jaypolicow@snet.net <jaypolicow@...>
Gary, Thanks for posting this...I've got to tear into mine now! It seems to work quite well but I like to be sure all my radios are at their very best when possible. Jay http://radiojayallen.com
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--- In ultralightdx@..., D1028Gary@... wrote: 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@.../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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