[Elecraft] Faulty Resistor pack...

[Bob Nielsen]

On Mon, Oct 11, 2004 at 04:45:24PM +1300, Ron W wrote:
> Hi ,
>       Just been fault finding a K2 for a chap here. the problem was no V 
> bias-xfil , so the filters couldn't be set.  Nothing appeared to be coming 
> out of U10 on the Control board, and resistance values around it seemed 
> odd, so I gave the IC the chop. The resistances were still strange 
> ....impossible in fact, and it appeared that both RP2 and RP3 might be 
> crook. Something that sounded too strange to be true. I took out RP2 ( 82k) 
> . Better, but still had strange readings, so out comes RP3 ( 47k) and the 
> readings looked like what one would expect with all the components removed!!
> Metering RP3 showed it was not 5 individual resistances. They were all 
> joined together and ranged in resistance from 93k to 41k. In fact I was 
> getting a reading of 90k from pin 1 to pin 10......no wonder the poor old ( 
> now deceased) U10 was not functioning.
> Has anyone else been fooled by a crook RP?? It sure had me bluffed for a 
> while......
> Incidently......RP2 was fine....but has rather short legs now...
> Cheers.......Ron ZL1TW
> 

What is the number on RP3?  Did you install one of the other resistor
packs by mistake (which I did in one case)?  Some of them are individual
resistances, while others consist of several resistors all tied to a
single point.

Bob, N7XY