[roni44]

I setup up the GPS clock with a LPS from the start, so never had the chance to compare against the wall-wart..
I am going to add a DR 12V LT3045 regulator box in a few weeks - will report if any change.. I do not mind investing in power supplies as they always seem to be useful sooner or later.
I am just a little North of Shenzhen, sometimes hot, but LPS's are pretty cheap and freight is almost free.. so pretty easy for me to not have any switching PS in my stereo room..

I think our clocks are from Shenzhen, I usually stop by HuaQiangBei whenever I can to pick up few things, next time I'm in the area, might just stock up LPS and possible @FredA's clock just for fun.

 

[JaMo]

Hi,

You have tempted me again with this clock artifact for the U16!!
But I've got a little lost. Wich external clock would you recomend exactly?

Hi,
I think @FredA recommendation is very good. The importance is definately the OCXO used... There are many brands and shapes out there on the market. How the actual Crystal is cut has great impact on the performance. Please find the table a bit down in the Wiki-page: https://en.wikipedia.org/wiki/Crystal_oscillator
From the table You can find that the SC "Stress Compensated" cut has a few positive advantages over other cuts. The most important one is very low phase noise which we like very much. The SC-oven heating demands a bit higher feed (12V) for the higher temperature. Still small numbers.

@FredA 's seems to have the right, SC cut. Oscilloquartz 8663 and the clone of it UCT 108663-01 also has it.

Another link with good to know info: https://www.mutec-net.com/product_ref_10.php#description

/Jan

 

[FredA]

Thanks @JaMo. Glad to know my ears are still trustable.

 

[JaMo]

Thanks @JaMo. Glad to know my ears are still trustable.

Your ears are better than most. I ment more that the specs on the OCXO's out there are quite a challange to get.
In my case, my GPSDOCXO-box holds a Trimble 73090 5V OCXO. It is a decent OCXO but not much more. It is a single oven, average performing OCXO. Not bad but not brilliant either. I will put in an Double oven instead.
The Trimble does a surprisingly good job as it is but I still use the stock AC-DC adapter while I'm waiting for the LPS. So I am sure the performance will reach higher grounds... It's a part of the learning process to find out and better things up on the way..
-Right?!
/Jan

 

[FredA]

Your ears are better than most. I ment more that the specs on the OCXO's out there are quite a challange to get.
In my case, my GPSDOCXO-box holds a Trimble 73090 5V OCXO. It is a decent OCXO but not much more. It is a single oven, average performing OCXO. Not bad but not brilliant either. I will put in an Double oven instead.
The Trimble does a very good job as is but I still use the stock AC-DC adapter while I'm waiting for the LPS. So I am sure the performance will reach higher grounds... It's a part of the learning process to find out and better things up on the way..
-Right?!
/Jan

Getting an ultra-low noise psu will never hurt. It is as important as the xo. Looking forward to hearing more feedback when you get it.

 

[DACLadder]

This Mutec REF 10 clock looks interesting (and expensive $4K). Has published spec of -145 dBc/Hz at 10Hz. You get what you play for and hopefully this unit is tested to that spec before shipping.

Also Mutec REF 10 has a lot of good info. Under Description there is a paragraph called "Debunking the Atomic (clock) Myth" where they claim in audio short term stability (jitter/ phase noise) is more important than long term accuracy of locking a clock to the satellites. Got me to thinking... Anyway, too rich for my blood but good reading!

Be careful with pro audio equipment as it looks like the pros use 75 ohm impedances in addition to 50 ohms. This Mutec has 2 - 50 ohm and 6 - 75 ohm outputs
https://mutec-net.com/product_ref_10.php#description

 

[wushuliu]

FYI, put my U16 up for sale on ebay...

 

[JaMo]

REF 10 has a lot of good info. Under Description there is a paragraph called "Debunking the Atomic (clock) Myth" where they claim in audio short term stability (jitter/ phase noise) is more important than long term accuracy

This was primarily why I posted the link. I think it was unususal informative.
/Jan

 

[PLGA]

Hello guys,
One more question.

How long can it be the cable between the clock and the U16? As short as possible??? What about 5 or 6 feet long? Too much?

 

[517269]

Hello guys
Im sorry, but I still dont get it 100%.

The clock can be bought here or in any other similar place, thats easy:

https://www.ebay.com/itm/Latest-10M...814962&hash=item1a3d7e5642:g:TqQAAOSwPPpaOhYT

But then, I guess its 10 Mhz output should be connected to the only clock input on the U16 and the antenna should go positioned somewhere outside the house so it can get the GPS signal. Am I correct? Can the antenna get GPS signal inside the house? Is it just a plugg and play device?

I clicked on the URL and saw the squarewave version as well - https://www.ebay.com/itm/Latest-10M...noa=1&pg=2047675&_trksid=p2047675.c100623.m-1

I don't know if the receiver performs better with the squarewave....and its $13 less expensive than the sign wave.

 

[517269]

I clicked on the URL and saw the squarewave version as well - https://www.ebay.com/itm/Latest-10MHZ-SQUARE-WAVE-SQUAREWAVE-GPS-DISCiPLINED-CLOCK-GPSDO-LCD-Display/122872069750?_trkparms=aid=1110001&algo=SPLICE.SIM&ao=2&asc=20160323102634&meid=ec3a4da1a7344992a2deb2b5fef5e012&pid=100623&rk=3&rkt=6&mehot=ag&sd=112700839490&itm=122872069750&pmt=1&noa=1&pg=2047675&_trksid=p2047675.c100623.m-1

I don't know if the receiver performs better with the squarewave....and its $13 less expensive than the sign wave generator.
When I used a cell phone repeater for my 3G phone a few years ago, the repeater had to sync up to GPS. It had a 25' cord antenna that I had to bring to a window and it might take up to 12 hours to sync up as it barely reached the window. I don't know if this was specific to this particular box and not that this 10M clock necessarily needs to do this.
Once sync'ed, I could replace the 25' lead with the 5" stub antenna that plugged into the repeater.
This stuff is cheap enough that it might be worth a try some day. I just received my R8HE and waiting for it to burn in. I currently like NOS and am using an Antipodes CX/EX which is way better than my previous DX3 but the presentation is changing every day with different frequency ranges getting a little foggy. I was referencing Steve Plaskin's review of the Playback Designs MPD-8 DAC where it continued to open up to 1,000 hours.

 

[FredA]

I clicked on the URL and saw the squarewave version as well - https://www.ebay.com/itm/Latest-10MHZ-SQUARE-WAVE-SQUAREWAVE-GPS-DISCiPLINED-CLOCK-GPSDO-LCD-Display/122872069750?_trkparms=aid=1110001&algo=SPLICE.SIM&ao=2&asc=20160323102634&meid=ec3a4da1a7344992a2deb2b5fef5e012&pid=100623&rk=3&rkt=6&mehot=ag&sd=112700839490&itm=122872069750&pmt=1&noa=1&pg=2047675&_trksid=p2047675.c100623.m-1

I don't know if the receiver performs better with the squarewave....and its $13 less expensive than the sign wave.

I would go for the sine. Easier to transmit and the square is derived from sine i believe. I have both on my ocxo and the sine performs better.

 

[roni44]

Hello guys,
One more question.

How long can it be the cable between the clock and the U16? As short as possible??? What about 5 or 6 feet long? Too much?

Mine is 1.5 meter/5 feet and it works fine.

 

[Toni-Mang]

@roni44 thank you, ...but as always, the i2s as short as possibile, the termination and echo relevant for digital cables? 50-Ohms? and therefor no additional advice for the clock cable?

 

[517269]

https://www.ebay.com/itm/10MHz-OCXO...ystal-Clock-Frequency-Reference-/112479847613
It'd be nice to have the noise plot to know what this $55 buys you but it would be interesting to pair this with a low-noise regulator [Pulsar or SparkoS] and if it can fit, mount it right inside the USB>I2S converter.