Tent XO3 Problem?

[fmak]

I measured the ouput voltage of the XO3 supply and found it was only 4.3V. This is outside the specified opearting range of quite a few XOs.

Guido, how can the voltagebe increased?

[jean-paul]

Isn't is more efficient to send a mail to Guido Tent directly if you have a defective unit ?

[Guido Tent]

Originally posted by fmak
I measured the ouput voltage of the XO3 supply and found it was only 4.3V. This is outside the specified opearting range of quite a few XOs.

Guido, how can the voltagebe increased?

Hi Fred

4.3V is too low. I always keep slightly below 5V, for some reasons, for example avoiding " toching" the 5V rail of the circuit to be fed - better to be safe than sorry there

If you suspect malfunction, please return the unit. 5 years warrantee are still valid.

cheers

[fmak]

Hi Fred

4.3V is too low. I always keep slightly below 5V, for some reasons, for example avoiding " toching" the 5V rail of the circuit to be fed - better to be safe than sorry there

If you suspect malfunction, please return the unit. 5 years warrantee are still valid.

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I have managed to increase this by slighltly reducing R2 from 237R to 220R. It is now 4.85V which is fine.

The difference bewteen loaded and unloaded voltage is nearly 0.9V using your XO.

Is this normal?

[Guido Tent]

Originally posted by fmak
Hi Fred


The difference bewteen loaded and unloaded voltage is nearly 0.9V using your XO.

Is this normal?

Hi Fred

It is more than intended. Did you load all outputs ?

I have some series resistance in the supply lines, to dampen the Q of the power supply decoupling circuit.

Iy you want I can send a new XO, what frequency are you using ?

cheers

[fmak]

Hi Fred

It is more than intended. Did you load all outputs ?

I have some series resistance in the supply lines, to dampen the Q of the power supply decoupling circuit.

Iy you want I can send a new XO, what frequency are you using ?

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No, just one output and spdif. The unit seems to work and I have re-adjusted the pot for lowest noise. I actually ahd to change the pot as Bournes one always seem to have problems after a few adjustments. What is the intended voltage drop bewteen load and no load?

A new XO won't help as I have tried different makes, all drawing about 20-30mA when operating.

One question: The XO casing is decoupled to ground via a 1uF cap for DIL14 XOs but not for your DIL8 XO. Why?

I have found that different XOs interact quite differently with the PS. Yours and Valpey give the lowest noise voltages. Some chip type XOs give rather large hf noise voltages as seen on my 400 MHz scope.


cool:

[fmak]

Originally posted by jean-paul
Isn't is more efficient to send a mail to Guido Tent directly if you have a defective unit ?

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You interject with my posts too frequently. Not your business.

I don't see why I should not post topics that may be of interest to others.

[Guido Tent]

Originally posted by fmak
What is the intended voltage drop bewteen load and no load?

A new XO won't help as I have tried different makes, all drawing about 20-30mA when operating.

One question: The XO casing is decoupled to ground via a 1uF cap for DIL14 XOs but not for your DIL8 XO. Why?

I have found that different XOs interact quite differently with the PS. Yours and Valpey give the lowest noise voltages. Some chip type XOs give rather large hf noise voltages as seen on my 400 MHz scope.


cool:

Hi Fred,

Load - no load shouldn't change more than 500 mV

The decap is in place just when XO3 is in TentLaink mode. In that case a VCXO is mounted in the socket, the 1uF decouples the control voltage of the VCXO.

On noise: Did you happen to find out if some XO's spit back noise in the supply lines ? (I did with lots of other oscillators)

best regards
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[fmak]

Load - no load shouldn't change more than 500 mV

On noise: Did you happen to find out if some XO's spit back noise in the supply lines ? (I did with lots of other oscillators)

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Hello Guido

Can you tell me which resistors are dropping the voltage between load and no load. This way I can check what is causing the 0.8V drop. This was the case when the unit was new. I asked you then and you didn't say there was a problem.

On noise, yes, different XOs behave very differently. I have found it useful to use a 620 uF OSCON across the input to the XO. This way, the supply noise is limited to about 50mV pk-pk 400MHz bandwidth, 5 mV pk-pk 20MHz, and 2uV 1MHz rms. The chip XOs tend to give much higher distortion type waveforms on the PS.

Sonics doesn't seem to be necessarilly dependent on noise and chip LDOs seem to perform quite well also.

In my systems, your PS+XO seems to have a slightly more mechanical sonic signature than the ALW Jung regulator. PS impedance effect? Difficult to isolate.

[jean-paul]

Originally posted by fmak

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You interject with my posts too frequently. Not your business.

I don't see why I should not post topics that may be of interest to others.

I am not aware of interjecting with your posts ( and certainly not frequently if at all ), I am aware of your hostile reaction though ( which is my business ).

Nobody said you should not post topics, it just seems more effective to adress directly to the seller of a product in case of a defective unit instead of adressing to that person on a public forum. It might be different with a problem that affects a whole series of a product and/or if the manufacturer/seller does not respond to the complaint.

Anyway, don't feel offended as it only gives you a bad feeling.