Tandberg 2041 (series 2000) Erase Head Problem. - UK Vintage Radio Repair and Restoration Discussion Forum

scottie_UK · 8th Nov 2011, 12:10 am

Hello Folks, this is my first post here (first of many I expect).

I have a Tandberg 2041 and recently the erase head has began to malfunction. In the first instance just one channel would not be erased fully (R channel). I took a look at the erase head and saw that the conductors were not aligned with the tape, the bottom most one was lower than the tape. So I tuned the adjustment screws the move the position of the head so it is inline with the tape. Only now, erase does not work well on either channel. What should I do next? I'm guessing either the erase head is kaput, or that I have aligned it wrong.

scottie_UK · 8th Nov 2011, 1:24 am

This problem now seems to me more serious than I initally thought and the recorder now exhibits problems recording onto the L channel. However, I put a unimportant tape into the machine and noticed that when I pressed the tape gently against the record head I would hear the recorded sound though the playback head but it was not of good quality.

ricard · 8th Nov 2011, 8:36 am

Don't know what you mean by 'in line with the tape'; the uppermost pole piece of an erase head should extend over the top edge of the tape by a minute amount, something like 0.1mm to 0.25mm . The lower pole piece will cover the upper half of the bottom half of the tape, so you can't really use it for measurement.

The service manual for this machine can be found at

http://www.sportsbil.com/tandberg/2000-sm.pdf

which has diagrams showing how the head should be aligned. It is very unlikely that it would slip out of alignment so much as to cause insufficient erasure.

If erasure is failing and also record, I would check that the internal operating voltage is up to spec, if it starts to drop due to a bad voltage regulator for instance I would expect the erase voltage to go down and similar for the recording current.

scottie_UK · 8th Nov 2011, 10:02 pm

I can't seem to get the erase head to align with the tape properly, the height of the head is to low, and turning the three screws (L and K in fig 3.2) moves the head a little but not enough. You also get a guide because you can see on the head where the tape once was.

ricard · 9th Nov 2011, 9:01 am

It's not the spring underneath the head (which presses is up against the screws) has broken?

scottie_UK · 9th Nov 2011, 4:44 pm

I'll double check this. If this is the problem what is the remedy? How easy is it to get hold of replacements?

scottie_UK · 9th Nov 2011, 10:18 pm

Ok so further information. I have completely unscrewed the mounting plate for the erase heas and it appears there is and never was any spring underneath the head.

However, by lifting up the head and loosely placing it in what I believe to be the correct hight the erasing seems to work as I would expect. So this leaves the first action item

1) How can I raise the head when the screws will not allow it to go into the correct position. The plate which the head is affixed is sort of kite shaped with the left and right sides curling up underneath. (see picture below).

Secondly, I have noticed that the device does not record on the L channel. The VU meter shows sound is entering the device to a similar extent to the R channel. Could this be the position of the record head. I'd hate to move it, and potential cause further issues if there is a simple check I can do.

ricard · 10th Nov 2011, 6:51 am

The picture seems to be missing from your post.

I'll have to take a look on my 4000 to see exactly what it is supposed to look like.

If recording on the R channel works, then the record head is at least at the same height as the playback head, so assuming you can play back L and R from a known good tape, it shouldn't be necessary to adjust it. Does it look like the L (upper) pole piece is outside the tape? Perhaps a picture of the whole tape path with a tape in position could help us figure out what is wrong.

Heads never get this much out of alignment unless something is seriously wrong, or most likely someone has tried to fiddle with the adjustments without knowing what they are doing.

DOFFERY · 10th Nov 2011, 2:44 pm

Regarding your comment about the lack of a spring, the head plate itself which bends under is the head support spring. It sounds as if someone in the past has altered the tape path, without sight of the tape path as suggested we are working in the dark.
Colin.

scottie_UK · 10th Nov 2011, 9:36 pm

Yeah I realised I had missed the image but as far as I am aware I can not edit the posts yet. [edit]Oh now I can

[/edit]

Ok, here are the images. Though I think I have the erase heads working now. I fixed it by removing the spring plate and bending outwards slightly the curled metal pieces underneath. Quite why they went out I'll never know as when I purchased the machine 2 weeks ago the erase head appeared to work much better (it wasn't perfect though). Now there is no remnants of the previous recordings remaining.

What is still an issue however is recording only on the R channel.

http://www.scottieuk.plus.com/EraseHead1s.jpg
http://www.scottieuk.plus.com/EraseHead2s.jpg

ricard · 10th Nov 2011, 9:50 pm

Perhaps someone in the past has tightened the screws far too much, causing the integral support spring to bend permanently, loosing its spring function?

At any rate, the head height looks fine now (same for the record head incidentally).

Regarding loss of recording on the R channel, is there absolutely nothing on the tape, or is the recording just very weak and possibly also distorted?

Without doing some form of measurement it's very hard to know, it could be anything from a faulty record amplifier to a bad connection to an open winding in the record head.

scottie_UK · 10th Nov 2011, 10:14 pm

Ok tell me what tests to do. I have a modern digital multimeter to measure OHM, DVC, ACV, ACA, DCA and HFE.

Tractorfan · 10th Nov 2011, 10:26 pm

Hi,
I don't know this machine, but could it be something as simple as a dirty record/play switch? I've often found that this can cause all sorts of peculiar problems.
I have a Philips tape recorder and as well as the abovementioned record/play switch, the track selector switch required a good dose of cleaner as well.
Hope this helps.
apologies if I'm stating the obvious.
Cheers, Pete

scottie_UK · 10th Nov 2011, 10:44 pm

Ok further testing shows that when monitoring the recording via the playback head the right channel is quiet and muffled. When I press the back of the tape gently against the record head with my index finger the sound picks up.

If I turn the recording volume for that channel way up all I get is a quiet distorted sound. This would be expected I suppose as anything past a setting of 2 puts the vu meter in the red.

Could this be the position of the head or is this some other fault.

ben · 11th Nov 2011, 1:56 am

the second picture in post 10 shows some serious wear on that erase head.
if the others are similar condition-wise, then it is possible that one channel will drop out. usually the left (outermost tape track) is the first to go.

And yes, I have seen problems with the erase head mountings going floppy on some tandbergs of this era. I think you could fit rubber mountings or springs in lieu.

scottie_UK · 12th Nov 2011, 6:09 pm

Quote:

Originally Posted by ben

the second picture in post 10 shows some serious wear on that erase head.
if the others are similar condition-wise, then it is possible that one channel will drop out. usually the left (outermost tape track) is the first to go.

And yes, I have seen problems with the erase head mountings going floppy on some tandbergs of this era. I think you could fit rubber mountings or springs in lieu.

That maybe true, but how can I test my heads to see if there is no life left in them?

ben · 12th Nov 2011, 7:39 pm

generally, an experienced tech and a microscope will be able to get an idea on sight as to overall condition. You can tell by their sonic performance if they're past it or not.

scottie_UK · 12th Nov 2011, 7:57 pm

Quote:

Originally Posted by ben

generally, an experienced tech and a microscope will be able to get an idea on sight as to overall condition. You can tell by their sonic performance if they're past it or not.

My canon DSLR has an 18mp sensor. Would I be able to take a high definition photo of the head and post it up here?

Andrew.

scottie_UK · 12th Nov 2011, 9:02 pm

Ok here are 4 close up photos of the erase (left) and record (right) heads. There each from slightly different angles or have different camera settings, hopefully this may enable you to spot any tell tale signs.

http://www.scottieuk.plus.com/Rec-Play1.JPG

http://www.scottieuk.plus.com/Rec-Play2.JPG

http://www.scottieuk.plus.com/Rec-Play3.JPG

http://www.scottieuk.plus.com/Rec-Play4.JPG

DOFFERY · 13th Nov 2011, 8:45 am

Scottie,
It is rather difficult to see the faces of the heads to determine the state of same. However as you state you get a signal exerting some pressure on the head/s, check the reverse torque on the feed spool, there should be some slight backwards movement(check on pause) to retain the tape path. Also check the pressure pad on the bracket (erase head)is in contact & is "clean & not worn away, this contact also assists the tape path. As for the head/s alignment, difficult to tell from the pics. I have seen worse heads give a signal & your comment on applied pressure, points me to the above.

Difficult to be precise Scottie without sight of the head block but do ensure the heads , in particular the record head you mention is perfectly clean , sometime ingrained deposits require more than the cotton bud treatment, remember nothing abrasive or metal.

Colin.

8th Nov 2011, 12:10 am	#1
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Tandberg 2041 (series 2000) Erase Head Problem. Hello Folks, this is my first post here (first of many I expect). I have a Tandberg 2041 and recently the erase head has began to malfunction. In the first instance just one channel would not be erased fully (R channel). I took a look at the erase head and saw that the conductors were not aligned with the tape, the bottom most one was lower than the tape. So I tuned the adjustment screws the move the position of the head so it is inline with the tape. Only now, erase does not work well on either channel. What should I do next? I'm guessing either the erase head is kaput, or that I have aligned it wrong.

8th Nov 2011, 1:24 am	#2
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. This problem now seems to me more serious than I initally thought and the recorder now exhibits problems recording onto the L channel. However, I put a unimportant tape into the machine and noticed that when I pressed the tape gently against the record head I would hear the recorded sound though the playback head but it was not of good quality.

8th Nov 2011, 8:36 am	#3
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg 2041 (series 2000) Erase Head Problem. Don't know what you mean by 'in line with the tape'; the uppermost pole piece of an erase head should extend over the top edge of the tape by a minute amount, something like 0.1mm to 0.25mm . The lower pole piece will cover the upper half of the bottom half of the tape, so you can't really use it for measurement. The service manual for this machine can be found at http://www.sportsbil.com/tandberg/2000-sm.pdf which has diagrams showing how the head should be aligned. It is very unlikely that it would slip out of alignment so much as to cause insufficient erasure. If erasure is failing and also record, I would check that the internal operating voltage is up to spec, if it starts to drop due to a bad voltage regulator for instance I would expect the erase voltage to go down and similar for the recording current.

8th Nov 2011, 10:02 pm	#4
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. I can't seem to get the erase head to align with the tape properly, the height of the head is to low, and turning the three screws (L and K in fig 3.2) moves the head a little but not enough. You also get a guide because you can see on the head where the tape once was.

9th Nov 2011, 9:01 am	#5
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg 2041 (series 2000) Erase Head Problem. It's not the spring underneath the head (which presses is up against the screws) has broken?

9th Nov 2011, 4:44 pm	#6
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. I'll double check this. If this is the problem what is the remedy? How easy is it to get hold of replacements?

9th Nov 2011, 10:18 pm	#7
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. Ok so further information. I have completely unscrewed the mounting plate for the erase heas and it appears there is and never was any spring underneath the head. However, by lifting up the head and loosely placing it in what I believe to be the correct hight the erasing seems to work as I would expect. So this leaves the first action item 1) How can I raise the head when the screws will not allow it to go into the correct position. The plate which the head is affixed is sort of kite shaped with the left and right sides curling up underneath. (see picture below). Secondly, I have noticed that the device does not record on the L channel. The VU meter shows sound is entering the device to a similar extent to the R channel. Could this be the position of the record head. I'd hate to move it, and potential cause further issues if there is a simple check I can do.

10th Nov 2011, 6:51 am	#8
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg 2041 (series 2000) Erase Head Problem. The picture seems to be missing from your post. I'll have to take a look on my 4000 to see exactly what it is supposed to look like. If recording on the R channel works, then the record head is at least at the same height as the playback head, so assuming you can play back L and R from a known good tape, it shouldn't be necessary to adjust it. Does it look like the L (upper) pole piece is outside the tape? Perhaps a picture of the whole tape path with a tape in position could help us figure out what is wrong. Heads never get this much out of alignment unless something is seriously wrong, or most likely someone has tried to fiddle with the adjustments without knowing what they are doing.

10th Nov 2011, 2:44 pm	#9
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Tandberg 2041 (series 2000) Erase Head Problem. Regarding your comment about the lack of a spring, the head plate itself which bends under is the head support spring. It sounds as if someone in the past has altered the tape path, without sight of the tape path as suggested we are working in the dark. Colin.

10th Nov 2011, 9:36 pm	#10
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. Yeah I realised I had missed the image but as far as I am aware I can not edit the posts yet. [edit]Oh now I can [/edit] Ok, here are the images. Though I think I have the erase heads working now. I fixed it by removing the spring plate and bending outwards slightly the curled metal pieces underneath. Quite why they went out I'll never know as when I purchased the machine 2 weeks ago the erase head appeared to work much better (it wasn't perfect though). Now there is no remnants of the previous recordings remaining. What is still an issue however is recording only on the R channel. http://www.scottieuk.plus.com/EraseHead1s.jpg http://www.scottieuk.plus.com/EraseHead2s.jpg

10th Nov 2011, 9:50 pm	#11
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg 2041 (series 2000) Erase Head Problem. Perhaps someone in the past has tightened the screws far too much, causing the integral support spring to bend permanently, loosing its spring function? At any rate, the head height looks fine now (same for the record head incidentally). Regarding loss of recording on the R channel, is there absolutely nothing on the tape, or is the recording just very weak and possibly also distorted? Without doing some form of measurement it's very hard to know, it could be anything from a faulty record amplifier to a bad connection to an open winding in the record head.

10th Nov 2011, 10:14 pm	#12
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. Ok tell me what tests to do. I have a modern digital multimeter to measure OHM, DVC, ACV, ACA, DCA and HFE.

10th Nov 2011, 10:26 pm	#13
Tractorfan Dekatron Join Date: Mar 2008 Location: St. Frajou, l'Isle en Dodon, Haute Garonne, France.(Previously: Ellesmere Port, Cheshire, UK.) Posts: 3,183	Re: Tandberg 2041 (series 2000) Erase Head Problem. Hi, I don't know this machine, but could it be something as simple as a dirty record/play switch? I've often found that this can cause all sorts of peculiar problems. I have a Philips tape recorder and as well as the abovementioned record/play switch, the track selector switch required a good dose of cleaner as well. Hope this helps. apologies if I'm stating the obvious. Cheers, Pete __________________ "Hello?, Yes, I'm on the train, I might lose the signal soon as we're just going into a tunn..."

10th Nov 2011, 10:44 pm	#14
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. Ok further testing shows that when monitoring the recording via the playback head the right channel is quiet and muffled. When I press the back of the tape gently against the record head with my index finger the sound picks up. If I turn the recording volume for that channel way up all I get is a quiet distorted sound. This would be expected I suppose as anything past a setting of 2 puts the vu meter in the red. Could this be the position of the head or is this some other fault.

11th Nov 2011, 1:56 am	#15
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Tandberg 2041 (series 2000) Erase Head Problem. the second picture in post 10 shows some serious wear on that erase head. if the others are similar condition-wise, then it is possible that one channel will drop out. usually the left (outermost tape track) is the first to go. And yes, I have seen problems with the erase head mountings going floppy on some tandbergs of this era. I think you could fit rubber mountings or springs in lieu. __________________ Regards, Ben.

12th Nov 2011, 7:39 pm	#17
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Tandberg 2041 (series 2000) Erase Head Problem. generally, an experienced tech and a microscope will be able to get an idea on sight as to overall condition. You can tell by their sonic performance if they're past it or not. __________________ Regards, Ben.

12th Nov 2011, 9:02 pm	#19
scottie_UK Retired Dormant Member Join Date: Nov 2011 Location: Cardiff Posts: 81	Re: Tandberg 2041 (series 2000) Erase Head Problem. Ok here are 4 close up photos of the erase (left) and record (right) heads. There each from slightly different angles or have different camera settings, hopefully this may enable you to spot any tell tale signs. http://www.scottieuk.plus.com/Rec-Play1.JPG http://www.scottieuk.plus.com/Rec-Play2.JPG http://www.scottieuk.plus.com/Rec-Play3.JPG http://www.scottieuk.plus.com/Rec-Play4.JPG Last edited by scottie_UK; 12th Nov 2011 at 9:21 pm.

13th Nov 2011, 8:45 am	#20
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Tandberg 2041 (series 2000) Erase Head Problem. Scottie, It is rather difficult to see the faces of the heads to determine the state of same. However as you state you get a signal exerting some pressure on the head/s, check the reverse torque on the feed spool, there should be some slight backwards movement(check on pause) to retain the tape path. Also check the pressure pad on the bracket (erase head)is in contact & is "clean & not worn away, this contact also assists the tape path. As for the head/s alignment, difficult to tell from the pics. I have seen worse heads give a signal & your comment on applied pressure, points me to the above. Difficult to be precise Scottie without sight of the head block but do ensure the heads , in particular the record head you mention is perfectly clean , sometime ingrained deposits require more than the cotton bud treatment, remember nothing abrasive or metal. Colin.