Dial cord threading for Ferranti 147 and 347. - UK Vintage Radio Repair and Restoration Discussion Forum

johnlees · 29th Jan 2007, 10:19 pm

Does anyone please have a diagram of how to re-thread the broken dial/tuning cord on my Ferranti 347 Console model? (I have Paul's service sheet but it does not include this.)

Darren-UK · 29th Jan 2007, 11:13 pm

Apparently it's the same as on the model 147 tabletop set. This is Trader 897 which shows a diagram and text notes. Attached is the diagram.

johnlees · 30th Jan 2007, 3:54 pm

That's the one! Many thanks, Darren. Looks a bit hard to get at this to fix it, though.

johnlees · 31st Jan 2007, 9:44 pm

Looking at the diagram and looking at the actual set it would appear that there are two entirely separate pieces of cord - one is the cursor drive cord and the other is the gang drive cord. Is my thinking correct here? (Or is it only one complete length of cord devilishly and cunningly wrapped round ?? I'd like to know the answer before I get in a mess unravelling it to repair it.)

(Turning the tuning cap. by hand still moves the dial cursor, but the tuning knob moves nothing, therefore it would appear that only the "gang drive cord" is broken.)

Darren-UK · 31st Jan 2007, 11:33 pm

Quote:

Originally Posted by johnlees

Looking at the diagram and looking at the actual set it would appear that there are two entirely separate pieces of cord - one is the cursor drive cord and the other is the gang drive cord. Is my thinking correct here? (Or is it only one complete length of cord devilishly and cunningly wrapped round ?? I'd like to know the answer before I get in a mess unravelling it to repair it.)

(Turning the tuning cap. by hand still moves the dial cursor, but the tuning knob moves nothing, therefore it would appear that only the "gang drive cord" is broken.)

Yes there are two cords; one drives the gang drum from the tuning knob spindle ( shown as a broken line ) and the other drives the cursor from the drum.

As you say turning the drum by hand still moves the cursor, then one of two things is happening ...... 1. The cord from drum to tuning control is indeed broken or 2. the cord is intact but slipping. On the latter point, how easy is it to turn the drum by hand ? I note from the diagram that this cord only winds 1½ times around the tuning control spindle; if the tuning gang has gone stiff for some reason then the cord may well be intact but slipping.

johnlees · 31st Jan 2007, 11:39 pm

Thanks, Darren. Yes, the one cord is actually broken and the two ends are dangling in there. I'll have to get in there and dig down deep.

When I first got the set the cord was not broken but it was very hard to turn the tuning knob. Suddenly the cord attached to the tuning knob broke and it is now very easy to move the tuning cap. by hand (which in turn easily moves the dial pointer.)

Clearly it's just a simple mechanical problem which I shall have to sort out.

Many thanks.

Darren-UK · 1st Feb 2007, 12:26 am

Quote:

Originally Posted by johnlees

When I first got the set the cord was not broken but it was very hard to turn the tuning knob. Suddenly the cord attached to the tuning knob broke and it is now very easy to move the tuning cap. by hand (which in turn easily moves the dial pointer.)
Many thanks.

Ah so you forced it and ended up busting it

Tuning control stiff but turning freely now cord's broken suggests a problem with either a seized gang or seized pulleys. However, as you said the drum turns freely by hand this clearly isn't the problem.

What I suspect is that the tuning control-to-drum cord had overlapped itself and 'locked' on the tuning knob spindle. When this happens you can normally turn the knob one way but not the other.

By the way, the service data says you need two feet of cord for the gang drive and that whilst fitting the gang should be set near to its maximum capacitance position to make the job easier. You need three feet of cord for the cursor drive; it may be a good idea to replace this too while you're at it; very annoying if you replace one cord and then the other fails soon after you've replaced the chassis in the cabinet.

johnlees · 1st Feb 2007, 9:39 pm

OK, yes, guilty. I forced it (well only gently) and bust it. At least I know not to do it again.
You are right in your diagnosis as when I looked at it closely the two cords were overlapping each other, and yes it was easier to turn in one direction than the other. Thanks again.

johnlees · 4th Feb 2007, 9:59 pm

This restringing has been done successfully today, so thanks for the help.
Although the two cords both looked original I can't see how they managed to get overlapped (which they were) by themselves. I have restrung it slightly differently so that they are on "the correct side of each other" on the big drum and it seems to work OK (so far!)

29th Jan 2007, 10:19 pm	#1
johnlees Hexode Join Date: Oct 2004 Location: Cheltenham, Gloucestershire, UK. Posts: 283	Dial cord threading for Ferranti 147 and 347. Does anyone please have a diagram of how to re-thread the broken dial/tuning cord on my Ferranti 347 Console model? (I have Paul's service sheet but it does not include this.) __________________ Now that's the kind of Long Wave I like ! (Severn Bore near Gloucester)

29th Jan 2007, 11:13 pm	#2
Darren-UK Retired Dormant Member Join Date: Apr 2003 Location: Blackpool, Lancashire, UK. Posts: 4,061	Re: Dial cord threading diagram for Ferranti 347 Console model needed. Apparently it's the same as on the model 147 tabletop set. This is Trader 897 which shows a diagram and text notes. Attached is the diagram. Attached Thumbnails Last edited by Darren-UK; 29th Jan 2007 at 11:31 pm. Reason: Added image.

30th Jan 2007, 3:54 pm	#3
johnlees Hexode Join Date: Oct 2004 Location: Cheltenham, Gloucestershire, UK. Posts: 283	Re: Dial cord threading diagram for Ferranti 347 Console model needed. That's the one! Many thanks, Darren. Looks a bit hard to get at this to fix it, though. __________________ Now that's the kind of Long Wave I like ! (Severn Bore near Gloucester)

31st Jan 2007, 9:44 pm	#4
johnlees Hexode Join Date: Oct 2004 Location: Cheltenham, Gloucestershire, UK. Posts: 283	Re: Dial cord threading diagram for Ferranti 347 Console model needed. Looking at the diagram and looking at the actual set it would appear that there are two entirely separate pieces of cord - one is the cursor drive cord and the other is the gang drive cord. Is my thinking correct here? (Or is it only one complete length of cord devilishly and cunningly wrapped round ?? I'd like to know the answer before I get in a mess unravelling it to repair it.) (Turning the tuning cap. by hand still moves the dial cursor, but the tuning knob moves nothing, therefore it would appear that only the "gang drive cord" is broken.) __________________ Now that's the kind of Long Wave I like ! (Severn Bore near Gloucester) Last edited by johnlees; 31st Jan 2007 at 9:45 pm. Reason: Grammar

31st Jan 2007, 11:39 pm	#6
johnlees Hexode Join Date: Oct 2004 Location: Cheltenham, Gloucestershire, UK. Posts: 283	Re: Dial cord threading diagram for Ferranti 347 Console model needed. Thanks, Darren. Yes, the one cord is actually broken and the two ends are dangling in there. I'll have to get in there and dig down deep. When I first got the set the cord was not broken but it was very hard to turn the tuning knob. Suddenly the cord attached to the tuning knob broke and it is now very easy to move the tuning cap. by hand (which in turn easily moves the dial pointer.) Clearly it's just a simple mechanical problem which I shall have to sort out. Many thanks. __________________ Now that's the kind of Long Wave I like ! (Severn Bore near Gloucester) Last edited by johnlees; 31st Jan 2007 at 11:52 pm. Reason: Added info.

1st Feb 2007, 9:39 pm	#8
johnlees Hexode Join Date: Oct 2004 Location: Cheltenham, Gloucestershire, UK. Posts: 283	Re: Dial cord threading diagram for Ferranti 347 Console model needed. OK, yes, guilty. I forced it (well only gently) and bust it. At least I know not to do it again. You are right in your diagnosis as when I looked at it closely the two cords were overlapping each other, and yes it was easier to turn in one direction than the other. Thanks again. __________________ Now that's the kind of Long Wave I like ! (Severn Bore near Gloucester)

4th Feb 2007, 9:59 pm	#9
johnlees Hexode Join Date: Oct 2004 Location: Cheltenham, Gloucestershire, UK. Posts: 283	Re: Dial cord threading diagram for Ferranti 347 Console model needed. This restringing has been done successfully today, so thanks for the help. Although the two cords both looked original I can't see how they managed to get overlapped (which they were) by themselves. I have restrung it slightly differently so that they are on "the correct side of each other" on the big drum and it seems to work OK (so far!) __________________ Now that's the kind of Long Wave I like ! (Severn Bore near Gloucester)