Constructor's Suggestions

Radio Record, Volume III, Issue 6, 23 August 1929, Page 29

Constructor's Suggestions

JN changing to parallel feed on my four-valve BD, writes Mr. Wm. Seddon, I found I could increase the primary by at least five and still maintain stability. Also the increase gives a decided increase in amplification though tuning is flattened slightly. I also found that by inserting an earthed copper screen between the aerjal coil, ‘condenser, RF valve and the RF transformer: that reception" was .very much clearer. No doubt this is brought about by stopping any coupling between aerial coil and RF transformer. This screening I find.much better than totally enclosing the separate stages in sereening boxes, as these produce a serious damping or loss of signal strength. Do you think it possible ‘to make use of screens only between the three stages in the 2RF, BD instead of copper boxes and do away with the losses incurred by enclosing each stage? Would it be possible to maintain stability by the suggested plan? {Most unlikely, feed-back and interaction would cause instability--Tech-nical Editor.] Now a word praising the really firstclass service put across by the R.B.C. I think, and I am not alone in asserting that no sane person could find fault with such a system of entertainment. It is very entertaining reading some of the "growlers’" remarks in "Radio Record." It makes one wonder just how much, or what, some people really do want for their license-fee.