Re: [time-nuts] fast switching quiet synthesizer

On 10/7/14, 2:26 PM, Poul-Henning Kamp wrote: In message <20141007200046.02aa9406...@ip-64-139-1-69.sjc.megapath.net>, Hal Mu rray writes: Timing on Ethernet is as good as RS-232 if you have a point to point link rather than a huge network full of crappy software. That is a "truth" w

Re: [time-nuts] fast switching quiet synthesizer

http://gmcatalog.kratosepd.com/index.cfm?act=prodsforgroup&grp=45 http://ams.aeroflex.com/ASCS/micro-ASCS-prods-synthesizers.cfm are the relevant webpages Bruce > On October 7, 2014 at 11:06 PM "br...@ko4bb.com" wrote: > > > Kratos (www.kratosepd.com) do fast switching synthesiser subsystems that

Re: [time-nuts] fast switching quiet synthesizer

Kratos (www.kratosepd.com) do fast switching synthesiser subsystems that can be locked to a reference.. Aeroflex (www.aeroflex.com/ASCS) do 250ns settling time synthesisers. Bruce > On October 7, 2014 at 7:52 PM Jim Lux wrote: > > > On 10/7/14, 1:19 PM, Don Latham wrote: > > I have two "vers

Re: [time-nuts] fast switching quiet synthesizer

Jim, Bob Yarbrough's built units do 50 to 4400MHz, +10dBm and input for external 10MHz ref signals, though has an internal 10MHz TCXO. It sounds worth a try if it can be programmed to step fast enough, min step size is 1kHz (from memory). Alan G3NYK - Original Message - From: "Jim Lu

Re: [time-nuts] fast switching quiet synthesizer

On 10/7/14, 4:43 PM, Bob Camp wrote: Hi The output spectrum of some DDS’s is pretty rich. You may find that a 1 GHz DDS can be filtered to operate directly over the 3.1 to 3.4 GHz. Oh, clever idea.. Yes.. there is substantial harmonic content, and one could easily arrange to have more. And

Re: [time-nuts] fast switching quiet synthesizer

On 10/7/14, 1:19 PM, Don Latham wrote: I have two "versions" of the ADF4351 dds. One is the AD eval board, and the other the TPI synthesizer (http://www.rf-consultant.com/calibrated-signal-generator/) at $280 that might do the job. The latter device performs well. It will be as good as the 4351,

Re: [time-nuts] fast switching quiet synthesizer

On 10/7/14, 12:43 PM, Anders Wallin wrote: We've been using/testing an AD9912 eval-kit board. It can take 10MHz input and has an internal 66x PLL and VCO for a 660MHz DDS sample-clock (just out of spec actually, vco is min 700MHz if I read the datasheet correctly). Output looks like so: http://w

Re: [time-nuts] fast switching quiet synthesizer

Hi The output spectrum of some DDS’s is pretty rich. You may find that a 1 GHz DDS can be filtered to operate directly over the 3.1 to 3.4 GHz. Bob On Oct 7, 2014, at 7:36 PM, Jim Lux wrote: > On 10/7/14, 10:32 AM, Magnus Danielson wrote: >> You should be able to use DDS test-boards and by t

Re: [time-nuts] fast switching quiet synthesizer

On 10/7/14, 10:32 AM, Magnus Danielson wrote: You should be able to use DDS test-boards and by timing your last write, you should be able to time the frequency jump. The STEL-1173 takes 6 bytes, but writing the last one latches all 6 bytes over to a single 48 bit word. I expect that other DDSes

Re: [time-nuts] fast switching quiet synthesizer

On 10/7/14, 10:28 AM, Poul-Henning Kamp wrote: In message <54341cbf.9080...@earthlink.net>, Jim Lux writes: Maybe some DDS in a box product? That will take my nice clean 10 MHz reference? DDS is by far the easiest, but the question is if it is clean enough. Yes, probably clean en

Re: [time-nuts] fast switching quiet synthesizer

Hi Don, Jim, that is the one I was refering to, It has a VCO as the source (all part of the AD4351) but I think your description of the unit is more accurate that mine. Contact him directly he is keen to contact new areas and hobbyists. There are two units one is a source with 4 output levels, I

Re: [time-nuts] fast switching quiet synthesizer

Jim, This reminds me of a project I did back in the early1990's. (Hopefully we have advanced a bit since then.) It used a bunch of quad latches, some 74138's, a UART, and an RS232 converter. It drove a PTS 40. The UART used the first 4 bits for BCD frequency and the last four bits to address

Re: [time-nuts] fast switching quiet synthesizer

In message <20141007200046.02aa9406...@ip-64-139-1-69.sjc.megapath.net>, Hal Mu rray writes: >Timing on Ethernet is as good as RS-232 if you have a point to point link >rather than a huge network full of crappy software. That is a "truth" with an almost uncountable number of footnotes..

Re: [time-nuts] fast switching quiet synthesizer

Hi Anders, in the absence of a true phase noise analyzer the next best thing is to use one of the Agilent 856x analyzers with the phase noise measurement software plug-in. By chance I had looked at Ebay over the weekend and those two can be had for around $3500 these days (with an 8561E).

Re: [time-nuts] fast switching quiet synthesizer

What is your definition of low noise / purity ? DDS and low noise take some pretty good engineering. What is the min frequency ? What is the step size ? As to PTS's it took me around an hour to make a cable write the C code to convert to its interface needs. If I had not lost the documentatio

Re: [time-nuts] fast switching quiet synthesizer

On Tue, Oct 7, 2014 at 8:32 PM, Magnus Danielson wrote: > > > Some of the modern DDSes can take 10 MHz directly and step it up > internally before hitting the DDS core, but it may be that you need to > synthesize a higher clock from the 10 MHz first. > We've been using/testing an AD9912 eval-kit

Re: [time-nuts] fast switching quiet synthesizer

jim...@earthlink.net said: > I could hook a Prologix on the back of a PTS with GPIB, and hit it over the > ethernet, but I'm not sure I'd be able to get the steps to occur when I > want them (ethernet and determinism do not go well together). Timing on Ethernet is as good as RS-232 if you have

Re: [time-nuts] Galileo launch puts two satellites into wrong orbit.

Here's the latest on the root cause: http://gpsworld.com/improper-fuel-line-installation-led-to-incorrect-galileo-orbit/ /tvb - Original Message - From: "jim s" To: "Discussion of precise time and frequency measurement" Sent: Saturday, August 23, 2014 6:27 PM Subject: [time-nuts] Gali

Re: [time-nuts] fast switching quiet synthesizer

I have two "versions" of the ADF4351 dds. One is the AD eval board, and the other the TPI synthesizer (http://www.rf-consultant.com/calibrated-signal-generator/) at $280 that might do the job. The latter device performs well. It will be as good as the 4351, I think. It has a programmable attenuator

Re: [time-nuts] fast switching quiet synthesizer

Hi Consider that stepping every ms means settling in much less than that. If you need < 100 us settling, a pair of synthesizers is probably the only way to go. Use some sort of modulator / switch between them to keep the key clicks from driving you nuts. Bob On Oct 7, 2014, at 1:02 PM, Jim L

Re: [time-nuts] fast switching quiet synthesizer

Jim I am not sure if this will meet your requirement for "hygene" but google Trinity Power Inc (Bob Yarbrough) he has a unit that was featured in EDN some time around a year ago. I doesnt switch fast enough at present but that could be altered. the problem might be that I think it is a PLL R

Re: [time-nuts] fast switching quiet synthesizer

In message <54341cbf.9080...@earthlink.net>, Jim Lux writes: >Maybe some DDS in a box product? That will take my nice clean 10 MHz >reference? DDS is by far the easiest, but the question is if it is clean enough. Some of the HP generators which go cheap-ish in eBay are pretty agile to

Re: [time-nuts] Yokogawa TA320 Time Interval Analyzer

Yokogawa has been around for quite some time. They make some very nice self contained data recorders and data acquisition systems. Think of high resolution oscilloscopes with 8 or 10 channels and large hard drives for data storage. They have interchangeable amplifiers, for thermocouples or voltage

Re: [time-nuts] fast switching quiet synthesizer

You should be able to use DDS test-boards and by timing your last write, you should be able to time the frequency jump. The STEL-1173 takes 6 bytes, but writing the last one latches all 6 bytes over to a single 48 bit word. I expect that other DDSes have the same distinct transfer-phase if you

[time-nuts] fast switching quiet synthesizer

At work, I'm putting together a multichannel stepped frequency CW radar breadboard, and I'm looking for something to serve as a source that I can step quickly. I'm looking at stepping every millisecond or so. Right now, I use a Ardunino type microcontroller driving a serial DAC driving a VCO,

Re: [time-nuts] WTB: GPS Antenna Splitter

John, Note that Mini-Circuits seems to have made lots of other (GPS) splitters for Lucent and others. http://www.ebay.com/itm/Mini-Circuits-3-Way-Power-Splitter-Combiner-ZB3PD1-1575DC1S-/270834416075 -- Björn > Björn, > Thanks for letting us know - price isn't too bad - gotta love th

Re: [time-nuts] Yokogawa TA320 Time Interval Analyzer

Those units (TAS320, TAS520, TAS720) were designed mainly for the optical drives test and it seems that they are limited to 20ms maximum time interval measure in time stamp mode, not suitable for PPS measurements. On Tue, Oct 7, 2014 at 1:53 AM, wb6bnq wrote: > Dave, > > Should have included the

Re: [time-nuts] WTB: GPS Antenna Splitter

Björn, Thanks for letting us know - price isn't too bad - gotta love the P/N - ZAP D - makes you wonder if they have a sense of humor. Regards, John W. *Ordering,Pricing & Availability Information* *Select Country*

Re: [time-nuts] WTB: GPS Antenna Splitter

Hi, Regarding DC load, a friend had problems, so my quick fix was a BNC tee with a SMD inductor in series with a load resistor between tip and shell on one of the BNC branches. Fixed the problem so that when the receiver saw the load it also accepted the GPS signal it was already seeing but dis

Re: [time-nuts] WTB: GPS Antenna Splitter

Hi, For those with a junk basket full of generic splitter/combiners and DC-blocks, go ahead and put something together. Note that most receivers wish to have a DC-load of around 200ohm to not raise antenna fault alarms. I have not found a dedicated GPS splitter cheaper than this from Mini-Circuit