Defiant T14 - UK Vintage Radio Repair and Restoration Discussion Forum

gary_crutchley · 26th Jan 2016, 9:31 pm

Hi all,

I have what I think is a Defiant T14 reel to reel tape recorder, at least it has the extra 4 track switch as opposed to the T12. The chassis looks to be pretty much untouched, we checked the mains leads, transformers etc. and it looked okay, so we tried it on the lamp limiter. It seems to work okay, but we ran it only for a short period of time to check it was serviceable.

My question is where to start with the electrical restoration please? I noticed there are a number of Hunts caps under the chassis and at least a couple of waxies. I prefer the 'change one and try it method', so I am wondering where to start please, which caps should I target first?

I have the circuit diagram, so any advice would be appreciated.

Best regards,

Gary

McMurdo · 26th Jan 2016, 10:27 pm

I'm always suspicious of those 'mixed dielectric' capacitors (blue-purple and white) on the left, especially if used as a suppressor..they go short.
And I've seen many of those Plessey electrolytics go open or short in equal amounts.

Is it a BSR mech?

mark pirate · 26th Jan 2016, 10:35 pm

Quote:

Is it a BSR mech?

It certainly is, these were used on countless machines in the sixties. A clunky but reliable deck, but just like record changers it will need all the old hardened grease removed and a good relube to work properly.

I agree with Kevin, those Plessey caps have got to go. I would start with the higher voltage caps first.
The main smoothing can is usually still fine.

Mark

gary_crutchley · 26th Jan 2016, 11:11 pm

Quote:

Originally Posted by McMurdo

Is it a BSR mech?

Hi,

It is a BSR mech, a Type TD2 apparently.

Regards,

Gary

gary_crutchley · 26th Jan 2016, 11:14 pm

Quote:

Originally Posted by mark pirate

I agree with Kevin, those Plessey caps have got to go. I would start with the higher voltage caps first.
The main smoothing can is usually still fine.

Thanks Mark,

Which would you recommend we start with please? I was thinking C3?

Regards,

Gary

Michael Maurice · 27th Jan 2016, 9:40 am

All the capacitors marked in red should be replaced on sight, all the resistors marked in blue should be checked that they haven't gone high and replaced where necessary, the bridge rectifier indicated by the green arrow will almost certainly be past it. Replace with a modern silicon bridge and add a 100R resistor in series with one of the AC legs.

gary_crutchley · 27th Jan 2016, 11:29 pm

Thanks very much! That's a great help.

Regards,

Gary

26th Jan 2016, 9:31 pm	#1
gary_crutchley Heptode Join Date: Apr 2013 Location: Bloxwich, West Midlands, UK Posts: 554	Defiant T14 Hi all, I have what I think is a Defiant T14 reel to reel tape recorder, at least it has the extra 4 track switch as opposed to the T12. The chassis looks to be pretty much untouched, we checked the mains leads, transformers etc. and it looked okay, so we tried it on the lamp limiter. It seems to work okay, but we ran it only for a short period of time to check it was serviceable. My question is where to start with the electrical restoration please? I noticed there are a number of Hunts caps under the chassis and at least a couple of waxies. I prefer the 'change one and try it method', so I am wondering where to start please, which caps should I target first? I have the circuit diagram, so any advice would be appreciated. Best regards, Gary Attached Thumbnails

26th Jan 2016, 10:27 pm	#2
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,274	Re: Defiant T14 I'm always suspicious of those 'mixed dielectric' capacitors (blue-purple and white) on the left, especially if used as a suppressor..they go short. And I've seen many of those Plessey electrolytics go open or short in equal amounts. Is it a BSR mech? __________________ Kevin

27th Jan 2016, 9:40 am	#6
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,225	Re: Defiant T14 All the capacitors marked in red should be replaced on sight, all the resistors marked in blue should be checked that they haven't gone high and replaced where necessary, the bridge rectifier indicated by the green arrow will almost certainly be past it. Replace with a modern silicon bridge and add a 100R resistor in series with one of the AC legs. Attached Thumbnails __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

27th Jan 2016, 11:29 pm	#7
gary_crutchley Heptode Join Date: Apr 2013 Location: Bloxwich, West Midlands, UK Posts: 554	Re: Defiant T14 Thanks very much! That's a great help. Regards, Gary