Thanks for pitching in. I dunno why it's off, it's already beyond my knowledge. Maybe due to it's age? The thing is more than 30 years old. Toying with the T11 is intriguing idea but I think I better live with the error and treat it as a collectible. As you said it's too much of a PITA.

Frank於 2018年8月3日星期五 UTC+8下�11時40分09秒寫�：
On Wed, 01 Aug 2018 22:26:27 -0700, Fotopiggie wrote:

Thanks but that's Sw7600's manual. Mine is a ICF-7600D, an older model.
I
actually have got the service manual but I don't have the proper gears
like a RF generator to do the job. Better find someone else to do it.....

Or buy another one and keep your current one for parts. Or just live
with the error. The cost of getting a qualified tech to even diagnose
the radio might exceed the cost of a good used radio.

The only thing I can see that looks like a screwdriver adjustment to
change the radio's frequency is T 11, the AM 2nd IF VCXO adjustment.
It's a crystal oscillator at 55.395 Mhz. Could T11 pull the crystal
oscillator 5 MHz? That's more than I'd expect but I dunno. Anyway, why
would it be off? These things should hold their adjustment within a
small range indefinitely.

If you want to try your luck, try pressing around the circuit board with
the plastic part of a stick pen or some other nonconductor like that. If
the display corrects itself, you probably have found a bad solder
connection.

Otherwise, it's probably too much of a PITA to make it work perfectly
again.

I have newer Tecsun and Grundig. They definitely perform better than the old Sony. I'm just very into that 80s Sony industrial design so that's why I'm keeping it. I want to fix it since the sound comes out from it is warmer and fuller, compared to my newer radios.


æ–¼ 2018å¹´8月4日星期å…* UTC+8上å�ˆ1時49分43秒寫é�“：
On Friday, August 3, 2018 at 8:40:09 AM UTC-7, Frank wrote:
Or buy another one and keep your current one for parts....
I had one, and in the 1980s, it was a technological marvel. One downside (also mentioned in a WRTH review) is that it is a terrible battery-eater. If you get a different radio, I would opt for one of the newer 7600 variants or something from Sangean or Grundig; they will have more memories and the batteries will last a little longer.

Join the ICF 2010 group .)and ask
this question. There is a way I just can't recall it.
Chuck

Fotopiggie wrote:
No idea if it's's like that while it was new. I got it from ebay some years ago but didn't play with it seriously until recently. FYI this is the correct manual:

http://diagramasde.com/diagramas/otr...e%20Manual.pdf

So is there a chance to fix it? Thanks



於 2018年8月2日星期四 UTC+8下�9時30分28秒寫�：
On Wednesday, August 1, 2018 at 10:21:54 PM UTC-7, Fotopiggie wrote:
Thanks for the response. Yes it's consistently roughly
5 kHz below the designated frequency. For example if I
want to tune in 11815 kHz I need to key in 11810 kHz to
hear the signal (not perfect, still need tune up a bit
with fine tuning dial) I don't know the exact amount of
the frequency off as you may know the radio tuning is
in a 5 kHz step.
So if IF alignment is the case I don't think I can
handle the job. May need to find a technician to do the
job...
Was it like then it was new? If so, it may be a manufacturing error. IF filtering is often done with ceramic resonators, and if they used 450 kHz instead of 455 kHz (or vice versa), that could explain it. It is unlikely that it would have spontaneously shifted frequency. I tried to look at the circuit diagram that Frank cited, but my eyes are too old and the my monitor resolution is too poor for me to read it.

Thanks!

ka6uup於 2018年8月5日星期日 UTC+8下�9時09分13秒寫�：
Join the ICF 2010 group .)and ask
this question. There is a way I just can't recall it.
Chuck

Fotopiggie wrote:
No idea if it's's like that while it was new. I got it from ebay some years ago but didn't play with it seriously until recently. FYI this is the correct manual:

http://diagramasde.com/diagramas/otr...e%20Manual.pdf

So is there a chance to fix it? Thanks



於 2018年8月2日星期四 UTC+8下�9時30分28秒寫�：
On Wednesday, August 1, 2018 at 10:21:54 PM UTC-7, Fotopiggie wrote:
Thanks for the response. Yes it's consistently roughly
5 kHz below the designated frequency. For example if I
want to tune in 11815 kHz I need to key in 11810 kHz to
hear the signal (not perfect, still need tune up a bit
with fine tuning dial) I don't know the exact amount of
the frequency off as you may know the radio tuning is
in a 5 kHz step.
So if IF alignment is the case I don't think I can
handle the job. May need to find a technician to do the
job...
Was it like then it was new? If so, it may be a manufacturing error. IF filtering is often done with ceramic resonators, and if they used 450 kHz instead of 455 kHz (or vice versa), that could explain it. It is unlikely that it would have spontaneously shifted frequency. I tried to look at the circuit diagram that Frank cited, but my eyes are too old and the my monitor resolution is too poor for me to read it.