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 Radio Service
Data Sheet covers the Philco Model 59, 4-tube AC Midget superheterodyne receiver. Most - if not all
- electronics servicemen had subscriptions to these magazines because they were a ready source of not
just these service sheets, but because of the extensive articles offering advice on servicing radios
and televisions. In fact, many electronics manufacturers had a policy of supplying service data only
to bona fide shops. A large list is included at the bottom of the page of similar documents from vintage
receiver schematics, troubleshooting tips, and alignment procedures. They were originally published
in magazines like Radio-Craft, Radio and Television News, Radio News, etc.
I scan and post them for the benefit of hobbyists who restore and service vintage electronics equipment.
Philco Model 59, 4-Tube A.C. Midget Superheterodyne Receiver Radio Service Data Sheet
(Broadcast band; police calls on lowest band; high sensitivity; high power output for its size.)
This midget superheterodyne operates only on 105-125 V. A.C. Total power consumption is 52 W. When
tuning the set, use an accurate signal generator. To adjust I.F.T., remove cap lead of VI and attach
generator lead in its place. Set volume control at full-on position and receiver dial at 600, and set
C1 and C2 for maximum output. Next replace cap on VI, and set receiver tuning dial so that condenser
plates are just starting to mesh. Set signal generator at 1,400 kc. and tune in the signal by means
of condensers C3 and C4. Replace the dial pointer in the proper position. An output meter should be
attached to the primary of the output transformer.
The final adjustment must be made with the sensitivity control condenser, C5. With the set connected
to an antenna, tune in a station at about 130 on the dial. With a screwdriver, turn the small fibre
hex-head screw which is located at the back of the chassis directly below the antenna and ground terminals.
until the set squeals (circuit oscillates). Then turn the hex-screw 1/4 -turn back until the oscillation
stops. Tune in other stations at all parts of the dial to make certain that there is no squeal or oscillation
at any point. If the tube V2 is replaced it will be necessary to readjust condenser C5.
Voltages are given in the following table:
Above voltages are taken with a line supply voltage of 115 V. They should be taken from the underside
of the chassis using test prods and a suitable A.C. voltmeter for the filaments and a high-resistance,
multi-range D.C. instrument for all other readings. The volume control is set at maximum and the station
selector at the low-frequency end of the band. Readings taken with a plug-in adapter will not be satisfactory.
The following table gives the color code of the power transformer:
Posted June 17, 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
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