies:

"It took a lot of coordination over many years to get SAREX, now ARISS, on a consistent band plan. I have been doing frequency coordination for ARISS and SAREX since 1991. It was very painful to get this coordinated internationally. Especially within Regions 1 and 2. I think you know that ARISS can’t use 145.20 in Region 2.

The big issue we (ARISS) have on 2 meters is that we need the transmit and receive frequencies to be split on voice. And they will need to be separated beyond the OSCAR weak signal subband (145.8-146). This would not have been an issue if the second OSCAR subband (around 144.3-144.5) was still in place. But that was reallocated to other domains."

We would wish to collaborate with AMSAT to avoid interference with future ARISS activity on the 144.49 MHz frequency that we currently share in IARU Regions 2 and 3.

Carol F. Milazzo, KP4MD/W6

Our VHF WSPR Group meeting at 2012 Pacificon/ARRL National Convention was very well attended. Thanks to all who participated in our meeting.
Here is a link to our presentation slides.

All WSPR operators are welcome to read and join the 2 meter WSPR study discussion on the Google Group at Anyone may ask Glenn N6GN or myself for an invitation or log onto the site to request a subscription to the e-mail list.

The latest ARRL Propagation Broadcast mentions our 2 meter WSPR study. Check it out on

Welcome to W6SZ, W6IEE and N3IZN in Southern California!
Our group station info is posted in the table at
The spots between N6KOG and N3IZN (624 km) now hold the DX record among our group!
Thanks for activating Southern California in the California study group!