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Old 8th March 2010, 10:54 PM   #1001
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Here is the data sheet :
TQ2-12V pdf, TQ2-12V description, TQ2-12V datasheets, TQ2-12V view ::: ALLDATASHEET :::

they use gold plated silver contacts
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Old 9th March 2010, 12:56 AM   #1002
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Now, not to push on anyone's feelings, but we used equal or better relays more than 40 years ago, and we used similar parts in the JC-80, starting in 1982. We use a hermetically sealed version of this part in the new project. This is very old, tried and true, and just OK. Silver on Silver switches are better.
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Old 9th March 2010, 01:27 AM   #1003
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Hermetically sealed, that should be the best of cause because silver is the best conductor. In open air silver develops a sulfur contamination very quick,. In fact sulfur contamination gets worse every year because air polution is still rising. i heard that labs that are researching air contamination use that effect to test polution, Contrary to popular beleave this world still gets more poluted every minute.
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Old 9th March 2010, 03:02 AM   #1004
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Silver on silver switches are still better, because they self clean when you use them. Relays have more difficulty with self cleaning, that is why they should be sealed.
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Old 9th March 2010, 06:27 AM   #1005
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Quote:
Originally Posted by Joachim Gerhard View Post
Here is the data sheet :
TQ2-12V pdf, TQ2-12V description, TQ2-12V datasheets, TQ2-12V view ::: ALLDATASHEET :::

they use gold plated silver contacts
Nice relays. I tend to use Omron relays, which are largely equivalent to the Nais.

One thing that still intrigues me is the spec for 'minimum current/voltage'. Both the Nais and Omrons spec 10uA/10mV here. What exactly is the meaning of this spec?

Nais doesn't detail it, Omron calls it 'failure rate' (for connection?).
It is tested to the limit of 100 ohms contact resistance max.

Now, in audio, signal levels will routinely be below 10uA/10mV. Would that mean that these relays cannot be counted on for their 'official' low contact resistance of 30 or 50 milliohms? It could make a big difference in, say, a stepped attenuator whether the contact resistance is 50 milliohms or 50 ohms!

jd
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Old 9th March 2010, 07:06 AM   #1006
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We have used the Nais TQ5-TQ12 and Omron equivalents on the DCB1's signal inputs/outputs with no apparent resolution penalty.

In the first picture there is a Hypnotize build with one output relay. The second one comes from a Mezmerize build measurement with Nais TQ both on input and output. If they can pass a smidgen of 3rd Harmonic to be displayed on the -130dB grass, I guess their contacts are OK?
Attached Images
File Type: jpg HypnotizeExample.jpg (240.8 KB, 534 views)
File Type: gif ResolutionMez.gif (46.9 KB, 511 views)
File Type: jpg MezGru.jpg (169.2 KB, 503 views)
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Old 9th March 2010, 07:40 AM   #1007
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Quote:
Originally Posted by Salas View Post
We have used the Nais TQ5-TQ12 and Omron equivalents on the DCB1's signal inputs/outputs with no apparent resolution penalty.

In the first picture there is a Hypnotize build with one output relay. The second one comes from a Mezmerize build measurement with Nais TQ both on input and output. If they can pass a smidgen of 3rd Harmonic to be displayed on the -130dB grass, I guess their contacts are OK?
Well, the 'smidgen of 3rd' is of course part of the total signal which maybe on the order of 100's of mV or even a volt?
Even AP uses these types of relays in their analyzers, so yes they perform well.
But as I said, I'm not sure what the significance is of that spec. It is there, it is tested so it should mean something.
Anybody can shed any light on this?

jd
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Old 9th March 2010, 07:52 AM   #1008
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Hi Joachim,
I guess it is P1 that trims the final offset, not P2 as you claim in the schematic?

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Old 9th March 2010, 09:09 AM   #1009
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First P2 and P3 are adjusted to 180 Ohm including the drain resistor.
Then the input Fets are grounded and P1 is lifted from ground.
Then adjust P1 for zerro offset from A to ground.
Then wire everything back. Adjust P2 for lowest offset at the output and then fine adjust offset with P4.
I hope this is clear now. The nice thing with this trimming is that lowest offset should also come with lowest distortion in this schematic but i will measure it and look whats happening too.
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Old 9th March 2010, 08:00 PM   #1010
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Quote:
Originally Posted by janneman View Post
Well, the 'smidgen of 3rd' is of course part of the total signal which maybe on the order of 100's of mV or even a volt?
jd
Forgot to tell that If there is digital zero for input, hence no signal output, the noise floor does not change shape or -dB level, remains like when passing the 1kHz at hundreds of mV to 1 or 2V if that can show something, towards your query.
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