Radio broadcast .. (1922-30)

kLL^^^^^Mi'^^^^^^^M PROFESSIONALLY 5 6 7 I t • 2 3 4 5 6 7 i S 2 SPKAKI'NG 1930 AND SERVICE IF, AS THE general service manager of a large and well-known radio manufacturer believes, the 1930 service problem will be one of negligible importance, the entire industry will have put behind it a most serious problem. The question of whether a manufacturer should send service litera- ture to the "independent" serviceman or whether he must compel all servicing to be handled by servicemen attached to authorized dealers has been solved by the majority of manufacturers to their own satisfaction. The "independent" has no place in this picture. The rea- sons as cited by the service manager quoted above are: 1. He (the "independent") does not fit into the manufacturer's scheme of positive control over field service or- ganizations. 2. The manufacturer has no claim upon his loyalty. 3. He is under no obligation to ex- ecute the manufacturer's policy with respect to guarantee, etc. 4. There is nothing to prevent the discontinuance of his activities in any locality thereby leaving that place with- out adequate service facilities. 5. The manufacturer cannot logically support his own field service organization on the one hand, and encourage the in- dependent service organization as a group on the other hand. Granting all these points, and granting the fact that we are not on the firing line of service but are in a comfortable office far from the front, we believe there is but one attribute of service that needs considera- tion—is the service adequate? This means, does the remedy cure the ill, is the cost commensurate with the effect secured, and does the service require only a reasonable amount of time? We believe that being connected with a dealer is no assurance that a serviceman is a good one. On the other hand, we believe such a serviceman is probably not as good as his brother who gets out and hustles for himself. As soon as a serviceman learns his calling and becomes an efficient and effective unit, he discovers that the meager salary the dealer can afford to pay is less then he can make on his own. Therefore, he gets out of the dealer's shop and goes after business for himself. One trouble seems to be that a dealer cannot afford to hire a good man. The ser- viceman can make more money on his own; therefore, he becomes an "indepen- dent." Perhaps some scheme like the following would work out. We have already sug- gested that the manufacturer pick all servicemen by a technical examination. This would obviate the difficulty that the dealer, not being a technical man himself, has trouble in knowing a good serviceman when he sees one. After the prospective serviceman has passed the examination, let the dealer take him on and, except for a percentage of the income to pay for the service share of the rent and for the use of the dealer's instruments, let the serviceman take all the profits. The examination will prove that he is a good technician; the fact that all the money goes to the serviceman makes it possible for him to work as hard as he likes with the certainty that the money will be his. The tendency for large dealers to farm out their service is a step toward the latter scheme. It is a fact that no dealer can afford to pay a serviceman enough money to make it worth the while of the latter to stay out of the "independent" role. The farming out process can take place only in Why the industry does not recognize the inde- pendent radio serviceman. A solution to the combined problems of radio dealers and servicemen. How will the pentode tube improve radio re- ceiver design? large communities, and, although a large percentage of all sales is made by a smaH number of dealers, these sales take place where there is plenty of service available. It is the customer in small districts who needs service the most and who has the least chance of getting it. But let us hope that the 1930 service problem will be one of negligible import- ance. If 1930, however, is marked by an- other race to see who can make the most receivers at the lowest price, we believe there will still be a service problem of considerable importance. NEW TUBES A new tube which had been spoken of quite calmly in Europe finally broke into the public press in January, thereby dis- turbing the entire radio industry to a considerable degree. This tube is the pen- tode, a five-element tube. In Europe it had taken the form of a power-output tube of superior sensitivity and efficiency. In this country there are two such tubes, the power-output tube and a screen-grid tube with an additional grid. The pentode power tube came into the limelight slowly and was demonstrated before a well-attended meeting of the Radio Club of America. Knowing the pro- pensity of the newspapers to exaggerate the importance of any technical develop- ment, the authors of the paper "hedged" and said the new tube would not make any startling difference in radio receiver de- sign. The other pentode was announced by a tube manufacturer with the statement that it would make possible a $50 receiver by cutting out sufficient tubes from the present type of sets. It was described as twice as good as present-day tubes. The newspaper writers took up the matter with great glee and soon the trade associations thought something ought to be done about this pentode business before the public began to look for the new set and to refuse the old. The statement of the trade association was made with very little regard for the cold hard facts with which the engineering profession deals and which, we believe, ought to be interpreted to the buying public. The statement denied practically everything that had been said in favor of the new tubes. Aside from whether or not the various statements were ill advised and devoid of facts, the situation is indeed unique. So far as we know, for the first time in the history of the industry a tube manu- facturer developed a tube in his own laboratory and instead of hiding his i light under a bushel until he could get tooled up or had sold the rights or whatever it is you do to corner the other fellow's market, he distributed characteristics of the tube to engi- neers and asked their suggestions. Set engineers have asked such co- operation before. They have wanted tube designers to present their charac- teristics, and ask for the suggestions of circuit engineers so that the final tube design could be worked out with the circuit people in mind. While it is quite probable that not a dozen circuit engineers in the country have any ahead-of-the-minute ideas about what to do with a new tube when one is presented for criticism, it is a good idea anyhow. Let the tube people make a tube, and ask the circuit people how to make it better for their needs. Conversely, let the circuit people lay down a diagram and beg for a new tube to fit into it. Let us look at this pentode business seriously. There are two kinds, the power tube and the amplifier. The pentode power tube delivers about the same output as a 245-type tube but is roughly 15 DB more sensitive. Calculations on page 338 of this issue show that such a tube with a screen-grid detector ought to make it possible to get along with only four tubes plus a rectifier and make a set just as good as present-day sets with more tubes. But you still need two stages of r.f. amplifica- tion, and therefore, even if a new screen- grid tube which was twice as good as pres- ent tubes made its appearance, it would not be good enough (because the overall gain of two stages is the product and not the sum of the individual stages). In other words, the pentode voltage amplifier is not good enough to act with a power pen- tode to make a three-tube set practicable. It is better, but not enough. The pentode power tube will undoubt- edly fit into the picture of many manu- facturers. There is no reason for everyone to rush into the design and production of a pentode set, because the public won't be able to tell the difference, except perhaps in price. It makes a four-tube set possible but not a three-tube set. As for the screen-grid pentode, it must be proved that it really is worth the bother of adding terminals to the base and to the socket and other circuit changes. RADIO BROADCAST FOR APRIL • 339