Higher And Higher, past radio waves and visible light

I still remember my first 23cm transverter and my fear from frequencies above 1 GHz. What am I going to do? How am I supposed to measure, even how to tune anything on these high frequencies? It's not that long ago, about 15 years. Of course we managed that frequency. We also managed 10 GHz, later even 24 GHz. I have bought my 47GHz transverter from DB6NT. Now, these wonderful units from VK put us on 122 GHz ...

Harry WA0CNS and Herbert AF4JF made several short QSOs on 122GHz before making our 5.25 km contact on November 7th. See the posting here (click).

We have been playing with optical communications in the early days of the SLAMS group, see pictures here (click). The BARS group was also planning on some optical communications here (click), but we have never made a full bi-directional QSO until today (click here). Harry WA0CNS and Herbert AF4JF used the opportunity and tested their old equipment while waiting for other participants of the team meeting that we started holding in the Creve Coeur Memorial Park again. Witnessed by Ron KO0Z, our first QSO using red light took place. Harry used his station with two Fresnel lenses, TX with red LED diode wavelength 635 nm and RX with photo diode BPW34. Herbert used his old 5 mW red laser module wavelength 650 nm and a solar panel (!!) from old garden light as RX. No additional lenses used on Herbert's side. First QSO was difficult, especially aiming the stations at each other. We clearly have some work to do here, similar to our experience with 122GHz mentioned above. Using rifle scopes on these frequencies is a MUST!

Harry was actually using voice audio on transmit. That was surprisingly clear and easy to understand on Herbert's side. Herbert responded with 30% AM modulated CW (using shunt modulator).

Harry also built an optical beacon with infrared diodes (the little box on a smaller tripod on the right picture above). These diodes have lenses built in and the beam width is about 5 degrees. Built-in processor transmits beacon patterns and some text with Harry's callsign. I will try to record it and post the recording here next time.

So, what is next? Definitely attempt on longer distances on both, 122 GHz and 462 THz. We will keep working on mechanical stability, improving precise aiming and get more ready for next year.

73 Herbert

AF4JF

Many things happened in September

The SLAMS/BARS group was unusually active in September. Here are the events that took place and links to postings on the SLAMS page (click on the links for more details):

SLAMS September 2020 Breakfast

Sunday, September 6th, Mel K0PFX, Harry WA0CNS, Herbert AF4JF, Armand KD0PFX, Ron KO0Z, Debbie KC9ULA convened at Creve Coeur Park at 9:00 am to test out some gear.  Mike N0OBI came by, but somehow we missed each other.  COVID-19 is still among us, so we met outdoors, wore masks and kept socially distant.

WB9PNU Beacon back on the air

After several months of being off the air, the WB9PNU 10 GHz beacon is once again up and operating from DePaul Hospital in Bridgeton, MO EM48ss thanks to the hard work and dedication of Mel K0PFX and John WB9PNU.  The beacon was thoroughly checked out by Mel and the slot antenna mount was replaced with a stronger mount and the assembly put into a water proof container. 

The beacon operates at 10.368.900 with an AFSK CW telemetry.  The telemetry data is no longer accurate because of control voltage issues.  That will be a future project to re-calibrate the telemetry.

September 2020 Tropo Opening

Tuesday evening, September 15 around 7:25 pm (September 16,00:25 Z), we set up our 10 GHz stations to attempt a 10 GHz QSO with Gedas W8BYA in northern Indiana EN70jt and with Russ KB8U in EN71sw. We didn't make any QSO, but we heard each other with Gedas. Click on the link to know more.

ARRL 10 GHz And Up Contest - September 2020

COVID-19, busy work schedules, grandchildren, moving QTH locations all combined took its toll on this year's SLAMS efforts to be radio active for the ARRL 10 GHz and Up contest.  Still, it's hard to keep uW hams away from a contest and Harry WA0CNS, Herbert AF4JF and Ron KO0Z put in a day's worth of activity on Sunday, September 20, 2020.  We weren't trying to break any records.  Instead, we wanted to try 122 GHz and get some activity on the air.  Herbert and Harry tried to work Gedas W8BYA in Indiana, but the path just wasn't there.  KO0Z didn't even try.  His path to Gedas would involve shooting into a thick forest.

ARRL 10 GHz And Up 2020 as seen by AF4JF

The short contest attempt as seen by AF4JF.

222 MHz and UP Sunday

Sunday, August 2, 2020; COVID-19 Virus is once again on an exponential rise, plaguing the nation.  Social distancing is the order of the day.  Still, Herbert AF4JF, Ron KO0Z, Debbie KC9ULA and Harry WA0CNS ventured out this morning to practice some "radio activity" while still maintaing social distancing.

Herbert, Ron and Debbie went to Eagle Roost at Pere Marquette State Park near Grafton, IL EM48rx and Harry went to High Ridge, MO in EM48rl, a distance of almost 35 miles.  Herbert, Ron and Debbie were on the road by 7:00 am and crossed over the Mississippi River into IL via the Grafton Ferry boat.  By 8:40 am we were QRV.  At 9:16 am, Ron made a two-way CW 10 GHz QSO with Harry.  Right after that we made a two-way SSB 10 GHz QSO.  S-9 signals both ways, both times! 

Next on the agenda, Herbert using a BBQ dish antenna and his PLUTO SDR transceiver made could hear Harry's 2.3 GHz SSB signal!  After a little tuning, Harry was able to copy Herbert's 2.3 SSB 10 milliwatt signal with his downconverter and IF rig!  AF4JF then put in a 1-2 watt amp and both stations copied each other's SSB signals with 5 X 7 reports.

AF4JF then made a 1.2 GHz two-way QSO with WA0CNS with 10 milliwatts and a WA5VJB PC log periodic antenna!

By 10:30 am we finished packing up and we were on our way back to St. Charles.  Herbert went back via the ferry boat and Ron and Debbie continued southward on the Great River Road, enjoying the scenic view, towards Alton before taking Hwy 367 back to I 270.

Not a bad way at all to get some exercise, some radio and still social distance during the pandemic. It was great "seeing" (hearing) everyone today!   

                Herbert waiting to board the Grafton Ferry to Illinois and EM48rx

    Crossing the mighty Mississippi to Illinois

                    AF4JF's 1.2 and 2.3 GHz set-up using a PLUTO SDR

     K00Z's 10 GHz dish at Eagle Roost EM48rx pointing south towards WA0CNS near High Ridge, MO EM48rl about 35 miles away.

          AF4JF's PLUTO SDR computer screen.

Herbert summed up today's outing with this email:

Ron and Harry,

Thanks for coming out with me on such short notice! I wasn't sure until Friday evening if I will find the time .. I am glad that I did.

What I wanted to test today was:

- if Harry will copy me and if I copy him on the PCB antenna on 2.3/3.4 GHz .. negative, this didn't work on 2.3GHz so we didn't even try on 3.4GHz

- if Harry will copy me and if I copy him on the BBQ dish antenna without PA .. positive, this worked both ways

- if Harry will copy me using the LUXUL PA/preamp unit ... positive, this worked. RX preamp was fine, but TX needs adjustment of driving power

- if Harry will copy me and if I copy him on lower microwave bands (903/1296MHz) using the PCB antenna ... positive, we made 2-way QSO on 1296. Wow!

These results gave me an idea what I need to put in the box with SDR PLUTO to make it multi-band rover transceiver with as simple band switching as possible. 

73 Herbert

Harry WA0CNS in EM48rl, High Ridge, MO working EM48rl, Pere Marquette State Park, IL 35 miles

      

                                  Darcy is a relaxed microwave companion

                       This chap likes KO0Z or he's an Illini fan, orange and blue colors!

                                      EM48rx hitchhiker

Debbie KC9ULA and Toula along for the ride.

                                     AF4JF's multiband power amp.

ARRL VHF June Contest 2020

It has been a while since I have obtained a new SDR (Software Defined Radio) Unit made by Analog Devices, called "ADALM PLUTO".

This is actually a learning module, capable of operation in a frequency range (after a simple hack) from 70MHz to 6GHz. There are several software programs able to work with PLUTO, I am using the SDR Console (note that this software does both, receive and transmit).

I am usually operating from outdoor locations, sometimes as a "rover". That brings a big challenge - how to squeeze everything inside one car? I have used this year's ARRL VHF June Contest to test my idea of using the PLUTO with simple wide band amplifiers and antenna for multi-band operation.

The antenna used for this VHF contest was a logarithmic-periodic PCB antenna made by Kent WA5VJB.

This antenna gives me access to all HAM bands between 900MHz and 6GHz. During this test, I have concentrated on 1296 MHz, 2304 MHz and 3456 MHz. I have also used the PLUTO on 222 MHz, but that was a different antenna.

I have obtained a cheap RX preamp from eBay (35dB gain / 2.5dB noise). I know this is not the greatest, but is was cheap, quick and simple.

The TX exciter (used as a PA capable of up to 100mW here) with GALI84 was from eBay too.

Along with these modules, I also used RX-TX Relay (cheap version on W1GHZ board) and USB-controlled relay board to switch the antenna relay and power for RX or TX amplifiers.

During the contest, I made 14 QSOs during its first 2 hours - 8 of them using the PLUTO. Distance covered by these QSOs was around 4.6 km, the station worked was Harry WA0CNS. However, we have made a test with Zack W9SZ one week before the contest (see here) and made a contact on 2.3 GHz SSB over 24.3 km with good signal.

I believe that the PLUTO is a good way how to improve VHF and microwave activity on HAM bands. I will work on improvements and post them here after next contest.

As for the lower bands, I have used FT857D and ring antennas installed on my car. The multiband microwave antenna was inside the car on the dashboard.

Harry WA0CNS used his home made transverters and antennas on azimuth rotor installed on his car.

My dog Darcey (on last picture) supervised the activity and made sure we followed the contest rules :-)

73 Herbert
AF4JF

June MAD 2020

Rather than rewrite our first uW outing of the season, Please connect to the SLAMS blogsite:  http://slams-stlouis.blogspot.com/  for more details about our first Microwave Activity Day of the season.

                                          Zack W9SZ setting up 24 GHz at EM49rx

                     Harry WA0CNS and Herbert AF4JF setup at EM 48 qs near SCCC

                              Pointed towards Pere Marquette State Park in IL from St. Peters, MO