Originally posted by John Gaitskill
View Post
Avionics dimmer question
Collapse
X
-
We taped a small flat LED light from Radio Shack over the sensor when ours quit. Had to tape a small battery and wires out of the way, but it worked.
Leave a comment:
-
Originally posted by Russell Holton View Post
It's possible that all the radios are supposed to have something in common, but because of a failed splice, those three are now separated.
Leave a comment:
-
Originally posted by Andy Alson View Post
That's what I thought and why I asked about whether those three avionics items might have one common connection to something that the other radios didn't. Haven't found anything that fits that as yet.
Leave a comment:
-
Originally posted by Terry Carraway View PostIf three separate devices start misbehaving the same way at the same time, my money is on some that is common to all three, not a similar failure in all 3 devices at the same time.
Leave a comment:
-
If three separate devices start misbehaving the same way at the same time, my money is on some that is common to all three, not a similar failure in all 3 devices at the same time.
Leave a comment:
-
Originally posted by Bruce Gorrell View Post
Dumb question. Did you try cleaning the sensor?
Leave a comment:
-
Originally posted by Andy Alson View Post
Nope. Each of the three items that dim have their own sensor that makes the radio brighten when we shine a flashlight on the sensor. Nothing blocking any of the three.
Leave a comment:
-
Originally posted by Rod Madsen View PostThose radios apparently thinks it's very dark in the cockpit, so they need to go dim. Is there some object blocking the ambient light sensing device?
Leave a comment:
-
Those radios apparently thinks it's very dark in the cockpit, so they need to go dim. Is there some object blocking the ambient light sensing device?
Leave a comment:
-
I agree that replacement is a better option than trying to repair these old units. Just really curious that three of them developed the same symptom at the same time and it wouldn't be something other than the radios themselves? I know we have rotary dimmer controls for the instrument lighting and for the eyebrow lights at the top of the panel, but I don't know that we have any "airplane's wiring/dimmer" that controls the radio brightness.
Andy
Leave a comment:
-
Originally posted by Ray Tackett View PostI suspect the "dim" setting circuit has died or gotten out of calibration such that "dim" is "too dim".
Originally posted by Ray Tackett View PostThe electronic details of the dimming cicruit depend upon the type of display.
Either way, I suspect the problem is with the airplane's wiring/dimmer, not the radios.
Leave a comment:
-
In an airplane, ground and DC return are the same thing. There is nothing separate about thedisplay dimmer. If you were somehow missing a ground connection (just about impossible with a metal case radio and the coaxial antenna cable), the radio would not work at all. Disconnecting ground, if you could do it (unlikely) would behave identically with disconnecting power.
Back in the incandescent radio light days, there might have been a connection from the radio to the panel light dimmer, but no more.
I suspect the "dim" setting circuit has died or gotten out of calibration such that "dim" is "too dim". The electronic details of the dimming cicruit depend upon the type of display. A good radio tech should be able to fix it, but given the costs, it may well be upgrade time.
The radio removal and replacement labor is the same either way. A couple hours of bench time plus parts would be some percentage of a new radio. FAA paperwork costs would likely be similar either way. Your friendly radio tech can run a cost comparison for you.
Leave a comment:
-
Avionics dimmer question
So our 1981 Mooney has some older radios in it. Recently we've noticed that at night 3 items (#2 Com, ADF-yep, still have one of those in there, and the autopilot annunciator) all go dark with the glowing displays not visible unless you shine a flashlight into the light sensor on the unit. The other radios (Garmin 430W, Nav#2) and everything else seem to work normally, as do the questionable radios which work just fine except for the dimming of the display.
Question is, does the dimming circuit somehow use a ground connection as a reference of some sort which might be common to the units that are having the problem, and not used by the radios that work correctly, rather than all three developing internal problems at the same time?
During the day everything works normally.
Just wondering what everyone thinks before we discuss it with our avionics guy whose response will predictably be time to replace all of our radios with a new stack which is not gonna happen <G>.
AndyTags: None
Leave a comment: