Am 04.12.2014 um 00:04 schrieb paul swed:

Congrats!

Can't help to ask some questions:
The MTI-260, is that a CMOS level or a sine output version on 5 MHz?
Where I'm right now, I have the Lucent pair, one of them dismantled,
but no power supply & no scope, that has to wait until the weekend.

I'd like to make a small board that directly takes the 5 MHz from the
Osc, buffers it, doubles it with the NIST FET doubler and provides 4 SMA
+12dBm outputs at 10 MHz via 4*AD8009 or LMH6702.
There is enough free space on the front plate.
I'd like to hear that the osc delivers a sine, since that makes
doubling easier.

BTW I have another 10 MHz MTI-260 and did measure phase noise with
an E5052B. That was not so funny. Probably it's orientiented towards
long term stability at the cost of noise with absolutely minimum crystal
dissipation. I'd like to repeat the measurement under better controlled
environmental conditions b4 I tell numbers.
But it seems that Morion rulez, noise-wise.

regards, Gerhard

Hi

Be careful when you do this.

A signal with harmonics 20 db down and sub-harmonics 30 db down will make a fine reference input for a counter / signal generator / spectrum analyzer.

A signal with a 1 second ADEV of 5x10^-10 will look absolutely perfect on any spectrum analyzer ever made. It will not be a good a reference for an instrument as a source at 5x10^-12.

Close in phase noise / ADEV is what you need to set up to check. A relative test is fine ( divide 10 by 2 and compare to 5), but that’s what you need to check

Bob

Paul - could you elaborate on where you made the connections?  A few photos perhaps?

Nice work,

Anthony

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Bob
I agree with your comments.
For the test gear on the bench this will be very fine.
Regards
Paul
WB8TSL

On Wed, Dec 3, 2014 at 7:40 PM, Bob Camp kb8tq@n1k.org wrote:

On the output of the crystal oscillator you will want to buffer it and then
do whatever you like. Its a sine wave and as I recall of fair level several
volts. I did see a bit of distortion on the sine wave. It can be obtained
at J8 the unpopulated jack.
Now back to putting it in its case.
Regards
Paul
WB8TSL

On Wed, Dec 3, 2014 at 7:33 PM, Gerhard Hoffmann dk4xp@arcor.de wrote:

Hi

The OCXO in the TBolt beats the Morion parts by a wide margin.

Bob

On Wed, Dec 03, 2014 at 08:46:58PM -0500, Bob Camp wrote:

That implies all Tbolts have the same OCXO... is that actually

true of most of the surplus ones ?  Weren't there varients in
some of the early lots at least ?

And there certainly were widely different date codes...

--
Dave Emery N1PRE/AE, die@dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."

Hi

For phase noise, they all are quite good, the newer ones are a bit better. For ADEV and wander, the newer (post 2002) parts are the better bet.

Bob

Hi

So how does the 5 MHz get into the FPGA and / or  CPU?

In order to discipline the OCXO and to generate the PPS, there must be a path. If that path is independent of the 15 MHz (or 15 and 10) multiplier(s) then you have a lot of things you can do. If either of the existing multipliers need to be kept running, that limits you a bit.

Bob

J8 its unpopulated right next to the oven.
Regards
Paul
WB8TSL

On Wed, Dec 3, 2014 at 7:36 PM, Doug Ronald doug@dougronald.com wrote:

I have a pix of the point to tap. Its on the bottom of the board. Not sure
I can skinny it down to fit Time Nuts has to be sub 100K.
I will tinker tomorrow night and see if I can get it down.
Regards

On Wed, Dec 3, 2014 at 10:40 PM, paul swed paulswedb@gmail.com wrote:

Well that was easier then I thought. Here is the tap off point.
Bottom of the board. I have not been able to trace the place it comes from.
Between the two caps is a via and I have ohm'ed out lots of them and never
hit the other end. I wanted to attach from the top.
Also a pix of the el2020 buffer. The red coax feeds the old 15 MHz output
after cutting the old trace on the bottom.
Regards
Paul
WB8TSL

On Wed, Dec 3, 2014 at 10:42 PM, paul swed paulswedb@gmail.com wrote:

Alex wrote:

Yes, all of those (specifically referring to the Trimble p/n 37265
OCXO used in the later Tbolts that we usually see as surplus).

Note that some earlier (and perhaps, later) Tbolts used different
Trimble oscillators that are not as good as the 37265 with respect to
phase noise, and many earlier Tbolts used a rather undistinguished
Piezo (brand) OCXO.

Best regards,

Charles

Hi

In the context of the message that was a reply to;

Phase noise

Bob

Hi

Of course the point I made is not as useful as it might be.There are a ton of Morions out there and very few Trimble OCXO’s outside of TBolts. I doubt anybody is going to scrap out a working TBolt for it’s OCXO :).

Once you get them surplus, there is no reason to believe the Trimble parts survive the scrap out process any better than the Morions. Also since the TBolt they came out of is worth far more than the OCXO, it’s not at all clear why you would pull one from a working unit. If they unit was broke - was it the OCXO ?? Hmmmm…..

Bob