Dial Cord Question - UK Vintage Radio Repair and Restoration Discussion Forum

PsychMan · 11th Apr 2018, 12:37 pm

I restrung my first dial cord last night (Bush SRG86) and have a few questions.

How tight should the string be?

What I have done works fine, and while I can't visibly see any slack as such, it certainly could be tighter.

I noticed after aligning the indicator on the string, if I align to the dots on the right (as manual states), when I turn the dial to the other extremity it's a little too far to the left. I'm imagining this is caused by a small amount of slack in the cord.

Aside from this it seems to work fine and does not appear to slip on barrel of the tuning dial.

I have some more dial string, so I can re-do it. Unfortunately the piece I used last night I dropped some superglue on the knots, so tightening it as it is will be tricky if acetone doesn't allow me to unknot one side of it.

I'm tempted to leave as it is, but the then the perfectionist in me doesn't feel right about it. Views much appreciated

kevinb · 11th Apr 2018, 12:52 pm

I would suggest the dial cord should be taught but not tight, the pressure of the spring should be enough, if it works its fine, its a bit trial and error

ukcol · 11th Apr 2018, 1:00 pm

The dial cord should have the right tension if the springs are stretched by the right amount. You should be able to judge that from the diagram below.

PsychMan · 11th Apr 2018, 2:38 pm

The trouble with this chassis is it looked the same before and after, in that the springs seemed to be resting on the centre plastic bit and not really doing much tension wise. That said the cord was frayed when I got it, perhaps this dropped the tension before it went.

I'll compare my pictures again tonight, if it's different I'll have to try and remove one of the links and apply more tension

John10b · 11th Apr 2018, 3:45 pm

I usually make sure the spring has extended about 50%, it can be tricky to get it right but with some perseverance you will succeed.
Cheers
John

vinrads · 11th Apr 2018, 3:46 pm

Not sure what you mean to far to the left, is it a problem, running off its guide, if aligned as per manual I would leave it, are the stations in the correct place on the dial, also sometimes you can tighten the cord by losing a bit on the pointer/cursor.

Mick.

PsychMan · 11th Apr 2018, 8:26 pm

On the left side there are also dots, and you might expect they would also line up with dial indicator

I had a look at some of my earlier pictures and I see exactly what you mean about spring tension. My job had next to none on it. I had enough string to redo so I’ve done that tonight and it’s nice and taught now, really pleased with it, job's a good un. The dial still doesn’t line up with the left dots but oh well, I’ve aligned that as per the manual, probably just a quirk of this model.

I’ll keep the first bit of cord, I’m sure it will fit a smaller radio. Incidentally I bought the cord NOS from a chap on eBay and it’s excellent “as new” condition, and looks identical to the original stuff in composition

11th Apr 2018, 12:37 pm	#1
PsychMan Octode Join Date: Jun 2013 Location: Fleet, Hampshire, UK Posts: 1,764	Dial Cord Question I restrung my first dial cord last night (Bush SRG86) and have a few questions. How tight should the string be? What I have done works fine, and while I can't visibly see any slack as such, it certainly could be tighter. I noticed after aligning the indicator on the string, if I align to the dots on the right (as manual states), when I turn the dial to the other extremity it's a little too far to the left. I'm imagining this is caused by a small amount of slack in the cord. Aside from this it seems to work fine and does not appear to slip on barrel of the tuning dial. I have some more dial string, so I can re-do it. Unfortunately the piece I used last night I dropped some superglue on the knots, so tightening it as it is will be tricky if acetone doesn't allow me to unknot one side of it. I'm tempted to leave as it is, but the then the perfectionist in me doesn't feel right about it. Views much appreciated

11th Apr 2018, 12:52 pm	#2
kevinb Pentode Join Date: Dec 2005 Location: Leicestershire, UK. Posts: 218	Re: Dial Cord Question I would suggest the dial cord should be taught but not tight, the pressure of the spring should be enough, if it works its fine, its a bit trial and error

11th Apr 2018, 1:00 pm	#3
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Re: Dial Cord Question The dial cord should have the right tension if the springs are stretched by the right amount. You should be able to judge that from the diagram below. Attached Thumbnails

11th Apr 2018, 2:38 pm	#4
PsychMan Octode Join Date: Jun 2013 Location: Fleet, Hampshire, UK Posts: 1,764	Re: Dial Cord Question The trouble with this chassis is it looked the same before and after, in that the springs seemed to be resting on the centre plastic bit and not really doing much tension wise. That said the cord was frayed when I got it, perhaps this dropped the tension before it went. I'll compare my pictures again tonight, if it's different I'll have to try and remove one of the links and apply more tension

11th Apr 2018, 3:45 pm	#5
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dial Cord Question I usually make sure the spring has extended about 50%, it can be tricky to get it right but with some perseverance you will succeed. Cheers John

11th Apr 2018, 3:46 pm	#6
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,762	Re: Dial Cord Question Not sure what you mean to far to the left, is it a problem, running off its guide, if aligned as per manual I would leave it, are the stations in the correct place on the dial, also sometimes you can tighten the cord by losing a bit on the pointer/cursor. Mick.

11th Apr 2018, 8:26 pm	#7
PsychMan Octode Join Date: Jun 2013 Location: Fleet, Hampshire, UK Posts: 1,764	Re: Dial Cord Question On the left side there are also dots, and you might expect they would also line up with dial indicator I had a look at some of my earlier pictures and I see exactly what you mean about spring tension. My job had next to none on it. I had enough string to redo so I’ve done that tonight and it’s nice and taught now, really pleased with it, job's a good un. The dial still doesn’t line up with the left dots but oh well, I’ve aligned that as per the manual, probably just a quirk of this model. I’ll keep the first bit of cord, I’m sure it will fit a smaller radio. Incidentally I bought the cord NOS from a chap on eBay and it’s excellent “as new” condition, and looks identical to the original stuff in composition