Digital transistors - UK Vintage Radio Repair and Restoration Discussion Forum

Snarf81 · 13th Jul 2019, 3:36 pm

Hi all.

I'd like some help with trying to get two replacement transistors for my Sony SL-HF950UB superBeta VCR please. I need a C144 ESV and a C114 ESX
I've had a quick look online for replacements but can't find the exact ones. Data sheets, cross referencing and all of that is all Greek to me unfortunately.

If anyone has some for sale or compatible ones could you let me know please?

Many thanks,
Richard.

Radio Wrangler · 13th Jul 2019, 4:02 pm

Standard practice in Japan is not to mark the full type number. Try 2SC144 etc

David

paulsherwin · 13th Jul 2019, 4:17 pm

They appear to be available from eBay sellers for a pound or two. I can't see anything fancy about them so lots of general purpose Si types are likely to work if the voltage and current ratings are adequate. Watch out for the leadout arrangements.

https://alltransistors.com/transisto...ansistor=11919
https://alltransistors.com/transisto...ansistor=11486

It looks as if a BC337 will sub for both of them amongst many others.

Are you certain your transistors are bad? They don't usually fail in the absence of another fault.

Snarf81 · 13th Jul 2019, 4:35 pm

Hi,
Thanks for the replies.
The transistors are most definitely bunk, they're part of a Sony modification that were held down to the board by a sticky black pad. The pad had gone hard so I removed it and in doing so noticed that it had actually corroded some links, a resistor and damaged those two transistors.
Darn it.
So if I get some transistors from Ebay for example, as long as they are C114 and C144, should they be fine?

Many thanks again.
Rich.

paulsherwin · 13th Jul 2019, 4:38 pm

They should be OK if there isn't another fault. Personally I would fit whatever suitably rated transistors I had to hand and test. You can always fit the correct transistor types later.

Snarf81 · 13th Jul 2019, 4:43 pm

Before I removed the black pad the VCR was working fine, but I was advised to remove the pads due to them becoming conductive. I have some C144 transistors from a scrap board of a different betamax model but the last 3 letters are different. I wasnt sure if that made a difference to it or not. I don't have any C114 transistors to use though.

Cheers
Richard.

McMurdo · 13th Jul 2019, 5:00 pm

are they a digital (pre biased) transistor?

Snarf81 · 13th Jul 2019, 5:04 pm

Hi Kevin,
Unfortunately, I have no idea, I'm not very knowledgeable on transistors I'm afraid. How would one find out?

Cheers
Richard.

paulsherwin · 13th Jul 2019, 5:06 pm

From the datasheets and Towers they both appear to be old metal can types, which fits with a 3 digit number. Presumably they were subsequently made in plastic, which is what the suffixes are about. They seem to be pretty bog standard planar types.

Snarf81 · 13th Jul 2019, 5:12 pm

Ah right. Thank you. I'll take a look on Ebay and see if I can see any for sale.

Many thanks again
Richard.

McMurdo · 13th Jul 2019, 5:14 pm

quite probably not a 2sc144 or 114 but actually a DTC144ES and DTC114ES which are digital transistors, if so they won't test like a normal transistor even if they're good.

The giveaway is the TO92S package, its alot smaller than a standard TO92 and has a trapezoidal cross section. QUite common in jap consumer gear.

paulsherwin · 13th Jul 2019, 5:22 pm

You could well be right, but they made lots of ordinary transistors in that encapsulation too.

Snarf81 · 13th Jul 2019, 5:27 pm

Would it say in the service manual what type of transistor it is do you think? Or just the Sony part number?

McMurdo · 13th Jul 2019, 5:31 pm

usually had the dtc in a little dotted boxshowing the encapsulated biasing components

Snarf81 · 13th Jul 2019, 5:34 pm

There's no dotted box on the two transistors just those numbers and letters as I put in my original post.

Cheers
Richard.

Snarf81 · 13th Jul 2019, 7:15 pm

I just found the service manual amongst all of my Beta literature, it seems the C144 transistor is DTC144ES.

I'll have a look online to see if I can buy some. I'm assuming that the C114 will be DTC114 as it's not listed in the service manual, or supplements regarding that factory modification.

McMurdo · 14th Jul 2019, 10:29 pm

I think cricklewood probably have them

PS, here's a screenshot of the diagram (its complicated!!) showing a couple of the symbols for a digital transistor

Snarf81 · 15th Jul 2019, 7:45 am

Thanks Kevin,
That's brilliant. I'll take a look on their website presently.

Cheers
Richard.

Snarf81 · 17th Jul 2019, 2:14 pm

All sorted.
Thanks for all the replies and advice.

Regards
Richard.

AC/HL · 17th Jul 2019, 2:31 pm

Some theory: https://www.rohm.com/products/faq-search/faqId/234

13th Jul 2019, 3:36 pm	#1
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Digital transistors Hi all. I'd like some help with trying to get two replacement transistors for my Sony SL-HF950UB superBeta VCR please. I need a C144 ESV and a C114 ESX I've had a quick look online for replacements but can't find the exact ones. Data sheets, cross referencing and all of that is all Greek to me unfortunately. If anyone has some for sale or compatible ones could you let me know please? Many thanks, Richard.

13th Jul 2019, 4:02 pm	#2
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,867	Re: Transistor information required please. Standard practice in Japan is not to mark the full type number. Try 2SC144 etc David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

13th Jul 2019, 4:17 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,937	Re: Transistor information required please. They appear to be available from eBay sellers for a pound or two. I can't see anything fancy about them so lots of general purpose Si types are likely to work if the voltage and current ratings are adequate. Watch out for the leadout arrangements. https://alltransistors.com/transisto...ansistor=11919 https://alltransistors.com/transisto...ansistor=11486 It looks as if a BC337 will sub for both of them amongst many others. Are you certain your transistors are bad? They don't usually fail in the absence of another fault.

13th Jul 2019, 4:35 pm	#4
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. Hi, Thanks for the replies. The transistors are most definitely bunk, they're part of a Sony modification that were held down to the board by a sticky black pad. The pad had gone hard so I removed it and in doing so noticed that it had actually corroded some links, a resistor and damaged those two transistors. Darn it. So if I get some transistors from Ebay for example, as long as they are C114 and C144, should they be fine? Many thanks again. Rich. Attached Thumbnails

13th Jul 2019, 4:38 pm	#5
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,937	Re: Transistor information required please. They should be OK if there isn't another fault. Personally I would fit whatever suitably rated transistors I had to hand and test. You can always fit the correct transistor types later.

13th Jul 2019, 4:43 pm	#6
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. Before I removed the black pad the VCR was working fine, but I was advised to remove the pads due to them becoming conductive. I have some C144 transistors from a scrap board of a different betamax model but the last 3 letters are different. I wasnt sure if that made a difference to it or not. I don't have any C114 transistors to use though. Cheers Richard.

13th Jul 2019, 5:00 pm	#7
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,270	Re: Transistor information required please. are they a digital (pre biased) transistor? __________________ Kevin

13th Jul 2019, 5:04 pm	#8
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. Hi Kevin, Unfortunately, I have no idea, I'm not very knowledgeable on transistors I'm afraid. How would one find out? Cheers Richard.

13th Jul 2019, 5:06 pm	#9
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,937	Re: Transistor information required please. From the datasheets and Towers they both appear to be old metal can types, which fits with a 3 digit number. Presumably they were subsequently made in plastic, which is what the suffixes are about. They seem to be pretty bog standard planar types.

13th Jul 2019, 5:12 pm	#10
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. Ah right. Thank you. I'll take a look on Ebay and see if I can see any for sale. Many thanks again Richard.

13th Jul 2019, 5:14 pm	#11
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,270	Re: Transistor information required please. quite probably not a 2sc144 or 114 but actually a DTC144ES and DTC114ES which are digital transistors, if so they won't test like a normal transistor even if they're good. The giveaway is the TO92S package, its alot smaller than a standard TO92 and has a trapezoidal cross section. QUite common in jap consumer gear. __________________ Kevin

13th Jul 2019, 5:22 pm	#12
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,937	Re: Transistor information required please. You could well be right, but they made lots of ordinary transistors in that encapsulation too.

13th Jul 2019, 5:27 pm	#13
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. Would it say in the service manual what type of transistor it is do you think? Or just the Sony part number?

13th Jul 2019, 5:31 pm	#14
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,270	Re: Transistor information required please. usually had the dtc in a little dotted boxshowing the encapsulated biasing components __________________ Kevin

13th Jul 2019, 5:34 pm	#15
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. There's no dotted box on the two transistors just those numbers and letters as I put in my original post. Cheers Richard.

13th Jul 2019, 7:15 pm	#16
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. I just found the service manual amongst all of my Beta literature, it seems the C144 transistor is DTC144ES. I'll have a look online to see if I can buy some. I'm assuming that the C114 will be DTC114 as it's not listed in the service manual, or supplements regarding that factory modification. Attached Thumbnails

14th Jul 2019, 10:29 pm	#17
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,270	Re: Transistor information required please. I think cricklewood probably have them PS, here's a screenshot of the diagram (its complicated!!) showing a couple of the symbols for a digital transistor Attached Thumbnails __________________ Kevin Last edited by McMurdo; 14th Jul 2019 at 10:37 pm.

15th Jul 2019, 7:45 am	#18
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. Thanks Kevin, That's brilliant. I'll take a look on their website presently. Cheers Richard.

17th Jul 2019, 2:14 pm	#19
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Transistor information required please. All sorted. Thanks for all the replies and advice. Regards Richard.

17th Jul 2019, 2:31 pm	#20
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Digital transistors Some theory: https://www.rohm.com/products/faq-search/faqId/234