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...
All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
Sometimes finding an existing instance
of one of the vintage radios is difficult or impossible. The RCA Victor Model 54Bx
portables are an exception. Plenty can be found for purchase on
eBay as this is written, as was a 54B1, 54B3, and a 54B4. I did a capture of
some of the listing images for a
Model 54B2, and had Archive.org story a copy for once the eBay site deletes
it. In the internal photos, all four miniature vacuum tubes (3S4,
1T4) can be clearly
seen. Note also in the photos you can see where, per the alignment procedure, rubber
bands have been place around the tubes in order to keep them from moving. The extremely
cramped space required particular attention to the routing of interconnect wires.
Note how much room the 67.5 V, "B" battery needs.
RCA Victor Models 54B1, 54B-N, 54B2, 54B3 Radio Data Sheet 335
RCA Victor Model 54B2
Model 54B2 was on eBay at the time of this posting.
Frequency Range 550-1,600 kc. Intermediate Frequency 455 kc.
Test Oscillator - Connect test oscillator as indicated in chart, keeping the
output as low as possible to avoid a.v.c. action.
Output Meter - Connect meter from top lug of TB1 (plate of 354) to ground. Turn
volume control to maximum position.
*Steps 3, 4 and 5, shown in alignment table, require a coupling loop from the
signal generator to feed a signal into the receiver loop located in the lid. This
loop should be approximately one turn of 6 x 3? inches coupled to the signal generator
through a 200 μμf capacitor, and loosely coupled to the receiver loop antenna at
about 1? inches distance, so as not to disturb the receiver loop inductance. Ground
test oscillator through 0.1 mf. capacitor to receiver chassis.
Critical Lead Dress
1. Dress blue, green and black leads of second i.f. transformer as direct as
possible. If excess lead exists, dress down side of socket and flat as possible
against chassis to transformer opening.
2. Cross the green and the black leads inside the first i.f. transformer can,
keeping the green lead to the outside. Keep the blue and the green leads separated
as far as possible throughout their length.
3. Dress audio coupling capacitor (C14, .002 uf.) and the lead to the volume
control up and underneath the shelf supporting the output transformer.
4. Dress the three capacitors pyramided behind the speaker, parallel to the complete
assembly and with enough room behind the battery holder to allow the holder to move
when a battery is installed or removed.
5. Dress the "B" battery leads behind the gang frame and over the top of the
6. Observe the outside foil connections on all paper capacitors, also the polarity
of the electrolytic capacitor (C17).
7. Keep blue and red leads of output transformer above the mounting shelf.
Note: Do not install "A" battery without cardboard cover.
A rubber band should be placed around each one of the tubes for cushioning.
Posted May 7, 2021
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.