Reduction resistance checks - ok to move onto voltages? [resolved]

Neuronal · 1779

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Offline Neuronal

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Hi Bottleheaders -

Just finished my Reduction, and things look good except some of the resistances are off. I rechecked the wiring, all looks correct, as do the joints. Measurements that are off include

27 - 1 MOhm (supposed to be *) - this seems to match 1 MOhm on 6, so maybe a typo?
43 - 20 Ohms (supposed to be 0)
45 - * (supposed to be 0 Ohms)
46 - .1 Ohms (supposed to be OL)
47 - * (supposed to be OL)
49 - 10 Ohms (supposed to be 0 Ohms)
54 - 30 Ohms (supposed to be 0 Ohms)

In addition 37, 38, 39, 41, 42 are all * - these move, but with my meter they move VERY slowly, much slower than on the other * terminals.

Thanks in advance for advice/suggestions - hoping these are just manual typos and I can safely go onto the voltages!
« Last Edit: June 29, 2020, 11:06:41 AM by Paul Birkeland »

Bob D
Rega P2, Cosecant DAC, Reduction, EFP III, Paramount V1.0 + soft start, Omega CAMs + DeepHemp 8s


Offline Paul Birkeland

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Reply #1 on: June 29, 2020, 08:56:50 AM
Regarding the * terminals, from the manual:

Also, the values signified with a * are going
to vary from ohmmeter to ohmmeter because these terminals are connected to the filter
capacitors, which try to charge themselves off the battery in the meter, causing a fluctuating
reading. If the circuit is connected properly these readings will wander in the tens or hundreds of
Kohms or higher range. What you want to watch out for is a zero reading at one of these
terminals, which would indicate

43 would read high if the transformer screw isn't tight there.
45 says OL in the manual I have dated 10/3/19.  There was an issue with that revised manual distributing itself properly.
46 says 0 for the same reason above.
Same with 47
49 and 54 also indicate loose transformer screws.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Neuronal

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Reply #2 on: June 29, 2020, 10:47:19 AM
Thanks, Paul!

Tightened the transformer screws down, now at 0 Ohms, so perfect.

for 45 and 47, things on my meter are fluctuating (for sure) but values are between .3-.9 MOhms - is this the equivalent of OL for our purposes? Onto voltages?

thanks again for the advice -
b

Bob D
Rega P2, Cosecant DAC, Reduction, EFP III, Paramount V1.0 + soft start, Omega CAMs + DeepHemp 8s


Deke609

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Reply #3 on: June 29, 2020, 10:57:17 AM
for 45 and 47, things on my meter are fluctuating (for sure) but values are between .3-.9 MOhms - is this the equivalent of OL for our purposes?

Yup. Per PB in Reply #1 above:

Regarding the * terminals, ... If the circuit is connected properly these readings will wander in the tens or hundreds of
Kohms or higher range. What you want to watch out for is a zero reading ...

You're measuring 300 to 900 Kohms at those terminals.

cheers, Derek



Offline Neuronal

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Reply #4 on: June 29, 2020, 11:06:10 AM
Thanks Paul and Derek - onto voltages!

Bob D
Rega P2, Cosecant DAC, Reduction, EFP III, Paramount V1.0 + soft start, Omega CAMs + DeepHemp 8s


Offline OverAnalyst

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Hi Guys,
Hope this is an obvious fix for you all, but after reviewing instructions, I can’t seem to find the problem. Maybe I've been staring at it too long.
I’m going to piggy back off of this post because I'm having some resistance issues.
Here's what I'm getting for the following terminals:

38 - 7.7ohms (should be *)
39 - 1.1kohms, not fluctuating (should be *, but per the previous reply, if not 0, should be okay?)
41 - same result as 39
42 - same result as 38

For the following, I get very similar to Neuronal, so I’m assuming they’re ok?

45 - * (should be 0 ohms)
46 - .7 ohms (should be OL)
47 - * (should be OL)



Offline OverAnalyst

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and assuming those resistance values are okay, I went ahead and proceeded with voltage checks. Here are my off-nominal readings:

44 - 78V (should be 180V)
45 - 77 V (should be 0V)
47 - 175V (should be 0V)

I’ve checked for missing wiring and diode/cap orientation, but don’t see anything wrong. Perhaps I’m growing delirious.
« Last Edit: August 11, 2020, 05:42:43 AM by OverAnalyst »



Offline Paul Birkeland

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Can you let us know what the date is on the PDF of the manual you're using?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline OverAnalyst

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per the filename, 7.21.19



Offline Paul Birkeland

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That's just an issue with an out of date manual that had some errors in the voltage check section.  This was corrected quite some time ago, but there have been a few hangups with the manual downloading service that we (by we I mean Doc B.) are working through right now. 


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man