Work Day 9th November 2019

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 On Launch Ae Plate wm.jpg

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.

T86 Top JB Before wm.jpg

T86 Top JB After wm.jpg

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

T86 Radar Consol Labeks Before wm.jpg


T86 Radar Consol Labels After wm.jpg

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.

LCP I-O Rack Base Fan Refurb wm.jpg

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.


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.

Direction of rotation          Anti-Clockwise, viewed toward rotor
Available from

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

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

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

Direction of rotation          Anti-Clockwise, viewed toward rotor
Available from

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

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?


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