Featured
Latest
Share:
Notifications
Clear all

Forum 141

RGD Deep 17.

52 Posts
11 Users
57 Likes
5,016 Views
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 
Posted by: @katie-bush

I guess the real acid test will be in how many switch on cycles it can withstand. Probably a million reasons why not, but, would it be possible to snub the surge with addition of, say, a PTC device of some kind, across the heater?

Hi Marion,  the heaters are very well controlled by the Mullard VA1026 thermistor at the top of the heater chain. As for the failure of the tube we'll put it down to simply bad luck.  I was always extolling the merits of the AW43-80 but now I'm not so sure.

Till Eulenspiegel.

 
Posted : 06/09/2020 7:57 pm
irob2345
(@irob2345)
Posts: 546
Honorable Member Registered
 

ETF in Hilliard Ohio have a 17ATP4 that should suit. You will have to change the heater arrangements tho.

 
Posted : 07/09/2020 2:22 am
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

Today. The Deep17A chassis is now on the bench to receive a replacement CRT.  But first the  old CRT must be removed, but that's not going to be easy, the tube is stuck fast on it's mounts. Seems like those cork composition pads are well and truly stuck to the metal parts and the CRT glass bowl.  

Can't use too force because there's danger of implosion, the AW43-80 is tough little tube I'm sure but why take chances on a scrap tube? Or any tube for that matter! A much better plan will be to take the tube down to air by drilling a tiny hole through the end of the base, the method employed by tube regunning firms.

So I'm off to the workshop right to do that task so that the tube will be ready for removal tomorrow. Then, I can use as much force as is necessary to take tube out.

Till Eulenspiegel.

RGD Deep17A CRT
RGD Deep17A CRT 2

 

 
Posted : 17/10/2020 8:30 pm
PYE625
(@pye625)
Posts: 5121
Famed Member Registered
 

A flat bladed knife gently pushed between the glass and cork may be enough to seperate said items, but you probably know that well enough anyway. ? 

Be a pity to break up the cork and end up having to use something else to replace it.

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 17/10/2020 9:07 pm
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

Hi Andrew, I've applied RS Components switch cleaner to soften up the cork just because it was close to hand. Anyway, I'll be in the workshop soon so we'll see how things progress.

Till Eulenspiegel.

 
Posted : 17/10/2020 9:14 pm
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

Tube is down to air.  That's it, I'm out of here. Get back home now.

 
Posted : 17/10/2020 9:44 pm
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

The CRT was made safe.

RGD Deep17A CRT 3

Fitted the tube that was in the Stella ST1007U. It looks bright but in fact the picture is dim, just like it was in the Stella.

RGD Deep17A CRT 4

The MW43-80Z will be used. A focus magnet is required with this tube.

RGD Deep17A Focus Magnet

Till Eulenspiegel

 
Posted : 19/10/2020 7:10 pm
freya, PYE625, freya and 3 people reacted
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

Yesterday the focus magnet and MW43-80Z CRT was fitted on the Deep17 chassis. Excellent results.

Note the CRT does not use an ion trap.

RGD Deep17A MW43 80Z

Till Eulenspiegel.

 
Posted : 21/10/2020 8:47 am
Nuvistor, Derren, Nuvistor and 3 people reacted
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

Mullard CRTs MW43-69, MW43-80 and MW53-80 have pentode guns and I assume it is the same with the non ion-trap MW43-80Z. 

From the Mullard Maintenance Manual:

Prefocussing; The spot size and uniformity of focus depends upon Va2 Va2 at zero or negative with respect to the cathode the spot size at the centre of the screen and width of the electron beam are such that the optimum uniformity of focus is obtained over the whole of the screen. If Va2 is increased, the spot size at the centre is reduced but the width of the electron beam in increased, resulting in inferior focus at the edge of the screen. With increased Va2 the power of the focus magnet has to be increased.

MW43-80 A2 is pin 7 whereas the focus electrode in the AW43-80 is pin 6.  Va2 is connected to the the cathode, pin 11.

Till Eulenspiegel.

 
Posted : 24/10/2020 11:38 am
MurphyV310
(@murphyv310)
Posts: 453
Honorable Member Registered
 

@till

Amazing sets with as you say very reliable. They are simple designs with a low component count which no doubt aids reliability.

Cheers,
Trevor.
MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

 
Posted : 31/10/2020 10:15 pm
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

An export version of the RGD Deep17?  Found this magazine on ebay France.  It'll be interesting to read the comments about the set. 

RGD Deep17 Fr

Till Eulenspiegel.

 
Posted : 07/02/2021 4:21 pm
Till Eulenspiegel
(@till)
Posts: 4947
Famed Member Registered
Topic starter
 

It's not an 819 line version of the RGD Deep17.  The illustration simply depicts an example of current UK TV set manufacturing, although it's safe to suggest by 1960  the Deep17 will have been superseded by slim models with 110* CRTs.

RGD Deep17 Fr 2

Till Eulenspiegel.

 
Posted : 21/02/2021 4:45 pm
Page 3 / 3
Share: