[time-nuts] STUPID QUESTION: Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812
Anthony Roby
aroby at antamy.com
Tue Nov 18 11:49:52 EST 2014
If you search through the recent messages, you'll see a link to a set of photos I posted. This one https://drive.google.com/file/d/0B5tlecUITRBLc3JyMElTdUwzMHM shows the front of the units. J7 provides the GPS power.
Anthony
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Don Murray via time-nuts
Sent: Tuesday, November 18, 2014 10:30 AM
To: time-nuts at febo.com
Subject: [time-nuts] STUPID QUESTION: Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812
Hello all...
Just getting up to speed on the KS-24361...
My stupid question (s)...
Where does the GPS antenna connect??
Does the GPS antenna port power the antenna?
Need a replacement for my dead HP Z3816A... ;-(
TIA...
73
Don
W4WJ
In a message dated 11/18/2014 3:26:52 A.M. Central Standard Time, mark at alignedsolutions.com writes:
One of my Z3805's (with the double oven 10811 ocxo iirc) also performs
similarly at times to the 58503A mentioned by Said. From an adev perspective
it's close to my BVA at some tau's (around a hundred seconds or so iirc.)
At times though the output seems to "jump" in frequency. My other Z3805
from the same source doesn't work as well.
None of the 10811's in my various pieces of test gear (some of which I basically purchased to get the 10811's) worked all that well from an Adev perspective. I used to buy HP5328 counters on the usual auction site with
10811's and the 500MHz C channel for quite low prices. At least I still have
a nice collection of frequency counters.
Sent from my iPad
On 2014-11-17, at 1:23 PM, Said Jackson via time-nuts <time-nuts at febo.com>
wrote:
> Correct on all counts Bob.
>
> My two 58503A units from China are great for both ADEV and PN
measurements, better than anything else I have as a combo (I have Wenzel ULNs for even lower PN testing but they don't have any usable ADEV). I also have a costly BVA and it can't compete against the HP unit.
>
> Those 10811s just rule.
>
> In fact my only complaint about the 58503A are the 60Hz related small
spurs you can see in the plots...
>
> Bye,
> Said
>
> Sent From iPhone
>
>> On Nov 17, 2014, at 12:28, Bob Camp <kb8tq at n1k.org> wrote:
>>
>> Hi
>>
>> The 58503 is a Z3801 with a pretty instrument style package put
>> around
it - right?
>>
>> If so, it might / should have a 10811 in it rather than an MTI OCXO.
The 10811 is rated for -155 dbc at 100 Hz. That is much better than the noise floor that the MTI ??s seem to produce at 100 Hz. About the only other GPSDO OCXO that gets to that level is the one in the original TBolts . There you very much have to deal with spurs. That make the noise floor of limited use in a practical system.
>>
>> Bob
>>
>>> On Nov 17, 2014, at 2:26 PM, SAIDJACK at aol.com wrote:
>>>
>>> Hi Bob,
>>>
>>> yes, the 10MHz plot is rotten, no doubt. The 15MHz plot is quite
>>> good
till about 40Hz offset, then it becomes pretty rotten too.
>>>
>>> Here is one of my 58503A units (using the 10811 OCXO) as a
comparison.. measured against our DROR-IIA (this plot was actually done to show the DROR-IIA PN, but since that unit actually has less noise and spurs than the 58503A we can simply use it as the reference for this purpose).
>>>
>>> The good news is that getting the close-in phase noise to be good
>>> is
very hard to do and the unit delivers that out-of-the box already. Filtering out the noise and spurs above 40Hz offset is pretty easy to do. It should be fairly straight forward to cobble up a small PN filter for those units to get rid of the noise and spurs above 40Hz offset.
>>>
>>> bye,
>>> Said
>>>
>>> In a message dated 11/17/2014 09:31:46 Pacific Standard Time,
kb8tq at n1k.org writes:
>>> Hi
>>>
>>> Here ??s the phase noise on the 15 MHz. There are a few spurs, and
>>> an
very real hump out at the likely frequency of the Lucent switcher. The 15 MHz is pretty clean compared to most /all of the other units I ??ve seen on the surplus market.
>>>
>>> I would not multiply this up to 40 GHz with a broadband multiplier.
>>> I
would be quite happy to run it into a PLL with a rational bandwidth. You will beat the noise on the output with a fairly simple VHF VCXO past 100 Hz.
No reason to have a bandwidth outside the 20 to 80 Hz range.
>>>
>>> Math:
>>>
>>> 15 MHz to 150 MHz -> 20 log (N) -> 20 db.
>>>
>>> -140 dbc / Hz shown below at 100 Hz offset -> -120 dbc/Hz
>>>
>>> You can get numbers better than -120 dbc/Hz at 100 Hz offset out of
>>> a
number of pretty simple VHF VCXO circuits. Bert has one that seems to work fine for him.
>>>
>>> Bob
>>>
>>> <DROR-IIA_Phase_Noise.png>
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
More information about the time-nuts
mailing list