PSX radar tests

[Hardy Heinlin]

GAIN is a rotary switch with 10 positions in 30° intervals.

TILT is a pot. It must be of good quality because it has trigonometric effects that can quickly go from zero to infinitely long when you turn it, i.e. a millimeter more or less may make a big difference on the display regarding the horizon of terrain reflections below or clouds above.


Cheers,

|-|ardy

[farrokh747]

Thanks! - i assume a single turn pot for TILT..?

fc

[Hardy Heinlin]

Single, 270°.

[Blake H]

Hi guys, I found this thought it might be handy...

http://www.smartcockpit.com/data/pdfs/flightops/aircraft/Collins_WXR-2100_Operator's_Guide.pdf

I concluded from the document the AUTO LR switch on page 4-3 figure 4-3 is latching, the rest of the switches are momentary? Any light on this. I thought all were latching.

Very interesting.

[John H Watson]

Switches as follows

Latching:
AUTO
L/R
TEST

Push & Hold (spring-loaded):
GC

Latching, but unlatches with selection of others in group:
TFR
WX
WX+T
MAP

[Blake H]

Thanks John.

That will be difficult  to design and construct if your a sim builder.  

I made the earlier model wx on my pedestal the new version is a bit beyond me to construct.

[Jeroen Hoppenbrouwers]

Although not necessarily realistic, remember that you can leave the unlatching of "radio buttons" to PSX. You just need to provide the momentary.

You may be able to construct something where the actuators which the human finger pushes on are mutually heaving, so you imitate the button movement and one remains stuck down. Normal momentary switches under the actuators then can pick up the push-down event for PSX.


Jeroen

[Blake H]

Thanks Jeroen. I will have to have a think how to make one.

I have made a dual pots before. I found I was unable to get hold of dual pots at low quantities. I had one seller that wanted me to buy 20,000 dual pots. Just needed 10. This is a factor for some builders considering this type of panel.

Does anyone know why Boeing have gone for the split system with duplicated control? Was there a incident or something?

[Jeroen Hoppenbrouwers]

Machines break. Controls break, too. You don't need an incident to get irritated when your radio won't tune any more because the inner knob refuses to work when you turn it to the left. And then you need a swap at the next stop. Grrr.

Better to have stuff redundant, everywhere, and hope that the techs catch half-broken stuff in time.

[Blake H]

Weather radar test as per Boeing fcom manual.

'the test pattern and PWS symbol remain displayed until WXR is selected off on the EFIS control panel, another mode is selected on the Mode Selector, or an actual PWS alert is detected. The source of any faults displays in the weather radar tilt field on the ND'.

John Watson's quote "Latching for Test"?

Any thought with the fcom and John's quote above?

[Hardy Heinlin]

The test pattern is also displayed when both TFR switches are pressed. TFR means transfer which means in this double case: the left pilot gets the right pilot's WXR settings and the right pilot gets the left pilot's settings, which means: both have the chicken as well as the egg and the system doesn't know what comes first. I.e. only one pilot can chose the option to get the other pilot's settings.

I wonder what raster image the PWS will generate in this unlogical case. In PSX, the test pattern remains, only WINDSHEAR will be annunciated over the test pattern and the aural warning will activate.


|-|

[Blake H]

Quote from the Collins manual.

'If you test system 1 then test system 2 is selected without first deselecting TEST, aural and visual windshear annunciations will be inhibited.

Any luck with the previous question latching or momentary test switch?

[Hardy Heinlin]

Any luck with the previous question latching or momentary test switch?

TEST mode is a mode. TEST switch is alternate action and overrides other modes electronically (other mode switches don't move by the TEST switch action).

Switches as follows

Latching:
AUTO
L/R
TEST

Push & Hold (spring-loaded):
GC

Latching, but unlatches with selection of others in group:
TFR
WX
WX+T
MAP

[Blake H]

Thanks.  :mrgreen: