B ELIMINATOR CONSTRUCTION

Radio Record, Volume I, Issue 20, 2 December 1927, Page 12

B ELIMINATOR CONSTRUCTION

REGARDING CONDENSERS One or two queries haye heen sent in regard to the use of the ordinary Mansbridge type condensers in the B eliminator, asking as to their ability to stand up to the fairly high voliage in use. It is nearly twelve months since the original eliminator was constructed, and at the time cight Dubilier fixed condensers of two microfarads each were included in the circenit, It was quite expected that one or two of these might soou break down, bnt they have been in daily use for scyeral hours ever since, aud not one has yet given out, A small experimental eliminator has just been put together, and, strange to say, one of four uew condensers included broke down almost at once. l'rom this it must he understood that the condensers will stand up to the work well, but there is the chance of one giving out, but once the weak one is thus discovered there is chance of little further trouble. The writer will investigate the chances of repairing this class of condenser. Both the Dubilier and ‘T.C.C. condensers have been used and found reliable, and they are comparatively cheap at &s and 7s. each. Ihe Sangamo two microfarad, which the writer has not vet tested, are made in two grades, A and B, the former guaranteed for continuous operatiou at 250 volts a.c, or 400 volts d.c., and the latter at 500 a.c. and 1000 volts d.c. Thes¢ sell at lls. Sd. and 18s. 6d. each respectively. Many constructors will probably prefer to use the less expensive condensers and risk a break. Condensers can he tested roughly before installing Ly putting the 230 volt house current across them with a lamp in series. Several corresponden's have inguired as to the possibilitv of making these fixed condensers, but it has already been stated that the factorymiade article is so efficient and compact that to buy the materials in (Continned on next page.)