Sony 9-90UB cogging - UK Vintage Radio Repair and Restoration Discussion Forum

Panrock · 21st Oct 2006, 10:19 pm

I'm sure this has been discussed on the board before somewhere but does anyone have a quick fix (with a location guide for the part) for the well-known line cogging this Sony exhibits on Test Card? Dried up electrolytic in the sync separator or something?

Thanks,

Steve

Kat Manton · 21st Oct 2006, 10:51 pm

Hi Steve,

C603, 3uF cap in the sync separator, I got to the bottom of this problem eventually with mine (replaced it with 2.2uF, possibly 4.7uF might've been better but I've not tried it yet.)

See post #23 in this thread.

Regards, Kat

Panrock · 21st Oct 2006, 11:54 pm

Ace! Thanks Kat. But I don't have the schematic for this set. Does anyone have a scan from the R&TVS book they could kindly post?

Thanks

Steve

TNC · 22nd Oct 2006, 12:02 am

Just a thought re Test Card C cogging on the Sony...are you using a Domino standards converter? My Sony cogs on Test Card C when using one...but not when using a David Grant Dinosauer converter. (Live signal however is fine and "cog-free")

Trevor.

Panrock · 22nd Oct 2006, 12:16 am

Yes I'm using the Domino. BTW I find that reducing the signal level to 'noisy' level improves the cogging somewhat.

There do seem to be some compatibility issues between the various converters and certain sets. For example I've recently seen a TV22 here which was fine with the Domino but exhibited some line hooking at the top of the picture with the Aurora.

Theories welcome, though probably this would mean a new thread...

Steve

Kat Manton · 22nd Oct 2006, 1:58 am

Hi Steve,

Quote:

Originally Posted by Panrock

Ace! Thanks Kat. But I don't have the schematic for this set.

Ahh... in that case, this may be of use... I thought it'd been posted as an attachment in a thread referenced from the thread I referenced. But it'd been linked and it's not there now. Fortunately I downloaded a copy...

Regards, Kat

ppppenguin · 22nd Oct 2006, 9:03 am

Quote:

Originally Posted by Panrock

For example I've recently seen a TV22 here which was fine with the Domino but exhibited some line hooking at the top of the picture with the Aurora.

Try switching off the EQ pulses on the Aurora.

Panrock · 22nd Oct 2006, 10:22 am

Kat, many many thanks. The resources of this board and its members never ceases to astonish me. So I've now got another job to tackle today...

Jeffrey, this sounds a great idea. I haven't got an Aurora myself and hadn't thought about the equalising pulses. I'll now contact the owner and suggest he tries this.

All the best,

Steve

Mikey405 · 22nd Oct 2006, 10:54 am

Hi everyone.

Do the modulators that are generally available produce a double or vestigal sideband signal? I was wondering whether this has anything to do with incompatibilities between different converters / modulators and TVs. My 9-90 doesn't like Dave Grant's modulator very much (although it works absolutely fine on most other sets I've tried it with), but works fine with a huge prehistoric Marconi signal generator wired up as a modulator...

From Mike.

ppppenguin · 22nd Oct 2006, 10:57 am

Quote:

Originally Posted by Mikey405

Do the modulators that are generally available produce a double or vestigal sideband signal?

All known modulators, except 1, produce a double sideband signal. The exception is Darius's VSB filter which could, in theory, be used with any modulator design.

Kat Manton · 22nd Oct 2006, 3:03 pm

Hi,

I just remembered, I should add that the schematic is for earlier sets, up to s/n 80000. In another thread it was mentioned that the design changed completely from 80001 on.

Regards, Kat

Steve_P · 22nd Oct 2006, 3:24 pm

Looking at the circuit and the adjustments, have you tried adjusting C807 and C808 for pulse width. Then re-locking the Line Frequency (VR602 and VR603) before adjusting VR601 (Line Hold).

Just a thought.

Cheers,

Steve P

Panrock · 22nd Oct 2006, 3:32 pm

Quote:

Originally Posted by Kat Manton

I just remembered, I should add that the schematic is for earlier sets, up to s/n 80000. In another thread it was mentioned that the design changed completely from 80001 on.

Well mine's 24912 so I'm okay. I put 10uF in C603 and in my case I also found it necessary to replace C602 as well (I had a tiny 1uF electrolytic to hand which I used for this).

I originally obtained two of these sets from Ebay and did a 'cut-&-shut' job to obtain one good set from the best bits of both. Thanks to Kat it's now as it should be.

Here's the result:

S

21st Oct 2006, 10:19 pm	#1
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,533	Sony 9-90UB cogging I'm sure this has been discussed on the board before somewhere but does anyone have a quick fix (with a location guide for the part) for the well-known line cogging this Sony exhibits on Test Card? Dried up electrolytic in the sync separator or something? Thanks, Steve

21st Oct 2006, 11:54 pm	#3
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,533	Re: Sony 9-90UB cogging Ace! Thanks Kat. But I don't have the schematic for this set. Does anyone have a scan from the R&TVS book they could kindly post? Thanks Steve

22nd Oct 2006, 12:02 am	#4
TNC Hexode Join Date: Apr 2003 Location: Westcliff-on-Sea, Essex, UK. Posts: 386	Re: Sony 9-90UB cogging Just a thought re Test Card C cogging on the Sony...are you using a Domino standards converter? My Sony cogs on Test Card C when using one...but not when using a David Grant Dinosauer converter. (Live signal however is fine and "cog-free") Trevor.

22nd Oct 2006, 12:16 am	#5
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,533	Re: Sony 9-90UB cogging Yes I'm using the Domino. BTW I find that reducing the signal level to 'noisy' level improves the cogging somewhat. There do seem to be some compatibility issues between the various converters and certain sets. For example I've recently seen a TV22 here which was fine with the Domino but exhibited some line hooking at the top of the picture with the Aurora. Theories welcome, though probably this would mean a new thread... Steve

22nd Oct 2006, 10:22 am	#8
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,533	Re: Sony 9-90UB cogging Kat, many many thanks. The resources of this board and its members never ceases to astonish me. So I've now got another job to tackle today... Jeffrey, this sounds a great idea. I haven't got an Aurora myself and hadn't thought about the equalising pulses. I'll now contact the owner and suggest he tries this. All the best, Steve

21st Oct 2006, 10:51 pm	#2
Kat Manton Retired Dormant Member Join Date: Jul 2005 Location: West Yorkshire, UK. Posts: 1,700	Re: Sony 9-90UB cogging Hi Steve, C603, 3uF cap in the sync separator, I got to the bottom of this problem eventually with mine (replaced it with 2.2uF, possibly 4.7uF might've been better but I've not tried it yet.) See post #23 in this thread. Regards, Kat

22nd Oct 2006, 10:54 am	#9
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	Re: Sony 9-90UB cogging Hi everyone. Do the modulators that are generally available produce a double or vestigal sideband signal? I was wondering whether this has anything to do with incompatibilities between different converters / modulators and TVs. My 9-90 doesn't like Dave Grant's modulator very much (although it works absolutely fine on most other sets I've tried it with), but works fine with a huge prehistoric Marconi signal generator wired up as a modulator... From Mike.

22nd Oct 2006, 3:03 pm	#11
Kat Manton Retired Dormant Member Join Date: Jul 2005 Location: West Yorkshire, UK. Posts: 1,700	Re: Sony 9-90UB cogging Hi, I just remembered, I should add that the schematic is for earlier sets, up to s/n 80000. In another thread it was mentioned that the design changed completely from 80001 on. Regards, Kat

22nd Oct 2006, 3:24 pm	#12
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Sony 9-90UB cogging Looking at the circuit and the adjustments, have you tried adjusting C807 and C808 for pulse width. Then re-locking the Line Frequency (VR602 and VR603) before adjusting VR601 (Line Hold). Just a thought. Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?