CTV 110 delta crts

Philips G9 used them, also Pye in the 70,s. Never lasted as long as the 90 deg.

Telefunken 711 chassis used a 110° delta tube (A66-140X in the 26" sets) whilst SABA used an A67-200X. As Malc says, they didn't last too well. We had examples of both. Pretty sure Grundig used them too.

The Pye 731 also used a 110 degree delta CRT.  In my experience chassis with 110 degree delta tubes were not that reliable compared with 90 degree and as others have said the tubes didn't have a long life.  Thyristor line stages so loved by the Continental manufactures suffered from dry joints and got fairly baked after a few years I suppose due to the high currents involved, This usually meant that by the time the tube was starting to lose emission the chassis had been repaired a fair bit and the set was disposed of.

The G9  and the expensive Saba "Telecommander" were probably the best but the G9 suffered but with those horrid electrolytics that leaked gunk which often wrote off the large signals panel. The Pye 731 got very cooked around the line stage and a short circuit capacitor on the A1 supply often took out the tripler the LOPT and the soldered in line output transistor which could be a sod to change. I remember seeing lots of them disposed of somewhat prematurely compared to other sets at the time.

  The Telefunken 711 was a problem as early sets were designed for 220V so at five years old they were well baked, the line driver transformer would burn out taking the tightly packed panel with it resulting in the set being written off.  Grundig models could be OK until the myriad of large wire-wound resistors burned a hole in the panel and again suffered from cooked line stages and dry joints. 

This may explain why the sets are scarce by now. When I scrapped a 110 degree delta the whole set usually went, it wasn't worth keeping the tube as it was usually assumed to be low and there wasn't much demand for a second hand 110 degree tube as mostly the sets were not worth repairing by the time the tube was low. I remember scrapping a Dynatron 731 at about five years old because it had been so unreliable, the wealthy owner couldn't be bothered with it anymore so I gutted it and installed a new G11 into the cabinet. I did keep the tube from that as I knew it was good but I can't remember using it, it probably went in the bin lorry when I moved workshops...

To be honest I was glad to see the back of 110 degree delta sets especially the Thyristor models but of course worse was yet to come! 

Was there a GEC chassis that used a Mullard/Philips 110° delta CRT? I don't ever recall seeing one. I think every other UK manufacturer with the exception of Thorn had them.

Rediffusion got a batch of quick heat A56-120X from Mullard. These were fitted to the RBM A823 chassis (RT529/22) when they were refurbed into RT559/22. Within 3 seconds a good picture, the degause cycle was visible. 

@jayceebee As far as I know GEC went from 90 degree delta to 20 AX There may have been a short lived model that I didn't see especially if it was as reliable as the 20AX model. I hardly saw any in for repair, A mate sold and rented loads and rarely had any faults.

Another mate worked for a Bush dealer when the T20 came out, now he was very busy! 🤣 They were changing their rentals over from Korting Hybrids he says they were better off with the old Kortings! 

Well if anyone happens to come by one, I'm interested!

The Kriesler 59-01 chassis was a well-engineered design based on the Philips K9. And a reasonably reliable set they were too. They ran cool - no massive dropper resistors, no live chassis, no huge copper and iron mains transformer.

Those Philips 110 degree Deltas were not an easy tube to drive and required some mind-bending complexity to get the perfect results that are possible with a 59-01.

Did you see the Philips K9 in the UK? (no pun intended!) The version Philips made and sold here had the special isolated "studio" switched-mode power supply that was used in Europe only in TVs with AV input sockets added.

We saw a range of continental models during the 'colour boon' in the early to mid '70's including the K70, when demand exceeded UK home market production. I don't remember seeing any Philips K9 models as such but there was a short lived 26" solid state chassis that was I believe a Philips continental chassis that was sold briefly.

I think it was either between G8 and G11 or possibly between G11 and K30.  I think I saw one or two, fairly old at the time and past their best. ISTR it had a vertical PCB with lots of modules. It could have been a K9 maybe? 

Not sure about K9 but the K80 made it to our shores.

Two vertical swing-out boards hinged at the sides with lots of modules in little aluminium cans. Signal on the LHS, deflection on the RHS.

The user control and speaker panel at the front hinged down to reveal a large set of convergence controls - a joy to use!

Power supply in the middle below the CRT in a metal cage.

The K9 had some strange anachronisms in its design that were not copied by Kriesler, such as diode detection for luma and chroma (vs synchronous demod in the 59-01) and colour difference drive with matrixing done in the CRT (vs RGB cathode drive in the 59-01). Philips in trade talks during the introduction tried to claim superiority for their method, this was not borne out in comparisons, the 59-01 was identical to the K9 in side-by-side picture quality tests. Kriesler engineers were clearly taking no risks with most of the by-then-proven design, the modules were copied in a more field-serviceable form using a different and larger connector while retaining the same pin numbers! This was great if you needed to service a Philips module, Philips didn't publish the circuits of their modules but Kriesler did!

Kriesler re-designed the SMPS controller, making it better behaved if a fault such as a failed tripler developed in the set and able to operate a class B audio amp without issues.The Philips had a Class A audio circuit that ran from the 145 volt rail.

Those power supplies were the hardest thing for the service techs at the time to get their heads around!