KB WV20 Warwick - Built to last!
 

I collected this television last weekend from another Steve (Regentone001) down Coventry way. Nice to meet you Steve!

This set had a sorry tale to tell, having been accidentally knocked to the ground from a dining room table after Steve's Jack Russell was spooked by a firework. The blow split one end of the cabinet open and the chassis received a hefty whack, causing some distortion, but miraculously the crt escaped being necked although the plastic 'bowler hat' was damaged (luckily I have a spare). A couple of the wooden blocks on which the tuners and use controls are mounted broke free and need re-gluing. I'll probably strip everything out in order to do it properly.

Despite it's accident, the KB still works very nicely, with Steve's previous restoration work holding out well. Prior to his custody I suspect it may have been a one owner set, the pre-accident condition being so good. It's fitted with a twin-panel Brimar 'Plus' A47-13W which looks to be the original and produces a really bright, well contrasted picture. I have a soft spot for these 1960s STC group sets- KB, Regentone and RGD. They produce great results and the chassis is very well engineered (and tough!) I'm not aware they have any particular weak points. The cabinets and presentation are always very attractive too.

One casualty of the accident was the shatterered VHF tuner knob (main and fine tuner). I think it would have been the classic KB 'lightning flash' type. If anyone has one knocking around in a spares box I'd be very grateful!

Steve

Re: KB WV20 Warwick - Built to last!
 

They are beautiful sets. The original Brimar twin panel in my VC1 is great too. They were made about 3 miles from where I live and many retired people round here remember working for them. A friend has just given me a dismembered VC2 chassis. I will ask him if he has a tuner knob

Re: KB WV20 Warwick - Built to last!
 

That's very kind Steve, thank you!

Steve

Re: KB WV20 Warwick - Built to last!
 

great sets these we did loads of ace vv15 with the vc1 chassis at telebank . there was a mod to increase range of frame hold change a 1.8k resistor to a 6.8k . the later vc51 chassis[regentone mv818/918] used a 10k in the same position .can,t remember cct ref but was a grid resistor it was many moons ago
brian

Re: KB WV20 Warwick - Built to last!
 

Lovely set.

I've never actually worked on a KB/RGD/Regentone model of that era with a "thermometer" type UHF tuner channel indicator. These must have been a more expensive model than the usual VC1/2/3 sets with a rotary UHF tuner knob (with a concentric channel indicator disc), located on the RHS with the other customer controls.

I see the UHF tuner is a Philips type - a new one for me on a VC1/2/3 chassis set.

Re: KB WV20 Warwick - Built to last!
 

Indeed! I have a Regentone set with the thermometer tuning arrangement (illuiminated on that model). I'll check and see what tuner it uses.

The Warwick is certainly in the de-luxe class with it's no-expense-spared use of twin speakers...!

Steve

Re: KB WV20 Warwick - Built to last!
 

Great sets, one my bucket list to get.
Greg.

Re: KB WV20 Warwick - Built to last!
 

From my experience of the other makes of valve UHF tuner fitted in these sets (AB Metal Products and Sydney S Bird - "Cyldon"), the Philips tuner is likely to actually work (with good valves fitted) and be more reliable!

Re: KB WV20 Warwick - Built to last!
 

Hi Steve
it was great to meet you and I am glad to see the set working.
I still haven't come across the original coil but when I do I will send it to you
Steve

Re: KB WV20 Warwick - Built to last!
 

Hi Steve,
If your set has the VC1 chassis has the frame sync modification been done? Well worth doing if the frame hold is critical. The triode section of the PCL84 is rewired to serve as the frame sync amplifier and clipper.
All subsequent chassis have the modification.
VC1 has the ECC81 line oscillator, it works OK but all later chassis employ the PCF802. Triode section operates as a reactance valve the pentode as a sinewave oscillator.

DFWB.

Re: KB WV20 Warwick - Built to last!
 

Hello Steve. Peter Sanders has come up with the attached KB knob. Any good for you?

Re: KB WV20 Warwick - Built to last!
 

Hi,
Back in the 70s, when I was a lad, I remember ITT-KB tellies with that chassis sporting a 'Hand Wired' logo. I think this implied that they were more reliable than PCBs. Or that the customers trusted them more?
Cheers, Pete.

Re: KB WV20 Warwick - Built to last!
 

Like this, which was first used around 1966-67:

Re: KB WV20 Warwick - Built to last!
 

Frame sync modification (copied from an STC Consumer Products publication):

To convert the triode section of the PCL84 from functioning as a 405 vision interference limiter, to a frame sync pulse amplifier (as used in VC2 and all subsequent dual standard chassis):

Using the triode section of the PCL84 in place of the OA81 diode.

Components required:
680kΩ ½W 10% resistor
68kΩ ½W 10% resistor
2.2kpF 10% capacitor

Procedure:
1. Remove C66, R61 and OA81 diode
2. Replace R74 10kΩ resistor by 68kΩ
3. Replace R76 1.8kΩ resistor by 10kΩ
4. Connect cathode of PCL84 triode to junction of R71 and R72 and leave grid of valve connected to chassis.
5. Connect triode anode of PCL84 to junction of R74 and C72
6. Fit 680kΩ resistor from HT line to triode anode of PCL84
7. Fit 2.2kpF capacitor in parallel with R74

For the circuit of this change, refer to the VC2 chassis circuit diagram, V7 triode section.

Re: KB WV20 Warwick - Built to last!
 

Hi Steve, that's looks about spot-on to me! Many thanks to Peter for digging it out. I'll send you a PM.


Steve

Re: KB WV20 Warwick - Built to last!
 

I jusrt wanted to extend my very grateful thanks to Steve N for sourcing a VHF tuner knob for the KB. I didn't see the original but this one looks a perfect match. The set will need stripping out for some internal cabinet repair work, but looks a lot happier already!

Steve :)

Re: KB WV20 Warwick - Built to last!
 

Looks lovely!

Re: KB WV20 Warwick - Built to last!
 

What a beauty Steve , they always looked modern to me with their slim cabinets.
Regards Gary.

Re: KB WV20 Warwick - Built to last!
 

Hi Gary,

Yes, one of my 60s favourites too!

Steve

Re: KB WV20 Warwick - Built to last!
 

Lovely looking set. That VHF tuner knob looks spot on too.