Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
This is
another Radio Service Data Sheet that appeared in the May 1936 edition of Radio-Craft magazine.
I post this schematic and functional description of the Philco-Packard Deluxe, 7-Tube Superhet
Car Radio manufacturers' publications for the benefit of hobbyists and archivists who might
be searching for such information either in a effort to restore a radio to working condition,
or to collect archival information.
Philco-Packard Deluxe, 7-Tube Superhet Car Radio
(Iron-core I.F.Ts.; both volume and sensitivity controls; automatic tone compensation;
manual tone control: non-polarized "A" leads.)
A fully-charged heavy-duty battery must be used when attempting to align this set.An output
meter is connected to the output tube, V6, by means of an adapter. The trimmers are very carefully
adjusted at the factory and ordinarily no adjustment is needed.
When the receiver is adjusted while installed in the car, the regular car antenna should
be connected and a wire run from the service oscillator close to, but not connected with the
lead-in. In this manner the R.F. stage may be adjusted under conditions of actual operation.
When working on the I.F. amplifier, the service oscillator should be connected to the grid
cap of V3 and then V2 through a 0. 1-mf. condenser. The same condenser is used for R.F. alignment.
High-frequency adjustment is made at 1.500 kc. with the plates of the tuning condenser all
the way out. A piece of thin paper is placed between the rotor and stator plates and the former
turned out until they come to the paper. Alignment at this position of the plates will give
the true setting for 150 on the dial. Low-frequency adjustment is made with the dial turned
to 580 kc. Alignment of the R. F. stage is made with the service oscillator connected in series
with a 00.1-mf. condenser, a 200 mmf. condenser and the antenna lead of the receiver. The
alignment frequency is 1,400 kc. This completes the receiver adjustments.
The color code of the I.F. transformers is as follows: Plate, white "B", red; grid, lead
from top; grid-return, green. Replacements must be made with a complete new unit, since parts
are not furnished separately.
There are no voltages given for this set, since the maker feels that, due to wide variation
in battery voltage, any receiver voltages would tend to be misleading.
Note the use of a sensitivity control, which is needed because of the high gain of the
receiver.
The output operates in class B.
Posted May 18, 2015
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 227 Radio Service Data Sheets as of
December 28, 2020.
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 World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while typing up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
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