SGS IW 9566 transistor. - UK Vintage Radio Repair and Restoration Discussion Forum

Heatercathodeshort · 24th Oct 2019, 10:29 am

This transistor is the 4.433mc/s local oscillator transistor in my UNAOHM EP684R PAL colour generator. It has an intermittent O/C fault that slight pressure will temporarily cure.
Has anybody any data on this transistor? I have looked in my vast transistor data book but no joy.
The maker is SGS and all numbers are IW 9566 IFU13. Thanks, Regards, John.

Heatercathodeshort · 24th Oct 2019, 11:13 am

On further investigation the final number on the transistor appears to be 1W 9566 IF013 not IFU13.
John.

Terry_VK5TM · 24th Oct 2019, 12:58 pm

I've had a look through some SGS databooks ranging from mid 70's to early 80's and nothing even remotely similar showing up there.

Could possibly be a house number.

If you know whether it is npn or pnp, I would think the humble BC548 or BC558 would do the job if the component values around it indicate a lowish current draw for that part of the circuit.

Heatercathodeshort · 24th Oct 2019, 2:43 pm

Thanks Terry. Yes it is an odd one but the circuit from what I can make out is conventional.
I have soldered some thin tinned copper wire, replacing the transistor so that I can have a play around without damaging the P/C board. A circuit would be a great help but my attempts at downloading one have not been successful! Thanks again, John.

paulsherwin · 24th Oct 2019, 3:15 pm

If you can persuade the original to work, even intermittently, you should be able to determine if it's Ge/Si and NPN/PNP. I would expect any general purpose type to work in that sort of oscillator circuit.

Radio Wrangler · 24th Oct 2019, 5:22 pm

Most jellybean silicon transistors should have no problems with a crystal oscillator at 4.43MHz.

A quick poke with a voltmeter ought to show whether it's biassed-up for NPN or PNP and give an idea of the supply voltage. Shouldn't be too hard to pick a device.

One other possibility is that the crystal has gone a bit iffy and is not as active as it should be (Yup, I've seen this several times) Not uncommon with solder-sealed crystal units.

David

Heatercathodeshort · 24th Oct 2019, 5:31 pm

Thanks again! It was the weird number that made me think it was a strange odd ball device. I removed it from the P/C board and it read O/C all ways.
I put some extensions on the board as I reckoned it would take a few attempts to find a device that worked.
As you have suggested, it is nothing special and fitting a BC147A did the trick first time.

Yes David I remember that one from the early colour days. I had a number drift off frequency and become intermittent or dry joint. This one was OK.

It's quite a nice generator and will continue be fine for the dwindling vintage colour receivers that come my way. Thanks all, John.

paulsherwin · 24th Oct 2019, 7:26 pm

BUT, a BC147 is a Lockfit. I honestly wouldn't fit one of those even if I had a drawer full of the things. I'm sure you have something suitable in the junk box - BC108, BC182, BC54x, 2N3904, 2N2222, 2SC1815 etc etc.

24th Oct 2019, 10:29 am	#1
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	SGS IW 9566 transistor. This transistor is the 4.433mc/s local oscillator transistor in my UNAOHM EP684R PAL colour generator. It has an intermittent O/C fault that slight pressure will temporarily cure. Has anybody any data on this transistor? I have looked in my vast transistor data book but no joy. The maker is SGS and all numbers are IW 9566 IFU13. Thanks, Regards, John.

24th Oct 2019, 11:13 am	#2
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: SGS IW 9566 transistor. On further investigation the final number on the transistor appears to be 1W 9566 IF013 not IFU13. John.

24th Oct 2019, 12:58 pm	#3
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,342	Re: SGS IW 9566 transistor. I've had a look through some SGS databooks ranging from mid 70's to early 80's and nothing even remotely similar showing up there. Could possibly be a house number. If you know whether it is npn or pnp, I would think the humble BC548 or BC558 would do the job if the component values around it indicate a lowish current draw for that part of the circuit. __________________ Terry VK5TM https://www.vk5tm.com/

24th Oct 2019, 2:43 pm	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: SGS IW 9566 transistor. Thanks Terry. Yes it is an odd one but the circuit from what I can make out is conventional. I have soldered some thin tinned copper wire, replacing the transistor so that I can have a play around without damaging the P/C board. A circuit would be a great help but my attempts at downloading one have not been successful! Thanks again, John.

24th Oct 2019, 3:15 pm	#5
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,970	Re: SGS IW 9566 transistor. If you can persuade the original to work, even intermittently, you should be able to determine if it's Ge/Si and NPN/PNP. I would expect any general purpose type to work in that sort of oscillator circuit.

24th Oct 2019, 5:22 pm	#6
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: SGS IW 9566 transistor. Most jellybean silicon transistors should have no problems with a crystal oscillator at 4.43MHz. A quick poke with a voltmeter ought to show whether it's biassed-up for NPN or PNP and give an idea of the supply voltage. Shouldn't be too hard to pick a device. One other possibility is that the crystal has gone a bit iffy and is not as active as it should be (Yup, I've seen this several times) Not uncommon with solder-sealed crystal units. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

24th Oct 2019, 5:31 pm	#7
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: SGS IW 9566 transistor. Thanks again! It was the weird number that made me think it was a strange odd ball device. I removed it from the P/C board and it read O/C all ways. I put some extensions on the board as I reckoned it would take a few attempts to find a device that worked. As you have suggested, it is nothing special and fitting a BC147A did the trick first time. Yes David I remember that one from the early colour days. I had a number drift off frequency and become intermittent or dry joint. This one was OK. It's quite a nice generator and will continue be fine for the dwindling vintage colour receivers that come my way. Thanks all, John.

24th Oct 2019, 7:26 pm	#8
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,970	Re: SGS IW 9566 transistor. BUT, a BC147 is a Lockfit. I honestly wouldn't fit one of those even if I had a drawer full of the things. I'm sure you have something suitable in the junk box - BC108, BC182, BC54x, 2N3904, 2N2222, 2SC1815 etc etc.