SWB-8 HF Transmitter

The Marconi SWB-8 HF transmitter was originally produced in the late 1930s as a shipboard transmitter, having an all-brass cabinet construction to prevent corrosion. During and after WWII, these transmitters were also employed as land based transmitters in point-to-point service. During its service life, it acquired the moniker "SWAB 8".


Power: 2 to 3.5 kilowatts
Frequency Range: 3 to 22.2 MHz
Frequency control:  Used a two valve Franklin oscillator which was mounted right at the bottom of the transmitter, on the floor, where temperature change was minimal. This was particularly important.
Power input - ?
Weight - ?
Dimensions - ?
Tube (Valve) types: Output stage- ACT9
                               Intermediate stages- 807, KTW61, ML6
                               Power supply- G020 (mercury vapour)

For additioanl information on the SWB-8,  go to this link.

This is only the RF unit, and not the power supply and  modulator cabinet.The unit was restored to its present pristine condition by  volunteer Ron Sevior of the Civil Aviation Historical Society  Museum (CAHS).  Perspex panels permit a view of the interior which would have been covered by brass-mesh plates when the transmitter was in service. (Photo courtesy CAHS. Used with permission) .

Contributors and Credits:
1) Civil Aviation Historical Society (CAHS) Museum, Essendon Airport, Melbourne, Victoria,
2) Roger Meyer - President, CAHS
3) http://www.weyvalleyarg.org.uk/pages/xtras/weyaheads/weyahead_0307/weyahead_0307_p1.html
4) Brian Summers, co-curator of the new Falkland Islands Museum. <brian.summers(at)horizon.co.fk>

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May 6/15