Jump to content


Student of Military HistoryWeston Instruments Division MODEL NO. 898 TYPE NO.15 MFR’S NO. 521273

  • Please log in to reply
3 replies to this topic

#1 Bomber Bob

Bomber Bob
  • New Members
    • Member ID: 172,930
  • 3 posts

Posted 04 November 2017 - 01:34 PM

I'm interested in military technology.


The thing that interests me at the moment is something that I believe is called a glide-slope indicator (displays aircraft pitch and roll). I have one labeled:


         Weston Instruments Division 

         MODEL NO. 898 TYPE NO.15

         MFR’S NO. 521273


This is a sealed device, and I don't really want to open it, but I'd really like to know how it was connected electrically or what the interior schematic might be.


I've googled every term I can think of and can't seem to find any information on this device.


Thanks for any information you can provide.



#2 Steve B.

Steve B.
  • Members
    • Member ID: 9
  • 2,053 posts
  • Gender:Male
  • Location:Oregon

Posted 04 November 2017 - 02:33 PM

A glideslope indicator uses a horizontal needle that deflects up or down to indicate where the aircraft is in relation to the ideal glide-slope or glide-path.  It is normally a fairly simple connection consisting of little more than a pair of wires for the up-down needle, and a pair of wires for an on-off (or "flag") signal.  There are possibly  power and ground connections for internal lighting.  Receiving and processing of the glideslope signal was done by a receiver separate from the indicator.


Glideslope indicators are usually part of a single instrument that also shows left-right information.  The left-right information can indicate if the aircraft is lined up with the centerline of the runway, or if it is left or right of centerline.  In this instance, it is called a localizer.  Again, the signal is received and processed in a receiver separate from the indicator.  Localizers and glideslopes are used together, although it is possible to have a radio with localizer but without glideslope.  However, I have never seen a glideslope without a localizer.


On many indicators, the left-right needle can also be used display  VOR (VHF Omni-Range) course information, but that's a whole new discussion!


I found several photos on-line of a Weston Model 888, but so far have struck out with a Model 898. 


Weston has been in business for a long time, and there is lots of info out there.  Keep digging, and I'll let you know if I find anything.

#3 Cobra 6 Actual

Cobra 6 Actual
  • Members
    • Member ID: 159,798
  • 917 posts
  • Gender:Male
  • Location:Virginia

Posted 04 November 2017 - 02:35 PM

Hello and welcome, Bob. In addition to what Steve wrote, if you need even more info, I think your question might be better addressed in a different sub-forum from this intro one. Perhaps one of the more experienced members can make a suggestion?

Edited by Cobra 6 Actual, 04 November 2017 - 02:36 PM.

#4 Bomber Bob

Bomber Bob
  • New Members
    • Member ID: 172,930
  • 3 posts

Posted 05 November 2017 - 04:14 PM

So, this may not technically be a "Glide-slope Indicator."


The front has:

A picture of a cross section of an airplane as viewed from the rear.

The horizontal needle is labeled "U" and "D" which, I presume, means UP and DOWN, probably relative to the nose.

The vertical needle is labeled "L" and "R" which, I presume again, means LEFT and RIGHT. Because airplanes tend to roll through turns I expect that this indicates roll direction rather than turn direction.

There is also an indicator light labeled RELEASE.


The back has:

A screw labeled “+” and one labeled “-“ which I expect are for application of 28 VDC standard aircraft power.

There is also a 18 pin electrical connector.

Eight of the pins seem to be connected together in pairs.

Two pins (including one of the eight) are connected to each of the two previously mentioned screws.

Three more pins  (including two of the eight) are connected to the indicator light

Four pins don't seem to be connected to anything


Thanks for any help understanding this.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users