Resistance Check Problems on Control Board for Build 7174

[roeradio]

Greetings!

I have completed the control board and I am getting some interesting
resistance readings that I cannot figure out. Can anyone help me out. I have
not done the K2 AGC Level mod (waiting on the resistor) but every other step
is complete in the manual for build 7174.

Here are my readings:

Test point
P2 Pin 1 to ground: >10k, reads, 12.6k
U5 out (5V pin): >2K, reads, 12.48K
U4 out (8v pin): 3-7k, reads, 3.62k
Q1 Collector: >1M, reads 341k
Q2 Collector: >1M, reads, 311k
U3 Pin 8: >10k, reads, 93.6k
U6 Pin 13: >100k, reads, 57.4 k
U6 Pin 14: >100k, reads, 55.4k
U6 Pin 29:70-90k, reads, 57.8k
U6 Pin 30: 70-90k, reads 57.4k
U8 Pin 2:>100k, reads, 58.3 k
U8 Pin 15: >100k, reads, 46.9k
U8 Pin 16: >100k, reads, 44.8K

I have maintined proper ESD precautions, followed the manual exactly and
have thoroughly examined the board. Any ideas what is happening?

Thanks in advance
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[Don Wilhelm-4]

  Jerry,

Are you using an old VOM or VTVM to make those measurements?  If so,
find yourself a DMM - the inexpensive ones will do just fine ($3.99 on
sale a Harbor Freight). VOMs and VTVMs use a high voltage to measure
resistance, and can cause semiconductor devices to conduct.  The typical
resistance measurements were made with a DMM, and a similar instrument
is necessary for comparison.

If you are using a DMM, ignore my statement above - but do check to see
if you were using "auto-ranging"  If so, that can give erroneous results
on some meters - switch to a fixed range greater than the "expected"
reading.

73,
Don W3FPR

On 6/2/2011 10:34 PM, Jerry Roe wrote:

> Greetings!
>
> I have completed the control board and I am getting some interesting
> resistance readings that I cannot figure out. Can anyone help me out. I have
> not done the K2 AGC Level mod (waiting on the resistor) but every other step
> is complete in the manual for build 7174.
>
> Here are my readings:
>
> Test point
> P2 Pin 1 to ground:>10k, reads, 12.6k
> U5 out (5V pin):>2K, reads, 12.48K
> U4 out (8v pin): 3-7k, reads, 3.62k
> Q1 Collector:>1M, reads 341k
> Q2 Collector:>1M, reads, 311k
> U3 Pin 8:>10k, reads, 93.6k
> U6 Pin 13:>100k, reads, 57.4 k
> U6 Pin 14:>100k, reads, 55.4k
> U6 Pin 29:70-90k, reads, 57.8k
> U6 Pin 30: 70-90k, reads 57.4k
> U8 Pin 2:>100k, reads, 58.3 k
> U8 Pin 15:>100k, reads, 46.9k
> U8 Pin 16:>100k, reads, 44.8K
>
> I have maintined proper ESD precautions, followed the manual exactly and
> have thoroughly examined the board. Any ideas what is happening?
>
> Thanks in advance
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
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Please help support this email list: http://www.qsl.net/donate.html