please, correct me if i am wrong... but from the datasheet doesn't seems that 85 is the best temperature to get best phase noise.
As Andrea already said, a crystal doesn't have a proper Phase Noise. you can measure it in a context of an oscillator... when crystal... oscillates (duh !)
to me seems only they set a value as reference to keep the measurements consistent across all the devices.
For long term freq stability is something to be worried about... not otherwise.
I'll leave the explanation to the experts.
The guidance as I understood it at the time was, find the serial number of the crystal, and set the temperature in the center of the crystal to the TP1 temperature for that crystal. You can see they specify the range as 75 to 90C but each has the optimal number from their testing.
The guidance as I understood it at the time was, find the serial number of the crystal, and set the temperature in the center of the crystal to the TP1 temperature for that crystal. You can see they specify the range as 75 to 90C but each has the optimal number from their testing.
Thanks gionag for measurement samples,How did you apply the silicone, over the entire surface of the crystal, or by points.
Quite pathetic attempt to evalute with "household" tools
i have used two cellphone, one with high datarate acquisition over accelerometers, while the other was generating vibrations (with the vibration motor).
i will redo all of this with proper sweep test over wide range of frequencies...
but for the moment i'll leave you with this (imho promising) results.
the first is the transmitted vibration with the two devices coupled rigidly together.
the second is with 3 stud of 5mm diameter/5mm height closed cell neoprene.
i also tested by adding a whole 500gr spool of solder between the two devices, at this high frequencies was almost like having a direct connection
the last is the two devices isolated by the silicone dampener.
Thanks for the interesting measurement.
I`m really curious how your results would compare to a sand isolation for vibration damping.
Not the same application, but I made very good experiences with sand in my full range horns.
There's a photo, few posts back, on how the shell look like.
The silicone she'll wraps tight around the HC casing.
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OK... FWIW, for those of us who believe that WTMC makes a positive impact on sound, adding the oven set to 85C provided more of the same. No need to re litigate whether sound quality is a real thing or not or double blind tests. Just curious how long term frequency stability would impact sound and why Andrea would have us go to the trouble of building these things if they provide no sound benefit.
If you are using Ian's Fifo is mandatory because you have to fit the STS boards on the FIFO board.
I suggest to keep anyway the STS out of the oscillator box because it generate a lot of harmonics since the sine to square conversion is merely done adding infinite harmonics to the sine wave. (the square wave is just the sine wave plus infinite harmonics).
I suggest to keep anyway the STS out of the oscillator box because it generate a lot of harmonics since the sine to square conversion is merely done adding infinite harmonics to the sine wave. (the square wave is just the sine wave plus infinite harmonics).
Hello Andrea,
Yesterday Sligolad from Italy published a photo with two clocks in one housing. And he also put two frequency doublers in the same housing.
I think Hammond does not have the suggested enclosures in stock and the rectangular tubes i have in stock are a bit to short for the clock boards.
It is almost impossible to find the right chassis on the net if you are looking for a kind of tight fit.
Board seize is 151X75 mm without the connector . SO if you wanna wrap the board in some foam/fabric you should go for 180x 95 mm INTERNAL dimensions and 30 mm height at least. You can find these kind of tubes cut to your own desires but they are rather expensive,
What i can do is ask some old co worker to bend and weld some aluminium '' containers '' from 2 or 3 mm thick aluminium with only an opening on the side where the connectors are.
I will not go for mounting the boards by means of the SMA connectors to the frontplate because that will diminish the vibration killing properties of the foam.
The groundplane of the power supply input should be connected to the chassis. IF so than the chassis will be '' interconnected '' because all '' ground wires '' will meet at the power supply.
Greetings, Eduard
Yesterday Sligolad from Italy published a photo with two clocks in one housing. And he also put two frequency doublers in the same housing.
I think Hammond does not have the suggested enclosures in stock and the rectangular tubes i have in stock are a bit to short for the clock boards.
It is almost impossible to find the right chassis on the net if you are looking for a kind of tight fit.
Board seize is 151X75 mm without the connector . SO if you wanna wrap the board in some foam/fabric you should go for 180x 95 mm INTERNAL dimensions and 30 mm height at least. You can find these kind of tubes cut to your own desires but they are rather expensive,
What i can do is ask some old co worker to bend and weld some aluminium '' containers '' from 2 or 3 mm thick aluminium with only an opening on the side where the connectors are.
I will not go for mounting the boards by means of the SMA connectors to the frontplate because that will diminish the vibration killing properties of the foam.
The groundplane of the power supply input should be connected to the chassis. IF so than the chassis will be '' interconnected '' because all '' ground wires '' will meet at the power supply.
Greetings, Eduard
I don't use Ian's Fifo. It is very convenient to use STS with DRIXO in one box. But I will do as you suggested: separate them.
Found some strange absent parts in TWTMC-DRIXO-SF BOM:
TWTMC-DRIXO-SF 22.5792 MHz, 24.576 MHz
--------------------------
absent C27, R21 - is that right?
Hello,
The manual does not show or tell if the external part of the DC input connector is connected to the chassis or not!
What do you consider the minimum internal height to have the clock and the frequency doubler boards wrapped in foam inserted into the '' tube ''?
Greetings, Eduard
P.s If an old co worker will make the '' containers '' for me it wont be difficult to add let us say 4 mm extra aluminium on to the tubes where these are opposite each other. This will be easier than creating extra distance.
The manual does not show or tell if the external part of the DC input connector is connected to the chassis or not!
What do you consider the minimum internal height to have the clock and the frequency doubler boards wrapped in foam inserted into the '' tube ''?
Greetings, Eduard
P.s If an old co worker will make the '' containers '' for me it wont be difficult to add let us say 4 mm extra aluminium on to the tubes where these are opposite each other. This will be easier than creating extra distance.
Yes, the DRIXO at 24.576 MHz does not need C27.
R21 was used during the development of the DRIXO to set the drive level of the crystal modifying the treshold of the AGC circuit.
Then we have found the optimal setting and we have replaced it with a pair of fixed resistors (R32 and R33).
So it is not needed.
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