HP-10811AB-OCXO interface questions
Hi all,
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
pictures.
Questions:
- Is it worth keeping the interface board?
a. If yes, does anyone have the schematic and the data on the ICs?
b. What is that TO220 device? and
c. why is it mounted on a standoff on the back of the PCB? - Any advice/caution on matching the OCXO output impedance?
- Any recommendation for a (>= 4-ch) distribution amplifier?
- Any advice on a low jitter comparator for further digital processing,
e.g. for a 1pps signal?
Thanks and 73
Manfred VK3AES
For sine to square wave conversion use LTC6957 (select variant to suit following logic).
Bruce
On 02 September 2020 at 17:24 Manfred Bartz <vk3aes@gmail.com mailto:vk3aes@gmail.com > wrote:
Hi all,
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
pictures.
Questions:
1. Is it worth keeping the interface board?
a. If yes, does anyone have the schematic and the data on the ICs?
b. What is that TO220 device? and
c. why is it mounted on a standoff on the back of the PCB?
1. Any advice/caution on matching the OCXO output impedance?
2. Any recommendation for a (>= 4-ch) distribution amplifier?
3. Any advice on a low jitter comparator for further digital processing,
e.g. for a 1pps signal?
Thanks and 73
--
Manfred VK3AES
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Hi
On Sep 2, 2020, at 1:24 AM, Manfred Bartz vk3aes@gmail.com wrote:
Hi all,
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
pictures.
Questions:
- Is it worth keeping the interface board?
They make an adequate “burn in” board. There isn’t a lot of use for them
otherwise.
a. If yes, does anyone have the schematic and the data on the ICs?
You can trace it out. It’s an ECL doubler or something like that.
b. What is that TO220 device?
It’s the 12V regulator to drive the oscillator. The 10811 uses > 20V
for the oven and ~ 12V for the oscillator
and
c. why is it mounted on a standoff on the back of the PCB?
It shipped that way to keep it safe. It mounts on the chassis of the
instrument this board plugged into.
- Any advice/caution on matching the OCXO output impedance?
10811 is designed to run into a 50 ohm or 1K ohm load. Most run them
into a 50 ohm load.
- Any recommendation for a (>= 4-ch) distribution amplifier?
Depends a lot on what you are after. I did a post of some op-amp
data back a few months. None of them would “preserve” the far removed
phase noise of the 10811.
- Any advice on a low jitter comparator for further digital processing,
e.g. for a 1pps signal?
The previous post about the LTC part is one way to go. A simple biased
gate (like that used on the interface board) is another way. A lot depends
on just how low “low jitter” needs to be.
Bob
Thanks and 73
Manfred VK3AES
<HP-10811AB-OCXO-IMG_20200805_201555.jpg><HP-10811AB-OCXO-IMG_20200805_201615.jpg>_______________________________________________
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I remember the days when we had to build our own discrete Schmitt trigger to
do this. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of Bruce
Griffiths
Sent: Wednesday, September 2, 2020 1:46 AM
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] HP-10811AB-OCXO interface questions
For sine to square wave conversion use LTC6957 (select variant to suit
following logic).
Bruce
Ordered a bunch of these to test against the TAPR device
https://www.aliexpress.com/item/4001231758949.html?spm=a2g0s.9042311.0.0.151
84c4d1hMhZs
TLV3501 Single Chan High Speed Comparator Frequency Meter Front Shaping
Module DC 2.7-5V Frequency Counter SMA
Specifications:
Supply voltage: 2.7-5VDC
Input voltage: 8-1000mV (effective value)
Output level: rail to rail output, can directly TTL / CMOS level
Input frequency: 1Hz-120 MHz, Min.1Hz
shape: SMA female head (external screw hole)
Input impedance: 20 K ohm
Product Use:
Sine wave
The zero crossing comparator
comparator
Colour:green
Material:metal
Size:about 5*2.5cm
Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
lester@veenstras.com
452 Stable Ln (HC84 RFD USPS Mail)
Keyser WV 26726
GPS: 39.336826 N 78.982287 W (Google)
GPS: 39.33682 N 78.9823741 W (GPSDO)
Telephones:
Home: +1-304-289-6057
US cell +1-304-790-9192
Jamaica cell: +1-876-456-8898
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@lists.febo.com] On Behalf Of Mike
Feher
Sent: Wednesday, September 02, 2020 10:01 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] HP-10811AB-OCXO interface questions
I remember the days when we had to build our own discrete Schmitt trigger to
do this. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of Bruce
Griffiths
Sent: Wednesday, September 2, 2020 1:46 AM
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] HP-10811AB-OCXO interface questions
For sine to square wave conversion use LTC6957 (select variant to suit
following logic).
Bruce
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
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and follow the instructions there.
Hi
That interface board may use a biased transistor to convert sine to square.
It’s been a while since I looked at it …..
Bob
On Sep 2, 2020, at 10:00 AM, Mike Feher mfeher@eozinc.com wrote:
I remember the days when we had to build our own discrete Schmitt trigger to
do this. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of Bruce
Griffiths
Sent: Wednesday, September 2, 2020 1:46 AM
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] HP-10811AB-OCXO interface questions
For sine to square wave conversion use LTC6957 (select variant to suit
following logic).
Bruce
time-nuts mailing list -- time-nuts@lists.febo.com
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and follow the instructions there.
On 9/1/2020 10:24 PM, Manfred Bartz wrote:
Hi all,
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
Manfred, the -hp- system of numbering would indicate that this was from
a 5328 counter. There are two versions of that board on the ko4bb site,
not identical, but they may be of some help.
Dan
Look in the HP5328A counter manual for the circuit - that's what this
came from, indicated by the board marking. Seems like an awful lot of
extra circuitry to support the OCXO. The only thing I can think of
offhand is it may be a PLL circuit to allow locking to an external
reference. You'll probably find it not needed or wanted for a fresh
GPSDO system, but save the connector to go with the 10811.
Ed
Manfred,
The 05328-20027 part number is the HP part number for the bare PCB used in the A3 assembly 05328-60027 interface board. You can find the schematic for that assembly in the manual for the militarized version of the 5328A (AN/USM-459) at [ https://radionerds.com/images/9/9a/TM_11-6625-2941-14%26P.PDF | https://radionerds.com/images/9/9a/TM_11-6625-2941-14%26P.PDF ] and the associated manual [ https://www.liberatedmanuals.com/TM-11-6625-2941-24P.pdf. | https://www.liberatedmanuals.com/TM-11-6625-2941-24P.pdf. ] .
Cheers,
Dave M
From: "Manfred Bartz" vk3aes@gmail.com
To: "Discussion of precise time and frequency measurement" time-nuts@lists.febo.com
Sent: Wednesday, September 2, 2020 12:24:21 AM
Subject: [time-nuts] HP-10811AB-OCXO interface questions
Hi all,
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
pictures.
Questions:
- Is it worth keeping the interface board?
a. If yes, does anyone have the schematic and the data on the ICs?
b. What is that TO220 device? and
c. why is it mounted on a standoff on the back of the PCB? - Any advice/caution on matching the OCXO output impedance?
- Any recommendation for a (>= 4-ch) distribution amplifier?
- Any advice on a low jitter comparator for further digital processing,
e.g. for a 1pps signal?
Thanks and 73
Manfred VK3AES
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Manfred wrote:
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
pictures.
The 05328-20027 "Oscillator Support Assembly" (also, the 05328-60027
"Oscillator Support Assembly") was used to interface an HP 10544A OCXO
(predecessor to the 10811 OCXO) to an HP 5328A frequency counter. It
contains two voltage regulators, an amplifier chain to enable the
external standard input on the 5328, and a 10:1 divider to generate a
1MHz output in addition to the 10MHz output.
A similar "Oscillator Support Assembly", HP 05328-60038, was used to
interface an HP 10811 OCXO to the HP 5328A frequency counter.
There was also an earlier "Oscillator Support Board", HP 05328-60018,
which contains only the voltage regulator.
Schematics for all of the oscillator support boards can be found in
various generations of the HP 5328A service manual, which are easily
found on line.
Best regards,
Charles
Missing body of my previous message (I hope):
As others have said, there are a number of versions of the 5328A
oscillator support board. Yours looks like it is from a MIL version of
the 5328A with the 10811 OCXO. Attached is the most-likely schematic,
which is from the manual for the 5328AH99 TRI-SERVICE COUNTER found in
Keysight obsolete products:
https://www.keysight.com/en/pd-5328AH99%3Aepsg%3Apro-pn-5328AH99/tri-service-counter?pm=PL
Steve
On 9/1/2020 10:24 PM, Manfred Bartz wrote:
Hi all,
I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
The OCXOs came with an interface board HP 05328-20027, see attached
pictures.
Questions:
- Is it worth keeping the interface board?
a. If yes, does anyone have the schematic and the data on the ICs?
b. What is that TO220 device? and
c. why is it mounted on a standoff on the back of the PCB? - Any advice/caution on matching the OCXO output impedance?
- Any recommendation for a (>= 4-ch) distribution amplifier?
- Any advice on a low jitter comparator for further digital processing,
e.g. for a 1pps signal?
Thanks and 73
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Wow, thanks for all the information.
Thanks Bruce Griffiths, the LTC6957 is expensive but looks very good
for sine to square wave conversion.
Thanks Lester Veenstra for the details on some of the devices on the
interface PCA and the link to the TLV3501 signal conditioning module.
Thanks Bob kb8tq for the info and comments to each question.
Glenn Little WB4UIV, I think that I might recover and reuse the OCXO
connector from the interface PCAs. If you are still interested I can
send you the PCAs minus those connectors for the cost of the postage,
email me directly.
Thanks Dave M for the detailed part number references.
Thanks Ed Breya, Dan Rae and Charles Steinmetz. Useful to know where
the interface PCA and OCXO were originally from and where more info can
be found.
Thanks Steve Longcor for digging up the interface PCA schematic.
Looks like I have a bit of reading, designing and building to do now. :-)
Cheers
Manfred VK3AES