RF Cafe Software
About RF Cafe
1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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August 1945 Radio-Craft[Table of Contents]
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Radio-Craft was published from 1929 through 1953. All copyrights are hereby acknowledged. See all articles from Radio-Craft.
I did not see anything particularly stand-out-ish about the Wells-Gardner Series 062 automotive superheterodyne radio. The 'eliminator' option of the 'eliminator or battery' label presumably refers to an AC-to-DC power supply that can be used either during maintenance or if the listener chooses to employ the radio in use outside of a vehicle - or else has a very long extension cord ;-) As with all these radio data service pages, this one is posted for the benefit of both researchers and for restoration types who need troubleshooting and alignment information.
(Incorporating types '36, '37, '38 and '39 tubes; also A.V.C.)
Numerous mail-order houses sponsor this chassis under their particular trade name; consequently, it is better remembered by its circuit connections than by the name of the chassis manufacturer.
In the No. 062 Series automotive receiver the following electrical values arc used:
Resistor R1, 0.5-meg.; R2, 7,000 ohms; R3, 1. meg.; R4, R13, 0.5·meg.; R5, R12, 0.1-meg.; R6, R7, R8, 2 megs.; R9, 1,000 ohms: R10, 20,000 ohms; R11, 15,000 ohms; R14, 350 ohms; R15, 1,300 ohms.
Condensers C1, C2, C3, equipped with trimmers, constitute the tuning gang; C4 is the oscillator padding condenser; C5, C6, C7, I.F. trimmers; C8, .006-mf.; C9, .02- mf.; C10, C14, 4 mf.; C11, .002-mf.; C12, C18, 05-mf.; C13, C15, C16, 0.1-mf.; C17, .001-mf.
Operating potentials are as follows: Filament potential, all tubes, 6 volts. Plate potential, V1, V3, 177 volts; V2, 173 volts; V4, zero; V5, 54 volts; V6, 159 volts. Screen-grid potential, V1, V3, 80 volts; V2, 76 volts; V4, zero; V5, 77 volts; V6, 165 volts. Control-grid potential, V1, V3, 3 volts; V2, 7 (depending upon dial setting); V4, zero; V5, 6 volts; V6, 15.5 volts. Plate current, normal, V1, V3, 3.6 ma.; V2, 0.9-ma. (depending upon dial setting); V4, zero; V5, 1.2 ma.; V6, 10 ma. All bias voltages must be read from cathode to ground.
Do not check the "A" and "B" potentials at the multi-point socket on the cable head, as the pilot light may be burned out when the switch is turned off. (This is due to the high inductance of the speaker field, which will increase the voltage at the break of the circuit.) Also, when the cable head and multi-point socket are taken off, the connections between the chassis and power unit are open so that readings are not made under load conditions.
To read the voltages at the sockets the chassis box, in most cases, will have to be removed from its mounting. In some instances, the cables, which may be attached to the dash or at other points. will have to be removed. The voltages can be read at the sockets with a long plug or with a pair of log, insulated test prods.
All tubes must be inserted and all units connected. A signal will effect the control voltages on V1, V3 and V5. If signals are received, ground the antenna and remove V4 to take the other readings.
The diode current establishes a drop across a resistor network; this potential is used as an additional bias potential on V1, V3 and V5, giving A.V.C. action.
The full control potential is applied to V1, two-thirds to V3, and one-third to V5. As the signal increases in intensity, the applied control potential is increased, thus giving uniform output as set by the manual volume control. The manual volume control varies the diode A.F. potential applied to V5.
The tone control is mounted on the dynamic reproducer, which derives its field supply from the storage battery in the car.
Aerials are preferred in the following order: Roof antenna; tape antenna on roof (this is not very effective where a grounded chicken-wire mesh remains inside the roof); plate antenna (strung underneath the running board); undercar antenna (A wire fastened from the right right of the rear axle to the lowest point under the motor, then back to the left rear axle, forming a V. At the vertex of the V is a spring to take up the slack. The lead-in is brought up from the vortex end.).
Do not turn the set on until all the wiring connections of the installation have been completed - this is extremely important.
To adjust the antenna trimmer, tune in a weak signal at the high frequency end of the dial with the manual volume control about three-quarters on. On one end of the chassis box is a small metal plate. Remove the two screws holding this plate. Directly under the hole in the chassis box is the antenna trimmer condenser screw. Adjust this up or down until maximum output is obtained.
Noise, in some instances, may be due to weak pickup caused by a poor antenna. The action of the automatic volume control, due to the low pickup, causes the set to operate at maximum sensitivity, thereby increasing noisy reception, due both to external pickup and internal conditions.
Noisy operation is also caused in some instances by loose parts in the car body or frame. These loose parts rubbing together affect the grounding and cause noises, due to the rubbing or wiping action. Tightening up the frame and body at all points and, in some cases, the use of copper jumpers, will eliminate noise of this nature.
Loose lamps or wiring are also a common cause of noisy operation.
Compensate for the increased battery drain occasioned by the radio set, by increasing the charging rate of the car generator. After a week of car operation, check the condition of the battery and readjust the charging rate accordingly.
Two fuses are used on this receiver. The 10 A. "A" fuse is located on the multipoint socket; the 1/8-A. "B" fuse, inside the control unit. The pilot lamp is a standard 6 volt No. 40 unit.
Poor operation may be due to moisture, from car-washings or storms, seeping into undesired places.
Radio Service Data Sheets
These schematics, tuning instructions, and other data are reproduced from my collection of vintage radio and electronics magazines. As back in the era, similar schematic and service info was available for purchase from sources such as SAMS Photofacts, but these printings were a no-cost bonus for readers. There are 161 Radio Service Data Sheets as of January 3, 2017.
Posted January 9, 2015