Work Day November 28

Pete Murray checked to see if the RGB video signal produced by CHARGE could be connected to a 15″ CRT monitor using an RGB to VGA converter. The result, still no joy but sort of expected. Pete took some pictures off the scope such as RGB timing and further investigations will take place off-line. We need to understand the RGB requirements of the Mitsubishi monitor and work back from that, is the RGB it expects actually ‘standard’ RGB?

Neil and Ian spent the day in the T86 removing covers then removing their chrome handles. Neil confirming that we now have a complete set of keys for all the locks in the T86 which, including the door lock, comes to six! It took two visits to a local locksmith to sort the lack of keys of which none were in the radar when it was acquired. As in the previous week a bit more board testing, specifically GX and GL processors which were not serviceable. Perhaps off-line learning to fault find and repair these units is a top priority – along with all the other top priorities.

The Tech. Sup’s monitor lost its vertical hold and no amount of adjusting could stop the picture ‘wandering’ in the horizontal. Remember, the display monitors are mounted in the console on their ends so Vertical as displayed is actually Horizontal re adjustment. We’ll have a look at this monitor again next week and if necessary remove it to the workshop for fault finding.

Work Day November 21

Initial tests on RGB to VGA conversion for the display monitors using an Extron Video Converter which will convert RGB to VGA. The plan was to carry out some initial testing with CHARGE connected to a 15″ CRT monitor. CHARGE uses non-standard video frequencies, so there are no guarantees that the converter/monitor combination would work and today we did not have success so will continue testing next week.

Set about removing covers in the T86 radar racks so they can be sent for re chroming. Sounds easy enough but one little problem was that we do not have the EHT key or keys to fit the covers on the Tx rack! The locks I had keys made for last week fit the drawers in the cabin but NOT the Tx covers. Also, what I thought was an EHT key wasn’t. We did manage to remove most covers and the actual EHT interlock lock. So it’s back to the locksmith tomorrow!

Most of the day in the LCP was spent testing our spare A700 cards. We ran the sim, checked everything was OK and then systematically replaced the known good cards in the A700 with

Checking all our A700 cards in live simulator. Over the past year, at least, we had replaced cards to resolve faults etc. but it was the usual problem of did we think a card was U/S but it was something else causing the fault etc. etc. Anyway, some surprises, one being an ME170 GX processor that was thought to be U/S wasn’t and also discovered that the ME172 Floating Point Processor in situ was in fact U/S as it gave corrupt bearing information on the P Display between 340 – 350 degrees – something that was noticed by chance! Bottom line: We have a serviceable set of cards in the LCP’s A700 and at least one serviceable spare for each card. The U/S cards we will need to get repaired. A700 board swapping is something we wouldn’t have done up to a few months ago as it was certain to cause more problems than it fixed but as the simulator now runs reliably, we power it up and down, swap boards and it still runs just fine unlike the many months spent when it developed a fault or stopedp running when we took a tea break (hope I haven’t spoken too soon)

Work Day November 14

Had a productive day refitting all the lamp lenses on P-Rack. The simulator ran well again following an initial problem with a WEETABIX card at power on, not a fault as such as the WEETABIX cards just needed pulling and re inserting. The simulator ran well apart from a couple of display (mains) glitches which always happen at lunch time. The reliability of the simulator is now so good we refitted the covers to the computer racks! Trying to develop a PeriBus simulator. Yet to be completed but the timing of the serial PeriBus L5 and L6 is done as is one of the L1/L4 lines. This will enable us to drive the I/O cards for stand-alone testing.