[Elecraft] Resistance checks on RF board page 38

[Don Wilhelm]

Mike,

The place to go next is to continue onto page 39 of the manual.
Note that for those values listed have a ">" symbol - which means 
'greater than' (see page 22, top of the 2nd column).
A reading in the Megohms range is definitely greater than 20k, so no 
problem.

The same thing applies to the R1 and R2 readings - greater than 1 megohm 
can be an infinite reading, which apparently your meter indicates as 
"OL" (overload) - it should be the same thing as is displayed with the 
probes connected to nothing.

Some meters show a "1" in the 1st digit position for an infinite 
resistance condition, others blink the display, and others indicate "OL" 
as yours does.  Know how your meter responds to an infinite resistance 
(open leads) and also to zero ohms - and be aware of the meter range, 
especially if using auto-ranging.  An old wise saying among the lab 
engineers I worked with was "Test Engineer, know your tools, and know 
when *not* to believe them" - refer to the manual for your tool if there 
is any question about what is being indicated, many are different in 
subtle ways.

73,
Don W3FPR

On 5/12/2013 5:14 PM, VE3WDM wrote:
> Good evening Don,
> Here is what I have done,
> 1. I have tried reversing the leads on the DMM and the readings for lets say
> U1 pin 4 to ground went from 3.9 mega ohms to 2.9 mega ohms. so not really
> the reading I am looking for.
>
> 2. I heated up all the solder connections on the board and added solder
> where needed. I am using the WES51 iron turned all the way up.
>
> Here is one of my trouble shooting paths I did for U1 pin 4.
> 1. From U1 pin 4 to K13 pin 10.....result .02 ohms....a good result
> 2. From U1 pin 4 to K13 pin 1.......result  239.8 ohms a good result as this
> is the coil of K13
> 3. From U1 pin 4 to K9 pin 1.........result  239.8 ohms a good result as
> again this is coil of K13 only.
> 4. From U1 pin 4 to K9 pin 10.......result   480.6 ohms a good result
> reading coils from K13 and K9.
> 5. From U1 pin 4 to U1 pin 13.......result   480.6 ohms a good result again
> reading both coils K13 and K9
> Note C82, C57 and C208 are in this circuit but not as yet installed.
>
> Now I go from ground to Pin 4 and am reading in the Mega ohms. And no matter
> which ground point I go to I get the same high ohm reading.
>
> As for R1 and R2
> 1. On R1 going from bottom terminal (terminal above R2) to C1 top side and
> get reading of .02 ohms...this is good
> 2. From same position on R1 again to other side of C1 and get OL.
> 3. I then go from the same position on R1 again to ground and again get OL.
>
> Not sure where to go next Don.
> Mike
> VE3WDM
>   
>
>
>
> --
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