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Wireless Set B70

B70 front view

The B70 is a portable microwave relay, operating in the frequency range 4580 to 4860MHz. It could provide up to 14 channels at 20MHz spacing. In operation the unit used two dish aerials with the unit mounted behind them, all supported on a tripod.

It worked line of sight - approx 20 miles - and this could be extended by using B70's as relay stations in between.

This equipment uses two CV228 heil tubes, one for transmit and one for receive, which can be seen here. The two cavity assemblies can be seen along with the heil tube magnets. B70 internals
B70 CV228 closeup Here is a closeup of the receiver heil tube showing the magnet and the base of the valve.

The later Wireless Set B70 No. 2 used CV485 heil tubes.

These photographs are copyright Peter Barker and used with his kind permission. Peter also provided information on the set.

This file was last modified 15:30:49, Tuesday September 02, 2014