[Heatercathodeshort]

Pics of the ion trap magnet. Looking from the back the arrow should be on the left pointing towards the screen. Note it is a critical adjustment. Only a small twist will loose the raster.

If you put it on back to front it will work just as well but the magnet will be at the top.

I have also included a picture of the regular 1T9 ion trap with conventional securing strap. The original is completely over the top with a spring like a man trap, hence your scratched neck! I would suggest removing the spring and giving it a tug to relieve some of the tension. It should be just a snug fit.

The LOPTs on these are quite reliable but I would certainly suggest passing about 30m/a through the overwind EY51 anode to PL81 anode for a few days. Check that the overwind is just warm, if not increase the voltage. If your overwind is the high resistance spec you may need around 100-200v to create any warmth.

The MW36-24/44 is a good tube. It can suffer from internal shorts but this was not common.

Just for reference the CRT voltages measured with a DVM with a normal picture displayed are: Cathode- 148v Grid- 47v First anode- 534 and the EHT measured with an analogue meter- 16kv. The mains input here is high at- 245v.

Note when it comes time to adjust the Ion trap, it must be adjusted for MAXIMUM brightness. Corner cutting, picture position and focus are provided with their own adjustments.

Checking my Ferguson files I discovered that I have two copies of the advance service information for the 991T. You are welcome to it and together with your Trader sheets, may come in useful. John.