Weird Display Problem

motoelph · Post by **motoelph** » Fri Mar 01, 2002 6:49 am

Having a strange issue with one of my MCX1000's. When I put my hand, or even a piece of paper, near the VF display, it fades to black. Move away, and it comes right back.. anybody ever seent this before?

thanks

Post by **wavetar** » Fri Mar 01, 2002 4:42 pm

It would be a problem if it didn't work that way! You have stumbled across the automatic dimmer feature. I haven't looked at one in a while, but there's a small photo-diode (looks like a black LED) on the front panel. It detects light. When it's dark in the vehicle, the display is dim. When there is a lot of ambient light in the vehicle, the display gets brighter to help you see it better. Pretty cool for a 15 year old radio.

Todd

April · Post by **April** » Fri Mar 01, 2002 5:44 pm

So does my MCX100 even older. The old Motrac radios had a dimmer on the green light in the control head. The older Motrac, HHT vintage have a dimmer that works on both the green "ON" light and the "Transmit" light, and yes these are real light bulbs, # 51 a 6 volt lamp and a resistor is series on twelve volts. We always used a #53, 12 volt for replacement.

motoelph · Post by **motoelph** » Fri Mar 01, 2002 6:38 pm

Wow, i had no idea.. I thought the only dimming was in the DIM button. The weird thing is, my other MCX's dont do it, and it seems to be dimming PER character. that is, if i move my finger along the display from left to right, the fading follows my finger! Seems it would have to have lots of photodiodes to do that...