Philips-A-5V-BC-AC-1934 电路原理图.pdf

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1、PHILIPS1 FIRST AUSTRALIAN SUPERHET John W. Stokes In Australia receiver manufacture had been commenced on a small scale in 1931 with the production of a 3-valve TRF, model 1203, but appears to have languished somewhat thereafter and not until 1934 did Philips again become active on the manufacturing

2、 scene. By this time manufacturers every- where had turned to the superhet circuit, which meant that it was time for Philips to get into the act too. But where to start? To what extent Philips in Australia were subject to overseas control is not known, but it is a matter of record that the circuitry

3、 of the first Australian made Philips superhet closely followed a design which had been published by Philips in Holland in June 1933. At that time they took the unprecedented step of issuing a comprehensive bulletin, printed in three languages - English, French and German - containing a circuit diag

4、ram and full constructional details for building a 5-valve superhet. It is interest- ing to note that it was well over a year later before Philips actually produced a superhet in Europe, and when they did its circuitry bore no resemblance to that published in the 1933 bulletin. By comparison, the de

5、sign of their first Australian made superhet, the model A, as advertised in September 1934, appeared to be firmly based on the above mentioned data and for this reason it is interesting to see how the two designs compared* Both used the same valve line-up: E446 as an autodyne mixer, E447 IF amplifie

6、r, E444 diode detector combined with tetrode AF amplifier, E443H directly-heated output pentode. The Australian version differed in the following ways: 1. Omission of the long-wave band. 2. Separate primary winding on aerial coil. 3. Manual RF gain control (no AVC) 4. Modified oscillator circuit. 5.

7、 Self bias instead of back bias on output valve. 6. Use of hybrid1 valves, i.e standard 4-volt European types fitted with American style bases. 7. If changed from 125 to 175 kHz. The cabinet used on the model A was in the current full length (legless) console style with a distinctive speaker grille

8、embodying, in modified form, the Philips waves, stars and circle motif. Although this motif had been used overseas on both table and floor model cabinets, it was always in the original form complete with a circular rim or border; in fact this ring represented ore of the three ideas expressed in the

9、famous logo. In the vertically elongated form as used on the Australian cabinet it was imposs- ible to include the circular border and thus one of theideas was lost. It would be interesting to know whether this modification had the approval of Philips in Holland, but in the event its use was not con

10、tinued on any further models, although the 1935 version, model 5501/02, appeared in the same cabinet, presumably to use up existing stocks. * Incidentally, I once stated that Philips had never used the autodyne mixer circuit in any production model receiver (NZVRS Bulletin 7-4-6 Feb.1987), but this

11、should be ammended to read: any European production model. 1561 4090 443 H Suggested layout for a 5-valve superhet, May 1933 7 RadioFans.CN cc Condensers Cl,2,3=gang. C4=.02 C5* C6,17,1.0! C7=padder C8,13,U,26-.lflP C15,18.21-.5jiF. C16,20=250pF C33=25pF 25V C24,25=8pF 500V Resistors R1.2-1K R3=3.2K

12、(vol cont) R4=300 ohms R15115K voltage divider R6,12=500K R7,9=1M R8=4K R10=250K R11=25K R13-15K (tonecont) R14=400 ohms *C5 is a 27pF neutralising condenser pre-set at the factory. AUSTRALIAN PHILIPS MODEL A Circuit diagram from Radio & Electrical Merchant Oct.19,1934 by courtesy of Darryl Kasch E446E4475444E443 H ttf m, ,f. yL/i /i fc* EVdW7u/s? dun 3c/tf/rrci sle monraoe donne 5u/r garanrie cjuant a /a jororecr/on erf/?/tja/e/oar aes a/riet*, S/K-c/7 o/circuiJiayf-um wiMou/ /uatenS oA/yao,* on wr part PHILIPS R945778/5 -J3 RadioFans.CN