Studies of ionograms show supremacy of 5 MHz band

The ionograms generated by the South African ionosonde network clearly illustrate the supremacy of the 5 MHz band for short range, near vertical incidence skywave (NVIS) communications under certain conditions.

These typically happens during the morning and late afternoon when the 7 MHz band does not support short range, sky wave communications and the 3.5 and 1.8 MHz bands suffer from high noise levels.

During the middle of the day the 7 MHz (and 10 MHz during high solar activity) band is typically the most effective medium for short range, sky wave communications.

Permanent access to the 5 MHz band will ensure that the amateur radio community can efficiently contribute to emergencies requiring short distance communications beyond line-of-sight as typically required in hilly and mountainous terrain.

The South African ionosonde network is unique in Africa and place South African radio amateurs in the very fortunate position to monitor reigning, short range propagation conditions and to improve their skills and experience accordingly.

Spain gets experimental permission for 5 MHz

Following steps taken by URE, the Spanish national amateur radio society,  SETSI, their regulator, has issued a resolution authorizing use of the following frequencies during the first half of 2014:

5268, 5295, 5313, 5382, 5430 and 5439 kHz.

3 kHz bandwidth, Power Limit 100W, CW/SSB [USB]

For the full text of the resolution, in which the conditions of use specified band visit - http://www.ure.es/noticias/2315-2013-12-20-10-05-22.html

UK Radio Amateurs extend 76 GHz distance record

Another new distance record of 129km was achieved on 76GHz Saturday 23rd November 2013, with contacts between Brown Clee Hill in Shropshire (IO82QL) and Winter Hill, Lancashire (IO83RO).

Operating on three mm-bands, 24, 47 and 76GHz, were Ian Lamb G8KQW and John Hazell G8ACE at Brown Clee Hill and also on the three bands at Winter Hill was Roger Ray G8CUB with John Wood G4EAT who was operational on 76GHz.

Contacts on all three bands were made using NBFM, signals on 76GHz were exchanged for one hour with some QSB at time primarily due to changes in atmospheric conditions along the path.

This tremendous success follows closely after the previous distance record was set by Ian Lamb and John Hazell on 14th September 2013 with a contact of 102km. Earlier in 2013 the existing 79km distance record had been bettered 3 times, this reflecting the increasing level of interest in mm-band operating in UK and the culmination of much hard work on-going to improve system performance.

By calculating the link budget and path loss of this path it was possible to predict what environmental conditions would potentially give sufficient margin for success. The weather forecasts (specifically the dew-point temperature) were carefully monitored during the preceding week to ensure the conditions on the day would allow the possibility to establish contact over the distance.

The team are indebted to Jim G8UGL and the Telford and District Radio Society, without their kind assistance in arranging access to Brown Clee Hill and support on the day, this would not have been possible.