Tuning is obtained with rotatable drum selectors for VHF and variable rotatable capacitor for UHF.
A rotatable drum containing twelve pre-defined channel-specific filters determines the received channel, where the inductors of the input matching, the channel filter and the LO tank circuit are changed. The tuner is divided into two chambers for maximum isolation between the sensitive RF input and the mixer-oscillator-IF section with its much larger signals. Also on the drum there are eventually two separate sub-modules.
It's completely based on tubes technology.
With this concept, which essentially turned the tuner module into a kind of Lego building block construction, many different tuners became possible. Depending upon the country of destination and its associated standard and IF settings, the required filter modules would be selected. Service workshops and tv fabricants could later even add or exchange modules when new channels were introduced, since every inductor module had its individual factory code and could be ordered separately. As a consequence more versions of the tuner were produced, covering at least standards B, B-for-Italy, C. E, F and M.
The principle of the drum tuner. On an axis two times 12 regularly spaced channel-specific filter modules are mounted. In front are twelve channel filter modules for both the channel filter and LO tank circuit tuning. Seven contacts are available, and one module is shown removed. The second row contains 12 modules with five contacts for the input filter circuit. In the tuner module the front section (for mixer-ocillator and channel filter) is separated by a metal shield from the rear RF input and pre-amp section. [Philips Service "Documentatie voor de kanalenkiezers met spoelenwals", 1954]
Examples of the filter modules as used in the drum tuner. Left the 5-contact input filter, right the 7-contact BPF and LO tank filters. In both modules the coils are co-axial for (maximum) mutual coupling.
The second new valve introduced in the tuners family was the PCF80, a triode-pentode combo valve specifically designed for the VHF mixer-oscillator role. First order the circuit principles didn't change too much from the previous ECC81 based generation, with the triode acting as a Colpitts oscillator with a tuned feedback from anode to grid. The oscillator voltage was minimally 5V at the grid, and would be inductively coupled to the input of the mixer pentode. This inductive coupling was achieved by putting the oscillator coil S7 and the BPF coils S5 and S6 on the same rod inside the drum tuner filter modules, see Fig.5 above. By adjusting the distance between these coils for each channel filter module, the coupling constant could be kept more or less constant across all channels, providing as much as possible a frequency-independent mixer performance. For the mixer the pentode replaced the previous triode, providing more feedback isolation between anode and grid. All in all the new tuner must have given a considerable performance improvement compared to the previous generation.
Here you can see a nice PHILCO Washing Machine.
A good point on good old B/W Televisions.....................
The Sixties was a time of great change for TV. At the start of the decade there were just monochrome sets with valves, designed for 405 -line transmissions at VHF. By the end there was 625 -line colour at UHF, with transistorised chassis that used the odd IC.
The following decade was one of growth. The "space race" had begun in 1957, when the USSR launched Sputnik 1 and terrified the Americans. Thereafter the USA began to spend countless billions of dollars on space missions. This got underway in earnest in the Sixties, with the announcement that America would be going all out to get a man on the moon by the end of the decade. There followed the Mercury series of earth - orbit missions, then the Apollo launches. Success was achieved in 1969. Most of these missions were televised, and in those days anything to do with space was hot stuff. It was inevitable that everyone wanted to have a television set. At the time an average receiver would be a monochrome one with a 14in. tube - there was no colour until 1967. It would cost about 75 guineas.
TV sets were often priced in guineas (21 shillings) as it made the price look a bit easier on the pocket. Anyway 75 guineas, equivalent to about £78.75 in 2000's currency, was a lot of money then. For those who couldn't, rental was a good option. The Sixties was a period of tremendous growth for rental TV.
Much else was rented at that time, even radios, also washing machines, spin driers, refrigerators and, later on, audio tape recorders (no VCRs then).
For most people these things were too expensive for cash purchase.
There were no credit cards then. And when it came to a TV set, the question of reli- ability had to be taken into account: renting took care of repair costs.
TV reliability.........The TV sets of the period were notoriously unreliable. They still used valves, which meant that a large amount of heat was generated. The dropper resistor contributed to this: it was used mainly as a series device to reduce the mains voltage to the level required to power the valve heaters. These were generally connected in series, so the heater volt- ages of all the valves were added together and the total was subtracted from the mains voltage. The difference was the voltage across the heater section of the dropper resistor, whose value was determined by simple application of Ohm's Law.
As valves are voltage -operated devices, there was no need to stabilise the current. So the power supply circuits in TV sets were very simple. They often consisted of nothing more than a dropper resistor, a half or biphase rectifier and a couple of smoothing capacitors. If a TV set had a transformer and a full wave rectifier in addition to the other components, it was sophisticated!
As the valve heaters were connected in series they were like Christmas -tree lights: should one fail they all went out and the TV set ceased to function. Another common problem with valves is the cathode -to -heater short. When this fault occurs in a valve, some of the heaters in the chain would go out and some would stay on. Those that stayed on would glow like search- lights, often becoming damaged as a result. Dropper failure could cause loss of HT (dead set with the heaters glowing), or no heater supply with HT present. When the HT rectifier valve went low emission, there was low EHT, a small picture and poor performance all round. CRTs would go soft or low emission, the result being a faint picture, or cathode -to -heater short-circuit, the result this time being uncontrollable brightness. On average a TV set would have twelve to fourteen valves, any one of which could go low -emission or fail in some other way. All valves have a finite life, so each one would probably have to be replaced at one time or another. The amount of heat generated in an average TV set would dry out the capacitors, which then failed. So you can see why people rented!
The CRT could cause various problems. Because of its cost, it was the gen- eral practice to place its heater at the earthy end of the chain. In this position it was less likely to be overloaded by a heater chain fault. But during the winter months, when the mains voltage dropped a bit, it would be starved of power. This would eventually lead to 'cathode poi- soning' with loss of emission. The 'cure' for this was to fit a booster transformer designed to overrun the heater by 10, 20 or 30 per cent. It would work fine for a while, until the CRT completely expired. At about this time CRT reactivators came into being - and a weird and wonderful collection of devices they turned out to be. Regunned tubes also started to appear. You couldn't do this with the `hard -glass' triode tubes made by Emitron. These were fitted in a number of older sets. Yes, they were still around, at least during the early Sixties.
Developments................... A great deal of development occurred during the Sixties. Many TV sets and radios made in the early Sixties were still hard -wired: the introduction of the printed circuit board changed the construction of electronic equipment forever. The first one was in a Pam transistor radio. PCBs were ideal for use in transistor radios, because of the small size of the components used and the fact that such radios ran almost cold.
They were not so good for use with valve circuitry, as the heat from the valves caused all sorts of problems. Print cracks could develop if a board became warped. If it became carbonised there could be serious leakage and tracking problems. In addition it was more difficult to remove components from a PCB. Many technicians at that time didn't like PCBs. As the Sixties progressed, transistors took over more and more in TV sets. They first appeared in a rather random fashion, for example in the sync separator stages in some Pye models. Then the IF strip became transistorised. Early transistors were based on the use of germanium, which was far from ideal.
The change to silicon produced devices that were more robust and had a better signal-to-noise ratio.
Car radios became fully transistorised, and 'solid-state' circuitry ceased to be based on earlier valve arrangements. Many hi-fi amplifiers had been transistorised from the late Fifties, and all tape recorders were now solid-state.
Both reel-to-reel and compact -cassette recorders were available at this time. Initially, audio cassette recorders had a maximum upper frequency response of only about 9kHz.
To increase it meant either a smaller head gap or a faster speed. Philips, which developed the compact audio cassette and holds the patents for the design (which we still use in 2000!) wouldn't allow an increase in speed. Good reel-to-reel recorders had a fre- quency response that extended to 20kHz when the tape speed was 15in./sec.
This is true hi-fi. In time the frequency response of compact -cassette recorders did improve, because of the use of better head materials with a smaller gap.
This led to the demise of the reel-to-reel audio recorder as a domestic product We began to benefit from spin-offs of the space race between the USA and the USSR.
The need to squeeze as much technology as possible into the early computers in the Mercury space capsules used by the USA lead to the first inte- grated circuits.
This technology soon found its way into consumer equipment. Often these devices were hybrid encap- sulations rather than true chips, but they did improve reliability and saved space. The few chips around in those days were analogue devices. To start with most UHF tuners used valves such as the PC86 and PC88. They were all manually tuned. Some had slow-motion drives and others had push -buttons. They didn't have a lot of gain, so it was important to have an adequate aerial and use low -loss cable..............................
Crosley was one of the bigger players. Crosley exported also in quantities - for instance to Switzerland.
Founded: 1921
Closed: 1956
Radioproduction: 1921 - 1956
History:
The Crosley Manufacturing Corp. , founded by Powel Crosley Jr. of Cincinnati, Ohio, began selling low cost "Harko" crystal receivers (according to page 51 in "Radio collector's Guide 1921-1932) for $ 7 in 1921. An other (web) publication puts that to 1922 and for $ 9.00 and ads audion receivers (for $ 16.00) for 1922. In early 1923, Crosley bought another Cincinnati radio company, the Precision Equipment Co., which had been incorporated in 1919 and selling regenerative receivers under the "Ace" brand under license from Armstrong. He integrated it in 1924.
Once in control of an Armstrong license, Crosley renamed the combined company the Crosley Radio Corp. in 1924 and purchased a large manufacturing plant which he equipped to produce 5000 radios per day, including on-site manufacture of many of the basic components as well as the cabinets. Crosley borrowed low-cost high-volume manufacturing concepts from the automotive industry, which earned him the title of "The Henry Ford of Radio."
Crosley bought two more radio manufacturers, the DeForest Radio Corp. Ltd. of Canada in 1924 and Amrad in 1925. With the acquisition of Amrad, Crosley got a Neutrodyne license, allowing Crosley to begin production of more advanced recievers at a time when regenerative receivers were no longer state of the art. In 1927, Crosley began an association with the DeForest Radio Co. of Jersey City, New Jersey, which was in financial difficulty. Although it appeared that Crosley might purchase DeForest, this did not happen, and it seems that Crosley used its association with DeForest, which controlled a large patent pool, merely to gain more favorable terms in its purchase of a license to the RCA patent pool.
Notable models from Crosley included the two-tube regenerative model 51 for $18.50 in 1924 and the "Pup" in 1925, a one-tube regenerative set that sold for $9.75. In 1927, Crosley brought out a line of AC single-dial sets in metal boxes, similar to Atwater Kent's successful line at that time.
Crosley's sales and profits peaked in 1928. Although Crosley had been successful in the 1920s with low cost radios and high volume manufacturing, by the early 1930s, Philco replaced Crosley as the low cost leader. Crosley survived as an independent manufacturer until 1945, when it was purchased by Aviation Corp. (Avco). Crosley radio and TV products were produced by Avco until 1956.
Crosley owned radio station WLW in Cincinnati (still active today on 700 kHz) which for a time was the most powerful radio station in the U.S., operating at 500,000 watts from 1934-39. This station could be heard throughout much of the U.S. and even overseas. Many Crosley radios from the 1930s and 40s have "WLW" explicitly marked on the dial (the only station specifically named on dials which otherwise show only a frequency scale).
Ace, Administrator, Adventurer, Alderman, Announcer, Arbiter, Bandbox ,Bigfella, Bonniboy, Bubby-Boy, Cook Base, Buccaneer, Buddy, Cabriolet, Caroler, Casa, Cherio, Chief, Chum, Classmate, Clipper, Commissioner, Companon, Congressman, Constitution, Corsair, Crony, Cruiser, Director, Discoverer, Elf, Fiver, Galleon, Gembox, Gemchest, Governor, Jewelbox, Jewelcase, Leader, Legislator, Mate, Mayor, Merrimac, Merrymaker, Monotrad, Olymia, Oracle, Pal, Partner, Playboy, Playtime, Privateer, Pup, Repose, Reveler, Roamio, Rondeau, Secretary, Senator, Septet, Sevette, Sextet, Sheraton, Showbox, Showboy, Showchest, Six, Sixty, Sondo, Songster, Sonnester, Symphony, Ten, Tenace, Tenstrike, Totem, Travette, Travo, Thridyn, Troubator, Twelve, Vagabond, Viking, Washinton, Wigit
Philco, the Philadelphia Storage Battery Company (formerly known as the Spencer Company and later the Helios Electric Company), was a pioneer in early battery, radio, and television production as well as former employer of Philo Farnsworth, inventor of cathode ray tube television. It is currently a brand of Philips.
Philco's rise to the top of radio makers was an amazing feat. While other makers like Atwater-Kent, Zenith Electronics, RCA, and many now-forgotten others (Freshman Masterpiece, FADA Radio, AH Grebe, etc.) sold many battery-powered radios in the early 1920s, Philco made only batteries, "socket power" units, and battery chargers. With the invention of the rectifier tube, which allowed radios to be operated from the wall socket, Philco knew their business was doomed, and decided in 1926 to get into the booming radio business. By 1930 they would sell more radios than any other maker and hold that first place position for over 20 years.
Philco built many iconic radios and TV sets, including the classic cathedral-shaped wooden radio of the 1930s (aka the "Baby Grand"), and the very futuristic (in a 1950s sort of way) Predicta series of television receivers.
Philco started experimenting with television in the early 30s and financed for a while the experiments of Philo T. Farnsworth, considered by many as the “father of television.”An experimental TV station was licensed to Philco in 1931, one of the first all-electronic television ;
Today, the Philco brand name is carried by several different companies and holding groups throughout the world.
Some References:
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"The Museum of Broadcast Communications - Encyclopedia of Television - Farnsworth, Philo". www.museum.tv. Archived from the original on 30 April 2017. Retrieved 24 April 2018.
Mahon, Morgan E. A Flick of the Switch 1930–1950 (Antiques Electronics Supply, 1990), p.117.
A Brief History of Philco Archived 2005-08-02 at the Wayback Machine Oldradio.com
Internal Philco Corp. document Philco-Ford Image, by Glenn Allison, app. 1965
Mahon, p.116.
Mahon, p.127.
Peck, Merton J. & Scherer, Frederic M. The Weapons Acquisition Process: An Economic Analysis (1962) Harvard Business School p.619
Internal Philco Corp. book The Story Of The Philco Franchise, 1954
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Wall Street Journal, "Philco Claims Its New Transistor Outperforms Others Now In Use", December 4th 1953, page4
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https://docs.lib.purdue.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1890&context=cstech. Missing or empty
|title=
(help)
"Fifth Generation Computers - Patents and Licensing". www.fifthgen.com. Archived from the original on 4 October 2017. Retrieved 24 April 2018.
Saul Rosen (Jul 1968). Electronic Computers —- A Historical Survey in Print (Computer Science Technical Report). Purdue University Department. Archived from the original on 2016-03-04.
Inventing the Electronic Century, Author: Alfred Dupont Chandler Jr., Page 40
The Philco Serviceman, September 1955, Volume 23 No.9
Wall Street Journal: "Radio Men Told Of Rapid Counter", March 25, 1955
Wall Street Journal, "Chrysler Promises Car Radio With Transistors Instead of Tubes in '56", April 28, 1955, p.1
Hirsh, Rick. "Philco's All-Transistor Mopar Car Radio". Allpar.com. Archived from the original on June 3, 2013. Retrieved June 1, 2013.
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Wall Street Journal; June 28 1955; page 8; "Phonograph Operated On Transistors to Be Sold by Philco Corp."
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