The Screen Grid Browning-Drake

Radio Record, Volume II, Issue 30, 8 February 1929, Page 27

The Screen Grid Browning-Drake

Now on the N.Z. Market

asking for a diagram of the screen grid Browning-Drake, and so this week we publish that diagram with a few notes on the set, and this new type of Browning-Drake should prove equally as popular as its predecessor has done. The new upright type of 4element valve has made possible the greatest single advance in radio-receiving-set correspondents have written

performance of any new development within the last few years. As soon aS its possibilities became known it was clear that a standard of radio reception far above anything previously, exrienced could be obtained, both as . © sensitivity and selectivity. Easy to Build. "THERE has been a certain impression that it was difficult to build a receiving circuit using the upright, without the use of a great deal of care-

fully-placed shielding and without rather critical operation. While it is true that shielding appears to be absolutely necessary for anything like good performance when the upright valve is used with the tuned-plate method-now’' most generally employed -it is not essential to employ the tuned-plate impedance for very fine results. In fact, much more stable and

otherwise satisfactory operation is obtained if a correctly-designed radio-fre-quency transformer with a very high primary impedance is used instead. No Neutralisation Troubles. WHEN one of the new upright valves is used with such a R.F. transformer, in connection with the Brown-ing-Drake circuit, not only is the sensitivity or distance-getting ability of the receiver improved to a marked degree, but also the necessity for neu-