Partial solar eclipse propagation experiment, March 20th 2015

Discussion in 'Radio Propagation Questions' started by Steve Nichols G0KYA, Feb 16, 2015.

  1. Steve Nichols G0KYA

    Steve Nichols G0KYA Administrator

    The RSGB Propagation Studies Committee (PSC) is keen to encourage radio amateurs to take part in an experiment during the partial solar eclipse taking place on Friday 20th March 2015.

    The path of totality will pass north of us, over the Faroe Islands, but mainland UK will experience up to around 89% totality depending upon where you are (85% in Kent up to 97% in Orkney and Shetland).

    The partial eclipse starts in the Midlands at about 08:25 GMT on Friday March 20th and ends at 10:41 GMT. Maximum eclipse will be at about 09:30 GMT.

    This is a great opportunity to try some simple experiments to see how the sun’s ultra violet output affects our ionosphere and how some radio waves are propagated.

    On the morning of Friday March 20th 2015 the D layer above the UK may not be as strong due to the eclipse, and you may be able to hear stations on the lower bands – 1.8 MHz, 3.5 MHz and perhaps 7 MHz that would otherwise be inaudible during the day.

    For example, if you listen for a medium wave radio station that is more than 250-300 miles away during the day you may not hear it – it is too far away for its ground wave signal to reach us, and any sky wave signal is absorbed by the D layer of the ionosphere.

    But at night its sky wave signals are not absorbed as there is no D layer and they are free to be reflected back to earth from the higher E/F layers.

    This is why you can hear distant medium wave stations on a radio at night, but they aren’t there during the day. You get a similar effect on Top Band, and to a lesser extent 80m/40m.

    We are keen to encourage radio amateurs to conduct experiments during the eclipse, especially if they can use software defined radios (SDRs) to record the whole eclipse period for later analysis using Spectrum Lab or similar.

    Or you could use Spectrum Lab to capture the signal strength of a station every minute and save it to a file for later processing. I suggest turning your AGC off and setting up Spectrum Lab to log the time and highest amplitude reading a the one-minute period.

    Public Medium Wave experiment
    PSC has also devised a simple experiment for schools to undertake using portable medium wave radios. A PDF flyer about the
    eclipse propagation experiment is available to download here.

    The information we gather will also be shared with the Rutherford Appleton Laboratory at Harwell.


    G3PTU has also suggested 711KHz: Thourie: France (Near Rennes, Brittany): 300Kw Radio France international. It has the advantage that the channel is pretty clear apart from this station. This is in the opposite direction to the area of totality, but might be worth looking at.

    Before deciding on using the station, try and see if you can hear it at night, but not during the day.

    Medium Wave monitoring
    Members of The Medium Wave Circle intend to record large chunks of MW using software defined radio (SDR) receivers.

    LF monitoring/Opera
    A number of amateurs plan to use Opera on 477kHz and 1.8MHz. Information can be found in the usual LF user groups. Finbar, EI01CF should be transmitting on 477kHz.

    Andy F6CNI has confirmed Opera RX on 477/1.8/3.5

    For activity from Iceland see bottom of page.

    Stations should also duplicate the test either the day before or the day after for reference/calibration purposes.

    MF 477KHz / OP8, Tx @ 100% No CW ID
    HF 1.8MHz / OP4, Tx @ 100% No CW ID
    HF 3.5MHz / OP2, 7MHz / OP2 Normal operations

    RSGB QSO Party
    The RSGB Contest Committee is holding an Eclipse QSO Party in cooperation with the Propagation Studies Committee during the morning from 0800-11:30 UTC on the 20th. The aim is to find out if and how the partial solar eclipse will affect propagation on the lower HF bands, particularly 160m, 80m and 40m.

    Please note that this is not a contest, but some of the RSGB Contest Committee software and web facilities will be used to collect and display activity reports. All available radio amateurs are requested to participate - this is an opportunity to assist in the research of the Propagation Studies Committee, and to to contribute to our knowledge of propagation and the ionosphere.

    Click here for details of how to participate in this experiment. Those who cannot operate on the day of the eclipse can also find out how to contribute, if they have skimmer or SDR facilities.

    CW Skimmers
    A number of CW SKimmers will be in operation in the UK on 160/80/40m to capture S/N ratio figures during the event. feel free to join in if you have an SDR and the Skimmer software.

    How you can help with WSPR
    We are looking for amateurs to run WSPR on 160m and 80m. This will then automatically give us data, if you both TX and RX.


    For activity from Iceland see bottom of page.

    Karstin OY1DZ will also run WSPR at his club station in the Faroe Islands on 160m.
    Trygvi OY4TN is running 80m WSPR from the Faroe Islands.

    The other will hopefully be a WSPR beacon from G4JNT on 160m.

    There will hopefully be a CW beacon on 1810kHz from G3RAU.

    The plan is for 400W on 1810.05KHz, from 0815 to 1115Z. Antenna is inverted "L" with 19M vertical and lots of radials. It is a good dx antenna.

    Beacon will be CW: TEST TEST TEST DE G3RAU G3RAU G3RAU TEST TEST TEST DE G3RAU G3RAU G3RAU TEST TEST TEST DE G3RAU G3RAU G3RAU continuously and with no gaps from IO93RJ.

    Again, if you have the capability you could use Spectrum Lab to capture the signal strength every minute and save it to a file for later processing. I suggest turning your AGC off and setting up Spectrum Lab to log the time and highest amplitude reading over the one-minute period.

    Activity from Iceland

    TF1GW 80 m CW beacon

    TF1GW will transmit as follows from HP94SC in inland Southern Iceland on 3535 kHz at 12 WPM (60 char/min):

    Friday March 20th: 06:00 - 08:30 UTC 30 W 08:30 - 10:30 UTC 300 W

    Message: "VVV VVVV VVV de TF1GW TF1GW = eclipse test = info on = VVV VVV VVV de TF1GW" followed by a short break.

    Saturday March 21st for comparison: 08:30 - 10:30 UTC 300 W

    TF3DX on 80 m WSPR

    TF3DX will transmit as follows from Reykjavik on 3592.6 kHz USB dial frequency: Thursday March 19th, Friday March 20th and Saturday March 21st:

    06:00 - 08:30 5 W 08:30 - 10:30 50 W


    If all is well with WSPR transmissions, they will be left to the attention of YL TF3GD and TF3DX/M will park by the ocean to SE on Friday 20th and call CQ around 3527 kHz CW between:

    09:00 - 10:00 UTC (8 W radiated but boosted by salt water)


    TF3HZ is already monitoring 477 kHz for OPERA signals on 600 m in Reykjavik and will continue doing so until well past the event. Receiving only.


    TF3Y will keep his skimmer running on the low bands in Reykjavik, while otherwise busy at work during the eclipse.


    TF6JZ in the eastern-most part of Iceland has been monitoring BBC on 1341 kHz lately and will continue to do so during the eclipse.

    Steve G0KYA
    Chairman, RSGB Propagation Studies Committee
    Last edited: Mar 20, 2015
  2. Walter

    Walter New Member

    London is still transmitting on 720 kHz - I'm listening to it at the moment.

    From Steve G0KYA:
    Thanks Walter - in that case, I have removed the station from the suggested list.
    Last edited by a moderator: Mar 16, 2015
  3. Ruth Bamford

    Ruth Bamford New Member

    Hi Steve, I am not sure if I sent you the path of totality at the D, E and F layers produced by the Almanac office?
    Being a day off the equinox and such high latitude this is likely to be the most spreadout/slant that we can get between the ionospheric layers. Cheers Ruth

    Attached Files:

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