Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Oh that's interesting, I've not seen the non DDS version of the 5680 yet. The frequency division for output in the non option 58 ones I've had hands on was definitely done in a CPLD chip, the DDS was "for internal use only" as far as I could tell. On 10 Jan 2017 09:07, "wb6bnq"

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi Clint, Actually there are two versions of the 5680. The older version is exactly like the 5650 option 58 composition. The newer version has the DDS as part of the signal generation for the physics package. And it appears that they may be using an FPGA programmed as a divider to provide

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Yes, in the 5650 there's only DDS on opt 58, in the 5680 there is one in the main loop too, my bad for not being precise/muddled. On 10 Jan 2017 01:43, "wb6bnq" wrote: > HI Bob & Clint, > > If you look at the second message of this thread, I attached the manual > that applies

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

HI Bob & Clint, If you look at the second message of this thread, I attached the manual that applies to Option 58. Look at PDF page # 16 and you will see that there is no DDS in the physics package. The DDS is only used down stream in some variations of the product such as the Option 58

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Option 58 in a FE Rb is an additional sub board which has nothing to do with the physics package control loop. In an option 58 Rb there are two DDS chips. On 9 January 2017 at 17:48, Scott Stobbe wrote: > It very well could be. Based on Marks comments, it sounds

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

It very well could be. Based on Marks comments, it sounds like the DDS tone after being squared up is directly driving a 23-bit counter for the 1 PPS output. On Mon, Jan 9, 2017 at 12:17 PM, Bob kb8tq wrote: > Hi > > In most Rb’s (including the FE 56xx’s) the DDS is mixed with a

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi In most Rb’s (including the FE 56xx’s) the DDS is mixed with a fixed microwave frequency signal. The DDS only has to make up “part” of the total offset. You get roughly a three orders of magnitude improvement because of this. Rick has gone into all the gory details of why it gets done this

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

A 32-bit DDS synthesizing at 1/5 Fs, yields a tuning resolution of ~ 1 ppb. So, I would imagine a slightly lower frequency is programmed into the DDS and the c-field is trimmed to yield a higher precision. If the new synthesized tone you wish to generate is an integer number of DDS codes you could

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi Matt, Well, after rereading Mark’s paragraph in question, I think he did not properly develop his complete thoughts. The first statement about the Hydrogen Maser is absolute. The second statement is the one that is really vague. The third statement is the clue taken with the fact that

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

On 2017-01-04 10:16, wb6bnq wrote: Hello Bill Thanks for re-iterating over this. Yes, I do think the outer can covering is a MU-metal shield.  The bottom plate where the connector is located is not. That is reassuring thank you! I know the calculator that comes with Windows XP will

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

On 2017-01-04 11:08, Attila Kinali wrote: Hoi Attila So it's the usual curiosity and the need to have a reference for your 23cm radios? Yes exactly. Advantage of an GPSDO over an Rb is that you know it's on frequency, while with an Rb it can be off without you knowing it, if the

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hello Mathias, I did mis-speak. You're correct that only 32 bits (8 hex digits) are used to program the DDS chip. As Mark points out they store a 64 bit number and only use 56 bits but he does not elaborate on what is done with the bits beyond 32. Also, after reviewing my comment on the

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hoi Mathias! On Tue, 03 Jan 2017 17:55:32 +0100 Mathias Weyland wrote: > On 2017-01-02 12:18, Attila Kinali wrote: > > May I ask what you want to achieve? Resp. what you need a 10MHz > > reference for? > > I've always been wondering about those devices, I guess out of pure

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

On 2017-01-02 12:18, Attila Kinali wrote: Attila! Nice to see you around here ond au der es guez nois! May I ask what you want to achieve? Resp. what you need a 10MHz reference for? I've always been wondering about those devices, I guess out of pure curiosity. Once I learned that those

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

and if you glue a piece of non-magnetic material -- which could hold that connector -- it could be even some plastic, to the surface of the mu-metal , you do not need to worry about disturbing the magnetic conditions 73 KJ6UHN Alex On 1/2/2017 3:44 PM, Attila Kinali wrote: On Tue, 03 Jan

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

On Tue, 03 Jan 2017 11:02:54 +1300 Bruce Griffiths wrote: > Maybe a waterjet cutter would imapct less on the shielding properties of > tthe mumetal? I doubt it. mu-metal is pretty sensitive to vibration as well and a waterjet creates plenty of that. But anealing

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi My biggest concern is that they magnetize the shield as they drill it. It’s a “static” field, but it’s a static *near* field. I doubt that is a good thing …. Bob > On Jan 2, 2017, at 5:53 PM, Bruce Griffiths > wrote: > > One could always wrap the assembly with

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

One could always wrap the assembly with its impaired mu metal shield in several layers of flexible magnetic shielding foil to regain the desired magnetic shielding e.Most such foils can be cut with scissors without significant effect on their magnetic properties. Bruce On Tuesday, 3

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi > On Jan 2, 2017, at 5:02 PM, Bruce Griffiths > wrote: > > > Maybe a waterjet cutter would imapct less on the shielding properties of > tthe mumetal? > Maybe …. pretty good bet that the guys modifying these in their living room aren’t focused on much more

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Maybe a waterjet cutter would imapct less on the shielding properties of tthe mumetal? Bruce On Monday, January 02, 2017 12:58:55 PM Bob Camp wrote: > Hi > > > On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: > > > > Hello Mathias, > > > > I think you did not quite understand how

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi > On Jan 1, 2017, at 7:31 PM, wb6bnq wrote: > > Hello Mathias, > > I think you did not quite understand how the calibration process works with > that unit. The factory procedure is to set the pot to minimum and then bring > the DDS up to the step that produces the

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

On 2017-01-02 01:31, wb6bnq wrote: Hello Bill Thanks for your response and the pdf manual. There's lots of good information in there. You are certainly right in that there's a few things that I have not understood. Unfortunately this has not changed after having read your response: That "R"

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hoi Mathias! Wie goht's wie stoht's? :-) On Sat, 31 Dec 2016 15:33:53 +0100 Mathias Weyland wrote: > I'm new to this list. I got myself a FE-5650A Rubidium Standard off of > ebay. > It's the "option 58" 1 pps output variant, hence I have to modify the > tuning > word used

[time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hello guys I'm new to this list. I got myself a FE-5650A Rubidium Standard off of ebay. It's the "option 58" 1 pps output variant, hence I have to modify the tuning word used in the DDS phase accumulator to get 10 MHz out. I found a vast amount of awesome descriptions on how to do that on the

[time-nuts] FE 5650A Question

There are many versions of the FE 5650A just like the FE 5680. Recently we got a few FE 5650A option CPOM that internally are fairly similar to a FE 5680A. It also uses an AD9832A DDS and is 15 MHz but by changing 3 jumpers divides the 60 MHz by 6 instead of 4. Output is a nice sinewave.

Re: [time-nuts] FE 5650A Question

Hi Bert: I have a little info on FEI units, including some links to their patents, at: http://www.prc68.com/I/FEIFS.shtml The two patents with the title Precision oven-controlled crystal oscillator are about using a crystal that's not precision ground, i.e. it's near the desired frequency, but

Re: [time-nuts] FE 5650A Question

Brooke Thanks for the info. At least now I know where they came from also the two patents you mention are the basis for the FE 405 with minor changes. A very nice unit with great performance. Bert Kehren In a message dated 12/27/2013 2:31:38 P.M. Eastern Standard Time, bro...@pacific.net

[time-nuts] FE-5650A with a AD9955 DDS board.

Hi, I just found an FEI FE5650A which has an older DDS board in it. The board has an AD9955 DDS chip and 4 8way DIP switches. There is no serial port. It appears to be the universal DDS board shown in the manual. The unit is partially potted so tracing the circuit is not ideal. Does anyone have

[time-nuts] FE-5650A Option CPOM Information

Looking for FE-5650A Rubidium Frequency Standard Information. I have obtained a FE-5650A unit that came out a piece of equipment made for Lucent, which I think is telco equipment. RFS Part # FE-5650A UN 62832, S/N 0404-71672 Option 5650A OPTION CPOM. The options do not match with anything I

Re: [time-nuts] FE-5650A Option CPOM Information

Here's a start: http://www.leapsecond.com/museum/fei5650a/ Then: http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:rubidium_oscillators Then google: 5650A site:febo.com On 1/13/2012 5:41 PM, Rich (Buckeye) wrote: Looking for FE-5650A Rubidium Frequency Standard Information. I

[time-nuts] FE-5650A Rb: your opinions?

At this date I have no frequency standard at home. I'd like to buy one FE-5650A Rb used unit (230US$ s/h included) so I will be able to use it as a reference/comparation for my future DIY GPSDO. BTW, I found interesting the provision to use the internal DDS to generate different frequencies than

[time-nuts] FE-5650A

Elio, I have an FE-5650A, and am very pleased with it. Yes, it will operate on any frequency from 0 to nearly 20MHz, but I think it will depend on which option you get. Mine was an Opt 58 I think, which originally had outputs at 8.388688MHz and 1pps. It is now modified to add a serial link for

Re: [time-nuts] FE-5650A Rb: your opinions?

Given the low prices Thunderbolts have been selling for lately, I believe most people are better off with one of those, or a similar high-quality GPS slock. If you expect very poor GPS coverage with lots of complete signal dropouts, then perhaps an Rb-based standard makes more sense. -- john,

[time-nuts] FE-5650A problem

Hello all: I'm new to this list, but I've been lurking for a while I have a TrueTime XL-DC with and FE-5650A Rb Oscillator. I bought it off eBay, and it worked great for a couple of years. A few months back, the XL-DC lost lock, and poking around in the user interface I decided that it

Re: [time-nuts] FE-5650A problem

Hi Keith, On Sun Dec 2 20:08 , 'Keith Payea' [EMAIL PROTECTED] sent: Also, there was some mention that one of the list members had gotten a maintenance manual - can someone point me in the right direction? Yes, I've collected a few documents and zipped them up to a file on my website: