Pagoda SL Group
W113 Pagoda SL Group => Electrical and Instruments => Topic started by: Larry & Norma on September 04, 2014, 11:31:23
-
Anybody got a circuit diagram etc for a Becker Mexico TR please
-
I used this to repair mine. hope it helps :)
-
Thanks Andy that looks like the one.
Trying to figure how the self tuning mechanism works,
it's a work of art!
-
I certainly agree with you there. I went to the ends of the earth to get mine back and functioning and am so happy I did. To many of these beautiful pieces are either removed and replaced with modern monstrosities or are just left in place to fill a gap.
-
Andy does it only self tune from the left hand end of the scale?
-
Andy does it only self tune from the left hand end of the scale?
Larry,
Yes! ;)
All old mechancal Becker units with automatic tunig (station seeker) only go unidirectional from low to high frequencey numbers, i.e. from left to right.
Only the more modern electronic units (black, 80ies and thereafter) can seek bidirectional.
:)
Achim
(GP stereo collector)
-
Larry,
what is wrong with yours? If the automatic tuning bar does not work perhaps try this: manually tune the radio that the pointer is all the way to the left as far as it will go and then push the automatic tuning bar.
See: http://www.sl113.org/forums/index.php?topic=20316
Andy, is your schematic for a Mexico TR with auto tuning bar? I believe those came after model Nr. 305282
-
Alfred, the diagram is correct for mine which is probably the very first of the Transistorized units complete with a separate amp. Becker after a few years managed to miniaturize everything into one chassis. It was still called the Becker Mexico TR but probably had a different model number.
-
Thanks Andy.
I am really not familiar with these Becker Mexico models, I was just wondering whether the model bar on yours also serves as an automatic tuning bar, as it does on the Becker GrandPrix radios.
At least some Becker Mexico radios before they became transistorized appaerently had this function. This video claims that in 1953 the Becker Mexico was the first radio with this feature:
http://www.youtube.com/watch?v=qFKUglmhBuw
-
Alfred, it certainly does. The most wonderful feature on these old girls. Would have been quite the marvel in the day. If you want to see mine in operation take a look at this short clip. Note that some of the features demonstrated are not factory, but the auto tuning is.
https://www.youtube.com/watch?v=pqFt0jneYR4
-
Thanks guys, I had sort of worked out it only auto-tuned from one end but wanted to
confirm it.
Alfred I have just acquired the radio and have no history on it.
Needed a good clean and lube of mechanics, auto-tune now does something but
sometimes stops and the current draw shoots up?
Also volume is very low, I think the separate amp is ok as some of the crackles are really loud
when I change waveband etc.
What does the switch under the tuning knob do?
Thanks
-
Hi Larry, the lever on the same spindle as the tuning knob is a sensitivity setting for the automatic tuning I think. There are only two settings on mine. Whatever you do resist the temptation to spray the internals with WD40. It may work in the short term but will over time attract dust and eventually clog up the mechanism.
-
Thanks Andy, I have used some light oil, some contact cleaner and some white grease.
The volume problem seems to be bad contacts in the wavechange buttons, if I exert pressure on
the FM button then the volume is nice and loud. They do not look easy to take out and clean!
What does the big solenoid thing do? Does it push or pull?
Thanks
-
The volume problem is definitely two contacts on the FM wave change switch.
To get to it would involve complete strip down of the radio I think.
I could solder a link on the switch to make the contact as the radio will only ever be used on FM?
Still got the high current at times to solve.
-
My Becker Pinstripes with auto tune go in both directions when they function properly, which is seldom. The earlier ones are more mechanical, the later ones are more of an electronic contact switch, but we are still talking about pinstripe Beckers... What a pain the ass to get working right.
-
After studying the circuit and hardware I think the radio should:-
a) Pressing and releasing the self tune bar causes the radio to seek from left of scale to right.
b) Whilst seeking output is muted.
c) On reaching a signal of sufficient amplitude seeking stops and output is switched back on.
d) On seeking to fully right position the pointer will move automatically back to left extreme of scale
and start seeking again.
Is this correct please?
Thanks
-
Yes, that is exactly how it works when operating properly.
Hans
-
Thanks Hans :) :)
-
My Becker Pinstripes with auto tune go in both directions when they function properly, which is seldom. The earlier ones are more mechanical, the later ones are more of an electronic contact switch, but we are still talking about pinstripe Beckers... What a pain the ass to get working right.
Scott which one of your different models specifically go in both directions? Becker Mexicos?
According to Becker Autosound among the Grand Prix models only the TG does:
The early Grand Prix TG(1962-1965) had dual direction sig seek. All other Grand prixs had single direction.
-
Scott which one of your different models specifically go in both directions? Becker Mexicos?
According to Becker Autosound among the Grand Prix models only the TG does:
The early Grand Prix TG(1962-1965) had dual direction sig seek. All other Grand prixs had single direction.
I'm not positive, nor am I at home. My recollection is that my early Grand Prix TG seeks in both directions and is very mechanical in nature. My other seek radios are later Grand Prix and Mexico radios which I thought seek in both directions but it might be one direction and then full return to the left and start again. I have such trouble with the see function on the Mexico that it's almost better to disable it (removing the wire from the push bar) so it doesn't blow the fuse. When seek doesn't work, it basically blows a fuse if you have an in-line fuse.
I would like to know how to fix the seek function but I'm 100% confident that BeckerNJ isn't going to help with that as my observation is that they are interested in you sending them a radio to restore and no longer are interested in providing help or even parts support.
-
If it is any help the seek from left to right is powered by a spring which is tensioned when the pointer
is moved from right to left either manually or by the solenoid action. The solenoid is energised when the
pointer reaches the fully right position when auto seek is in operation. It is this solenoid which draws
high current and blows fuses.
The solenoid when energised pulls the pointer all the way to the left against the spring etc. It has a lot
of work to do.
There are no motors in the early auto seek radios.