Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
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.
A Google search for a photo of the Fada Model 190 only turned up this magazine advertisement
that appeared on the RadioMuseum.org website.
Fada 9 Tube Model 190 "Metal" All-Wave Receiver
(Four bands; covers 540 kc. to 24 mc. with no skips;
noise suppression; automatic tone regulator; delayed A.V.C.; push-pull output with 6 watts
power; 9 metal tubes; triple tuned I.F. coils.)
I.F. Adjustments
"First, disconnect the outside antenna system from the receiver. Second, disconnect the
control-grid lead from the 6A8 tube. Third, connect the high-potential lead of the signal
generator to the control-grid of the 6A8 tube, and the low-potential side to the receiver
"ground" lead'. Fourth, place an output meter (copper-oxide type) across the speaker voice-coil.
Fifth, place the signal generator in operation and adjust the carrier output to 456 kc.
Adjustment of S.-W. Band "A" Shunt Condensers
The compensators are located as indicated in the sketch. (A) Remove the signal generator
connection from the control-grid of the 6A8 tube and replace the control-grid lead. (B) Connect
the antenna wire of the receiver chassis through a 400 ohm carbon resistor to the high-potential
side of the signal generator. Adjust the carrier output of the signal generator to 20 mc.
(C) Turn the wave-band selector switch to band "A," left. Set the calibrated dial of the receiver
to read 20 mc. (D) Adjust the S.-W. band "A" oscillator shunt compensator for maximum signal
output. (E) Having determined the peak, and maximum setting for the S.-W. band "At oscillator
shunt condenser, adjust the S.-W. band "A" R.F. stage shunt condenser and the S.W. band "A"
detector shunt condenser for maximum signal output. Turn the receiver - dial to the image
point (20.9 mc.) to determine that both condensers have been adjusted to the correct peak.
(F) Adjust the carrier frequency output of the signal generator to 10 mc. (G) Turn the calibrated
dial of the receiver to pick up this 10 mc. signal and check for sensitivity at this point.
There is no variable oscillator series condenser at this frequency.
Posted August 24, 2017
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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and text used on the RF Cafe website are hereby acknowledged.
