X-Prog M

[Zmann]

Ok now I am confused. I'm not confused with the math, but with the mod itself. The original resistor that the blue pcb has is 182. So this is 1.8K or 1800 ohms. User elchip in post #699 on page 47 says to use 152 +100 in series to make 1600 ohms. But in his picture attached to his post, he instructs only to change the 182 to 152, so that makes it 1500 ohms, not 1600. But you are saying to do 153, which is 15,000 ohms plus 102, which is 1000 ohms, for a total of 16K? Wouldn't that lower the voltage too much? Also, is there even any room to put two resistors in series?

In Zmann's post, #707 page 48, he also uses 152 in place of the 182 (so 1.5K). I don't see any other resistors added? Also, I am trying to figure out what other mods he made. I see he changed the capacitors, but not sure if his are stronger than the ones that came with mine. I have some of the small yellow ones that I think are weak, but the ones near the 152 resistor are silver barrel style caps.

Also, I am trying to figure out which style LM317 he used. I googled it and see there are many different styles, with some being adjustable (not sure what that means). Any idea which lm317 I should buy? There are LM317LDR2, LM317LBDR2G, LM317LBDG, LM317LDR2G and so on ...

Thanks again for your replies

All of LM317's are the type of an adjustable voltage regulator IC. I made in a post possibily in this threat saying that 'THE TWO LM317 TO-92 PACKAGE USED IN THE BLUE XPROG-M CANNOT BE REPLACED WITH LM317 SOIC8 PACKAGE' like used in the green PCB unless the PCB lines are modified like mine, wrong lining in the blue PCB for SOIC8 package!

Resistor of 1.8 Kohm (between 1.5 and 1.8 K) is one of the voltage adjusting elements, typically should be a potentiometer (adjustable resistor) but here after well calculated they used fixed resistor of 1.8 Kohm. If only one SMD resistor of 1.6 Kohm (type 0805) is prefered as a replacement, I found that it's also available but may need slight effort to find them.

The blue Xprog in the photo is of the later built which they already replaced the small yellow and under rated tantalum capacitors with electrolytic capacitors of 35V rating (silver barrel).