Alignment Instructions for the Sony SRF-59 Analog Radio Family


Gary DeBock
 

Hello All,

The Sony SRF-59 was the radio that kicked off the original Ultralight
Radio boom in late 2007, and this model's popular variants (the
SRF-39FP "Prison Radio," the SRF-29, SRF-39 and SRF-49) have also
provided a lot of exciting DX for our members. The idea that a $16
portable radio was capable of receiving multiple TP stations across the
Pacific (594-JOAK, 747-JOIB and 972-HLCA) was enough to cause a
stampede of SRF-59 buyers to arise in December of 2007, depleting even
the stock of sellers like Amazon.com.

Unfortunately the SRF-59's DXing performance proved to be directly
related to its AM-RF alignment, which was rarely optimum. Sony's
Chinese factories were simply cutting too many corners in peaking the
AM sensitivity on this popular model, and North American DXers were
paying the price. After performing many free SRF-59 AM alignments for
Ultralightdx members I wrote up detailed procedures for AM alignment of
this radio, and posted them in January of 2008. The procedures are also
applicable for the SRF-39FP and other members of this analog family,
although the plastic, movable dial pointers in various models differ
somewhat. For those with confidence in performing the AM alignment
procedure (along with good eyesight and steady nerves) the procedures
are pasted below. Thanks to Mr. Gil of Phoeniz, AZ, who recently
aligned his SRF-39 using these procedures, and reminded me of the link
(while enjoying a great boost in his radio's AM sensitivity). From
January of 2008
(http://www.mail-archive.com/irca@hard-core-dx.com/msg21040.html ) the
following procedures are reprinted:

Hello All,

The recent availability of the Sony SRF-PSY03 Service Manual
(which has
circuitry identical to that of the SRF-59) has given us the ability to
turn
total turkey units into screaming DX birds of prey!

After performing seven of these full alignments, and seeing all
seven
units operating at peak sensitivity and DX effectiveness, it is
certain to me
that the procedure is worth the somewhat tedious necessity of
disassembly and
reassembly of the tiny little radio. Unfortunately, however, this
process
does require good eyesight, patience, steady nerves, and confidence.
The
SRF-59 is not a Heathkit, and was certainly not designed for
user-friendly
disassembly, or reassembly. Understand that despite these simplified
instructions, this little unit is still quite capable of sending
beginners to
the shrink.
Proceed at your own risk!

1) Turn off radio. Remove belt clip, headphones and battery.
2) Turn AM-FM switch to AM.
3) Without forcing, tune dial needle to far left stop (530).
4) Carefully note the exact position of the dial needle at this point.
(This is EXTREMELY important for proper dial reassembly!)
5) Remove the two screws from back panel. This will accomplish
absolutely nothing in making the panels separate.
6) Repeat to yourself, "This radio only cost 15 bucks."
7) Place thumbnail in slot between front and back panels at the
bottom edge of the radio. Work thumbnail in slot repeatedly,
carefully separating the front and back panels at the bottom
edge, first at the left side, then the right. This process may
require several minutes. Do NOT use tools!
8) After bottom edge of radio has significant separation between
front and back panels, slowly work up the left and right side
of the radio, to increase the separation. Gently rock the
front panel back and forth horizontally to increase the
separation, WITHOUT any forcing. Do NOT use tools!
9) When proper separation has been achieved between front and
back panels, the top edge may be separated by gently lifting
front panel circular plastic surrounding the headphone jack,
which will complete the separation of front and back panels.
At this point, the back panel may or may not break off from
the circuit board, but it is certain that the dial needle's
plastic gear will fall out of its front panel slot, making you
think that the radio is destroyed. Repeat Step #6 above.
10) Remove back panel from circuit board, if not already removed
(simply pull apart the small spot of glue).
11) Attach battery to contact spring (negative) and clip (positive).
Tape may be helpful in keeping in the contacts in place.
12) Turn on radio (center left switch on circuit board), and plug in
headphones.
13) An RF signal generator is required to verify frequency
coverage from 520-1750 kHz. If you do not have one, at
least verify coverage from 530-1700 kHz by checking
received stations close to these border frequencies.
14) If an RF signal generator is available, set it to 520 kHz,
turn the radio's tuner fully CCW, and peak L3 (the
red-slugged can close to the loop stick) with a non-
metallic (plastic or wood) flat-bladed alignment tool
to obtain loudest headphone volume of the carrier.
15) If an RF signal generator is available, set it to 1750 kHz,
set the radio's tuner fully CW, turn the circuit board over,
and peak CT1 (3/4) (the upper right trimming capacitor
on the tuner) to obtain loudest headphone volume of the
carrier. This is a sensitive adjustment.
NOTE: The frequency coverage has been perfectly
set on all seven units as received from the factory, so
lack of a signal generator is not a serious problem.
16) Turn the circuit board over, and use a very small flat-
bladed screwdriver to carefully scrape away all the wax
bonding the smaller loop stick coil (the one closest to
the tuner) to the ferrite bar. Clear a slide path on both
sides of the coil at least .25 inch long, free of wax, for
the next step. Verify freedom of coil to slide either way.
17) Set RF signal generator to 600 kHz, and set radio tuner
near 600 kHz (or, if RFsignal generator is not available,
use a live WEAK signal near 600 kHz for the next step).
18) Tune in RF signal generator signal, or the weak live signal
on or near 600 kHz. Carefully slide coil along ferrite bar
with a NON-metallic (wood, plastic) probe to peak the
received signal. Perform this step repeatedly to find the
exact spot of strongest, clearest audio (NOTE: This step
is the one most important to improve factory-unit
sensitivity).
19) Secure the small coil to this spot with a piece of tape, or
small spot of woodworking glue.
20) Turn circuit board over. Set signal generator to 1400 kHz,
and set radio tuner to near 1400 ( or, if RF signal
generator is not available, use a live WEAK signal near
1400 for the next step).
21) Tune in RF signal generator signal, or live weak signal
near 1400. Carefully peak CT1 (4/4) (the upper left
trimming capacitor on the tuner) for maximum clear
audio signal.
22) Turn off radio, unplug headphones, disconnect battery.
23) Restore tuner to maximum CCW position, and reinstall
orange plastic dial linkage in front-panel slot. As viewed
from front, place dial needle in the EXACT spot noted in
Step #4 above (this is EXTREMELY important!)
24) Slowly slide circuit board headphone jack under top
edge of front panel, and very carefully work the circuit
board into position adjacent to front panel. Ensure that
battery clips do not bind.
25) Carefully check tuner for bind-free operation. If tuner
binds, or if tuner frequency does not match the dial,
the circuit board must be removed and dial linkage
repositioned for correction (this is the trickiest step
in the alignment).
26) If tuner operation is smooth and frequencies match, you
have just guaranteed yourself success in this extremely
rough alignment! Congratulate yourself repeatedly!
27) Carefully reinstall back panel by sliding top edge under
top edge of front panel, and very gently (without forcing)
snap into place, observing slots along sides and bottom.
28) Reinstall two back screws, battery, headphones, and
belt clip.
29) Turn on radio. Log tons of DX. Call yourself a champion!


73 and Good DX,

Gary DeBock

SRF-59 Tech Trio Junior Member

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