How can I adjust the speed of the tape deck on my Becker BE1480?
I had the radio out today to take look indside. I couldn't find anything that looked accessible. Granted, I really have no experience with electronics so I only dissembled to the point where I was sure I could assemble again. I
I haven't been able to find any resources on this online so any help/comments are much appreciated.
I had the radio out today to take look indside. I couldn't find anything that looked accessible. Granted, I really have no experience with electronics so I only dissembled to the point where I was sure I could assemble again. I
I haven't been able to find any resources on this online so any help/comments are much appreciated.
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![IMG_0234[1].jpg](/community/data/attachments/470/470842-367722b35c027f0a0831f41a9e3f76c0.jpg?hash=Nncis1wCfw)
Its possible it may not be adjustable. As weird as it sounds, some motors have a mechanical governor that relies on centrifugal force and tiny weights. A good giveaway is that these type of motor usually have terrific torque compared to electronically regulated.
https://www.youtube.com/watch?v=yUT512DW8pg
https://www.youtube.com/watch?v=yUT512DW8pg
Is the pot near where the wires for the motor go into the board the adjustment?
Is the speed steady but fast and consistent for both directions?
Is the speed steady but fast and consistent for both directions?
It plays very consistently slow in both directions. This would suggest to me that the motor does not feature a governor. I'd reason that the speed would fluctuate if the governor was not working properly.
I did not try the small pot. Seemed to me that the wires from the motor was wedged in too close. However, looking at it again I'll just take them up and try the pot.
I did not try the small pot. Seemed to me that the wires from the motor was wedged in too close. However, looking at it again I'll just take them up and try the pot.
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![IMG_0235[1].jpg](/community/data/attachments/471/471381-82fddd8eb4c89045aa50d62ea103d0fe.jpg?hash=gv3djrTIkE)
That is a much better picture. Are there four wires to the motor ? If so then it may have an internal tacho generator which the motor drive circuitry uses to compare the tachos's frequency to a fixed oscillator... and alters the motor drive to keep the two constant.
Try Perrys suggestion first, but unless its just a dead spot on the pot then it sounds like something is amiss. In the first instance you need to check that the mechanics are free and that the motor turns freely.
Try Perrys suggestion first, but unless its just a dead spot on the pot then it sounds like something is amiss. In the first instance you need to check that the mechanics are free and that the motor turns freely.
Yes 4 wires. There are red and black wires that go directly to the motor and two green wires that go beneath the motor.
I tried the pot, but with no change in speed. Seems to me that it is not a pot, but it's only keeping the motor wires in place. It simply screwed right off.
Am I out of options here?
I tried the pot, but with no change in speed. Seems to me that it is not a pot, but it's only keeping the motor wires in place. It simply screwed right off.
Am I out of options here?
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![IMG_0250[1].jpg](/community/data/attachments/472/472104-82ad01cb1cadd94d241682713c17759e.jpg?hash=gq0Byxyt2U)
![IMG_0255[1].jpg](/community/data/attachments/472/472116-d295766b1ea8c15d6fdbe3718ab5e024.jpg?hash=0pV2ax6owV)
![IMG_0237[1].jpg](/community/data/attachments/472/472133-173c348ae124863639ec23ea8cec48f9.jpg?hash=Fzw0iuEkhj)
There are 3 pots along the top of the board. Is that what you turned?
I only have one becker manual. It's not likely exactly the same as yours but it appears to be similar. The following is a scan of the cassette deck board. You'll need to view it full size to read the text.
http://www.bcae1.com/temp/becker01b.png
This is the datasheet for the motor regulator:
http://datasheet.octopart.com/TDA1151-Philips-datasheet-106463.pdf
I only have one becker manual. It's not likely exactly the same as yours but it appears to be similar. The following is a scan of the cassette deck board. You'll need to view it full size to read the text.
http://www.bcae1.com/temp/becker01b.png
This is the datasheet for the motor regulator:
http://datasheet.octopart.com/TDA1151-Philips-datasheet-106463.pdf
Ahh I see.. What I was turning yesterday (red arrow) was not the pot. Kinda looked like one to me.
The pot is at the pink arrow, correct? And from what I can gather from the board diagram this should be the one adjusting the speed.. Guess I'll find out soon enough 🙂 Do I need to be very sensitive with these?
Thank you so much for the help.
The pot is at the pink arrow, correct? And from what I can gather from the board diagram this should be the one adjusting the speed.. Guess I'll find out soon enough 🙂 Do I need to be very sensitive with these?
Thank you so much for the help.
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Yes. That's the pot. I think you may have turned the head azimuth screw.
Those pots are a bit fragile but if you use a small screwdriver, you should be OK. You may need to use an insulated screwdriver if simply touching the pot makes the speed change.
Those pots are a bit fragile but if you use a small screwdriver, you should be OK. You may need to use an insulated screwdriver if simply touching the pot makes the speed change.
Success! Bob Dylan sounds normal again. Thanks a lot for the comments!
Is the pot limited to a certain range? It would only go to where the tape speed was normal. I would've expected that I could have sped up the tape even more..
I might have been just a little rough on the head azimuth screw. If I messed something up with this, is there anything I should be looking/hearing for?
Is the pot limited to a certain range? It would only go to where the tape speed was normal. I would've expected that I could have sped up the tape even more..
I might have been just a little rough on the head azimuth screw. If I messed something up with this, is there anything I should be looking/hearing for?
I don't know what range the pot gives.
If the head azimuth is off, the high frequencies will be muted. When I get back to the shop, I'll see if the manual shows what that screw/adjustment does.
If the head azimuth is off, the high frequencies will be muted. When I get back to the shop, I'll see if the manual shows what that screw/adjustment does.
A well designed circuit would typically allow control above and below the correct operating point, so the fact the pot is as one ended as you suggest seems to point to something being amiss somewhere.
You would need to study the circuit diagram closely and check that any supplies to the motor and its control circuit were correct. The components that determine the 'reference frequency' that the circuits oscillator runs at and that the motors tacho generator is compared to should be looked at closely too. One of those will probably be the pot you are adjusting, the other a small capacitor.
When something develops a problem and the alignment suddenly seems miles out then there has to be a reason... something has altered or changed.
You would need to study the circuit diagram closely and check that any supplies to the motor and its control circuit were correct. The components that determine the 'reference frequency' that the circuits oscillator runs at and that the motors tacho generator is compared to should be looked at closely too. One of those will probably be the pot you are adjusting, the other a small capacitor.
When something develops a problem and the alignment suddenly seems miles out then there has to be a reason... something has altered or changed.
When I started the car the other day at about 26 F it ran slow again. I waited for a couple of minutes and then I ran close to normal. There is still some wow and flutter present though. The tape deck was running slow when I bought the car earlier this year. So it could have been slow for years.
Is it safe then to assume that the problem is at a faulty capacitor?
Is it safe then to assume that the problem is at a faulty capacitor?
If this is the same as the diagram I posted, this is a simple two wire motor with no internal regulator. The external regulation has no feedback. The speed is set and the system relies in the assumption that the load will always be the same to have good speed control (for the motor).
The taps transport relies on a lot of other things to allow good speed control. Things that can cause wow and flutter.
* worn or hard pinch rollers don't keep the tape against the capstans and may not make contact with the capstans to ensure that the rollers pull the tape through at the right speed. They can also make the tape ride up or down as it passes between the capstans and pinch roller.
* Dried lubrication in the bearings for the capstans can cause speed problems. If the bearings are worn, the deck isn't likely salvageable unless the bearings are available from becker.
* a bad belt can cause wow and flutter as well as speed issues
* bad take-up reels can cause wow and flutter, especially if the adhesive holding the felt has bled onto the friction surface of the clutch.
The taps transport relies on a lot of other things to allow good speed control. Things that can cause wow and flutter.
* worn or hard pinch rollers don't keep the tape against the capstans and may not make contact with the capstans to ensure that the rollers pull the tape through at the right speed. They can also make the tape ride up or down as it passes between the capstans and pinch roller.
* Dried lubrication in the bearings for the capstans can cause speed problems. If the bearings are worn, the deck isn't likely salvageable unless the bearings are available from becker.
* a bad belt can cause wow and flutter as well as speed issues
* bad take-up reels can cause wow and flutter, especially if the adhesive holding the felt has bled onto the friction surface of the clutch.
One in a list of possibilities if the motor is an FG (frequency generator) tacho type.
Lets be absolutely sure on this. Do the two green wires enter the motor casing or do they go somewhere else ? That one thing determines the type of motor this is.
The green wires do not enter the motor. Parts do not seem to be available from Becker. But I can replace pinch rollers and belt, correct? What kind of lubrication should I use for the capstan bearings?
Oil suitable for sintered phosphor bronze bearings is the usual stuff to use although in practice any light oil should be fine.
If the motor is just a two wire then that does point to the regulator being a simple back emf sensing type which was common in the majority of cheap to mid price cassette decks of the 80's and 90's. In this case the regulator is mounted off the motor.
Often a standard size with 2400rpm rotational speed they were fairly universal, you just fitted the appropriate voltage motor (6, 9 or 12) and CW or CCW rotation. The speed regulator was adjustable via a little preset at the back of the motor. They use to cost peanuts but don't seem generally available now.
If the motor is just a two wire then that does point to the regulator being a simple back emf sensing type which was common in the majority of cheap to mid price cassette decks of the 80's and 90's. In this case the regulator is mounted off the motor.
Often a standard size with 2400rpm rotational speed they were fairly universal, you just fitted the appropriate voltage motor (6, 9 or 12) and CW or CCW rotation. The speed regulator was adjustable via a little preset at the back of the motor. They use to cost peanuts but don't seem generally available now.
The capstans face downward so you'll need to use a grease. Something like white lithium grease should be OK. You'll need to remove all of the old lubricant both inside the bearing and from the capstans.
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