Agilent 33120A / Option 001 Phase-Lock + external 10mhz standard

[HighVoltage]

Here is a nice agilent pdf to explain the option 001
http://www.home.agilent.com/upload/cmc_upload/All/Agilent33220A_FuncGenerator_Tutorial.pdf?&cc=DE&lc=ger

[dc101]

Check out Gerry Sweeney's youtube channel.  He did about 3 or 4 videos on this exact topic with the same freq counter and same rb source.  I believe the end result was that you were still better off getting option 001 even using an external ref due to the phase noise.  At any rate, Gerry ended up making his own OCXO carrier board for the counter.  Sorry if this was already posted in the thread.  I've been reduced to web surfing only with my ipad until I return home

[linux-works]

I saw gerry's video; it kind of was the push for me finally getting around to doing this

so, even with the Rb source, he found the XO to be better, overall?  maybe I should have saved my money on the Rb box, then.

I didn't notice he was using the same FG.  I'll have to rewatch a bit of it, I guess.

[dc101]

Oh you're right, he did it on an HP/Agilent counter not an FG... See what happens when I don't google model numbers just to double check myself.  It's been a long day sigh.... Anyways, I thought what he figured out was that using his counter with option 001 and an external rb was still better than using the counter with just the external rb.  Maybe the same logic will apply to the FG?  I could be wrong but I think the internal oscillator still contributes to the phase noise even if you're using an external time base.

[TiN]

I have option in my 33120A.
Can post a photo of board later...

[VK5RC]

Someone with better crystal knowledge may answer but I thought that a crystal can also make a pretty good filter, perhaps the good internal OXCO is filtering some phase noise from the Rb if the OXCO is still  in circuit once the Ext source is activated. Filtering a 10MHz source prior to even a relatively noisy PLL synthesiser (outputting at 1152MHz) can make a difference, see the 2 output spectra, one synthesiser with, one without filtering a 10MHz Ref ) pictures on page below.
http://www.vk3xdk.net46.net

[linux-works]

got it today:



was able to do a basic sanity check while at the seller's location.  it shows up as an additional menu option when its installed.  that's all we were able to check, so far.  I'll install this today and do a proper checkout later on.

so much money for such a tiny and not very high-tech board.  oh well.  HP doesn't stay in business entirely due to selling ink and printers, do they?  (oh right, they actually do!)

[linux-works]

excellent!  it works and works really well.

connected my Rb box to its rear bnc input and watched the output of the FG on my calibrated freq counter.  set the FG to 10mhz output just so that its easy to know when you are locked-on.

when you turn the Rb box on, it shifts its freq up and down while it tries to lock.  you can SEE THIS on the FG output, so you know its working.  the up and down shifts are sent thru to the FG's output and once the led turns off on the rubidium box, the freq is now locked and the FG stays stable to this.

exactly what I was hoping for.

[VK5RC]

Sounds good. Whilst HP-Ag-K-s know how to charge they do make really nice gear, I don't think you will regret it. Have fun. O0

[HighVoltage]

got it today:

May I ask, how much you paid for it ?
Thanks

[jpb]

got it today:

so much money for such a tiny and not very high-tech board.  oh well.  HP doesn't stay in business entirely due to selling ink and printers, do they?  (oh right, they actually do!)

I think the cost isn't too bad compared to many manufacturers.

If I want to get my WaveJet 334 oscilloscope talking to my computer I need to get a little ethernet card with just about one chip on it (my computer has USB but it is not functioning as it is pre the A series, I think it is just there for MCU programming or something). The cost of this card in the UK is typically £420 in the UK ($700 !!!) The cheapest I've seen it is Conrad at £375. Admittedly in the States it is $342 on Amazon but they won't ship out of the States.
http://www.amazon.com/LeCroy-WJ-A-LAN-Ethernet-Interface-Oscilloscopes/dp/B0094JXR4Y/ref=sr_1_1?ie=UTF8&qid=1396707751&sr=8-1&keywords=WJ-A-LAN

So your little card which also contains a TCXO, though not cheap at $200-$250, is relatively a bargain!

[linux-works]

got it today:

May I ask, how much you paid for it ?
Thanks

$200 cash price.  ebay price was higher but I went direct to the seller (it was a local pickup so that can work).

I believe he has one more left.

[linux-works]

it looks like the dave-dot effect has just hurt the opt-001 used market.  or helped it, depending on whether you are a buyer or seller.

there were 2 used upgrade cards for sale (in the US) when I first wrote about this; I bought one and it looks like very soon afterward, the other one went.  not only that, but the one that was listed from a non-US source just jumped up $50 higher.

[HighVoltage]

I am trying to find one for another one of my 33220A for several month already and no luck.
Agilent Germany quoted Euro 580 for it.

BTW, do you know, if the one you got would fit and work in the 33220A
Although the part number is different, it looks pretty much the same.
Almost hard to believe, that Agilent would design a new board, if the old one could work.

[linux-works]

sorry, I have no idea.  this was labeled as for the 33120a and given that hp is quite a large company, I could believe they'd do a new board for the new model.  small companies might try to use the same parts between models but larger ones rarely seem to.

[HighVoltage]

Thanks for your input.


For those who are interested, the 33120A Option 001 is on ebay Germany right nor for Euro 199
http://www.ebay.de/itm/HP-Agilent-33120A-Option-001-fur-Funktionsgenerator-15-MHz-Arbitrar-Generator-/291118882224?pt=Mess_Pr%C3%BCftechnik&hash=item43c8099db0