Tips and Jottings

Radio Record, Volume III, Issue 28, 24 January 1930, Page 30

Tips and Jottings

Panel Appearance, O far as screw holes are concerned, most panel-mounting components are now so made that the knobs cover any fixing devices, and the only screws ° exposed are those holding the panel to the brackets and securing it to the front edge of the baseboard. If the holes are in all cases counter-sunk somewhat deeper than necessary in order to make the screwheads flush, the small depressions above them can be filled up with wax, cut off with a sharp knife, and polished so as to be quite indistinguishable from the panel material. It is actually easier to do‘\this filling and polishing on mahogaxj™@fd walnut-finished panels than on plain and highly-polished black ebonite, for a little red and. brown wax can be blended to match the pattern perfectly. Improving Tuning Limits. yy many old-fashioned sets failure to tune down. below a certain limit is due to the fact that the variable condensers have what we should call nowadays an unduly high minimum capacity, though it was regarded as very low in the early days of broadcast receiving equipment. To substitute up-to-date variable condensers for old ones is a perfectly straightforward job which can be carried out in a few minutes in most sets. The expense involved is quite.small, for the price of condensers to-day is astonishingly low considering how well they are design-. ed and made. The best type to choose for the set intended for the reception of foreign as well as home stations is undoubtedly the straight-line frequency since this gives an almost equal separation of stations from near the bottom to near the top of its tuning limits. No condenser, whether ‘squarelaw or §.L.F., is likely to give a perfectly straight-line graph between zero and maximum, but when good patterns are used. with suitable valves and Circuits the curved portions of the graph will be very small and its straight portion very long in comparison. \