Saturday, 1 January 2011

The origins of 70.260 as a calling channel. By Don Hayter G3HJM

In the early 60's several stations interested in modifying the B44 for 4M discussed the frequency that should be used. A 6075 kHz crystal was readily available from JAN crystals in the States. This could be used as the receive channel crystal giving 70.260 as the transmit channel. The transmitter chain was designed for a X6 multiplier hence the choice of 11.710 MHz as the choice for the transmit channel. G3GVM myself then living in Worthing and a G3 from Bognor agreed that this would reduce the initial cost for beginners and help populate the band. Within a few months activity rapidly grew on the South Coast and spread North in to the London area.

In 1966 Mike G3JVL and I with assistance from Aussie who was keen to set up a 70 MHz beacon from Gibraltar decided that the beacon on Gibraltar should also operate on 70 .260 MHz. This would stimulate interest and activity in sporadic E propagation and enable the maximum number of operators to contact ZB2VHF and experience Es for the first time since the withdrawal of the 58 MHz band. We obtained frequency clearance from the military to operate on 4M and also received an offer to transport the beacon and the aerial by courtesy of the Royal navy.

Normally ZB2VHGF operated as a beacon but whenever possible Aussie would operate/monitor 70.260 putting out CQ's and listening for replies. The beacon was modified PMR unit giving out about 15 watts to a 4 element yogi antenna. The beacon was initially set up on the summit of the Rock. MS signals were soon heard by G3JVL and myself from the elevated site. To erase access it was decided to resite the beacon to the RAF station at sea level but with a clear get away towards the UK Then on the 4th June 1963 arround 1800 the band opened to the Lancashire followed shortly afterwards to the South coast.

Suddenly 70.260 MHz was filled with CW stations calling ZB2 and within a few minutes 4 south coast stations had made their first DX contact on 70 MHz. Subsequently many stations in all parts of the UK worked. This stimulated 70 MHz activity greatly.

By the start of the 70's Aussie had returned to the UK and the other two ZB2 stations ZB2BC and ZB2BO had also moved away from the Rock. Looking for other countries to activate Mike G3JVL established contact with TF3EA in Iceland with a view to installing a beacon. TF3EA managed to get approval both for the beacon and an personal operating licence. A beacon similar to ZB2VHF was constructed by G3JVL and with a few months TF3VHF/B started transmission with a 4 el beam pointing at the UK. Again MS signal were heard almost at once and after many hours of dedicated construction worked TF3EA for the first UK to TF contact on 4M.

Later VE2AIO now operating from GM requested that a second yagi should be installed in Iceland beaming towards Montreal. The second aerial was installed and after a few months Mike received a call from VE2AIO saying that he had detected the beacon but could nThe origins of 70.260 as a calling channel. By Don Hayter G3HJMot hear it audibly. Soon afterwards JVL received a communication from VE2AIO saying that he had HEARD signals from the beacon in Montreal, The propagation almost certainly by Au Es and not bistatic Au.

Since this period much work has been done on investigating Auroral E (note that the signal is fully coherent and sounds T9 and not rough like normal Au experienced in the UK. Recently Au E from Iceland, Gteenland and Spitzbergen has been heard on 50 MHz by a VE2 and a K1. Also Au E has been heard in Western Canada from VE8BY/B.

I hope that this gives newcomers on 4M an insight to the early thrills of operating on the band in the early days !
My first Es contact was in 1960 when I worked FA9VN 200 kms South of Oran on the edge of the desert.

Don Hayter G3JHM qrv on 4M since December 1958.

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