Sunday, February 28, 2021

Potential uW site in EM49lk

 On Saturday, February 27, Debbie KC9ULA, myself and the grand kids took a trip up MO Route 79 to Louisiana, MO to Henderson Park overlooking the Mississippi River in EM49lk.  It has unobstructed views towards the north all the way to southeast.  I would like to thank Ward Silver N0AX for making me aware of this park!

                                                             Looking east towards EN70

                                                              View to the north

                                                         View southeast.

Monday, January 4, 2021

47GHz Cumulative Contest

Following email (sent by Paul W1GHZ) landed in my mailbox today. I am going to accept the challenge and try to participate.

The 47 GHz Cumulative Contest for 2021

announced in January QST Microwavelengths
announcement and rules may be found at:

Monday, December 14, 2020

122 GHz again

Harry WA0CNS and Herbert AF4JF succeeded in extending the distance covered by QSO on 122GHz to 7.671 km (4.76 mile) today. Harry was at new SLAMS location on Iffrig Road in St Peters, MO (EM48qt74cu) while Herbert went across Mississippi River to the Winneberg Road on a hill near Brussels, IL (EM48qv90rv). Two-way CW QSO on 122GHz was completed at 10:59am today (December 14, 2020). This is not only our longest QSO on 122GHz so far, but it also seems to be the very first QSO between Missouri and Illinois on 122GHz ever.

Herbert and Harry met at the Iffrig Road first. Harry started setting up while Herbert went to Golden Eagle Ferry about 3 miles away. That ferry operates every day and has quite short waiting time. At least usually. Mr. Murphy has not overslept today, so Herbert's crossing on the ferry was delayed by a huge commercial barge crossing the path. It took over 15 minutes until that huge thing disappeared.

There is a hill just across the river. It is not that high (590 feet a.s.l.), but still high enough to block the line of sight to everything on the Illinois side. Harry and Herbert actually tried much longer distance (over 25km) on December 4, but this hill protruded into the Fresnel zones between our intended locations. Luckily Harry WA0CNS, Herbert AF4JF and Ron KO0Z have done their homework this time and identified the location on Winneberg Road prior to this test today. Looks like we will use these two locations for future tests.

The atmospheric conditions were not all that great today. Sure, it stopped raining and fog went away this morning, but the relative humidity was still too high:

  • temperature 3.6 deg. C
  • dew point -5.2 deg. C
  • pressure 1005.2 mBar
  • humidity 51.1 %
  • wind speed 2.4 m/s
Signal from Harry was S9 with QSB to S5. Herbert's signal was much weaker on Harry's side (Herbert uses a 21 dB horn antenna while Harry has a dish):

Herbert's AF4JF view towards Harry

Harry's WA0CNS view towards Herbert

Waiting for the ferry to return back to Missouri

Goal for today was met. However, we are still at the begin, many more miles to cross on 122GHz. Looks like this was probably close to the limit for a station with small horn antenna. We will try the same path with dishes on both sides next. Some other day.

Wednesday, December 2, 2020


 We came, we saw, we chatted.  Doing our best to avoid COVID-19, yet still wishing to get together, thanks to the ingenuity, diligence and efforts of Herbert AF4JF; we have been meeting by ZOOM.  A few days before the ZOOM meeting, Herbert sends out an email to all SLAMS members reminding them of the upcoming meeting.  Last night, December 1 we decided to meet on the first Tuesday of every month by ZOOM for the foreseeable future.

A wide range of topics were discussed including the January VHF contest, PLUTO, 24 GHz, door knob capacitors and even audio frequencies.  Mostly, it was nice to see everyone and to catch up.

Pictured from top left to right:  Herbert AF4JF, Ron KO0Z, Gedas W8BYA, Zack W9SZ, Harry WA0CNS, Bob N0IS, Sam W0PCE and Jim N5MU.  Not pictured is Armand KD0PXF.

Tuesday, November 17, 2020

Martian Weather Forecast

Did you know that weather prediction for the planet of Mars is done on regular basis and you can even find in on the Internet? I have learned that today .... click here to take a look!

Sunday, November 15, 2020

Further Experimentation

 Further Experimentation

Sunday, November 15, a blustery, albeit sunny day with temperature in the upper 40s around 9 am, found Harry WA0CNS, Herbert AF4JF and Ron KO0Z at Creve Coeur Memorial Park.  Harry and Herbert experimented with light communication. Harry was using red LED 635 nm in his station and Herbert was using 650 nm laser. That's a frequency around 462 THz! Harry also built an infrared beacon. Although the distance was only approximately 60 feet, both Harry and Herbert made successful 2-way QSOs using light.  Receiver sensitivity as checked and the experiment indicated that precise aiming of antennas is a necessity.  In early December, Harry and Herbert are going to further their 122 GHz distance record.

                             Harry WA0CNS receiving Herbert's AF4JF light signal.

                                      Herbert AF4JF transmitting to Harry WA0CNS

                                             Harry, Darcy and Herbert conferencing

                       Herbert AF4JF receiving Harry's WA0CNS signal at Creve Coeur Memorial Park

Saturday, November 7, 2020

Success on 122 GHz

Harry WA0CNS and Herbert AF4JF met together for another round of testing our new 122GHz units from VK. Ron KO0Z has been in some activity with his grand children and supported us on the phone.

We have decided to repeat the test from October 25 (2020) when Harry went to SSM facility in EM48rq and Herbert found a nice parking lot on Katy Trail in EM48rr. We didn't make that QSO on October 20. There is a direct line of sight between both locations, so we tried again using rifle scopes to aim our antennas today. Following pictures show Herbert's side of the path on Greens Bottom Road in EM48rr:

Thanks to using powerful binoculars, Harry spotted Herbert's car arriving at the parking lot and knew exactly where to aim the antenna. We have made our CW QSO at 08:43 am with signal strength S5-9 on both sides. The distance, according to Google Earth, was 3.26 mile (5.25 km):

Weather info taken in EM48rr at 08:30 am CST:

  • temperature 22.8 deg. C
  • dew point 9.3 deg. C
  • pressure 1010.2 mBar
  • humidity 43.1 %
  • no wind

This was first part of our plans for the day. The second part was moving to the town of Defiance, MO to our "backup location" along the Katy Trail. Harry stopped close to Defiance in EM48op and Herbert went a little further to Matson in EM48oo. The distance between these points is, according to Google Earth, 1.74 mile (2.80 km):

Weather info taken in EM48oo at 10:39 am CST:

  • temperature 26.8 deg. C
  • dew point 12.2 deg. C
  • pressure 1008.7 mBar
  • humidity 38.9 %
  • wind 2.2 km/h ( 2 feet / sec)

This location, despite the shorter distance, turned out to be more difficult due to a problem with direct line of sight - rifle scope on Herbert's side revealed that he was pointing at wrong location and had to move a little to see the correct one. After moving the station, QSO was made at 10:49 am CST wit the same strength as the first QSO (S5-9 QSB). However, thanks to the blowing wind, the frequency was a little unstable. We definitely need to pay more attention to thermal insulation of the 122GHz board to prevent wind from changing frequency through making temperature changes. Both stations were using GPS reference 1 pps, which seems to be too slow. We need to modify our stations for 10MHz reference signal disciplined by GPS.

Picture shows the "Judgement Tree" memorial park in Matson, EM48oo where Herbert was located:

Herbert is only using a 19dBi conical horn for antenna. Harry's station has a 13 inch dish antenna:

This was our last attempt for QSO for the day. Next topic on our plan was the SLAMS/BARS planning meeting at the Chandler Hill winery. We usually do not eat inside any facility these days, but this winery is offering outdoor seating and online ordering of food and drinks. Here is how the seating looked like (and Yes, this facility allows dogs even inside):

Everything considered, a very successful day! We have pushed our 122GHz record up to 5.25 km. Our next attempt, hopefully this year, will be to get it over 10 km. Watch for new posting soon!