Sony KV-1800 vs. KV1810 - UK Vintage Radio Repair and Restoration Discussion Forum

Racalfanatic · 3rd Nov 2007, 8:42 pm

Which should I go for and why please?

Chris55000 · 3rd Nov 2007, 9:06 pm

Hi!

Go for the KV-1800 - the KV-1810 has those horrible GCS-thingys that commit hari-kari and blow the mains out!!! (they're effectively in series across the rectified 275V Mains HT!!!)

The trouble with GCS devices is that they had to be switched *on* and *off* by precisely timed and shaped drive waveforms, and even *the smallest amount of deterioration* in line oscillator/driver stages, or the monostable/chopper driver stages on the power PCB will leave either/both of them switched on, resulting in instant failure!!!

Many articles were written about these dreadful things by a chappie called David Botto on their habits and I believe he published plans in TV Magazine to convert both PSU and Line Output to conventional BU208A transistors (put in a request for the "KV1810 GCS Conversion" articles on here - unfortunately I no longer have it I'm afraid!)

If you'd *rather* have a KV1810 I recommend you get yourself a copy of the full Service Manual, a Bush A823 Line Driver Transformer (in case you need to do the GCS conversion - I think SG6533s are totally extinct now!) and a copy of everything you can get that David Botto wrote about these horrors!

I would strongly recommend you go for the KV-1800 as this has conventional transistor line-output stage and power supply circuits!

I am willing to assist further if you need it, including visiting with equipment and helping you get a faulty one going - these are well worth restoring if the CRTs are OK!

Cheers,

Chris Williams

Steve_P · 3rd Nov 2007, 10:46 pm

When was it, about. I'll have a look.

They weren't THAT bad... just put a low fuse in the plug and do not exceed the rating on any fuses or fusible parts in the set. And have patience...

Cheers,

Steve P

dsergeant · 4th Nov 2007, 8:26 am

The article on the KV1810 conversion is in Television February 1987 by Colin Boggis, I have it if you need a copy. I remember I used this years ago, but it is not a particularly easy mod to do.

As others have said, steer clear of them. Almost guaranteed that the GCS's have blown, they are effectively unavailable these days. Save yourself a few headaches...

Dave

Racalfanatic · 4th Nov 2007, 2:23 pm

Thanks for your comments.
I'll keep a look out for a KV-1800 then.

Studio263 · 5th Nov 2007, 11:41 am

You could consider the KV-1820UB. This looks a bit like the 1810 model but is far more conventional / modern inside. There is one GCS in it but it's only used for EW correction and doesn't seem to give much trouble. The big advantage that this model has over the other two is that it has a proper PAL decoder, not the NTSC-based rubbish they used to use. The KV-2000UB is similar inside but there seem to be many minor changes that make panel swapping a pain.

The problem with the 1800 is that it has a special tube which (in this country at least) is unique to that model. It has a thick neck (like an A56 120X) which none of the other UK Trinitron tubes had.

Welsh Anorak · 5th Nov 2007, 1:46 pm

Hi
If you do decide on an 1800 do check the CRT's OK - that won't be too difficult as the set nearly always works. Check for red flaring and a general greenish hue - that'll be a duff tube. The only other downside is the rotary tuner - you either find it quaint or irritating.
I agree the 1820's a better bet than the 1810 (and the 1810 mkII's as bad!), but they are a bit thin on the ground.
Whenever you fixed an 1810 you had an urge to move house and change your phone number....that rrrr-ping noise haunts you and your bank account!
Glyn

Steve_P · 5th Nov 2007, 2:05 pm

The GCS's weren't the problem. The problem was the waveforms. As the sets got older, these deterioated and lots of the GCS's went ping! When one comes in, change caps on sight and make sure the waveforms are right. Then change the GCS's. A lot of people didn't and this is why these sets had problems.

If you fix them properly, which I admit takes time, they didn't come back for about 3 years.

Cheers,

Steve P.

dazzlevision · 5th Nov 2007, 6:04 pm

Hello,

I must admit to being a glutton for punishment, but I did rather like the KV1810UB!

I did quite a few of the conversions from GCS to transistors in the chopper and line output circuits and.,although they were quite involved, they did do the job.

Sony (UK) Ltd issued a list of standard checks and parts to replace as a matter of course when a KV1810 was in the workshop with two dead GCS. This included: small electrolytics in the chopper control circuitry and line oscillator/driver stages; a scan rectifier (or was it boost?) diode fed from the LOPT; the mains switch; the flyback tuning capacitor and so on......

I have found that the SG613 GCS or the later SG6533 (equivalent) are now obtaibnable on internet auction sites, etc - for little cost. If the repair is done carefully, the set's originality is maintained and they did work well.

IIRC, the KV1800 used a 90 degree CRT and was much deeper (and also heavier?) than the 110 degree KV1810UB. It also had rotary tuning, which was a pain for most people to use!

I agree that the KV1820UB is even better, for the reasons mentioned in earlier posts. However, it doesn't present the same challenge (or sense of foreboding) as a KV1810UB!!

Whichever set you decide upon, ensure the CRT is reasonable, as Trintrons don't reactivate!

Good luck,

Dazzlevision

Studio263 · 7th Nov 2007, 12:44 pm

IIRC, the KV1800 used a 90 degree CRT and was much deeper (and also heavier?) than the 110 degree KV1810UB. It also had rotary tuning, which was a pain for most people to use!

Actually the KV-1810UB has a 118 degree tube(!), this is a significant engineering acheivement and much was made of it at the time. Such a shame about the rest of it...

3rd Nov 2007, 8:42 pm	#1
Racalfanatic Retired Dormant Member Join Date: Aug 2007 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 105	Sony KV-1800 vs. KV1810 Which should I go for and why please?

3rd Nov 2007, 9:06 pm	#2
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,868	Re: Sony KV-1800 vs. KV1810 Hi! Go for the KV-1800 - the KV-1810 has those horrible GCS-thingys that commit hari-kari and blow the mains out!!! (they're effectively in series across the rectified 275V Mains HT!!!) The trouble with GCS devices is that they had to be switched on and off by precisely timed and shaped drive waveforms, and even the smallest amount of deterioration in line oscillator/driver stages, or the monostable/chopper driver stages on the power PCB will leave either/both of them switched on, resulting in instant failure!!! Many articles were written about these dreadful things by a chappie called David Botto on their habits and I believe he published plans in TV Magazine to convert both PSU and Line Output to conventional BU208A transistors (put in a request for the "KV1810 GCS Conversion" articles on here - unfortunately I no longer have it I'm afraid!) If you'd rather have a KV1810 I recommend you get yourself a copy of the full Service Manual, a Bush A823 Line Driver Transformer (in case you need to do the GCS conversion - I think SG6533s are totally extinct now!) and a copy of everything you can get that David Botto wrote about these horrors! I would strongly recommend you go for the KV-1800 as this has conventional transistor line-output stage and power supply circuits! I am willing to assist further if you need it, including visiting with equipment and helping you get a faulty one going - these are well worth restoring if the CRTs are OK! Cheers, Chris Williams Last edited by Chris55000; 3rd Nov 2007 at 9:21 pm.

3rd Nov 2007, 10:46 pm	#3
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Sony KV-1800 vs. KV1810 When was it, about. I'll have a look. They weren't THAT bad... just put a low fuse in the plug and do not exceed the rating on any fuses or fusible parts in the set. And have patience... 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...?

4th Nov 2007, 8:26 am	#4
dsergeant Octode Join Date: Mar 2006 Location: Bracknell, Berkshire,UK. Posts: 1,172	Re: Sony KV-1800 vs. KV1810 The article on the KV1810 conversion is in Television February 1987 by Colin Boggis, I have it if you need a copy. I remember I used this years ago, but it is not a particularly easy mod to do. As others have said, steer clear of them. Almost guaranteed that the GCS's have blown, they are effectively unavailable these days. Save yourself a few headaches... Dave

4th Nov 2007, 2:23 pm	#5
Racalfanatic Retired Dormant Member Join Date: Aug 2007 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 105	Re: Sony KV-1800 vs. KV1810 Thanks for your comments. I'll keep a look out for a KV-1800 then.

5th Nov 2007, 11:41 am	#6
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,577	Re: Sony KV-1800 vs. KV1810 You could consider the KV-1820UB. This looks a bit like the 1810 model but is far more conventional / modern inside. There is one GCS in it but it's only used for EW correction and doesn't seem to give much trouble. The big advantage that this model has over the other two is that it has a proper PAL decoder, not the NTSC-based rubbish they used to use. The KV-2000UB is similar inside but there seem to be many minor changes that make panel swapping a pain. The problem with the 1800 is that it has a special tube which (in this country at least) is unique to that model. It has a thick neck (like an A56 120X) which none of the other UK Trinitron tubes had.

5th Nov 2007, 1:46 pm	#7
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,919	Re: Sony KV-1800 vs. KV1810 Hi If you do decide on an 1800 do check the CRT's OK - that won't be too difficult as the set nearly always works. Check for red flaring and a general greenish hue - that'll be a duff tube. The only other downside is the rotary tuner - you either find it quaint or irritating. I agree the 1820's a better bet than the 1810 (and the 1810 mkII's as bad!), but they are a bit thin on the ground. Whenever you fixed an 1810 you had an urge to move house and change your phone number....that rrrr-ping noise haunts you and your bank account! Glyn

5th Nov 2007, 2:05 pm	#8
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Sony KV-1800 vs. KV1810 The GCS's weren't the problem. The problem was the waveforms. As the sets got older, these deterioated and lots of the GCS's went ping! When one comes in, change caps on sight and make sure the waveforms are right. Then change the GCS's. A lot of people didn't and this is why these sets had problems. If you fix them properly, which I admit takes time, they didn't come back for about 3 years. 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...?

5th Nov 2007, 6:04 pm	#9
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,611	Re: Sony KV-1800 vs. KV1810 Hello, I must admit to being a glutton for punishment, but I did rather like the KV1810UB! I did quite a few of the conversions from GCS to transistors in the chopper and line output circuits and.,although they were quite involved, they did do the job. Sony (UK) Ltd issued a list of standard checks and parts to replace as a matter of course when a KV1810 was in the workshop with two dead GCS. This included: small electrolytics in the chopper control circuitry and line oscillator/driver stages; a scan rectifier (or was it boost?) diode fed from the LOPT; the mains switch; the flyback tuning capacitor and so on...... I have found that the SG613 GCS or the later SG6533 (equivalent) are now obtaibnable on internet auction sites, etc - for little cost. If the repair is done carefully, the set's originality is maintained and they did work well. IIRC, the KV1800 used a 90 degree CRT and was much deeper (and also heavier?) than the 110 degree KV1810UB. It also had rotary tuning, which was a pain for most people to use! I agree that the KV1820UB is even better, for the reasons mentioned in earlier posts. However, it doesn't present the same challenge (or sense of foreboding) as a KV1810UB!! Whichever set you decide upon, ensure the CRT is reasonable, as Trintrons don't reactivate! Good luck, Dazzlevision

7th Nov 2007, 12:44 pm	#10
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,577	Re: Sony KV-1800 vs. KV1810 IIRC, the KV1800 used a 90 degree CRT and was much deeper (and also heavier?) than the 110 degree KV1810UB. It also had rotary tuning, which was a pain for most people to use! Actually the KV-1810UB has a 118 degree tube(!), this is a significant engineering acheivement and much was made of it at the time. Such a shame about the rest of it...