Work Day 23rd November 2019

T86

The Reference Aerial Modulator was removed from the aerial assembly for refurbishing and to give better access to the aerial boom. See the two accompanying photos showing the removed aerial modulator and the section of the aerial boom exposed.

 

The Radiation Absorbing Material (RAM) used on the radar is being refurbished as and when and this week the RAM material on the ledge of the pedestal was re sealed and stuck down with suitable sealant. See the accompanying photo which shows the RAM has lifted up slightly from its base.

LCP

The computer fans draw in air from the vents in the end wall of the LCP where the air conditioner unit was originally connected An air filter is located in the trunking under the LCP floor just inside the E.C’s door. See accompanying photo.

The original filter had disintegrated many years ago so it was important to replace it and prevent dust being drawn in. A further photo shows the newly fabricated filter in position.

After many months of fault free running the LCP/simulator developed a coupe of faults. The first being that all keyboard and tracker ball inputs were lost and changing the Multiple Channel Serial I/O card in the Argus 700 sorted that problem. The second being the loss of the LCP one second ‘ticking’ provided by the sequencing unit at the base of the power distribution rack (Z Rack). The suspicion being that the -50V DC that enables the one second pulses to the sequencing unit is being lost, possibly a fuse in the display console. Time ran out before this fault could be investigated further.

Pete

Work Day 16th November 2019

T86

The focus of the day was the reassembly of the Jamming Assessment (JA) aerial and the repainting of the In-Flight Reference (IFR) aerial. See the accompanying two photos, the JA aerial is awaiting the fitting of its glass fibre cover …

… and the IFR has received a coat of rubber sealing paint on its rubberised sheet of radiation absorption material (RAM).

Away from Cosford the refurbishing of fans from spare I/O rack trays is taking place. The fans are Papst (now ebmpapst) 4850n models, still available but expensive if all twelve in the I/O rack need replacing. It appears that the current fans are failing due to a lack of lubrication due to age! See the accompanying three photos, one showing the original condition of two fan blades the second showing one disassembled and the third the re assembled and tested fans after refurbishing.

 

 

LCP
The simulator was run and remains serviceable.

Pete H

Work Day 9th November 2019

T86
A few minor tasks carried out. The elevation Ward Leonard cover is back in place and the lid of the distribution box bolted down. The refurbishing of the Ward Leonards and the rear shelf of the T86 cabin is complete. Work was started on preparing the waveguide outlets for the On-Launch Reference aerials, see accompanying photo.

T86 items refurbished off-site:

Top Junction Box – top of pedestal. See the accompanying photos of before and after showing the RF connectors. The reason why the ‘white powder’ corrosion was so bad is that the seal on the top cover had completely perished.

Console labels – radar cabin. Mike S has done an excellent job of engraving and refurbishing several labels, see accompanying before and after photos.

 

LCP
To carry on with the off-site refurbishments. A fan assembly salvaged from the bottom of the I/O rack in LCP Ser No. 1006 has been refurbished, see accompanying photo.

The cadmium plated metalwork has been corrosion treated and painted black – to hide its original poor condition. Three new fans installed. This fan assembly is now held in the LCP as a spare.

 

FANS REQUEST
Here is a synopsis of the fans we could use from your spares drawer if you have any to donate please:

I/O Rack and Argus Fan Trays – Replacement Fans

Three Option Evaluated
X-Fan –             made in China
SUNON –          made in Taiwan
embpapst* – made in Germany
* Continue to manufacturer the original fans used in the Computer Racks

Two types of original fan both are 230V AC with a size of 120mm x 120mm x 38mm, one is a three bladed fan with a CFM of 59 as used in the I/O rack, the other a five bladed fan with a CFM of 95 used in the Argus fan tray.

Fans described as a ‘terminal’ version have a two-pin connector as per original fans.

X-Fan
Direction of rotation          Anti-Clockwise, viewed toward rotor
Available from www.rapidonline.com

Argus Fan Tray
X-Fan RAH1238B1 (Ball Bearing) £12.50
CFM 97
Sleeve version £1 cheaper
Five blade
Leads only no Terminals

I/O Rack Trays
No version of this fan for I/O trays (CFM 59)

Embpapast (original fan design)
Direction of rotation          Clockwise, viewed toward rotor
Available from uk.rs-online.com

Argus Fan Tray
embpapst 4650N – CFM 95 (Sleeve) £30.50
Five Blade
No bearing version
Terminals

I/O Rack Trays
embpapst 4850N, Flow = CFM 59 (Sleeve) £29.20
4856 is the bearing version
Three Blade
Terminals

SUNON
Direction of rotation          Anti-Clockwise, viewed toward rotor
Available from uk.rs-online.com

Argus Fan Tray
DP200A- 2123XST.GN (Sleeve) CFM 95 £17.20 OK
DP200A- 2123XBT.GN (Ball Bearing) CFM 95 £25.00 OK
Five blades
Terminals

I/O Rack Trays
No rating low enough a CFM of 59 required.
DP203A-2123LSl.GN CFM 72 (Sleeve) £14.80
DP203A-2123LBL.GN CFM 72 (Ball Bearing) £18.60
Five Blades
Leads, RS not suppling terminal version?

Summary

Manufacturer	Model	Bearing	db	Clock or Anti Clock	I/O or Argus Tray	Price
X-Fan	RAH1238B1	Ball	42/44	Anti Clock	Argus	£12.50
Embpapast	4650N	Sleeve	46	Clock	Argus	£30.50
Embpapast	4850N	Sleeve	32	Clock	I/O	£29.20
SUNON	DP200A- 2123XST.GN	Sleeve	44/49	Anti Clock	Argus	£17.20
SUNON	DP200A- 2123XBT.GN	Bearing	45/50	Anti Clock	Argus	£25.00
SUNON	DP203A-2123LSL.GN	Sleeve	36/32	Anti Clock	I/O	£14.80
SUNON	DP203A-2123LBL.GN	Bearing	37/39	Anti Clock	I/O	£18.60

END

Work Day 2nd November 2019

T86
Most of the current work on the T86 is treating corrosion and preparation for painting, not a very interesting topic to report on. What is provided by my regular blog are the highlights.

Resealing the Radar Absorbent Material (RAM) that covers the side of the In-Flight Reference aerial is now complete. The final task, sanding the sealant to provide paint adhesion has been carried out, see accompanying photo.

A second photo shows a waveguide end from the In-Flight Reference aerial. Condition is not good, obviously from water ingress, not surprising as there was no waveguide joint seal present!

Last week I put a first coat of paint on the rear pedestal roof edge. The paint was from the second batch of two tins of donated paint. We have used all the original two tins of paint. See the attached photo – the paint colour is different!

The two tins we are now starting to use are marked NATO Green, so the conclusion is , the first two tins were not.  NATO green is readily available and has a BS paint spec but  the NATO Green I have from a different supplier is not the same as the two donated tins we have!

The Jamming Assessment (JA) aerial is ready for re assembly. The refurbishment of the aerial gave us the opportunity to see if the offset dipole still rotates by patching mains voltage to the drive motor. It does, see accompanying video (animated GIF at 10fps).

The purpose of the JA aerial is to provide directional information and strength of any jamming, offset from the radar centre line. When we had stripped down and examined the construction of the aerial we were surprised at the size of the offset balance weight. Now we can see the eccentricity of the aerial reflector the lower balance weight size becomes apparent.

LCP
We didn’t run the simulator this week

Pete H

LCP 1006 – One We Couldn’t Save

LCP 1006 had been languishing for years at North Luffenham and we were fortunate to hear about it before the station was handed over to the army. We were welcomed in to salvage what we could to provide spares for our restoration project. This is the sight we were greeted with:

As we approached we were immediately greeted with this – the doors were wide open and evidence that others had been before.

Sure enough it had been raided and vandalised.

We secured the cabin label as evidence of the equipment there:

Next was to remove anything that might serve as useful spares or to build a test rig simulator; here I am, Mike Strange, getting down in the dirt and bird droppings!

Needless to say all of the computer and display equipment had long gone. What was sad to see that the glass faces of ever single meter had been methodically smashed! Outside the site cable drums were still there but guess what … yes all the cables had gone,

Anyway, lots of smal items and internal cables were retrieved and as we left Pete Harry appeared to be rather satisfied by what we obtained.

If only it had been put in a secure place and we had heard about sooner!

Mike S