HMV dial cord - UK Vintage Radio Repair and Restoration Discussion Forum

greenstar · 19th Apr 2020, 8:48 pm

Hi, I have an HMV Q286 radiogram. I believe the same chassis as several HMV and Marconiphone sets, circa 1934. Having noted Peter Lawn's post regarding the later jubilee chassis and intermediates, of which this seems to be one.

Anyway, I need to replace the cord. This doesn't look over complicated, being two cords, one around the tuning capacitor cylinder and drive knob shaft, the other around the capacitor cylinder, and two pulleys. What I am not sure of is how the two cords connect to the cylinder on the capacitor. The remnants of the cords are present, but there are no springs and one section of that cylinder seems to have no attachment points. Photos below. Hints appreciated - I've not done many of these!
Tony

vinrads · 21st Apr 2020, 11:52 am

Are you sure the springs are not in the cabinet or lost in the chassis somewhere, just looking at a Marconi the two springs are on the outside of the drum ,they hook on the small metal clips which fit in the holes on the drum. hope this makes sense.
Now that the chassis is out I will try and find a thinner spring looks like that was the only one I had at the time .Mick.

greenstar · 21st Apr 2020, 1:42 pm

Hi Mick, your photo is an enormous help. So it does look like two cords. Two springs, on on the chassis side, one on the scale side of the drum? The outer one for the scale looks straightforward. Not sure about the inner - that's a funny arrangement with the spring - any chance of a pic of the lower end? There seems no sign of the originals, but this set has travelled a little so not surprising they have vanished. Funny how both cords run also on the central section of the drum. I should eb able to work it out now anyway. Really appreciate you taking your set out of the case. Tony

vinrads · 21st Apr 2020, 4:14 pm

Hi Tony hope these help, Just a thought have you restored the chassis ,ie replaced the capacitors in the block etc ? you will need to check all the resistors mounted on the capacitor block ,I needed to replace four or five on mine ,if I were you I would fit the audio coupling cap external ,shortest path , back to the dial It looks like one of the clips was missing on mine so I tied the cord to the drum see pic ,I suppose you could make the anchor points, they are like a flat U shape pushed in the slot and a bit sticks out at both ends . Mick.

greenstar · 21st Apr 2020, 5:41 pm

Hi Mick, thanks, I am doing the capacitor block at the moment. Thanks for the tip re resistors and audio coupling cap. I must check up how to read the value those dog's bone resistors, although I have the excellent pdf giving the resistor numbers. Thanks for the extra pics. Good that your cords are different colours - that helps me! Looks like your springs are fairly strong, I have some which are finer but not sure if they will do.

21st Apr 2020, 5:45 pm

Dog bone, body, tip, dot. I have always found it funny that the most significant number, the dot for how many zeros, is the smallest.

greenstar · 21st Apr 2020, 7:10 pm

And often vanished.

greenstar · 22nd Apr 2020, 9:24 pm

MIck, you were right about the resistors on the panel over the block - on mine, four open circuit, two high. Will be checking the rest. Merlin, thanks for the info. Want to say also thanks to PJL for the pdf Marconi 286 service information here (ref to original thread https://vintage-radio.net/forum/show...t=19577&page=2 ). That is amazingly useful as chassis can differ from the service sheets.

greenstar · 27th Apr 2020, 1:31 pm

Just to add that the dial cord is now repaired. Both cords reinstated and it works well! With Mick's photo it made perfect sense. I have restuffed the condenser box, replaced the waxies, checked and replaced several resistors and have just the valves to look at before testing the set. Thanks again Mick.

vinrads · 27th Apr 2020, 2:10 pm

It's all sounding good up to now , hope all the valves are ok , Mick.

greenstar · 27th Apr 2020, 4:50 pm

I have to admit to losing the remaining anchor point. I had one side hooked up to the spring, and was looping the cord around when it came out of the slot, and the tensioned spring shot it across my workshop into oblivion. I may find it one day!

19th Apr 2020, 8:48 pm	#1
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	HMV dial cord Hi, I have an HMV Q286 radiogram. I believe the same chassis as several HMV and Marconiphone sets, circa 1934. Having noted Peter Lawn's post regarding the later jubilee chassis and intermediates, of which this seems to be one. Anyway, I need to replace the cord. This doesn't look over complicated, being two cords, one around the tuning capacitor cylinder and drive knob shaft, the other around the capacitor cylinder, and two pulleys. What I am not sure of is how the two cords connect to the cylinder on the capacitor. The remnants of the cords are present, but there are no springs and one section of that cylinder seems to have no attachment points. Photos below. Hints appreciated - I've not done many of these! Tony Attached Thumbnails

21st Apr 2020, 11:52 am	#2
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,766	Re: HMV dial cord Are you sure the springs are not in the cabinet or lost in the chassis somewhere, just looking at a Marconi the two springs are on the outside of the drum ,they hook on the small metal clips which fit in the holes on the drum. hope this makes sense. Now that the chassis is out I will try and find a thinner spring looks like that was the only one I had at the time .Mick. Attached Thumbnails Last edited by vinrads; 21st Apr 2020 at 12:14 pm.

21st Apr 2020, 1:42 pm	#3
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: HMV dial cord Hi Mick, your photo is an enormous help. So it does look like two cords. Two springs, on on the chassis side, one on the scale side of the drum? The outer one for the scale looks straightforward. Not sure about the inner - that's a funny arrangement with the spring - any chance of a pic of the lower end? There seems no sign of the originals, but this set has travelled a little so not surprising they have vanished. Funny how both cords run also on the central section of the drum. I should eb able to work it out now anyway. Really appreciate you taking your set out of the case. Tony

21st Apr 2020, 4:14 pm	#4
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,766	Re: HMV dial cord Hi Tony hope these help, Just a thought have you restored the chassis ,ie replaced the capacitors in the block etc ? you will need to check all the resistors mounted on the capacitor block ,I needed to replace four or five on mine ,if I were you I would fit the audio coupling cap external ,shortest path , back to the dial It looks like one of the clips was missing on mine so I tied the cord to the drum see pic ,I suppose you could make the anchor points, they are like a flat U shape pushed in the slot and a bit sticks out at both ends . Mick. Attached Thumbnails

21st Apr 2020, 5:41 pm	#5
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: HMV dial cord Hi Mick, thanks, I am doing the capacitor block at the moment. Thanks for the tip re resistors and audio coupling cap. I must check up how to read the value those dog's bone resistors, although I have the excellent pdf giving the resistor numbers. Thanks for the extra pics. Good that your cords are different colours - that helps me! Looks like your springs are fairly strong, I have some which are finer but not sure if they will do.

21st Apr 2020, 5:45 pm	#6
Guest Guest Posts: n/a	Re: HMV dial cord Dog bone, body, tip, dot. I have always found it funny that the most significant number, the dot for how many zeros, is the smallest.

21st Apr 2020, 7:10 pm	#7
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: HMV dial cord And often vanished.

22nd Apr 2020, 9:24 pm	#8
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: HMV dial cord MIck, you were right about the resistors on the panel over the block - on mine, four open circuit, two high. Will be checking the rest. Merlin, thanks for the info. Want to say also thanks to PJL for the pdf Marconi 286 service information here (ref to original thread https://vintage-radio.net/forum/show...t=19577&page=2 ). That is amazingly useful as chassis can differ from the service sheets.

27th Apr 2020, 1:31 pm	#9
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: HMV dial cord Just to add that the dial cord is now repaired. Both cords reinstated and it works well! With Mick's photo it made perfect sense. I have restuffed the condenser box, replaced the waxies, checked and replaced several resistors and have just the valves to look at before testing the set. Thanks again Mick. Last edited by greenstar; 27th Apr 2020 at 1:42 pm.

27th Apr 2020, 2:10 pm	#10
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,766	Re: HMV dial cord It's all sounding good up to now , hope all the valves are ok , Mick.

27th Apr 2020, 4:50 pm	#11
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: HMV dial cord I have to admit to losing the remaining anchor point. I had one side hooked up to the spring, and was looping the cord around when it came out of the slot, and the tensioned spring shot it across my workshop into oblivion. I may find it one day!