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Re: T1 Tuner Kit Control Board final check issues

Posted by Don Wilhelm-5 on May 24, 2021; 10:01pm
URL: http://elecraft.85.s1.nabble.com/T1-Tuner-Kit-Control-Board-final-check-issues-tp7669742p7669757.html

Erik,

Yes, using auto ranging on the DMM can cause false readings.  Try to set
the fixed range a bit above the highest expected resistance for the best
results.  It all depends on the voltage the DMM applies to the circuit. 
Too high a voltage can make ICs and transistors conduct causing a low
reading.

73,
Don W3FPR

On 5/24/2021 5:52 PM, Erik Tkal wrote:

> Hi Don,
>
> Everything appears correct and in place, already used magnification to
> check, and individual resistors all seem to measure correctly.  I
> still think it's my multimeter in auto mode.  I went back and retried
> the initial test using manual ranging and if I set the range to 600K
> it shows a reasonable value.  I suspect the caps in the circuit are
> fooling it, will have to google that and see if there is an
> adjustment.  The second test still shows a bit high as well, but  if I
> measure from the *cathode* of D3 instead of the anode then I get a
> reasonable value as well; perhaps the difference in meter currents
> used for measurements is messing up due to the diode being in the
> circuit as the check is worded?
>
>   Thanks and 73,
> Erik Tkal  -  W1QED
>
>
>
> On May 24, 2021, at 15:32, Don Wilhelm <[hidden email]
> <mailto:[hidden email]>> wrote:
>
> Since that is the case, check the value of the resistors and check out
> the soldering under magnification.
>
> 73,
> Don W3FPR
>
> On 5/24/2021 3:08 PM, Erik Tkal wrote:
>> Hi Don,
>>
>> Nope, D3 and D4 are correct, and the LEDs check out per the test...
>
>

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