Panasonic K Mech mechanical noise - UK Vintage Radio Repair and Restoration Discussion Forum

IanNVJ35 · 24th Sep 2014, 12:07 am

These are good mechansims but I have one that is a bit 'thumpy' on rewind - almost on every tape spool (right hand) I can hear a knock. At fast speeds it becomes a vibration. I can't see anything amiss from the top so I was wondering if this issue is a common known one - and if so what is it?

Also I did have some occasional resonation sounds in FF but a really good clean of the tape path seemed to help here - but maybe the two issues are interlinked?

The machine works well but something is not quite right so I thought I would ask.

Thanks!

Welsh Anorak · 24th Sep 2014, 8:55 am

Hi
Just wondered if it might be wear in the tape path - if the tape is sticking slightly on a guide this is the trouble I'd expect as the tape chatters. Try an empty cassette and slow the reels by hand - you should be able to feel if there's any trouble there.
Good luck!
Glyn

IanNVJ35 · 24th Sep 2014, 10:06 am

Thanks Glyn. You know what, I thought about this first of all and so checked the ususal culprit - the lower drum, but it was perfect - not polished or worn. However having a spare K mechanism here I see that there is a 'hidden' tape tensioner/guide which is below the pinch roller and indeed on my spare mech it is worn with a groove. I will check that on my deck later on as it is in the area of the noise. I will report back.

IanNVJ35 · 25th Sep 2014, 9:17 am

Right, I spent a good amount of time and checked over everything. I did find the felt pads a little contaminated and so cleaned these carefully. However I am now feeling that the fault is the tape chattering on the lower (fixed) head. Under a loupe this is in good condition and not polished - it's machining is clear. I have had a very worn machine with polished lower drum actually stall the tape in play. Anyway, I was wondering the best way forwards - I think there may be a fixed residue or even slight oxidisation causing uneven travel. I have got it as clean as possible using isopropyl and a usual cleaning so was wondering about whether a green washing up pad or even Duraglit may be an option. Any input welcome - there is probably a way of doing it that I have not considered.

Welsh Anorak · 25th Sep 2014, 1:34 pm

Hi
I wouldn't use a green pad as that will scratch the head - metal poilish might be the way to go here, but to be honest I've never been successful and you might make things worse. If it's not too bad I'd consider living with it - repeated running of tape through the machine might improve matters.
Good luck!
Glyn

24th Sep 2014, 12:07 am	#1
IanNVJ35 Heptode Join Date: Mar 2010 Location: Hemel Hempstead, Hertfordshire, UK. Posts: 846	Panasonic K Mech mechanical noise These are good mechansims but I have one that is a bit 'thumpy' on rewind - almost on every tape spool (right hand) I can hear a knock. At fast speeds it becomes a vibration. I can't see anything amiss from the top so I was wondering if this issue is a common known one - and if so what is it? Also I did have some occasional resonation sounds in FF but a really good clean of the tape path seemed to help here - but maybe the two issues are interlinked? The machine works well but something is not quite right so I thought I would ask. Thanks!

24th Sep 2014, 8:55 am	#2
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,918	Re: Panasonic K Mech mechanical noise Hi Just wondered if it might be wear in the tape path - if the tape is sticking slightly on a guide this is the trouble I'd expect as the tape chatters. Try an empty cassette and slow the reels by hand - you should be able to feel if there's any trouble there. Good luck! Glyn

24th Sep 2014, 10:06 am	#3
IanNVJ35 Heptode Join Date: Mar 2010 Location: Hemel Hempstead, Hertfordshire, UK. Posts: 846	Re: Panasonic K Mech mechanical noise Thanks Glyn. You know what, I thought about this first of all and so checked the ususal culprit - the lower drum, but it was perfect - not polished or worn. However having a spare K mechanism here I see that there is a 'hidden' tape tensioner/guide which is below the pinch roller and indeed on my spare mech it is worn with a groove. I will check that on my deck later on as it is in the area of the noise. I will report back.

25th Sep 2014, 9:17 am	#4
IanNVJ35 Heptode Join Date: Mar 2010 Location: Hemel Hempstead, Hertfordshire, UK. Posts: 846	Re: Panasonic K Mech mechanical noise Right, I spent a good amount of time and checked over everything. I did find the felt pads a little contaminated and so cleaned these carefully. However I am now feeling that the fault is the tape chattering on the lower (fixed) head. Under a loupe this is in good condition and not polished - it's machining is clear. I have had a very worn machine with polished lower drum actually stall the tape in play. Anyway, I was wondering the best way forwards - I think there may be a fixed residue or even slight oxidisation causing uneven travel. I have got it as clean as possible using isopropyl and a usual cleaning so was wondering about whether a green washing up pad or even Duraglit may be an option. Any input welcome - there is probably a way of doing it that I have not considered.

25th Sep 2014, 1:34 pm	#5
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,918	Re: Panasonic K Mech mechanical noise Hi I wouldn't use a green pad as that will scratch the head - metal poilish might be the way to go here, but to be honest I've never been successful and you might make things worse. If it's not too bad I'd consider living with it - repeated running of tape through the machine might improve matters. Good luck! Glyn