Details
Wavemeters:
a Wavemeter Mark 1 (150-600 metres) by Bowyer-Lowe Co. Ltd. Letchworth, in mahogany case with enclosed sloping panel and instructions in lid; and a Heterodyne Wavemeter, No. 904/32, by H.W.Sullivan Ltd. London, with valve and controls on ebonite top panel on teak base (2)
a Wavemeter Mark 1 (150-600 metres) by Bowyer-Lowe Co. Ltd. Letchworth, in mahogany case with enclosed sloping panel and instructions in lid; and a Heterodyne Wavemeter, No. 904/32, by H.W.Sullivan Ltd. London, with valve and controls on ebonite top panel on teak base (2)