Transequatorial Propagation on 144MHz
Tim Kirby GW4VXE reports on some interesting propagation on the 2m band, and also on a picture net using D-STAR.
I’m always interested to learn about VHF/UHF propagation in other parts of the world. Over the last month or so, there have been some very interesting contacts taking place from the Caribbean, into South America, on 144MHz.
Transequatorial propagation (TEP) takes place when there are ionising bands in the F layer on either side of the geomagnetic equator. 50 and 144MHz are usually affected, although TEP has been recorded on 432MHz. EA6VQ records some useful observations about TEP on the website below but the most important points are that a moderate level of geomagnetic activity seems to improve the chances of openings. www.dxmaps.com/tep.html
Some QSOs have been reported when the A index is over 30 as well as Solar Flux being lower than 70. Signal strengths are often high but there is typically a lot of fast fading and sometimes a surprising amount of Doppler shift. Openings usually occur around the equinoxes (February to April and September to November). The best time of day is usually one to three hours after sunset. The receiving station and transmitting station should be located at roughly equal distances from the geomagnetic equator and the path should be as close to North/South as possible (variance of up to around 15° has been noted).
In early October, Burt FG8OJ in Guadeloupe worked PY2PAL in Sao Paulo. FG8OJ posted a nice video on Twitter that he had received from PY2PAL showing his signals in Brazil. The distance was 4455km. Then at the start of November, PJ2BR in Curacao worked LW2DAF in Buenos Aires over a distance of 5312km. Once again, there’s a video – on LW2DAF’s Twitter stream − of PJ2BR’s 2m signals as heard in Buenos Aires. There is a lot more ‘warble’ on the signals than was noted on the FG8OJ/PY2PAL contact.
PJ2BR went on to work several other stations from Argentina, including LU2EPO, LU7DW, LU5BE, LU1DL and LU4DIR during the opening, which took place on November 3rd around 0000UTC.
Because of the warble/distortion introduced by TEP, all contacts that I am aware of have taken place on SSB. I suspect FT8 would not decode. Marvellous contacts and I am grateful to John EI7GL for highlighting them on his blog: http://ei7gl.blogspot.com
John EI7GL also reported another interesting contact from the Southern Hemisphere, this time on 70cm between Tom ZS1TA in Plumstead, South Africa and Garry ZD7GWM on St Helena on October 16th 2020. The distance is around 3135km and it was made on FM using modest equipment of around 35W to a vertical. Apparently, the path between ZS1 and St Helena opens fairly regularly on 2m, but as far as I know, this is the first time that a 70cm QSO has been reported.
The D-STAR Picture Net
Jef Van Raepenbusch ON8NT writes, with some information from Lewis Maxwell KB5HPT about the D-STAR picture net: “Every Thursday at 0130UTC there is a D-STAR Picture Net on REF072D with REF055D as a backup. The RS-MS1A Android App (available in Google Play) can be used by operators with the ID-31A PLUS, ID-51A PLUS (anniversary model) and ID51A Plus2. IC-705, ID-4100, ID-5100, and IC7100 radios will need the OPC2350LU data cable. If the Bluetooth module is installed in the 4100 and 5100, then the cable is not needed. The RS-MS1l App (available in iTunes Store) for iOS users can also be used with the ID-4100 radio only. IC-9700 users are welcome and encouraged to join too. We will be exchanging pictures, text messages, and positional information.
“The Kenwood D74 handheld will work with the RS-MS1A Android App. First, pair the handheld with the Android device via the radio’s Bluetooth. Start the App and go to the Application Settings. Tap to select a transceiver model. Select Other (Bluetooth) then close.
“There is a free Windows app, ST-4001W from Icom and ST-4001A (available on Google Play) that processes any .jpg or .png picture to the right pixel size and can add a signature or label to the edge. You can use the ST-4001 app to send the formatted picture over ethernet to the radio or just copy it into the /IC9700/Pictures folder on the IC-9700 formatted microSD card or to the Android device. Once the photos you want are copied, you can just plug the microSD back into the 9700 radio. The new pictures are then available to send from the choices that are available when the PICTURE menu is opened on the radio.
“Here is how we rate the pictures on the net. It depends on how many blocks are missing in the received picture.
P-1= Perfect picture
P-1 Minus= 1-5 blocks missing
P-2= less than 25% of blocks missing P-3= less than 50% of blocks missing P-4= less than 75% of blocks missing P-5= No picture
“After the picture has been sent the net control will poll each check-in by voice to get a picture report at their location.
“The format for this net is much like a
voice net in that check-ins will be taken and then the NCS will direct when the stations will send their pictures”.
Jef says that the net is in the early morning on Thursday for him, but he leaves his transceiver on overnight and then in the morning discovers all sorts of pictures.
Outside of the net, Jef has exchanged pictures and had D-STAR voice QSOs with KB5HPT, KL0YO, N0BF, DJ7FG, DL5OCD, N4JAP, VK1FLEX, VK2MET, W0AAS, KE0KIS, VE7VIB, WB6DJI, OE6SDG, M0SDF, M5BOP, WM3M, ON8DSW, WM6H, PD2V, ON4PN, WI3B, M0JMO, CT2CVW and ON4ARV.
Jef writes, “I also exchanged pictures with ON4PN on 144MHz simplex over a path of 22km, with 10W and 58 Signals both ways and with 100% copy of the pictures”.
Steve G4AQB worked OV3T (JO46) on 70cm FT8 at the end of September.
The 23cm Band
Simon G6AHX writes, “I attempted to do the 23cm UKAC in October and had absolutely no contacts! On investigation, my IC-9700 had stopped putting any RF out on certain parts of the band, particularly around the SSB section. I then discovered a software update issued in May this year that I’d missed [1.24]. It corrected the problem but by then I’d removed my 23cm beam. So, I’ve built a bi-quad antenna for 23cm to test the 9700. Thanks to Steve G4NZV, in Tewkesbury, I have been able to prove SSB on 23cm works again”.
Steve G4AQB writes, “23cm FM seems to be becoming more and more popular here in the North West. We have had an FM net on 1296.500MHz every Wednesday evening at about 8.15pm. Ross G6GVI is one of the founder members of the net and shared some information that he has collected over the last year or so. During the months we have had 25 callsigns that have called into the net from all over the North West. There have been up to eight stations in the net at any one time. Most stations are using horizontal antennas, but a few have used vertical antennas. Some stations are using commercial transceivers such as the Icom IC-9700, while others are using SG Lab Transverters. Everyone is welcome to join the net”.
Here in West Wales too, there is a growing interest with Peter Harston GW4JQP and Mike Probert GW4HXO encouraging local stations on to the band. Peter and Mike are regularly active on the band and welcome sked requests. They are both active during UK Activity Contests.
Satellites
Jef ON8NT received a number of SSTV pictures during the ISS ARISS event scheduled to run between October 4th and 8th, although Jef says it started a day early, so he missed some of the pictures
Kevin Hewitt ZB2GI (Gibraltar) took part in the SSTV event between October 3rd and 8th and received the complete set of 12 images. Kevin received the daytime passes from the top of the Rock at Signal Hill and the night-time passes from either Mid Harbour Marina or Eastern Beach. Kevin used his FT-817, a manually tracked 2m/70cm log periodic, a data interface and a Windows 7 Notebook running MMSSTV.
Graham Jones G3VKV (Cheltenham) writes, “On November 11th Christian F5UII was transmitting video on the QO100 satellite asking if anyone wanted a duplex contact, either video to video or SSB to video using both transponders. I gave him a call on 10489.830MHz SSB and had a QSO”.
My thanks to Patrick Stoddard WD9EWK (Phoenix) who tells the story of some rare satellite grid activity in the USA. “Summer has finally given way to autumn here in Arizona. The rare grid DL88 at Big Bend National Park in Texas was activated in late October, making many satellite operators around North America very happy. Others have been venturing to grids not heard often on satellites.
“For North American satellite operators, the rarest grid in the continental USA − DL88 − was heard in late October. Most of DL88 lies in Mexico, south of the Rio Grande River, but a sliver of the grid falls just inside US territory, at Big Bend National Park. Most of the park had been closed due to COVID-19 restrictions, but day trips to some remote parts of the park have been allowed since early October. This meant the DL88 activation was not on the air as long as it had been originally planned, but still enough to make many satellite operators happy. Doug N6UA and Ron AD0DX drove to Big Bend and used the special callsign K5Z for their DL88 activation. A few operators were able to make contact with DL88, completing their quest to work all 488 grids in the continental USA (similar to the Fred Fish Memorial Award ARRL offers for 6m operators).
“Without hamfests here in Arizona, my road trips away from home have focused on radio. I made one day trip to southern Arizona in the middle of October, operating from a few locations along two freeways on the way to the USA/Mexico border in grid DM41. During one of my stops, about a mile north of the border fence in southern Arizona, I had a visitor watching me and the area around me... a US Border Patrol agent. At that location, on a hilltop, I − and the Border Patrol agent – could easily see the border fence and into northern Mexico. The Border Patrol agent didn’t bother me, and I apparently didn’t bother him, as the agent didn’t come over to ask me what I was doing there. The Border Patrol agent was on the highest part of the hill, but where I parked was still very good for satellite operating − higher than most of the surrounding area.
“Early in November, just before the first snowfall in northern Arizona, I made a road trip out to the DM54/DM55 grid boundary. The spot I used is on the old Route 66, the famous US highway that ran from Chicago to Los Angeles. Sections of the old highway still exist in Arizona, even after the construction of freeways, which now carry traffic across that part of the state. I was able to park along the old highway, just east of a nearby freeway exit and west of Petrified Forest National Park, Fig. 4. I spent the day working passes in FM, SSB, and even tried packet via FalconSat-3. An afternoon storm forced me to sit in my car for about an hour, but the rest of the day was productive on the satellites. Both of these grids were rarely heard on the satellites, with no resident operators living in either of the grids. DM54 and DM55 are a little less rare now”.
Merry Christmas ßśand a Happy NewYear
That’s it for another year! Very many thanks to you who have sent in news and information and especial thanks to those of you who buy the magazine and read the column. I wish all readers and your families a great Christmas and New Year. I’m looking forward to reporting 2021’s VHF/UHF happenings for you. Thank you.