[time-nuts] Need info on MC24P and MC36P microwave mixers
I've been gathering up and organizing parts for my DMTD project, and also am revisiting my differential frequency counter that will go with it. I had started the counter project years ago, and had most of the big stuff mounted and ready to start building. This was to be a cascade of frequency multipliers a la the old Tracor (527, I think) frequency-phase meters, but using microwave frequencies for higher multiplication factors. Each stage was to take 10 MHz in, and make 1 GHz out, so 100x the frequency deviation against the reference channel. While looking for project stuff, I rediscovered a bunch of 4.7-5.2 GHz PLOs I had, and my notes from way back, where I considered them as alternates to the 1 GHz ones. I decided to finally resolve which setup to use, and rigged up a quickie 500x frequency multiplier. I found that these 5 GHz PLOs are remarkably stable, and actually seem to prefer a reference in the 10-20 MHz range, whereas the 1 GHz ones were apparently made for a higher range, and were not as good in this respect, with 10 MHz. The more I look at these 5 GHz PLOs, the more I like them. They are built for 24 VDC, but I've been running them at 20, and they seem fine. They are beasts on power output - around +18 to 20 dBm, I'm guessing. Imagine what they would do at full supply voltage. They are of the power oscillator/SRD multiplier/BPF variety, so the oscillator direct-drives the SRD. Imagine the RF VA level in the 1250 MHz cavity required, to tap off only a little bit of power to multiply four times, and deliver +20 dBm. I think this high power also helps with the stability, since there's plenty available to grab a little for the PLL sampler. I have about a dozen of these puppies, with about seven tested OK so far, and the rest with problems that need fixing. I only need three to make a two-stage multiplier up to 500 x 500x, so have plenty of spares. Since I'm moving everything up from the original plan, I need to use 5 GHz mixers. I have a bunch of MC24P and MC36P SMA mixers that I know are around the right range - most came from the same junked microwave gear as the PLOs. I've used these in a number of projects over the years, guessing that the part number may indicate the frequency range, as with many other RF parts. I have typically used the MC24P in 2-4 GHz applications, and the MC36P for 3-6 GHz, or even wider, and they have usually worked just fine. In this application, I'd like to optimize drive power, and know the real specs, to get the best possible S/N ratio. I vaguely recall that I had once found the data sheet for one or both, many years ago, but can't find them any more, or online. There are lots of them for sale out there, so they must have been very common, but apparently there are no data sheets or cross references that I could find. These units are marked Magnum Microwave brand, now owned by API Technologies. Their website denies that these exist, so I guess the parts and data are long gone. Looking at the one thing I could find there seemingly even slightly related, is their MC3XMS-3, which is in the 5-6 GHz range. The "MS-3" is the micro-strip package form, and a "6" in the X position means +13 dBm LO. If the same codes apply to the old parts, and if the P suffix means SMA connectorized, then MC36P might be a 6 GHz class, level 13 mixer, which could be about right. Or not. For reference, here's that datasheet: http://67.225.133.110/~gbpprorg/mil/xband/MC3XMS-3_-14.pdf Anyway, I'd like to find an actual datasheet for each of these mixers, especially right now, for the MC36P. I'd like to drive them as high as possible, but not risk damage. These PLOs have plenty enough juice to blow them out, if I get carried away or make a mistake, or don't know the mixer specs and guess wrongly. In my present experiments, I've been running about +10 dBm into both the LO and RF ports, so +13 altogether, which seems safe, and has been working nicely. If anyone has any info on these parts, I'd sure appreciate it. An old Magnum Microwave catalog from the 1980s would probably have it. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] U-Blox GPS Module At All-Electronics Corp
j...@westmorelandengineering.com said: > Just saw this at All-Electronics - thought some here could be interested: > https://www.allelectronics.com/item/gps-8m/gps-module/1.html No obvious PPS connection. There may be a PPS LED where you could pick it up, but I don't see any documentation. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] uBlox F9T testing - best settings?
Hello Anders, We did some work on single-frequency time-transfer with the F9P earlier this year which we presented at IFCS-EFTF in April. http://www.openttp.org/downloads/Multi-GNSS_IFCS-EFTF_2019.pdf There's a paper too, which I should upload. In short, the F9P is very suitable for code-based time-transfer, and we will be using it , or the F9T, in the next iteration of our time-transfer system. But, I don't see how you can feed an external 10 MHz and 1 pps to the F9T. There don't appear to be any inputs for this on the chip. The TIMEMARK inputs only seem to be useable for measurements. Have I missed something? Regards Michael On Sun, 22 Sep 2019 at 12:30 am, Anders Wallin wrote: > Hi all, we are testing an uBlox F9T (RCB-F9T timing-board) for the past few > days. Small uBlox puck antenna in a not-so-great location. > I get an ADEV of 3e-8/tau long-term (see pictures or blog) > > Through the UART there are lots and lots of settings to tweak with the > uBlox software - I am wondering if anyone figured out optimal settings for > stationary operation and best stability when the pulse1/pulse2 outputs are > configured for 1PPS and 10 MHz. Is it using just GPS (or multi-GNSS?), dual > or single-frequency, as the default setting? > > Also, it seems that on 10MHz there is dithering (8ns granularity?) - is > there any simple way to generate a round-number out of the uBlox, and use a > (simple) multiply/divide to get dithering-free 10MHz? > > we made a carrier-board for the RCB-F9T with an USB/UART conversion and > buffered dual BNC outputs for pulse1/pulse2 - this might be published > later... > > Further down the road, if the F9T really can do dual-frequency > observations, and either the receiver clock 1PPS measured (TICC?) against > an external 1PPS, or the entire receiver clocked from external 10M/1PPS - > and dual-frequency RINEX generated from this - then there seems to be an > obvious opportunity for making a low-cost dual-frequency time-transfer > setup? Or am I missing something? > PPP with F9T seems to be possible: > https://gpsd.gitlab.io/gpsd/ppp-howto.html > > thanks, > Anders > board https://www.u-blox.com/en/product/rcb-f9t-timing-board > antenna https://www.u-blox.com/en/product/ann-mb-series > blog http://www.anderswallin.net/2019/09/ublox-f9t-test/ > > [image: uBlox_oadev_tdev.png] > [image: uBlox_F9T_timeseries.png] > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Lucent KS-24361, aka HP/Symmetricom Z3812A
Dan mentions the sawtooth correction as part of one of the oncore messages, but wasn't sure if the ref-0 used it. You also mention it in the python script. Did you determine whether it was used in the ref-0 ? On Sat, Sep 21, 2019 at 8:31 PM Thomas Petig wrote: > On Tue, Sep 17, 2019 at 02:40:46PM -0500, Gregory Beat via time-nuts wrote: > > [...] > > Dan Watson explored modifications (August 2015) for the REF-0 boxes to > operate as a stand-alone GPSDO. Including an updated GPS receiver to > emulate the Oncore UT+ timing receiver. > > > https://syncchannel.blogspot.com/2015/08/standalone-operation-of-lucent-ks-24361.html > > > > Thomas Petig (Germany) built upon Dan’s work and explored the SCPI > commands available on this KS-24361. > > http://www.petig.eu/ref0/ > > Sweden actually. Also build some script to simulate the Oncore GPS with an > FTDI USB cable, PPS is send over CTS. This actually worked, the unit was > happy. > https://github.com/thpe/oncore > > Aim was to build PCB, with PPS input to accept an external PPS source with > optional sawtooth correction/time data converted in case the PPS comes from > a ublox: > http://petig.eu/schem/lucent-input.pdf > I produced the first batch, but there some hardware bugs and I didn't > continued further due to lack of time. > > > [...] > > /Thomas, SA6CID > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Lucent KS-24361, aka HP/Symmetricom Z3812A
On Tue, Sep 17, 2019 at 02:40:46PM -0500, Gregory Beat via time-nuts wrote: > [...] > Dan Watson explored modifications (August 2015) for the REF-0 boxes to > operate as a stand-alone GPSDO. Including an updated GPS receiver to emulate > the Oncore UT+ timing receiver. > https://syncchannel.blogspot.com/2015/08/standalone-operation-of-lucent-ks-24361.html > > Thomas Petig (Germany) built upon Dan’s work and explored the SCPI commands > available on this KS-24361. > http://www.petig.eu/ref0/ Sweden actually. Also build some script to simulate the Oncore GPS with an FTDI USB cable, PPS is send over CTS. This actually worked, the unit was happy. https://github.com/thpe/oncore Aim was to build PCB, with PPS input to accept an external PPS source with optional sawtooth correction/time data converted in case the PPS comes from a ublox: http://petig.eu/schem/lucent-input.pdf I produced the first batch, but there some hardware bugs and I didn't continued further due to lack of time. > [...] /Thomas, SA6CID ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] U-Blox GPS Module At All-Electronics Corp
To All: Just saw this at All-Electronics - thought some here could be interested: https://www.allelectronics.com/item/gps-8m/gps-module/1.html 73's, John AJ6BC ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Educational Opportunities?
Hi, in Europe there is teh European Time & Frequency Seminar EFTS (not to mix with EFTF, the European Time & Frequency Forum), see http://efts.eu/ In 2019 it took plaece beginning of July in Besancon. For German (or German speaking) members of the lit I can recommend the Crystal and Oscillator Workshop held by me at the technical Academy Esslingen (TAE), see https://www.tae.de/seminar/seminar-schwingquarze-quarzoszillatoren-und-filte r-33378/ The next one taking place on June 17, 2020. This has a more practically oriented focus. Best regards Bernd -Ursprüngliche Nachricht- I think I've mentioned this before but I attended the NIST T metrology seminar in June. Although a good chunk of of it was at least somewhat over my head, I definitely learned a lot and feel like I have a lot better handle on some of the questions I had. I may even consider going back for a second round in a year or two to try to move on to the next level. Definitely worth the admission fee. The other thing that re-learned (from my youth) is how well I absorbed advanced technical information in this type of format - that is, being immersed in data which has large chunks beyond my skill level. Sort of the "sink or swim" training method. A lot of the training I've ended up at recently is quite frankly a waste of time due to the classes trying to cater to everyone so the material is so watered down as to be largely useless. After walking out of a week of high-level training and realizing how much more I understand now I really think this is the type of educational opportunities I should be looking for. So, the question for the list: What other high quality seminars/workshops are out there? Is there anything else I should be considering along these lines (I.E. IEEE Membership, etc) in order to have other educational opportunities? ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] overtone crystal question
Sorry, I forgot the static capacitance C0, which is (without holder and strays) C0 (pF) = 0.024*Ael^2*f/N with electrode area Ael in mm^2 and f in MHz Best regards Bernd -Ursprüngliche Nachricht- Von: Bernd Neubig [mailto:bneu...@t-online.de] Gesendet: Samstag, 21. September 2019 08:42 An: 'Discussion of precise time and frequency measurement' Betreff: AW: [time-nuts] overtone crystal question Hi, There is nothing like a fixed ratio between R1 at 3rd or 5th overtone the R1 at fundamental mode. The best approach through C1 and Q. C1 reduces with the square of overtone N (for an infinite crystal plate). In reality C1(3rds about 85% of C1(fund/N^2. For the 5th and higher OT it is about 75 to 70% of C1(fund)/N^2.. Now Q comes into the game: The Q of a crystal designed for 3rd overtone is approximately such that Q*f = 2E12 (f in Hz), for 5th OT is may be 3 to 5*E12 . Fundamental mode crystals have lower Q*f , around 1E12 This all is for a plano-plano AT-cut crystal plates and is only a rule of thumb. It finally depends on the crystal size and shape and some design details. Small crystals with convex shape will have better Q*f at fundamental, mode, crystals with well polished and plaon-parallel surfaces may be better at 3rd OT and have lower Q*f at fundamental mode. C1 at fundamental mode is given by the equation C1(fF) = 0.15*Ael^2*f, with Ael = electrode are in mm^2 and frequency f in MHz With that and with the above estimated values for Q, the resistance can be calculated fundamentally from R1 =1/(2*PI*freq*C1*Q) - here is freq in Hz and C1 in F Have fun Best regards Bernd __ I wonder if anyone can shed any light on this question, since this forum is loaded with those who REALLY understand crystals. I am modeling crystal filters (VHF) in SPICE. There are some specific acoustic mode models for SPICE in some Post Doctorial papers, very interesting, they would be the best but rather painful to use. However I using simplified Rm, Lm, Cm, Cs, Cp, Ccase etc My question is, how does Rm vary with overtone number ? My assumptions are Lm stays the same, Cm reduces proportionally to the square of the overtone number. Those assumptions are close enough and canon. I of course need the Rm number to acurately model loss. 73 glen english VK1XX ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] overtone crystal question
Hi, There is nothing like a fixed ratio between R1 at 3rd or 5th overtone the R1 at fundamental mode. The best approach through C1 and Q. C1 reduces with the square of overtone N (for an infinite crystal plate). In reality C1(3rds about 85% of C1(fund/N^2. For the 5th and higher OT it is about 75 to 70% of C1(fund)/N^2.. Now Q comes into the game: The Q of a crystal designed for 3rd overtone is approximately such that Q*f = 2E12 (f in Hz), for 5th OT is may be 3 to 5*E12 . Fundamental mode crystals have lower Q*f , around 1E12 This all is for a plano-plano AT-cut crystal plates and is only a rule of thumb. It finally depends on the crystal size and shape and some design details. Small crystals with convex shape will have better Q*f at fundamental, mode, crystals with well polished and plaon-parallel surfaces may be better at 3rd OT and have lower Q*f at fundamental mode. C1 at fundamental mode is given by the equation C1(fF) = 0.15*Ael^2*f, with Ael = electrode are in mm^2 and frequency f in MHz With that and with the above estimated values for Q, the resistance can be calculated fundamentally from R1 =1/(2*PI*freq*C1*Q) - here is freq in Hz and C1 in F Have fun Best regards Bernd __ I wonder if anyone can shed any light on this question, since this forum is loaded with those who REALLY understand crystals. I am modeling crystal filters (VHF) in SPICE. There are some specific acoustic mode models for SPICE in some Post Doctorial papers, very interesting, they would be the best but rather painful to use. However I using simplified Rm, Lm, Cm, Cs, Cp, Ccase etc My question is, how does Rm vary with overtone number ? My assumptions are Lm stays the same, Cm reduces proportionally to the square of the overtone number. Those assumptions are close enough and canon. I of course need the Rm number to acurately model loss. 73 glen english VK1XX ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
