Tag Archives: 1296 MHz

23 cm Beacon monitoring: IC-9700 with minimalistic antenna

2021-11-18

Complainment about the need of having an elevated location and large antennas to become QRV on 23 cm with an IC-9700 inspired me to compare my regular equipment of:

  • Flex-1500
  • TV 144 MHz
  • TV 1296 MHz
  • LNA 0.35 dB NF
  • 3 m EcoFlex 15
  • Ringfeed
  • 3 m dish on top of the mast

with my IC-9700, usually in use for 2 m and 70 cm and a minimalistic antenna:

  • IC-9700
  • 5 m RG213
  • Ringfeed for 1296 MHz, just on a metal step on the roof

The dish in the upper right and the ringfeed to be seen in the lower left on the metal step, both beaming south. As signal source the beacon HB9BBD/B on 1296.050 MHz has been chosen, 323 km away, on the Rigi Scheidegg in Switzerland, 1670 m above sea level. It is transmitting 10 w into an array of 3 dipoles beaming north.

As the whole air space between Mainz, JN49CV, and Rigi Scheidegg, JN47GA26, is visible, a lot of reflections on airplanes can be expected.

The signal of HB9BBD/B is very strong in Mainz, 40 dB over the noise usually. The gain of the dish is estimated to 28 dBD. The gain of a ringfeed may be 2 dBD and as it has just been layed down on a metal step on my roof, I assume the difference to be more than 30 db.

As expected, the signal could be received with the IC-9700 as well. It is deep in the noise, but increasing, when airplanes cross the path, audible most of the time.

Wide Graph of WSJT-X is a nice tool to display weakest signals and I very often use it to monitor distant beacons. I recommend it to anyone, who want to start beacon monitoring.

Deep in the noise is the signal at the ringfeed and the IC-9700 at about the same time as on the screenshot before. But it is always there and many reflections can be seen, increasing the signal level. Interesting is that different reflections dominate in the two screenshots. That is caused by the different beam widths of the antennas.

The conclusion is, that there is no point of not to try on 23 cm with an IC-9700 and asmall antenna. In this example the difference of the receiving systems is assumed to be more than 30 dB. When using a LNA and a 3 m yagi with the IC-9700 the difference will be not more than 10 dB, resulting in 20 dB stronger signals.

Aircraft scatter relativizes the disadvantages of locations in valleys and urban areas.

The IC-9700 Effect?

June 16th, 2020

It was nice to paricipate in the recent Microwave Contest on first weekend in June. There was a lot of activity despite the fact, no multi operator stations have been there as big guns. Meanwhile the claimed scores for DL are available and I was surprised by looking at the number of german participants on the 23 cm band. 174 stations sent their logs, which is much more than the total numbers of single and multi operator stations in the past years.

So I guess, it may be caused by the popularity of the new ICOM IC-9700 SDR transceiver, covering the 23 cm band.

Addendum June 17th, 2020: Pit, DK3WE, the contest manager, had a look for me at the .EDI files and found among those, who entered the equipment, 40 entries of IC-9700.

New Beacon SR1KOL in JO74SE

July 30th, 2018

After I noticed some spots for SR1KOL in JO74SE on 1296.960 MHz, I monitored the frequency using WSJT-X Wide Graph. About 400 Hz below the nominal frequency traces of a F1 signal can be seen, when airplanes cross the path to the beacon. The signal is not audible, but I am pretty sure, it is SR1KOL.

Traces of SR1KOL in JO74SE, “1000” = 1296.960 MHz. The strong signal at the very left is a birdie.

Some information can be found on the website of Polski Klub UKF: It is located on a high rise building in Kołobrzeg, 40 m above ground. The power is 3 W into a slot antenna. Beacon keeper is Andrzej, SQ1GU.

The video shows an A380 crossing the path between DJ5AR and SR1KOL. At minute 2:00 the plane crosses the first time and at minute 4:00 after a turn it crosses a second time. Mind the traces at 580 Hz in the waterfall diagram. The 1000 Hz mark corresponds to 1296.960 MHz.

Irek, SP5MX, who was involved in building the beacon and who repaired it recently, told me, the beacons reference is an OCXO withtout any GPS-lock. So possibly the beacon may transmit 400 Hz lower than defined.

At least in the morning of July 31st audible reflections could be heard via an Airbus A330. This time the 1000 Hz mark correspondents to 1296.9596 MHz.

After 10 seconds the noise becomes a kind of ‘musical’. Another 10 seconds later experienced ears can hear the tone.

 

New Beacon DB0MFI on 23 and 13 cm

June 18th, 2018

This morning I had a look for DB0MFI, a new beacon on 1296.940 MHz in JN58HW. It is audible with 529 constantly via tropo and peaking 579 via aircraft scatter. The power is 5 W into a 4 times stacked big wheel antenna.

 

In the afternoon I went for it on 2320.940 MHz. Faint reflections on some airplanes were audible and traces could be seen in the waterfall of WSJT-X Wide Graph:

Microwave Contest June 2018

June 3rd, 2018

As can be noticed now, the fears, many Microwavers would prefer to go to the HAM RADIO fair in Friedrichshafen, were overdone. It was a nice contest and in the 23 and 13 cm sections I worked more stations than in the last contests in May and March, as well as in all previous microwave contests I participated in June before. As can be seen in the maps, my honey pot is the east.

QSOs on 23 cm in Microwave Contest June 2018

The signal levels were very strong and I managed to work HA5KDQ on 23 cm in SSB over a distance of 830 km via Aircraft Scatter (ODX). To be honest: I am sure, we would have been faster in using CW 😉

QSOs on 13 cm in Microwave Contest June 2018

Working on 13 cm was big fun and ODX was HG7F over 817 km in a quick QSO in CW (as usual). When I went to bed at night, I already had 22 QSOs on this band with an average of 457 km per QSO.

Hannes, OE3JPC, was so kind, to send an audio record of my signal on 13 cm.

First steps have been done on 3 cm. But there is a lot of potential for improvements.

So it was not really a problem to quit two hours earlier to attend a barbecue with the family.

VHF/UHF/SHF Contest May 2018

May 6th, 2018

It´s one of the rare moments in the life of a Radio Amateur, when his shack is cleared up. Beyond believe, everything was up and running 2 hours (!) before contest time. Being a kind of bewildered, I sorted the stuff on my desk. The amazing result can be admired in the photo I took hereafter.

Starting with a nice QSO with M1CRO in SSB on 23 cm, I tried the new 3 cm Equipment, mounted on the VHF/UHF pole. 1 W into a 50 cm dish should be enough to collect first experiences. Two QSOs over 100 km were entered to the log. Quite nice, but further tests showed, that the topography is not ideal to cover larger distances, without the help of e.g. tropo, aircraft or rain scatter.

QSOs on 23 cm in blue, on 13 cm in red

Then I had my focus on 1296 and 2320 MHz, as usual. At least 58 QSOs, 36 squares and 14 DXCCs on 23 cm and 32 QSOs, 25 squares and 10 DXCCs on 13 cm have been logged. ODX, as last year, was HG7F in JN97KR over 817 km on both bands. Having an easy exchange on 1296 MHz, it took us nearly 20 minutes of hard work to puzzle a QSO on 13 cm as well. I remeber, last year it was vice versa.

F5ZBM on Air again!

April 20th, 2018

The french beacon F5ZBM is on air again. I found it accidentally, when looking for other french beacons. It is at a new location in JN18MN near Paris transmitting on 1,296.8475 MHz. Nice to monitor it in Mainz via aircraft scatter over a distance of 406 km!


The keying is in F1 with a very narrow spacing. Power is 10 W ERP into a slot antenna, as can be seeen at BEACONSPOT.eu

Another view on F5ZBM in WSJT-X Wide Graph

 

A digital evening on 23 cm

October 25th, 2017

There was nice activity in JT9F on 23 cm tonight. It seems this mode works fine with aircraft scatter. I first worked Conrad, PA5Y in JO21VO (255 km) and Sam, G4DDK in JO02VO (540 km) via Tropo. Then logged a QSO with Neil, G4BRK in IO91HP using mainly aircraft scatter. In another test I decoded Neil, G4DBN in IO93NR (756 km) by reflections on airplanes. PA0JME and ON5KTO were calling CQ, but not replying to my calls. Instead I worked John, G4BAO in JO02cg (619 km) in an (too) easy way.

Worked stations in green, the heard ones in blue.

Anyway, it was a promising and exiting evening!

Addendum October 27th, 2017

Yesterday I logged Rien, PA0JME, Wim, ON5KTO and John, G4ZTR, also in JT9F on 23 cm.

Chatting with John, G4BAO, last night, I learned, he recently initiated a “Digifest” on the microwave bands every Wednesday. This resulted in what happened two days ago. In my opinion it´s a very good idea to have such an activity evening beside the regular contests.