Pock-marked metal on the Ward Leonard supporting shelf has been filled and the shelf primed ready for refitting the Ward Leonard trays. It is important to eliminate depressions in all metalwork so if at a future date the radar is exposed to the elements there will be no water holding on the metal work. See accompanying photo of the primed Ward Leonard shelves on the rear of the T86 cabin.
A check was carried out of the fan trays. The fans are now a common failure point but they are an important part of keeping the Argus computer serviceable and the simulator running. Fan reliability is an issue, as identified previously, but has to be expected due to age and the poor environment the LCP was stored in. The Argus fan tray and the fan assembly under the CHARGE cards (display system) have been removed for repair. Replacement fans are still available! See accompanying photo. Spot the RAF screwdriver, found in the bottom of a rack i9n the T86.
For those who worked on or with the MK2A LCP, see the accompanying photo taken on May 25th of the display system. The start-up screen here is displayed before OPS or SIMULATOR is selected by the Engagement Controller (E.C.), we can only select SIMULATOR of course!
Away from Cosford – 2nd Line
We are always on the lookout for reasonably priced spares for those items that are still available. Obsolete electronic components often appear on eBay, or with specialist electronic suppliers, but usually at silly (high) prices. Exceptions do occur and one recent ‘find’ was a new (old stock) Archive 2150L tape drive. See accompanying photo. An important spare to have as one of our tape drives has already failed. The Archive tape drive is an essential component of the Argus computer system as all software is stored on and backed up to ¼” tape (DC600A and DC6150).
It is vital for us to build up a spares stock of components including processor chips, i.e. 8086, Z80 and 2901 bit slices as well as the less esoteric such as TTL logic and memory ICs.
A reminder that we are totally self-funded so beg that you please have a look in your stash of ‘might come in useful one-day’ components and see if there are any can you can release to the Bloodhound cause; we thank you in advance.
Further work carried out of the Ward Leonard shelf frame, mainly corrosion treatment ready for filling areas of wasted metal and priming.
Following an extended period of the simulator being U/S it is now serviceable again. A faulty co-processor was found to be the problem. See the accompanying photo of the simulator back in action. A major task now facing us is the repair of Argus computer boards, work has started on various test rigs but it is early days as a lot of work has to go in to reverse engineering designs etc we have no test rigs or test specs.
Away from Cosford work has continued on refurbishing our spare fan tray for the Argus computer. Several of the original fans have now failed which is not surprising as they are now 30 years old and the damp environment they have been exposed to. See accompanying photo of the underside of an Argus fan tray. The original but corroded finger guards are also being replaced, the photo shows one of the originals has yet to be changed. The original design and positioning of the finger guards caused a problem, spot what the problem is on the accompanying photo.
The T86 rear cabin floor had been primed the previous week, see accompanying photo, so on Saturday the task was to replace the plywood floor. The plywood sections had been cut out previously and laying them in position was a bit like a giant jigsaw. A start was also made on bolting the floor down.
Preparation for painting the rear cabin wall of the T86 has started, see accompanying photo. The cabin wall needs to be painted before the Ward Leonards are put back on their shelf. Further work was carried out on fabricating the mounts for the Ward Leonards and they were also primed.
Some time was spent on investigating the fault that is preventing the simulator from running. Fault finding will continue this coming Saturday. We do have spares but the issue is we have no way of knowing if they are serviceable due to age, their history etc and we have no test specifications for these comlpex cards. Testing cards in situ is an obvious answer to this problem but insert a card and it appears unserviceable, leave it a month of so, insert it again and it’s working. Next time we run up the LCP its not working; very frustrating.
Three tasks completed on Saturday:
- Prime the rear cabin floor of the T86
- Preparing Ward Leonard fittings for re assembly
- Test GX Processors in the LCP
The rear cabin of the T86 is now ready to have new plywood floor panels fitted after the floor received anti corrosion treatment and priming. Preparation is now complete of the alloy floor panels, the steel wheel arches and the securing brackets for the pedestal raising and lowering worm drives.
As can be imagined any external steel fittings on the T86 cabin will have suffered from corrosion including the Ward Leonard fittings under their covers. The accompanying photo shows a batch of fittings after cleaning and corrosion treatment. Thank goodness stainless bolts were used originally.
Test were also carried out in the LCP with several Argus GX processors which give varying fault symptoms, a bit of a mystery. More work on the Argus will be carried out this coming Saturday. Photos below show the rack of Digital Output cards using the LEDs to assist with diagnosis, then there is a shot of the FT81 terminal showing the nature of the error messages received for us to interpret.
Away from Cosford our spare fan trays for the Argus computer are being refurbished. Two new fans are required due to failed armature windings. Also the accompanying photo shows a new fan against an original, obvious which is which and of concern is the amount of dirt getting in the fans and being blown through the Argus.