Author Topic: Economical option for precision frequency reference?  (Read 155312 times)

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Offline SoundTech-LG

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Re: Economical option for precision frequency reference?
« Reply #275 on: October 12, 2015, 01:02:02 am »
more
 

Offline SoundTech-LG

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Re: Economical option for precision frequency reference?
« Reply #276 on: October 12, 2015, 01:03:09 am »
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Offline SoundTech-LG

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Re: Economical option for precision frequency reference?
« Reply #277 on: October 12, 2015, 01:03:41 am »
a few more
 

Offline SoundTech-LG

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Re: Economical option for precision frequency reference?
« Reply #278 on: October 12, 2015, 01:06:49 am »
done
 

Offline Vgkid

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Re: Economical option for precision frequency reference?
« Reply #279 on: October 12, 2015, 01:28:40 am »
Thanks for the teardown, I was wondering when you would post more pics...
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline SoundTech-LG

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Re: Economical option for precision frequency reference?
« Reply #280 on: October 12, 2015, 02:45:37 am »
Hi,

Yes, testing came first.

 It appears possible to upgrade to the Morion Ultra LN OCXO double oven MV-209. Same footprint, just a tad taller.I doubt it would require a FW change.  I have to check the PS voltage, and whether Sine or CMOS output.

http://www.morion.com.ru/catalog_pdf/26_MV209.pdf

 

Online TheSteve

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Re: Economical option for precision frequency reference?
« Reply #281 on: October 20, 2015, 05:54:49 am »
I have been touring ebay for a distribution amplifier after reading that several people have used video amplifiers for the job. Decided on a Link Electronics video distribution amplifier that was 19.95 plus shipping. Opened it up, removed the eight 75 ohm output resistors and installed eight 49.9 ohm resistors. Set it to single ended mode, added an output terminator and then set the output level to 0 dBm into 50 ohms. The output looks good on my scope and spectrum analyzer. It will now be feeding 10 MHz to all of my devices. I liked this model because it had 8 outputs which should take me a long time to use and it uses less then 4 watts of power. Combined with the Trimble GPSDO the pair use under 10 watts which I think is fine to leave running 24/7 in the lab.

So anyone looking to run 10 MHz to a bunch of devices, check out the video amps on ebay.

EDIT:

After playing with this amp for a while I noticed I was able to see spurs above and below 10 MHz when using a very narrow RBW on my spectrum analyzer. Turns out they were 120 Hz above and below 10 MHz. A quick look at the amp explains while - it uses a full wave bridge rectifier, filter caps and no regulators. Internally it runs at plus and minus 10 volts. I cut some traces and wired in a 7805 and a 7905 with some caps. Before I did that I verified with an external supply that it seemed to run just fine at plus and minus 5 volts. The spurs are now gone and the output is cleaner. I may still get a 7808 and a 7908 next time I order from Digikey and wire them in to give a little more headroom. Turning the output all the way up though shows no clipping as it is. I believe the video input levels may be higher then the 1.5 vpp my GPSDO outputs.
« Last Edit: November 01, 2015, 05:54:17 am by TheSteve »
VE7FM
 

Offline Macbeth

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Re: Economical option for precision frequency reference?
« Reply #282 on: October 24, 2015, 03:34:18 pm »
Well, I got my Symmetricom module and some of those MCX-BNC leads :-+

Unfortunately the MCX socket for the GPS antenna appears to have been ripped from the board, and wasn't even to be found loose in the mail package. I will have to source one, but a bit of a PITA as it's a surface mount component. Also, there are two push buttons, MACT and RST. The MACT ones cap fell off and the spring contact vanished (if it was even there). Now those faults aren't so bad, but powering it up the DC/DC converter is ringing and no 5V, so no LED's or anything :(

I've powered up using the spare BT pin on the DBG connector using a 5V and everything kicks into life, but of course the oven isn't warming up :(

I've asked the seller for a return. He's initially responded with me finding the MCX connector locally and he will refund me that. Ok, but it was sold as used cosmetic wear and tear, fully functioning... If I didn't have a hot air station then I would be buggered.

So I'll carry on investigating this while I wait for his response and either return it for full refund or get a decent discount.

 

Online TheSteve

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Re: Economical option for precision frequency reference?
« Reply #283 on: October 24, 2015, 05:27:51 pm »
Well that sucks. Even if you do get it working they should probably give you a full refund as its not quite a simple fix at this point. Would you be able to provide some pics of the board? The ones on ebay are pretty crappy.
VE7FM
 

Offline Macbeth

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Re: Economical option for precision frequency reference?
« Reply #284 on: October 26, 2015, 11:10:52 am »
Well, one I took to send to the seller. Note the missing MCX and the dodgy looking MACT button. When I upturned the board the top fell off and the contact spring vanished  :rant:



The seller is telling me I could solder the socket with a normal iron "as its only 4 pins". I asked him how he would solder the 5th centre pin with an iron? hahaha. It's besides the point as it was advertised as working. Basically I've asked for a full refund or for him to send me a replacement. I've offered to return this at his cost of tracked delivery (£47), I somehow don't think he will want it back.

Nevertheless, I persisted with trying to get somewhere with it in the meantime. I found any voltage I applied to the 10A fuse (3.3V - 12V) would clamp my Rigol PSU at something around 3.3-4V. I had current limiting set to 2A but it would peak at about 1.6A. Ringing noise coming from the DC/DC converter and no indicator LEDs. The OCXO would get pretty toasty. There are various test points on board, 1.2V, 3.3V good, 5V was bad - less than 4V. A PWR test point going to the OCXO was around 8-9V even with only 5-6V supply. Another test point VREF is in the 4-5V range.

I found that not using the main power but the BT (battery?) connection on the 4 pin DBG (rx/tx) header with 5V flicked the board into life. Combining 2 supplies, 5V at BT and 6V for power in the ringing would stop when the OCXO got really hot and then would stop heating as the current dropped from 1.5A to 300mA or so. I can connect using serial OK and plenty of commands to play with. Looking at the diagnostic log this device was previously installed somewhere north of Tokyo back in 2014 ;)

When the DC/DC converter settled down I found I could remove the 5V BT supply and it would remain running. So I've been playing with the serial commands for now.
« Last Edit: October 26, 2015, 12:21:06 pm by Macbeth »
 

Offline Macbeth

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Re: Economical option for precision frequency reference?
« Reply #285 on: October 26, 2015, 12:17:29 pm »
Some interesting serial logs:

Powered on and help command

Code: [Select]

Symmetricom Boot Code ver. 1.01.01


Press Enter to go to boot
Image1: [1.0.0.2] [454535 bytes] [valid checksum:0x20AFA24] [timestamp:3]
Image2: [1.0.0.1] [454535 bytes] [valid checksum:0x2142B89] [timestamp:2]

Loading Image1
UCCM-P > ?
*IDN?
ALARm:HARDware?
ALARm:OPERation?
DIAGnostic:OUTPut ON|OFF
OUTPut:ACTive:ENABle
OUTPut:ACTive:DISable
OUTPut:ACTive:HOLDover:DURation:THReshold <seconds>
OUTPut:ACTive:HOLDover:DURation:THReshold?
OUTPut:INACTive
OUTPut:INACTive?
OUTPut:STATe?
SYNChronization:HOLDover:DURation:STATus:THReshold <seconds>
SYSTem:PRESet
SYNChronization:TFOMerit?
LED:GPSLock?
SYNChronization:FFOMerit?
GPS:POSition N or S,<deg>,<min>,<sec>,E or W,<deg>,<min>,<sec>,<height>
GPS:POSition?
GPS:POSition:HOLD:LAST?
GPS:REFerence:ADELay <numeric value>
GPS:REFerence:ADELay?
GPS:SATellite:TRACking:COUNt?
GPS:SATellite:TRACking?
DIAGnostic:ROSCillator:EFControl:RELative?
SYNChronization:TINTerval?
DIAGnostic:LOG:READ:ALL?
DIAGnostic:LOG:CLEar
SYSTem:PON
OUTPut:MODE?
SYSTem:STATus?
SYSTem:COMMunication:SERial1:BAUD 9600|19200|38400|57600
SYSTem:COMMunication:SERial1:BAUD?
SYSTem:COMMunication:SERial1:PRESet
SYSTem:COMMunication:SERial2:BAUD 9600|19200|38400|57600
SYSTem:COMMunication:SERial2:BAUD?
SYSTem:COMMunication:SERial2:PRESet
OUTPut:STANby:THReshold <seconds>
changeSN
SYNChronization:REFerence:ENABLE LINK|GPS
SYNChronization:REFerence:DISABLE LINK|GPS
SYNChronization:REFerence:ENABLE?
STATus
POSSTATus
TOD EN|DI
TIME:STRing?
REFerence:TYPE GPS|LINK
REFerence:TYPE?
PULLINRANGE 0|1|2|...|254|255
PULLINRNAGE?
DIAGnostic:LOOP?
DIAGnostic:ROSCillator:EFControl:DATA GPS|<value>
DIAGnostic:ROSCillator:EFControl:DATA?
OUTPut:TP:SELection PP1S|PP2S
OUTPut:TP:SELection?
GPSystem:SATellite:TRACking:EMANgle <degrees>
GPSystem:SATellite:TRACking:EMANgle?
DIAGnostic:TCODe:STATus:AMASk
DIAGnostic:TCODe:STATus:OMASk
DIAGnostic:TCODe:ERRor:AMASk
DIAGnostic:TCODe:ERRor:OMASk
DIAGnostic:HOLDover:DELay
DIAGnostic:HOLDover:DELay?
GPS:SATellite:TRACking:IGNore <PRN>, ...,<PRN>
GPS:SATellite:TRACking:IGNore?
GPS:SATellite:TRACking:INCLude <PRN>, ...,<PRN>
GPS:SATellite:TRACking:INCLude?
GPS:SATellite:TRACking:<select>:ALL
Command Complete
UCCM-P >

The STATUS command
Code: [Select]

UCCM-P > status

                 - UCCM Slot STATE -



1-1. #Now ACTIVE STATUS ---------------- [OCXO Warm]
1-2. #Before ACTIVE STATUS ------------- [OCXO Warmup]
2-1. #Reference Clock Operation -------- [Not Used]
2-2. #Current Reference Type ----------- [LINK]
2-3. #Current Select Reference --------- [LINK0]
2-4. #Current Reference Status --------- [NOT SELECTED]
     #GPS STATUS ----------------------- [Unavailable]
     #Priority Level ------------------- [LINK > GPS]
     #ALARM STATUS
     #H/W FAIL ---------- [ LINK ]
     #OPERATION ALARM --- [ Antenna ]
3-1. PLL STATUS ------------------------ [Enable]
3-2. Current: PLL MODE ----------------- [OFFSET OBSERVATION MODE]
Command Complete
UCCM-P >

POSSTATUS

Code: [Select]
UCCM-P > posstatus
-----------------------------------------------------------------------------
1/6/1980 00:07:58
-----------------------------------------------------------------------------
 Position : LAT(N 34:44:0.000) LON(E 135:21:0.000) H(0.00 m MSL)
-----------------------------------------------------------------------------
 Geometry : PDOP(0.0) HDOP(0.0) VDOP(0.0)
-----------------------------------------------------------------------------
 Channel Status
   num of visible sats > 0
   num of sats tracked > 0
   ------ Receiver Channel State ------
     CH 0 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 1 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 2 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 3 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 4 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 5 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 6 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 7 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 8 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 9 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 10 >  SateID(0) TrackMode(code search) SigValue(0)
     CH 11 >  SateID(0) TrackMode(code search) SigValue(0)
-----------------------------------------------------------------------------
  Rcvr Status(1) :
-----------------------------------------------------------------------------
  Antenna Voltage: 6255 mV,  Antenna Current: 0 mA
-----------------------------------------------------------------------------
Command Complete
UCCM-P >

I note the Antenna Voltage appears to track my supply voltage (6.5V in this case). This is a bit concerning as my GPS Antenna is only 3.3-5V. I have found powering the board up with less than 5.5 volts results in an error in the log regarding insufficient current for the OCXO. I have measured the reported voltage directly at the (stripped) antenna connection and it is correct.

Finally the SYST:STATUS? command

Code: [Select]

UCCM-P > syst:status?
-------------------------------------------------------------------------------
090-03861-03   serial number W5609120082   firmware ver 1.0.0.2-01     LINK mode
-------------------------------------------------------------------------------
Reference Status __________________________   Reference Outputs _______________
   Ref 8KHz 0: [LOS]
                                              TFOM     9             FFOM     3
                                              UCCM-P Status[OCXO WARM]

>> GPS: [no ref]
......................................................... [ GPS 1PPS Invalid ]
Tracking: 0 ____   Not Tracking: 0 ________   Time ____________________________
                                              GPS      00:20:17 [?] 06 JAN 1980
                                              GPS      Invalid: not tracking
                                              ANT DLY  +0.000E+00
                                              Position ________________________
                                              MODE     Survey:      0% complete
                                                       Suspended: track <4 sats
                                              INIT LAT N  34:44:00.000
                                              INIT LON E 135:21:00.000
                                              INIT HGT           +0.00 m  (MSL)




ELEV MASK  5 deg
-------------------------------------------------------------------------------

Command Complete
UCCM-P >

Now for the provenance of this thing. Obtained from Hong Kong, the system status INIT LAT and LON show somewhere between KOBE and OSAKA in Japan while the data recorded in the diagnostic logs (now overwritten - 500 line limit) show 2 site surveys in 2013 and 2014 some place called KOSHIGAYA north of TOKYO  ;)
 

Offline f1rmb

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Re: Economical option for precision frequency reference?
« Reply #286 on: October 31, 2015, 11:09:52 am »
Hi,

Some interesting serial logs:

...

I'm pretty interested with this board. Did you made some progress ?
 

Offline Macbeth

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Re: Economical option for precision frequency reference?
« Reply #287 on: October 31, 2015, 11:37:42 am »
Yes. I've asked the seller to send me a new one. He wanted me to send this one back, so I asked him to arrange his own courier or go through the cheapest tracked royal mail options available to be. Obviously he didn't want that. He eventually settled for sending me another one out. We will see.

While sorting that out I found an MCX socket on an old junk board and swapped it over using hot air so I finally got to see some satellites. I'm using one of those cheap 3.3-5V "GPS Mouse" antennas stuck to a drainpipe outside my window.

However, the DC/DC converter was still troublesome and now the board would power up with only one supply but the oven wouldn't heat up and I couldn't get my 10MHz output.

It turns out the OCXO runs at 12V generated from a single 5V supply by a TI boost converter module (which is now kaput). I removed the module and powered up from with 12V directly to the OCXO and 5V supply and now everything is working.

I was considering making a dual supply for it but I've found the exact drop in replacement boost converter on AliExpress for around £3  :-+ 
« Last Edit: October 31, 2015, 11:49:24 am by Macbeth »
 

Offline f1rmb

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Re: Economical option for precision frequency reference?
« Reply #288 on: October 31, 2015, 11:42:13 am »
Hi,

Yes. I've asked the seller to send me a new one. He wanted me to send this one back, so I asked him to arrange his own courier or go through the cheapest tracked royal mail options available to be. Obviously he didn't want that. He eventually settled for sending me another one out. We will see.

While sorting that out I found an MCX socket on an old junk board and swapped it over using hot air so I finally got to see some satellites.

However, the DC/DC converter was still troublesome and now the board would power up with only one supply but the oven wouldn't heat up and I couldn't get my 10MHz output.

It turns out the OCXO runs at 12V generated from a single 5V supply by a TI boost converter module (which is now kaput). I removed the module and powered up from with 12V directly to the OCXO and 5V supply and now everything is working.

I was considering making a dual supply for it but I've found the exact drop in replacement boost converter on AliExpress for around £3  :-+

Great to read that. I guess I'll click the button ;-)

Did you connect the power supply (on the first step, before DC/DC troubles) like on the Trimble:
http://www.ebay.com/itm/Trimble-GPS-Receiver-GPSDO-10MHz-1PPS-GPS-Disciplined-Clock-/181777773438

Also, do you have some documentation for this board (tried a quick google search without real success until now).

Cheers.
---
Daniel
 

Offline Macbeth

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Re: Economical option for precision frequency reference?
« Reply #289 on: October 31, 2015, 12:13:43 pm »
Great to read that. I guess I'll click the button ;-)
Oh yes, hopefully you won't have any trouble. They are sold as working after all. But it's well worth it even if you have the hassle I had.
Quote
Did you connect the power supply (on the first step, before DC/DC troubles) like on the Trimble:
http://www.ebay.com/itm/Trimble-GPS-Receiver-GPSDO-10MHz-1PPS-GPS-Disciplined-Clock-/181777773438
Yes. I started at 5V at the fuse and current limiting going up in steps to 12V, also down to 3.3V. I just had bad switching noise and the input circuit clamping my PSU voltage really low. Even with 12V it never got above 4V at the fuse. Boost converter eventually totally failed. (Not at 12V I might add - I had it running at 5.5-6V all this time to supply enough current to prevent reported OCXO failure, but it should really run at 5V alone)

Quote
Also, do you have some documentation for this board (tried a quick google search without real success until now).

Cheers.
---
Daniel
I'm looking but can't find anything specific. It does appear this board is a direct replacement for the Trimble though.
« Last Edit: October 31, 2015, 12:17:02 pm by Macbeth »
 

Offline f1rmb

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Re: Economical option for precision frequency reference?
« Reply #290 on: October 31, 2015, 12:18:14 pm »
Great to read that. I guess I'll click the button ;-)
Oh yes, hopefully you won't have any trouble. They are sold as working after all. But it's well worth it even if you have the hassle I had.
Quote
Did you connect the power supply (on the first step, before DC/DC troubles) like on the Trimble:
http://www.ebay.com/itm/Trimble-GPS-Receiver-GPSDO-10MHz-1PPS-GPS-Disciplined-Clock-/181777773438
Yes. I started at 5V at the fuse and current limiting going up in steps to 12V, also down to 3.3V. I just had bad switching noise and the input circuit clamping my PSU voltage really low. Even with 12V it never got above 4V at the fuse. Boost converter eventually totally failed. (Not at 12V I might add - I had it running at 5.5-6V all this time to supply enough current to prevent reported OCXO failure, but it should really run at 5V alone)

Quote
Also, do you have some documentation for this board (tried a quick google search without real success until now).

Cheers.
---
Daniel
I'm looking but can't find anything specific. It does appear this board is a direct replacement for the Trimble though.

Okay, many thanks for all these informations, I guess I'll order one board later today ;-)

EDIT: Ordered :-)

Cheers.
---
Daniel
« Last Edit: October 31, 2015, 06:16:08 pm by f1rmb »
 

Offline f1rmb

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Re: Economical option for precision frequency reference?
« Reply #291 on: November 01, 2015, 05:06:20 pm »
Hi,

Great to read that. I guess I'll click the button ;-)
Oh yes, hopefully you won't have any trouble. They are sold as working after all. But it's well worth it even if you have the hassle I had.
Quote
Did you connect the power supply (on the first step, before DC/DC troubles) like on the Trimble:
http://www.ebay.com/itm/Trimble-GPS-Receiver-GPSDO-10MHz-1PPS-GPS-Disciplined-Clock-/181777773438
Yes. I started at 5V at the fuse and current limiting going up in steps to 12V, also down to 3.3V. I just had bad switching noise and the input circuit clamping my PSU voltage really low. Even with 12V it never got above 4V at the fuse. Boost converter eventually totally failed. (Not at 12V I might add - I had it running at 5.5-6V all this time to supply enough current to prevent reported OCXO failure, but it should really run at 5V alone)

Quote
Also, do you have some documentation for this board (tried a quick google search without real success until now).

Cheers.
---
Daniel
I'm looking but can't find anything specific. It does appear this board is a direct replacement for the Trimble though.

   Did you measured the output signal level ? I'm looking to add an output buffer.

Cheers.
---
Daniel
 

Offline Macbeth

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Re: Economical option for precision frequency reference?
« Reply #292 on: November 01, 2015, 11:55:37 pm »
~1.5V p-p, 50 ohms IIRC when I had 12V going to it. I have it put aside for now waiting for the replacement.
 

Offline f1rmb

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Re: Economical option for precision frequency reference?
« Reply #293 on: November 01, 2015, 11:57:24 pm »
Hi,

~1.5V p-p, 50 ohms IIRC when I had 12V going to it. I have it put aside for now waiting for the replacement.

Excellent. Thanks again for everything. Can't wait to receive mine and start playing with.

Cheers.
---
Daniel
 

Offline Gandalf_Sr

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Re: Economical option for precision frequency reference?
« Reply #294 on: November 14, 2015, 07:31:14 pm »
OK, I'm looking to jump in on this bandwagon.  So here what I think my options are..

1. If I buy this Trimble system for $119, I just need a box and GPS antenna or
2. If I buy this Symmetricon unit for $49, I'll also need a PSU and the pigtails.

Is the Trimble the better buy? Or has someone got a better suggestion?

Thanks
If at first you don't succeed, get a bigger hammer
 

Online TheSteve

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Re: Economical option for precision frequency reference?
« Reply #295 on: November 14, 2015, 08:47:09 pm »
OK, I'm looking to jump in on this bandwagon.  So here what I think my options are..

1. If I buy this Trimble system for $119, I just need a box and GPS antenna or
2. If I buy this Symmetricon unit for $49, I'll also need a PSU and the pigtails.

Is the Trimble the better buy? Or has someone got a better suggestion?

Thanks

What will be your ultimate use for the device? If you are only interested in 10 MHz I'd recommend looking for a Nortel NTBW50AA - it has a cleaner 10 MHz with less phase noise and works with Lady Heather. It is much bigger though.
VE7FM
 

Offline Shock

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Re: Economical option for precision frequency reference?
« Reply #296 on: November 15, 2015, 02:02:33 pm »
FYI the LUCENT/SYMMETRICOM Z3810AS, KS24361 has gone up to $200 now. 9 left.

Last one is up for sale.
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 189, 87V, 117, 112   >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 

Offline Shock

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Re: Economical option for precision frequency reference?
« Reply #297 on: November 15, 2015, 02:12:20 pm »
I have been touring ebay for a distribution amplifier after reading that several people have used video amplifiers for the job. Decided on a Link Electronics video distribution amplifier .

This is what mine looks like, Extron ADA 6 300 MX HV, bit excessive but hey. I was originally going to get it for a Frequency Electronics Inc FE-5680A Rubidium standard, happy with my LUCENT/SYMMETRICOM Z3810AS, KS24361 RFTG/GPSDO instead.

« Last Edit: November 15, 2015, 02:16:08 pm by Shock »
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 189, 87V, 117, 112   >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 

Online TheSteve

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Re: Economical option for precision frequency reference?
« Reply #298 on: November 16, 2015, 06:57:06 am »
I have been touring ebay for a distribution amplifier after reading that several people have used video amplifiers for the job. Decided on a Link Electronics video distribution amplifier .

This is what mine looks like, Extron ADA 6 300 MX HV, bit excessive but hey. I was originally going to get it for a Frequency Electronics Inc FE-5680A Rubidium standard, happy with my LUCENT/SYMMETRICOM Z3810AS, KS24361 RFTG/GPSDO instead.

Very nice - you're going to need a lot of equipment to connect to all those ports.

btw, have you checked to see how clean the signal coming out is versus what is going in? With mine I can't see too much on my spectrum analyzer however when I feed the 10 MHz into some devices I can see that the output isn't as clean(but its always bang on frequency!). I can generally see a small difference with and without the amplifier. The devices I have experimented with are an HP8714C network analyzer and an HP 8921A service monitor.
I can also see small differences between my cheapie Trimble GPSDO and the Nortel unit - the Nortel is cleaner.

The one device I need to keep experimenting with is my N1996A spectrum analyzer. The noise floor specs are only specified for its internal oscillator and are generally not as good with an external reference(it claims anyway). However instead of using 10 MHz in it will also accept 1 PPS. I can't help but wonder if possibly 1 PPS might end up cleaner.
VE7FM
 

Offline Shock

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Re: Economical option for precision frequency reference?
« Reply #299 on: November 16, 2015, 11:58:26 am »
This is what mine looks like, Extron ADA 6 300 MX HV, bit excessive but hey. I was originally going to get it for a Frequency Electronics Inc FE-5680A Rubidium standard, happy with my LUCENT/SYMMETRICOM Z3810AS, KS24361 RFTG/GPSDO instead.

Very nice - you're going to need a lot of equipment to connect to all those ports. btw, have you checked to see how clean the signal coming out is versus what is going in?

I have 5/10/15Mhz references and about half a dozen devices with 10Mhz external reference inputs, haven't done anything yet with it, but I believe the op amps are fairly high bandwidth and should give good results. This model is the more expensive version, though I only paid about $10 for the unit.

Here is a great video by Gerry Sweeney showing the unit. My source signals are very clean, incomparable to what he is using, also I don't have to gut the power supply in my situation. I was thinking of other ideas like on some of the outputs increasing the gain or making some attenuated.

I don't have a SA suitable just FFT on the 100MHz oscilloscope and a low frequency SA. I can't seeing it being too much of a problem though but I'll guess I will find out eventually.

Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 189, 87V, 117, 112   >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 


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