• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

help with upd858 chip

C

cbman

Guest
hope someone can help me out.just got a trc458 off of ebay and who ever had it before me has got the solder traces on pins 1 thew 12 all messed up with solder and cuts.would anyone have a picture of the d858 chip on the trace side of the radio or a circuit diagram so i can get the reg 40 channels to work? looks like someone try to put xtra channels in the radio.need all the help i can get on this.thank's


</p>
 

hope someone can help me out.just got a trc458 off of ebay and who ever had it before me has got the solder traces on pins 1 thew 12 all messed up with solder and cuts.would anyone have a picture of the d858 chip on the trace side of the radio or a circuit diagram so i can get the reg 40 channels to work? looks like someone try to put xtra channels in the radio.need all the help i can get on this.thank's


</p>
 
sure they didnt mess with pins 13-17-19-20,21 and 22?
pin 19 should be soldered to ground for normal 1-40 channels
13 10 k drop 17 with 5 vdc adds 27.415 to 27.445 and with pin 19 unlocked and 5 vdc 27.815 to 27.845 with just pin 19 with the 5 vdc 27.455 to 27.805
with 5 vdc added to pin 20 27.845 to 28.045 pins 21 cut and reistor and 5 vdc added
26.455 to 26.805 on CH. 8-40 with pins 19 and 21 together 26.855 to 26.955 on
CH.8-16
hope this helps pins 13 thru 24 same side as channel selector ribbon wire

1 2 3 4 5 6 7 8 9 10 11 12 |
| |
) |
| 3 4 5 6 7 8 19 20 1 2 3 4 | pins 13 thru 24 this side ! closest to ribbonwire for channel selector

pete
 
i sure they didnt mess with pins 13-17-19-20,21 and 22?
pin 19 should be soldered to ground for normal 1-40 channels
13 10 k drop 17 with 5 vdc adds 27.415 to 27.445 and with pin 19 unlocked and 5 vdc 27.815 to 27.845 with just pin 19 with the 5 vdc 27.455 to 27.805
with 5 vdc added to pin 20 27.845 to 28.045 pins 21 cut and reistor and 5 vdc added
26.455 to 26.805 on CH. 8-40 with pins 19 and 21 together 26.855 to 26.955 on
CH.8-16
hope this helps pins 13 thru 24 same side as channel selector ribbon wire

1 2 3 4 5 6 7 8 9 10 11 12 |
| |
) |
| 3 4 5 6 7 8 19 20 1 2 3 4 | pins 13 thru 24 this side !
closest to ribbonwire for channel selector

pete
 
Last edited:

dxChat
Help Users
  • No one is chatting at the moment.