Tandberg Series 6 restoration help please - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

jascha · 27th Sep 2020, 11:57 am

I seem to have the original Model 6 which I found out uses a slightly larger belt than most others. Any ideas what size belt it requires please? Mine is stretched and will try to fit the belt I have on my Series 15 which is also stretched but might fit perfectly on this Model 6. I tried looking for the belt from a reputable gentleman who stocks them but has not got any in stock and could not help me out with this model.

Cheers

ricard · 29th Sep 2020, 5:53 am

The older Tandbergs, especially the ones with yellow or brown colored top plates, have larger reel pulleys than the later grey-topped ones. I'm not sure where the model 6 fits in, but early versions certainly might certainly have the larger pulleys as the model 6 was the first of the grey topped machines to enter the market. The motor pulley varies in size too depending on the motor used, but that's not especially significant as the belt wrap around the motor pulley is rather modest (unfortunately, it can be a problem when the belt gets old and stretched).

I've used O-rings for belts, they work quite well in Tandbergs even though they are not as resilient as real belts, I need to check exactly what sizes I've used, I think around 189 mm in length for the large-pulley machines.

jascha · 29th Sep 2020, 6:03 am

Thanks for the update Ricard. My machine has a grey top and I think it’s been fitted with chrome knobs, but not sure they are the original. Chris Reynard told me that I have the older model with the larger pulley on the motor. All I know is that the motor is green.
There are also 3 springs around the idler wheel rather than the usual 2 abd I believe it’s got the larger reel pulleys.

If you have any links of websites from where you got your belts with the correct dimension that would be great please. In the meantime I will try the belt that’s on my Series 15 and see if that does the trick since also that belt is stretched whilst I wait for the original belt of the Series 15 to arrive by post.

Cheers

jascha · 8th Oct 2020, 11:29 pm

Hi again,
My Tandberg Model 6 has now got a new pinch roller and fitted a new belt for it however I’m still having an issue with pinch roller torque which ok my opinion is not enough, in fact I can easily stop the tape with a feather lite touch. This morning I took out the pinch roller to readjust the box spring so it applies more pressure on the pin on which the pinch roller is mounted on plus I cleaned around the supply reel table as the friction plate has some gunk on it. It’s all running smoothly however towards the end of a tape I keep hearing a drop in pitch and my question is regarding whether the pinch roller mechanism can be adjusted so more pressure is applied on the capstan.
I did swap idler wheels with my Series 15 (that works fine) and it’s not the issue here it seems.
Any ideas please?

Thanks

ricard · 9th Oct 2020, 8:55 pm

If the tape stops with a 'feather light touch', it sounds like that it is slipping between the capstan and pinch roller, and not that the capstan stops (as owing to the flywheel action it would take the flywheel time to stop)?

One thing that comes to mind if any lubricant has made its way onto the capstan.

Another thing that can be problematic is if one of the capstan bearings, especially the lower one, has gummed up, essentially acting as a brake on the flywheel. Many Tandbergs have a stop brake on the flywheel (for some reason) so it can be slightly tricky to diagnose as the flywheel is normally barked to a stop in stop mode.

jascha · 10th Oct 2020, 2:50 pm

It’s better today than it has been, after cleaning the underneath of the take up turntable abd re adjusting the pinch roller spring. It’s worst closest to the end of tape on a 5” reel for some reason but it seems to settle down. I’m having my machine looked at by a friend on Monday whilst also visiting him as he’s more experienced with them than myself and see what else he spots that might need a slight tweak. It needs biasing as it’s sounding thin on recording on BASF LGS 35.
Looking forward to having it all set up and ready to be used properly.
It’s still rather noisy mechanically, even though the idler wheel was swapped around with my Series 15.

The capstan spins freely when the brake is released so that’s all ok.

What were these machines set up for originally? Agfa PE31 or Basf LGS perhaps? What do people set them up to for best performance?
Thanks again

ricard · 10th Oct 2020, 8:52 pm

In the manuals of the time, in this case the manual for the model 74B, Tandberg specified something like "American tapes of the highest quality should be used" (translating this from Swedish as I don't have an English language manual available).

Strangely enough, in the model 6 manual I have they've removed the word 'American'.

But my conclusion anyway is that they were set up for some 3M tape, Indeed, in the 1965 catalog, all machines are shown playing 3M tape.

27th Sep 2020, 11:57 am	#21
jascha Hexode Join Date: Nov 2005 Location: Kent, UK. Posts: 332	Re: Tandberg Series 6 restoration help please I seem to have the original Model 6 which I found out uses a slightly larger belt than most others. Any ideas what size belt it requires please? Mine is stretched and will try to fit the belt I have on my Series 15 which is also stretched but might fit perfectly on this Model 6. I tried looking for the belt from a reputable gentleman who stocks them but has not got any in stock and could not help me out with this model. Cheers

29th Sep 2020, 5:53 am	#22
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg Series 6 restoration help please The older Tandbergs, especially the ones with yellow or brown colored top plates, have larger reel pulleys than the later grey-topped ones. I'm not sure where the model 6 fits in, but early versions certainly might certainly have the larger pulleys as the model 6 was the first of the grey topped machines to enter the market. The motor pulley varies in size too depending on the motor used, but that's not especially significant as the belt wrap around the motor pulley is rather modest (unfortunately, it can be a problem when the belt gets old and stretched). I've used O-rings for belts, they work quite well in Tandbergs even though they are not as resilient as real belts, I need to check exactly what sizes I've used, I think around 189 mm in length for the large-pulley machines.

29th Sep 2020, 6:03 am	#23
jascha Hexode Join Date: Nov 2005 Location: Kent, UK. Posts: 332	Re: Tandberg Series 6 restoration help please Thanks for the update Ricard. My machine has a grey top and I think it’s been fitted with chrome knobs, but not sure they are the original. Chris Reynard told me that I have the older model with the larger pulley on the motor. All I know is that the motor is green. There are also 3 springs around the idler wheel rather than the usual 2 abd I believe it’s got the larger reel pulleys. If you have any links of websites from where you got your belts with the correct dimension that would be great please. In the meantime I will try the belt that’s on my Series 15 and see if that does the trick since also that belt is stretched whilst I wait for the original belt of the Series 15 to arrive by post. Cheers Attached Thumbnails

8th Oct 2020, 11:29 pm	#24
jascha Hexode Join Date: Nov 2005 Location: Kent, UK. Posts: 332	Re: Tandberg Series 6 restoration help please Hi again, My Tandberg Model 6 has now got a new pinch roller and fitted a new belt for it however I’m still having an issue with pinch roller torque which ok my opinion is not enough, in fact I can easily stop the tape with a feather lite touch. This morning I took out the pinch roller to readjust the box spring so it applies more pressure on the pin on which the pinch roller is mounted on plus I cleaned around the supply reel table as the friction plate has some gunk on it. It’s all running smoothly however towards the end of a tape I keep hearing a drop in pitch and my question is regarding whether the pinch roller mechanism can be adjusted so more pressure is applied on the capstan. I did swap idler wheels with my Series 15 (that works fine) and it’s not the issue here it seems. Any ideas please? Thanks

9th Oct 2020, 8:55 pm	#25
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg Series 6 restoration help please If the tape stops with a 'feather light touch', it sounds like that it is slipping between the capstan and pinch roller, and not that the capstan stops (as owing to the flywheel action it would take the flywheel time to stop)? One thing that comes to mind if any lubricant has made its way onto the capstan. Another thing that can be problematic is if one of the capstan bearings, especially the lower one, has gummed up, essentially acting as a brake on the flywheel. Many Tandbergs have a stop brake on the flywheel (for some reason) so it can be slightly tricky to diagnose as the flywheel is normally barked to a stop in stop mode.

10th Oct 2020, 2:50 pm	#26
jascha Hexode Join Date: Nov 2005 Location: Kent, UK. Posts: 332	Re: Tandberg Series 6 restoration help please It’s better today than it has been, after cleaning the underneath of the take up turntable abd re adjusting the pinch roller spring. It’s worst closest to the end of tape on a 5” reel for some reason but it seems to settle down. I’m having my machine looked at by a friend on Monday whilst also visiting him as he’s more experienced with them than myself and see what else he spots that might need a slight tweak. It needs biasing as it’s sounding thin on recording on BASF LGS 35. Looking forward to having it all set up and ready to be used properly. It’s still rather noisy mechanically, even though the idler wheel was swapped around with my Series 15. The capstan spins freely when the brake is released so that’s all ok. What were these machines set up for originally? Agfa PE31 or Basf LGS perhaps? What do people set them up to for best performance? Thanks again

10th Oct 2020, 8:52 pm	#27
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Tandberg Series 6 restoration help please In the manuals of the time, in this case the manual for the model 74B, Tandberg specified something like "American tapes of the highest quality should be used" (translating this from Swedish as I don't have an English language manual available). Strangely enough, in the model 6 manual I have they've removed the word 'American'. But my conclusion anyway is that they were set up for some 3M tape, Indeed, in the 1965 catalog, all machines are shown playing 3M tape.