[time-nuts] Speaking of 5370s

2013-08-30 Thread Christopher Brown
Working on reviving a 5370B, have everything working except the switches. (multiple switches took impact damage). So, if anyone has 5370 or 5345 front switch/control board(s) they want to part with, let me know. ___ time-nuts mailing list --

Re: [time-nuts] Speaking of 5370s

2013-08-30 Thread Bob Camp
Hi Don't know if the switches are compatible, but the 5334 and 5335 are a lot more common than the 5345 and 5370. For that matter I'd bet there are a bunch of same era DVM's and such that have switches that might work. Bob On Aug 30, 2013, at 2:32 AM, Christopher Brown cbr...@woods.net wrote:

Re: [time-nuts] Speaking of 5370s

2013-08-30 Thread Don Latham
I haven't looked on mine, but can you drill a 1/4 in hole and patch in little pb switches? or patch in the common small 4-pin pcb switches? looks ugly, of course, but... Don Bob Camp Hi Don't know if the switches are compatible, but the 5334 and 5335 are a lot more common than the 5345 and

Re: [time-nuts] Speaking of 5370s

2013-08-30 Thread Brian Alsop
This brings to mind the early 60's. You could go to Arrow Electronics on Long Island. The had trays of a large variety of ceramic switch wafers, switch bodies, shafts, bolts, nuts etc. You simply selected what your needed to build you MxNxP rotary switch.. Yearning for the past. Brian On

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Bob Camp
Hi Just to be very clear: a spec guarantee of 1.0 x 10^-13 at any tau between 1 second and 100 seconds is a very different thing than generally below 1.0x10^-12 at 1 second. That said, not all BVA's meet that spec. Bob On Aug 30, 2013, at 11:52 AM, Said Jackson saidj...@aol.com wrote:

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Mike Feher
Said - I bet you he meant exactly what you said, just had a mistake in the representation of the exponent. Hope all is well with you. Was just at GD all week. Regards - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Bob Camp
Hi The BVA's were specifically targeted at very good ADEV performance. It's sort of a left brain / right brain sort of thing. The time people look at ADEV and close in is usually 1 second and sometimes 0.1 second. The frequency people look at phase noise and really low is often 10 Hz, and

[time-nuts] frequency multiplication

2013-08-30 Thread Collins, Graham
Good day all, Lately I have been contemplating a variety of methods to take a high stability 10 MHz reference multiply it up to a suitable frequency for use a the reference clock for a DDS, for example 10 MHz to 80 MHz or 120 MHz (or whatever). On method is to use simple diode based doublers

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Said Jackson
Steve, 10E-013 means 1E-012. But the BVAs run in the low xE-013, about 10x better than that. And they are specifically designed to give great ADEV from at least 1s to 30s and more. Agreed, its very easy to find fantastic phase noise performance from NEL, Pascal, Wenzel and others. That

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Tom Knox
I may be mistaken but I thought the very close in Ultra Low Phase Noise was what the BVA name was built on, even more then Aging. But with the performance advances of Wenzel and others over the past few decades it is difficult to justify the price. Thomas Knox Ascent Concepts and Technology

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Martyn Smith
Hello, Today many manufacturers are producing 10 MHz oscillators that offer many advantages over BVA. Phase noise of -116 dBc @ 1 Hz with a -175 dBc noise floor, ageing of 5 x 10E-9 per month and a G sensitivity of 5 x 10E-11 /g in all axis is available on a new product. Also the short term

Re: [time-nuts] frequency multiplication

2013-08-30 Thread Bob Camp
Hi A discrete VCXO and PLL chip will always outperform the buit in VCO silicon parts. The CY2302 is quite noisy even by silicon standards. Your doubler / tripler will give you good close in noise, but poor performance broadband. A lot depends on what the ultimate use for the DDS output is. The

Re: [time-nuts] BVA Oscillaotrs

2013-08-30 Thread Said Jackson
Thomas, As Bob mentions phase noise and ADEV are not the same thing. We have a very good PN Wenzel here, and it has horrible ADEV. The BVA has much worse phase noise but 100x or so better ADEV than the Wenzel at 100s. These are apples and oranges. ADEV in the low xE-013 for 1s to 30+s is

Re: [time-nuts] frequency multiplication

2013-08-30 Thread Collins, Graham
Hi Bob, Agreed. I was looking around for some different ideas on frequency multiplication and stumbled across these built in VCO parts such as the CY2302. My first thought was that they seem to be targeted to multiplying and synchronizing clocks in digital systems rather than RF

Re: [time-nuts] frequency multiplication

2013-08-30 Thread Bob Camp
Hi Indeed, the output can never be better than the input with a DDS, but the Cy2302 is rated at a 90 to 100 ps jitter level. These days sub 1 ps jitter is a more reasonable spec for those sort of parts. A lot depends on how wide a band you want to cover. A VCXO can pull +/- 1000 ppm and

[time-nuts] GPSDO PLL convergence question

2013-08-30 Thread Bob Stewart
I finally (think I) understand enough about my hardware and the data that my PLL is working!  Now for the hard part: When do I decide it's converged?  I believe that the maximum time in seconds till convergence is on the order of: (OCXO range / DAC range) / (error count *  DAC volts per step)

Re: [time-nuts] GPSDO PLL convergence question

2013-08-30 Thread Bob Camp
Hi Convergence in a PLL has no absolute definition. In some cases 45 degree phase error = all is running fine. I would simply track GPS time vs OCXO time and declare it ok when it's inside some magic number of nanoseconds. Bob On Aug 30, 2013, at 7:08 PM, Bob Stewart b...@evoria.net wrote:

Re: [time-nuts] GPSDO PLL convergence question

2013-08-30 Thread Bob Stewart
Hi Bob, I'm not sure I understand what you mean by 45 degree phase error in a GPSDO.  This isn't a situation where I'm at the right frequency but at the wrong phase: at least not by my understanding of phase and frequency.  Maybe PLL is even the wrong term.  I dunno, but it feels right for

Re: [time-nuts] GPSDO PLL convergence question

2013-08-30 Thread Bob Camp
Hi A GPSDO is nothing more than a PLL that operates at 1Hz. If you use the same criteria as they do in some systems, as soon as the OCXO pulse is within 1/8 second (sort of 10%) of the GPS, the PLL is locked / converged / doing it's thing / functioning as it should. It's a time domain system,

Re: [time-nuts] GPSDO PLL convergence question

2013-08-30 Thread Bob Stewart
Hi Bob, You've given me a lot to work with.  Perhaps the best answer is to put in a user parameter for how many seconds between updates to consider a lock condition.  For warmup, I had planned to put in a 5 minute holdover period, but that could easily be user configurable, as well. Thanks