Four meter Sporadic E report

70Mhz Sporadic E report

Here are some sound clips of signals received summer 2010 on 70mhz. Click the call sign.

S51DI IZ6GSB 9A2SB IW4BET T70A CT1FJC EA1GAR IW0AWZ LA9DL SV9FOUR VARIOUS

Starting in the month of May through to mid August, on a number of days the Sporadic E MUF (Maximum Usable Frequency) will rise to 70mhz and above. This means that even with your  FM box connected to your dipole or mobile whip you will hear strange foreign accents and call signs coming out of your speaker over S9. One of the most common stations is Ivan S51DI   but a number of other countries will be active. Band openings can range from a few minutes to hours. QSOs are usually fairly brief, giving signal report QTH locator, (work it out ready). Heswall does not mean a great deal to a DX station, but IO83KH or 11 kilometers south west of Liverpool does. Names with brief station details are usually exchanged. Don’t hog the DX as there are many more UK stations wanting a crack at the DX but only a small number of them for us to work.

S5 call signs are from Slovenia, and they are one of the few countries out of the UK that have permission to use 70mhz.but the number of new countries is growing every year. During the 2003 season Denmark OZ and Faroe Islands OY obtained permission to operate on four. From 2004  Croatia 9A and Greenland OX will join us. More recently HA Hungary obtained permits for a short period. Others to have gained permission are CT, DL, OK, I, OH, LA, EA, ES, and SV. By 2010 leading DX'ers have been able to QSO 40 DXCC Countries in 170+ grids.

Sporadic E happens when the E layer in the earth’s atmosphere ionises and starts to reflect VHF signals back to earth, whereas normally they carry on into space. One bounce or “hop” puts your signal nicely down into S5 or ZB2 around 1500 kilometers. SV9  is twice the distance and requires two hops earth-E layer-earth-E layer-earth to get there. Consequently openings are less likely and less strong.

How do you know when the band is open?  For those with CW or SSB, beacons can be monitored as sometimes there are openings and no amateur operators are active. I monitor the DX spider cluster on packet looking for an increase in 50Mhz activity or 70Mhz spots directly. The ON4KST chat is a great way to find out what is happening. Also another way of telling that the MUF is up to 70 MHz is the appearance of East European broadcast stations in the band. Transmissions come from mainly Russia. 65 - 74Mhz is their equivalent of our 88 to 108 band. The signals are wide band FM and will appear very distorted in  narrow IF filters. If you only have FM start on 70.450 the DX will appear there. QSY's to an operating frequency are not very common as QSOs are fairly short. Be warned, signals can be stronger than your local 5 kilometres down the road.

70mhz beacon list. Thanks to The Four Metres Website. For up to date info visit.. www.70mhz.org.

73 and good DX.

Denis G3UVR  g3uvr@qsl.net

Return to construction and technical ideas menu