Batboard

Have a question on the levels going to the radios from 2 different RIB units. While trying to program a
Spectra radio, the 4008E RIB will sometimes work and other times give an error message even with a
new battery installed. Sometimes it is a serial bus error and other times it is a check sum error in the
control head. If I use the 1015C unit, it works every time with the same computer and the
same radio.

My guess is that the data line levels from the 1015C are slightly higher than those coming from the
4008E RIB. Can someone confirm this for me? If this is the case, has anyone made any resistor
changes to the 4008E RIB to correct this problem?

Jim

Try other serial cables and adapters (if used). Decrease lengh of serial cables. Try ferrite EMI filters on the both ends of cables. Try to decrease or disable FIFO buffer size. Try other PC with true hardware serial port controller. Something from can help.

Look at this page/schematic of the RIB for modifications, value changes, that can help the problems you are getting.

The levels are 5 volts on the radio side. +5 volts and negative $ volts on the RS232 side.

The negative voltage chip goes bad, or the 5 volt regulator, check the protection diodes on the radio side too.

The above mods have been proven programming thousands of radios, with many different RIB's.

If still a problem I still fix them, like Monty did. RIP Monty.....

I second the neg converter. Found and fixed a few of those myself.