We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
RADIO AGE for October, 1926
The Magazine of the Hour
Building 9 Tube Super Brings Back Faith in this Receiver
Absence of Oscillation and Simplicity of Construction are Features
SO MUCH has been written on superheterodynes at times it seems the subject has been worn threadbare, yet when we are just at the point of exhaustion something generally turns up that is interesting. These remarks apply aptly to the nine tube super which is herein described, and whose performance is such that it is felt readers of this magazine will find the flame of their interest renewed on the question of superheterodynes.
Simplicity of control and ease of assembly are the two features which should appeal to the set builder, while the selectivity of the receiver itself will appeal to both the set builder and the experimenter in search of good results.
Pictorially the nine tube super is shown on this page. A
glance will readily show the simplicity of assembly, everything being on a line. The baseboard layout was used instead of the subpanel on account of this type of arrangement being more pleasing to the set builder. If the set looks nice in this dress, it will look even better if done up in sub-panel fashion, although a bit more work is involved in following that form of construction.
Taking advantage of the fact that transformers designed for long wave work will serve nicely for the intermediate stages of a super, we secured a set of long wave transformers designed by the High Frequency Laboratories of Chicago and which are peaked for 37.5 kilocycles, this value being desirable to dodge between the ten kilocycle separation allowed by
the government to broadcasting stations.
The set consists of the first detector, four intermediate stages using long wave transformers, the second detector, the oscillator, and two audio frequency stages. No potentiometer is used since flexibility of the intermediate stages is provided through filament rheostat controlling all of the intermediate tubes. Amperites are used in the remainder of the circuit which does away with further filament control. A grid modulator serves to alter the volume in the loud speaker. Thus there are two major and one minor controls. The condenser on the left is that for the loop ; the condenser on the right is the oscillator. The rheostat for the intermediate stage filaments is shown as volume and is located at the left of
m •'"
mm
mMMMmg
In the upper picture is shown[the baseboard layout of the Radio Age Super 9. Beginning at the left of the baseboard the
transformers used are as follows: H210, H210, H215, H210, H215, F320, L42S, F320. The transformer shown between the two
Render condensers is an L430 RF transformer. Thergrid of the sixth and seventh transformer is not hridged directly to the
tube socket. See the schematic for the actual electrical connections