Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
My Yaesu FT-4700RH had 4 "grain of wheat" style lamps
to provide panel/display backlighting. 3 of them had burned out. These lamps are accessible from the back of the removable control head. They are covered with pliable orange plastic covers and inserted through holes in the PCB from the back side, with the two leads bent over and soldered to pads on the back side of the PCB, so they are easy to remove. (Save the orange plastic covers to use on the replacement bulbs.) To my pleasant surprise, I found that RadioShack's SKU 272-1092 (pkg of 2) were a physical fit. The lamp driver circuit in the FT-4700RH runs from 9V controlled by a PNP driver that is driven by a circuit that allows "bright" and "dim" (controlled by a front panel switch labeled "dim"). The RadioShack "micro lamps" are labeled as 12V 60 mA, and are not *quite* as bright as the original Yaesu part, but they are (IMHO) adequately bright, and should last a long time with the derating resulting from the 9V supply and the fact that there is a 4.7 Ohm resistor in series with each lamp. Cost - about $6.00 for four packages of two lamps (I bought spares). I hope that someone finds this useful - the same lamps *may* have been used by Yaesu in other models of similar vintage. 73, Carl - wk3c |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Hint on replacement for Yaesu panel lamps | Equipment | |||
FS: Connectors, Antennas, Meters, Mounts, etc. | Antenna | |||
FS: Connectors/Adapters/Meters/Etc. | Equipment | |||
FS: Connectors/Adapters/Meters/Etc. | Equipment |