Re: [time-nuts] Trimble Thunderbolt no longer determines the correct date
Thank you, Ralph! Indeed, I had tarred up the branch on github with your original code, not the branch with my changes...how embarrassing! I've updated the tarball and re-arranged the page to make it easier to find the latest. Also, if you make an official version I'll remove my download and just put back the startup scripts that I have added. Note that I didn't touch gpsclientd... Leigh/WA5ZNU On 08/01/2017 09:37 AM, Ralph Smith wrote: Thanks for doing this, I was just about to dive into this. I've been neck deep in some other things recently and just became aware of this issue. Could you check the source tarball? I just downloaded it and it appears to be the unmodified version of my code from 2010. Ralph AB4RS Sent from my iPhone On Aug 1, 2017, at 2:42 AM, Leigh L. Klotz, Jr WA5ZNU <le...@wa5znu.org> wrote: Based on Mark Sims updates to Heather v5.0 I've updated Ralph Smith's NTP daemon to handle the rollover. I haven't updated the gpsd. https://wa5znu.org/2011/08/tbolt/ It's not as ambitious as Mark's update; this one doesn't read system time so it will have to be recompiled again in about 20 years. I took Mark's Julian and Gregorian date calculations as is ;-) This is running now as well as it ever did. Thanks for the great community. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt no longer determines the correct date
Based on Mark Sims updates to Heather v5.0 I've updated Ralph Smith's NTP daemon to handle the rollover. I haven't updated the gpsd. https://wa5znu.org/2011/08/tbolt/ It's not as ambitious as Mark's update; this one doesn't read system time so it will have to be recompiled again in about 20 years. I took Mark's Julian and Gregorian date calculations as is ;-) This is running now as well as it ever did. Thanks for the great community. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather on low power CPU/Linux?
I use this on Linux: cd ~klotz/.wine/drive_c/Program Files/Heather wine heather.exe /IP=localhost:45000 /TW=250 I use Ralph Smith's tboltd so heather connects to a TCP port, but you can also just give a COM port to connect on the line above. The /TW=250 gives reasonable performance without tremendous CPU usage. http://wa5znu.org/2011/08/tbolt/ Leigh/WA5ZNU On 02/22/2012 04:45 PM, Mark Sims wrote: The roots of Lady Heather lie in a program written in the mid 1980's for controlling a Magellan GPS board (a multiplexed single channel receiver - Bruce has it now). That program ran under DOS. The code is pretty much straight ANSI C. I modified it to work with the Tbolt and added the graphing code (1024x768 screens only). It still was basically a DOS program, but could limp under Windows. The intent was (and pretty much still is) to dedicate a cheap laptop to running it (in fact there are some laptops out there with tbolts mounted internally, powered off the CD rom interface).I've run it on laptops that could not even be given away (and 2.4 GHz machines can be had for under $40, including OS) John Miles ported over the code to use his graphics and serial I/O library which made it work better under Windows. The serial code had problems so I rewrote that. Also the graphics library used a proportional font that made displaying tables rather ugly. That was modified to use fixed width fonts and just about any screen size. Also the adev code was modified to use John's incremental adev code. This allowed much better real-time adev calculations with pretty much unlimited depth even on VERY slow processors. The code was still kept up so that it could run on the cheapest, most minimal laptops around running DOS (EMS memory anyone). Then the evil Lady Heather got uppity and started adding all sorts of stuff, memory usage be damned. The DOS code is still there, but enabling it kills a whole bunch of stuff. It is pretty much requires a Windows level operating system now. The user and operating system interface is intentionally kept as primitive and basic as possible to make porting it easy. I really don't like having to run Windows just for this lone program and even then the screen design and over all user interface is primitive, even by Windows standards ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather for a noob
On 01/13/2012 01:22 AM, Javier Herrero wrote: For providing ntp, probably the best way is to use ntp :) Ralph Smith did a good integration for BSD NTP. I patched it and wrote some startup and monitoring scripts for it for Ubuntu. See http://wa5znu.org/2011/08/tbolt/ I run Heather under Wine with some flags and make it talk to the server; that cuts way down on the CPU time that LH would otherwise use in its tight loops. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] US New Year countdown - accurate?
I got a demo of a national network quality (and price) digital TV encoder from a ham friend in the industry. It took about 6 seconds delay itself to encode images. The compression has a lot of state and multiple heuristic systems as well (face trackers, for example). Leigh/WA5ZNU On 01/01/2012 09:09 PM, David I. Emery wrote: On Sun, Jan 01, 2012 at 05:54:46PM -0800, J. Forster wrote: To me the ball drop/fireworks was different from the on-screen time on FOX by a few secnds. I was watching the media pool HD satellite feed on AMC-1 and through a broadcast grade IRD (ex PBS Bitlink ) it appeared to be about 2 seconds slow relative to my house NTP timing. This would about exactly match what I would expect for uplink encoder, satellite path, and decoder delays. I would expect a TV station using that feed might add anywhere from 1-6 seconds to the delay in their internal processing to OTA... and a digital cable system might add further delay to that (couple of more seconds at least). Real time TV these days is only RELATIVELY real time. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] WeirdStuff tbolt $75
WeirdStuff has tbolts, no case, no info about firmware version, for $75. They were $495 but I sent them a note saying it wasn't a competitive price and they lowered it and they appear to be selling out quickly. http://www.weirdstuff.com/cgi-bin/category.cgi?item=29654 Also on their weirdstuff-inc ebay store for the so inclined. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Bulletin Board / Forum
without regard to setting up the bboard or not, I'd recommend creating an archive of time-nuts at Nabble. Nabble is more easily searchable than the standard mailman type archives, and it has a bboard format, and people can use accounts there and post back to the list. It's all transparent to the list owners; they just need to approve the account that receives the mail, and of course, agree with the whole thing in principle. I've done this for other mailing lists where there was a sizable minority who preferred to use a bboard. It keeps the information from being split, yet still provides both reading and writing formats. Leigh. Personal Preference, Restrictions with the mail list format, would like a better way to search content. Stanley - Original Message From: Brian Kirby kilodelta4foxm...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tue, August 24, 2010 9:36:24 PM Subject: Re: [time-nuts] Bulletin Board / Forum Whats the reason and motive for this ? On 8/24/2010 8:50 PM, Stanley Reynolds wrote: Started setting up a time-nuts board at: http://forums.n4iqt.com/modules.php?name=Forums Need ideas for topics. Stanley ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Need PICTIC II PIC
Now that Dan Schultz has kindly provided me with the elusive 74AC175PC, I still need a programmed PIC for the PICTIC II. Is there are thread where we're gathering together for another kind soul to distribute them? Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Remove Pictic boards from envelopes
I tried water, then isopropyl, but what worked was a quick cleaning with a white eraser. Leigh/WA5ZNU On 08/06/2010 08:15 AM, Ed Palmer wrote: You mean they are tinned? I received my two boards a couple of days ago. I thought that they missed the tinning solution. There's just an occasional splash of bright tin here and there, particularly on the back. The rest looks like oxidized copper. I haven't tried to solder them yet. Hope the rosin cuts through it. Ed Stanley Reynolds wrote: Please remove Pictic boards from envelopes when you receive them. Received a report that the tinning on the bottom of the board was discolored perhaps due to some contamination in the envelope. Will wrap boards in plastic wrap in the future. Stanley ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What's the latest correct PICTIC II Mouser project?
On 08/04/2010 03:29 PM, Heathkid wrote: I used this one: https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8736DCEE10 Here's Richard McCorkle's kind suggestions for the parts that are out of stock: 511-TS272CN Dual Op-Amp 512-2N7000BU FET 511-LM317LZ Regulator The 2n7000 and LM317 are probably available more easily for me around town. The 74AC175PC and the pre-programmed PIC are the big necessities not available there, so I'm hoping for a next round group buy. Leigh/WA5ZNU If there are multiple Mouser projects... which one is best (least backordered parts) and highest quality parts? Please send a link. Thank you in advance. Has anyone started updating the project to include substitutes? 73 Brice KA8MAV - Original Message - From: Leigh L. Klotz, Jr. WA5ZNU le...@wa5znu.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, August 04, 2010 1:16 PM Subject: Re: [time-nuts] What's the latest correct PICTIC II Mouser project? I've ordered the mouser project and skipped the parts that won't ship until 2011. So we're in the same boat. Leigh/Wa5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What's the latest correct PICTIC II Mouser project?
I've ordered the mouser project and skipped the parts that won't ship until 2011. So we're in the same boat. Leigh/Wa5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 74AC175PC
I would do the same .. -pete Please count me in for $10 plus shipping for qty 2, if anybody's counting. Leigh/WA5ZNU On Sun, Aug 1, 2010 at 11:03 PM, Heathkid heath...@heathkid.com wrote: Stanley, Would you be willing to do another group buy? Â I'll send you enough $ for 10 of them via PayPal before you buy and I know others are already willing to buy more. Â I just can't logistically do a group buy myself right now but would be willing to help pay for your time and efforts. Â I know what they are in quantities of 50. Â I'll pay $2 each. Â That should make it worth while... Â with fees, etc... I'll send you $25 for 10 of them. Will you do this? 73 Brice KA8MAV - Original Message - From: Stanley Reynolds stanley_reyno...@yahoo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, August 01, 2010 8:13 PM Subject: Re: [time-nuts] 74AC175PC I have had good luck with Quest they are showing stock. www.questcomp.com They do have a $25 min. Stanley - Original Message From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, August 1, 2010 4:20:44 PM Subject: Re: [time-nuts] 74AC175PC Hi At least at this point the surplus dealer has been checked out by others buying the parts from him. You might find there's enough interest to make another buy worthwhile. Bob On Aug 1, 2010, at 4:59 PM, Heathkid wrote: Hello. Does anyone have any of these left? I've checked with a couple of the guys that did a group buy but they are out of them. I'd prefer not to do SMT and don't really want to buy 50+ from an unknown surplus seller. I need six (6) - or at least one or whatever someone has to get me started. Thanks! 73 Brice KA8MAV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can Lady Heather Keep Computer Clock On Time?
On 07/29/2010 03:57 PM, Mark Sims wrote: Yes, there is a time sync command that causes the program to set the system clock at periodic intervals or whenever it differs from GPS by a given amount. I'm still out on the Project From Hell Mark II and I don't remember all the gory details... I think /TSA on the command line says sync the time whenever the clocks differ by a millisecond. There is also /TSO /TSD /TSH /TSM /TSS to set it once, hourly, daily, every minute or second. There is also a /TSX command to specify the time offset from the Tbolt serial command to GPS (which is usually around 45 milliseconds). TS from the keyboard just syncs the clock once. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. I realize this request is for Windows, but I thought I'd mention this for the benefit of others. I'm using tboltd by Ralph Smith on Linux. It provides the time to ntpd and LH 3.00 beta can talk to tboltd via the TCP connection, so monitoring can happen at the same time as the ntpd. It works great on Linux, as well as BSD (for which it was designed): http://www.mail-archive.com/time-nuts@febo.com/msg26129.html It runs well under wine like this: wine heather.exe /IP=localhost:45000 /TW=250 The /etc/ntp.conf config file stanza looks like this. (I admit I've guessed at the 0.0275 delay.) # for attached GPS tos mindist 0.030 server 127.127.28.0 minpoll 4 maxpoll 4 prefer fudge 127.127.28.0 time1 0.0275 stratum 1 refid GPS Serious use would probably call for a Soekris box, but not so serious use lets me use the tbolt time signal for free, as I have it on for the 10MHz reference. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Basic question regarding comparing two frequencies
... I use Peter G3PLX's SBSpectrum as the analyser, where you can trim the sample rate in tiny steps. It also has a frequency resolution of 25mHz, which is more than adequate for HF. My combination has won FMCs, but I still can't resolve 0.01Hz off-air. ... 73, Murray ZL1BPU You might also take a look at fldigi. It uses libsamplerate for conversion so you can do +/- ppm correction on the sound input, and also offers a tracking frequency measurement mode. A couple of years ago, I calibrated my radio clock against WWV at 10 MHz, then applied the resampling correction to get the sound card right, and then placed highly in the ARRL 7 Mhz FMT using this method. Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Basic question regarding comparing two frequencies
This is close to the project I showed at the SF Bay Area Maker Faire in May. I showed fractional ppb difference measurements using a $25 flea market scope. The photo below is by a former NIST Cs fountain researcher who stopped by: http://www.flickr.com/photos/oskay/4640673869/in/set-72157623988565617/ Leigh/WA5ZNU On 07/24/2010 10:28 AM, Mark Spencer wrote: Hello: Just for grins I decided to compare the frquency from my GPSDO to the time base in my 5328A counter. I connected the 10 mhz time base from the counter to channel A of my 100 Mhz scope, fed the 10 mhz signal from my GPSDO into Channel B and with a T adaptor also fed this signal into the input of the counter.I scope to trigger from Channel B. The drift betwen the two signals on the scope seems to match the error in the displayed frquency on the counter. (ie. if the counter shows .9998 it takes approx 5 seconds for the the wave form on channel A to slip a full cycle realitve to channel B.) Is this a reasonable approach or is there a better way to compare two frequencies using a scope ? Best regards Mark Spencer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FRS-C TTL / sine outboard filter question
Mike S wrote: It sounds like you made the changes to the A4 oscillator board, but not the ones to the A3 power supply board (several inductors, resistors and caps). I found that using a 1 uF for C16, instead of the documented 0.1 uF, gives a better signal. See the top of page A-15 in the manual. Thank you. This is just what I needed to hear. I had clearly overlooked that page. I've made an attempt at reading page A-15 for the 10 MHz sine option, and consulted the schematic and parts list on the succeeding pages. I still don't have legible values for L1, L2, and R16. If you have these values we can document the rest of this process in one place. 10 MHz sine TTL L1 ?.? uH L1 OMIT L2 1? uH Replace with R23 130 OHM 1 WATT R16 ?10 OHM NOM100 OHM NOM R17 1.0K 274 OHM NOM 1/4W R18 1.0K OMIT C8 47pF NOM JUMPER C9 6800pf NOM 0.47 uF NOM C16 0.1uF [1uF: see above] JUMPER C17 240pF NOM NP0 OMIT INSTALL JUMPER A-0 Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FRS-C TTL / sine outboard filter question
... [snip] If you need a sine wave output but don't want to change anything inside, just add a lowpass filter. A 5th order LPF (three inductors/ 2 caps or vice versa) should give you a clean sine wave output. Just add a coupling cap to remove the DC component. Adrian _ Thank you, Adrian. I'll pursue both options, internal fixes and external filter. A multi-pole LPF is easily understood, and I don't believe I care about passband ripple, though I wonder a little about the effect of the coupling on phase changes (i.e., does this have any unfortunate effect on adev?). I still don't know if a crystal ladder filter will suppress the harmonics, but I did get the answers that make me not need to ask anymore (1. fix the internal filter, 2. use the high Q xtal filter for optional removal of close-in noise) Given time I would do all of these things, but I may not get to them all! Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FRS-C TTL / sine outboard filter question
Thank you, Didier. That pretty much sums it up. I was aware of the signal level issue but didn't consider that passband ripple would be temperature sensitive. It's fun learning to think in the long time domain. In the meantime I've found a 10 mbit ethernet ISA card in my office and will follow Robert G8RPI's suggestion to use G4HUP's document to obtain a ready-made 10 MHz filter from it. Plus as a bonus the box had a BNC T connector in it. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] FRS-C TTL / sine outboard filter question
At the local flea market, I picked up what appears to be an Efratom FRS-C. It is marked TTL internally. It has the passive connector board, but not the active board with the 15 MHz synthesizer on it. Mine is marked TTL internally. The service manual has a chart showing the differences between the sine and TTL options, and I converted it to the sine version by changing a jumper to a resistor and populating an LC filter with 10uH and 100pF (~5 MHz). I also terminated the RF connection on the connector board with a 47 ohm resistor to ground. The output now doesn't have the tremendous overshoot it used to have, but it's also not very sinusoidal. That's not surprising given the simplicity of the on-board filter. Instead of a multi-stage LC filter, I wondered about a crystal ladder filter: since the output frequency is fixed, the high Q and low cost of the crystal filter might be an advantage, but I wasn't sure about how effective xtal ladder filters are at suppressing harmonics, as each individual crystals would have odd overtone responses, so it might not be a good plan. Does anyone have practical experience with a filter topology for cleaning up the output of the FRS-C at 10 MHz? Leigh. P.S. Just so that I can be topical, note that the FRS-C has a C-field adjustment 0-5V input, so I could use it as the reference oscillator for a TPLL. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Reciprocal Counters
There will likely be one of these at the Electronics Flea Market in Cupertino, CA this Saturday. I saw it last month with a $20 price tag, but my guess is that if you can lift it it's yours. it's the one with the stack of neon blubs for each digit. (Somewhere I have one in a garage as well...) Leigh/WA5ZNU Hi You could always set up a Beckman EPUT meter to do period and get effectively the same sort of result. No solid state in them at all. Full of warm glowing stuff (some of it glowed yellow, some of it glowed purple). Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke T-Bolt Monitor Dumb Question
Is that Daughter-Board soldered in or plugged in ? It looks like it's plugged into the connector but I can't get it to budge and I really don't want to apply too much force and wind up breaking it. Thanks, Dick, W1KSZ I believe it's soldered. I was able to do my mod using through-hold diodes without moving it. I just used a small-tipped soldering iron to remove one of the existing SMT diodes, tinned the two pads a bit (one empty going to V+, the other going to the still-present zero-ohm resistor) and tacked the new parts on. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke monitor
I fixed my fluke.l monitor. This evening I got mail today from Bob Mokia: The problem is too much volts on CPU (8051F330D). Must have diodes 1n4148 etc at D1 and D2. Drop cpu volts to 3.6volts. Maximum volts from data sheet is 4.2 volts. D1, D2, and D3 are zero-ohm SMT resistors in series from the 5V regulator output. They are visible from the CPU board edge. Without removing the CPU board from the display, I was able to remove D1 and tack a pair of 1N4148's in series from the D1 plus pad to D2, both right at the board edge. I left D2 and D3 in place. I made the leads as short as possible, but still had to bend the parts up a bit to fit it in the case. As soon as I plugged it in, it worked. It's been on about 15 minutes now with no problems. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Good scopes under $40 was Thunderbolt, Rb,
Can you really get a useful scope for $25? What's it like? It's 30 Mhz dual-trace analog Tek scope, a bit fuzzy looking. But it gets the point across that you don't need a high-end scope to do these measurements, just basic skills and thought. Here's someone who made the hard-drive scope before me: http://hackedgadgets.com/2006/06/01/making-a-hard-drive-laser-oscilloscope/ Mine has is good up to about 300 Hz. http://www.youtube.com/user/wa5znu#p/a/u/1/m8D_6AIS7eo Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Thunderbolt, Rb, Scopes at SF Bay Maker Faire this weekend
As part of the SF Bay Area Maker Faire this weekend, I'll be showing a Thunderbolt GPSDO and a FE-5680A Rubidium disciplined oscillator, both connected to a $25 flea-market oscilloscope. The demo is part of a hands-on things to do with oscilloscopes. In this experiment, we'll have visitors use a stopwatch to measure how long it takes for a 360 degree phase change, and use that to calculate the fractional PPB difference between the two frequencies. We'll be at the ARRL booth, which is in the Fiesta Building, near the Tesla Stage entrance. http://www.makerfaire.com/ Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt, Rb,
Thanks for thinking about and commenting on my project. The goal is to show how you can use a scope in interesting ways. One of the ways is to show that you can measure fraction PPB in stable, periodic signals, and you don't need a $5000 LeCroy, just a stopwatch and a few minutes. The FE5680A Rb DDS is settable to within 6mHz steps, so it's got a built in difference with the Tbolt already and should show one cycle difference in 1/6mHz ~= 160 seconds. I don't intend to do any demos that involve adjusting the C Field, since I used Mark Sims' program to calculate the closest divisor word for 10MHz already, by reading the 2^24 Hz divisor word and working backward, and I don't want to lose that calibration. Sadly, there's not a good view of over 50% of the sky, even though I'm able to place the antenna outside. But in my test today it was getting more than 4 sats and the scope was taking a minute or two to go from peak to peak, so I'm happy. Tomorrow, the school demo will be a paper scope made out of a yard stick, a marker, and wall-chart paper: one student holds the oscillating yard stick, a second pulls the paper steadily, and a third times it. Afterward, they count peaks and divide by time. Next student demo is the scope made out of a laser and hard drive with a mirror on the voice coil. For the real scope work, we won't show the Rb to the kids; they'll get an iPod with music on the scope, as it's more relevant to them. But please do stop by on Saturday or Sunday during the regular days and say hi. I'm really pleased with all the help I've gotten from this list and from reading its archives. Leigh/WA5ZNU Hi The rubidium should tune over a +/- 1x10^-9 range. A nanosecond per second isn't all that hard to spot. At 10 MHz you'll do a full 360 in 100 seconds. Bob On May 20, 2010, at 5:57 PM, WarrenS wrote: I hope it is a LONG show with a lot of patent people. This is way above the typical WWV stuff. Any good adjusted RB with a correctly set up Tbolt will take2.5 hrs to do the 360. Delta 1e-11 = 10,000 sec for 100 ns change. I understand it is not what your desired goal is, But would be much better off with a PC and Lady Heather, that way only need to wait a minute or less. Maybe a better test for the O-Scope is to show the noise jitter between them. ws time-nuts] Thunderbolt, Rb, Scopes at SF Bay Maker Faire this weekendLeigh L. Klotz, Jr. WA5ZNU Leigh at WA5ZNU.org Thu May 20 20:00:21 UTC 2010 As part of the SF Bay Area Maker Faire this weekend, I'll be showing a Thunderbolt GPSDO and a FE-5680A Rubidium disciplined oscillator, both connected to a $25 flea-market oscilloscope. The demo is part of a hands-on things to do with oscilloscopes. In this experiment, we'll have visitors use a stopwatch to measure how long it takes for a 360 degree phase change, and use that to calculate the fractional PPB difference between the two frequencies. We'll be at the ARRL booth, which is in the Fiesta Building, near the Tesla Stage entrance. http://www.makerfaire.com/ Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pingout for tu00-d200 module
I had a bunch of them and gave them away. For XY resolution I couldn't get better than 100m. And since it's not a Jupiter, no 10KHz output. I went to WSW and checked one there and it was the same part I got from China. Leigh/WA5ZNU I've seen a number of references to documents claiming to hold the pinout for the TU00=200 module but have not been able to make one work yet. This is the module commonly being sold from Weirdstuff and China, but it does not match the Jupiter pinout. Any help you could render would be appreciated. thanks, Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke monitor
You're right about the current. I just checked it with my DMM and got 45ma. My inline power meter must not be that it's not that accurate at the low end. The display works; the backlight works; the processor must be doing something since it prints a variety of messages. It's the RS232 that has flakey. The hardest thing at this point is to unsolder the 16-pin header. Bob suggests that a 12v regulator may have failed. Leigh/WA5ZNU In a message dated 12/05/2010 17:45:16 GMT Daylight Time, le...@wa5znu.org writes: The monitor is a recent model and has the regulator. I left it on overnight, in its original case and out in the open, hooked to a 13.5V supply. I had it on a ammeter the whole time, and it never draws more than 0.02A. The backlight is fine and the display works. -- Something doesn't seem right with that current consumption. Mine's not in use at the moment, as my test area is still stripped down, but when it was I measured a consistent 47mA once the regulator had a high enough supply to ensure it was regulating, in my case I was using 12 volts but the current is determined by the regulator output voltage so shouldn't vary much anyway. The display is what was fitted originally fitted to the iCruze module but the processor board has been changed so that Didier's Tbolt Monitor code can be used. The processor module circuit is pretty basic so I wouldn't have thought there was too much room for a design error. I'd be inclined to start by separating the processor board from the display and then reconnect using a temporary link of flexible wiring so as to be able to check if the processor circuitry is actually drawing current, then I'd probably continue by looking for quality issues, bad joints, solder bridges, etc. If that turned up nothing obvious then a more in depth examination of what the processor is doing would be my next step, in particular it would be interesting to know how it's handling the RS232 interfacing just in case it's a comms issue. Given that Didier's code is freely available, and the processor board schematic is easily traced, it shouldn't be too difficult as a last resort just to build a replacement. regards Nigel GMPZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fluke monitor
On 05/06/2010 12:29 PM, Arthur Dent wrote: But now here is the finding. The monitor board has the 7805 SMD version and I was feeding from +12Volt and after a while the SMD voltage regulator overheated and started to drop the voltage and it was the reason to receive/display garbled msg.the display is built into the same box as the gpsdo. the temp of the gpsdo was around 45 Celsius, so inside the box the temp also was elevated so no wonder why the SMD voltage reg overheated Ernie, Glad to hear you were able to find the problem. Quite often you can use a can of spray coolant to identify thermal problems like this one. The regulator is rated 0.5A but the amount of power it was asked to dissipate caused the thermal shutdown. It was working just the way it was designed. One suggestion I would make is to epoxy a small heatsink onto the chip to make sure this doesn't happen again. The 75 ohm resistor you're using will probably take care of the problem permanently but even a small heatsink cut and formed from a soda can wouldn't hurt. -Arthur My fluke.l monitor stopped working today after one overnight session. LH is connected at the same time and is reporting good data from the tbolt. I currently think that it's perhaps a clock speed issue, not a voltage issue, because I'm getting 5V out of the regulator right now and it's not working. Here's how I got here: The monitor is a recent model and has the regulator. I left it on overnight, in its original case and out in the open, hooked to a 13.5V supply. I had it on a ammeter the whole time, and it never draws more than 0.02A. The backlight is fine and the display works. It says No Message and occasionally gives garbled displays of other data. Once it said No Message / PowerSupply Fail but not again. Turning it off for an hour didn't help. I tried it at a lower voltage (8V) and it works some, alternating between No Message and some data or otehr every few minutes, but the data doesn't appear to be accurate (claiming 2D/3D mode when it's not, including question marks in numeric fields, etc). With 12.2V-13.5V in, I get 4.99-5.01V from the square via on the left of the board to the 3 round vias next to it, yet I still get No message or garbled data. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather Daemon for FreeBSD
On 02/02/2010 10:18 AM, Ralph Smith wrote: It should also port to Linux easily with minimal tweaking. I just don't have a Linux box available. Ralph I have tboltd running on Ubuntu 9 Linux. I have not yet tried the ntp part, but LadyHeather 3.00 Beta (running under Wine) connects. With tboltd -v, I get a lot of unknown packets. I'll separately send mail to Ralph with the output, for validation. For gpsdclient, I haven't figured out where to get the bedec16 routines for Linux. There's /usr/include/bits/endian.h but it doesn't contain them. There's mention of a freebsd man pages package which documents them, but no idea where the actual routines are or what package they are in. Leigh/WA5ZNU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Failure Imminent for WAAS satellite...
They spend most of the article on LEO hazards, but this is a geo-sync orbit. Leigh/WA5ZNU At 06:32 PM 5/3/2010, Dave hartzell wrote... And it gets even more interesting. Here's more backstory and detail... http://www.msnbc.msn.com/id/36919374/ns/technology_and_science-space/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FEI FE-5680A
On 03/24/2010 03:18 PM, Magnus Danielson wrote: Fellow time-nuts, ... Second, anything I should keep in mind as I power one up? ... Cheers, Magnus There's a bit of discussion in the archives about the need for a heat sink, and also about the whether it's necessary to anneal the case in a 400C Hydrogen reducing oven after the SMA modification. (Although I do have access to one, it is over the threshold for things I'm willing to do.) Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 60Hz mains clocking in computers
In 1984 we had a QBUS-based 68000 (dual 68K, due to the paging flaw) that ran 9-track tapes off the end and gained about a good fraction of an hour a day on its clock. We complained to the vendor and they swapped CPU boards for us. Tapes worked fine, and the clock was more accurate, but programs ran slower. Hmmm. Leigh. At 1:44 AM + 12/13/09, time-nuts-requ...@febo.com wrote: Date: Sat, 12 Dec 2009 17:29:17 -0800 From: Colby Gutierrez-Kraybill co...@astro.berkeley.edu Subject: [time-nuts] 60Hz mains clocking in computers To: time-nuts@febo.com Message-ID: 3058527a-cc99-4174-be75-21dd92334...@astro.berkeley.edu Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes I'm trying to get to the bottom of whether or not any computing equipment made around the advent of UNIX systems (or any time-slicing system) used the mains cycles of 60Hz as phase lock for the internal system clock. My guess is that perhaps they did not as the computing logic is DC based, but, I have memories of using an 68000 based UNIX system that I thought had its internal clock based off of the 60Hz mains... Not sure the vendor anymore. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP5328A repair experience
I have an HP-5216A that I got at the local flea market. One tube is bad and one driver. I found the drivers (they're special HP chips), but now I see it has about 10mA leakage current to ground. I've removed everything on the primary side and it seems to be the transformer. There's a slight chance I pinched a wire in the transformer cage but I haven't had the energy to try once more taking the transformer out. Oh, and I had to fabricate my own power connector as it's really old. (That's not the source of the leak as the current stops when I remove the fuse.) http://wa5znu.org/2009/08/hp5216a/ Leigh/WA5ZNU Fellow Time-nuts, Some time back I was given a HP5328A that was working well, but started eating fuses. Fortunatly all manuals came with it. It does eat fuses, but I failed to detect why at first. I went down some dead ends debug-wise, just to show that I am a bit rusty, but time to polish the rust of then... In the end, the negative rail cap had shorted out. Nothing obviously wrong with that side. The way that the PCB trails work, there is a separate PCB trail to the negative side of that cap, and that had bruned straight off so the rest of the negative side was almost working. Replacing both 4500 uF 35 VDC caps by RIFA 6800 uF 40 VDC PEH200 caps (works perfect as drop-in replacement as terminal screws and body size matches very well). Power up and everything checks out fine. Just... works. I have option 020 and 040 in mine, so it will do the funky jittered clock interpolation on averaging while achieving 10 ns singel-shot resolution from it's 100 MHz oscillator compared to 100 ns from the standard 10 MHz counting clock. I actually have a couple of 010 option boards with 10811 oscillators on them. While it is not by any means my best counter, it's nice to see it running again. So, hopefull someone apprechiate this little notice. Call it a distant echo from the past if you so wish. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5328 PSU nightmare...
And vacuum tube equipment using indirectly-heated cathodes: http://www.cpii.com/docs/related/23/Basic%20Tube%20Design.pdf Operating techniques that are proper for filamentary tubes are not necessarily correct for tubes with indirectly heated cathode emitters. In particular, the opera- tion of cathode types at reduced heater voltage can be destructive to the tube. Leigh. Mark Sims wrote: Be very careful powering up modern equipment on variacs and with light bulbs in series, etc. You go through areas where the bias voltages, etc are in the right place to cause serious damage. Switching supplies can be particularly entertaining... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Ideas for a long-wave receiver sought
Are you doing DGPS? An an alterative to the roll-your-own SDR, tou can build a direct conversion small receiver or IF converter with a SA602 chip, which contains a Gilbert cell mixer and a local oscillator. Here is a board that will do most of what you want, if you're willing to live with the SA602 limitation. http://home.att.net/~jacksonharbor/lfconv.htm You will get out of this board LO + (0 to 500 Khz), which you can the receive with an existing receiver that can receive the LO frequency. It comes with 4.0 and 10.0 MHz crystals. Here's an article about better input filtering against AM broadcast band interference, which will be useful for you no matter what route you take for LF and VLF reception. http://www.cliftonlaboratories.com/jackson_harbor_press_vlf_converter.htm There are many ham and non-hams who are using very low bit-rate signals in LF and VLF at micro power levels. As a result, they care about frequency stability, and some are building their own RX equipment. Here's a random sample: http://www.qrss.thersgb.net/Receiving-QRSS.html . Murray Greenman who is a member of this group did some pioneering work in VLF TX using the FE5680A as a transmitter, and he may have something to contribute on RX as well. If you need better phase noise and frequency stability, you won't get that from a product like the SA602, not the least because of its internal oscillator. You can build a receiver or IF converter yourself out of discrete mixers from Mini-Circuits, but you'll likely need a preamp as well as they generally require higher drive points (more loss), and output filters as well to deal with the image rejection. Leigh. Hi I want to build a small, cheap, yet precise long-wave receiver which can be tuned from the computer in the 2KHz - 200 KHz range (the intended use is to receive various time signal stations). Does a chip for such a receiver exist? Should I take the SDR route? I designed a DCF77 receivers some years ago, but I need something more flexible (and a bit more modern...) - Marc Balmer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A thermal management
For reference, Ridge Equipment has a photo of one of this year's crop of FE-5680A mounted to a large aluminum plate. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=330233071735 http://i43.tinypic.com/126cpcp.jpg Leigh/WA5ZNU Almost all rubidium standards DO specify the use of some form of a heat sink. For the FRK and M100 units this can be a heat sink with around 1 fins or just bolted to a metal plate or chassis. The military freq standard that had M100's in them had the unit mounted to a 5x5x.2 aluminum plate that was in turn bolted to the chassis. My Efratom PTB-100 time bases for the Tektronix TM500 mainframes have a large heat sink mounted to a FRK style oscillator. LPROs are supposed to be mounted to a metal chassis (they usually come with a thermal pad attached to them). I have seen them lose lock in free air. I saw one mounted in a piece of cell phone equipment. It was bolted to a large heat sink that formed most of the front of the enclosure. I have also seen FE-5680A's in their native habitat (again, cell phone equipment). They were mounted to a thick (1/8?) PCB around 6x16. The side of the PCB that the 5680 was bolted to had a solid ground plane. The 5650A's had one side bolted to a metal chassis. _ Hotmail® has ever-growing storage! Don’t worry about storage limits. http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage_062009 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolts, time references, NTP etc.
It's fluke.l not flukel who I've dealt with quite recently, and many other more venerable folks on this list have commented on as well. Leigh. Is this good value, and a trusted seller? I went looking for Fluke1 as listed earlier on here for these devices (Thunderbolt GPS disciplined referenced sources) but though I (eventually) found the user, no activity was shown for some time. So, I went looking for the product instead, and found (among other things) this item 170344432395 (you know where to look.) ... Dave B. G0WBX. ___ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A heat sink
Yes, thank you to all. I'll go ahead with the heat sink on the bottom and consider a fan nearby. Leigh/WA5ZNU I think we've all learned from this. Good info about the Efratom unit, and sounds as though we should aim for around 38C with the FEI units as well. The FE-5680 looks to be easier to deal with than the FE-5650, so I'll look into that first. Murray ZL1BPU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A heat sink
Bruce, Thank you for this point. I've seen Mu metal competitors but I can't tell what the case is made from. Pretty much everybody I've seen on this has had to make some kind of allowance for getting the RF out. I drilled a hole for an SMA connector and had it exit on the digital half of the chassis (not the physics half), as they're separated by a very large bar, perhaps brass. It has a few ways to get wires through, but it didn't seem to be a good idea. The SMA is a jumper I bought on eBay from a Chinese manufacturer, with an IPX connector on one end and the SMA bulkhead on the other. Hirose U.Fl and IPX are said to be compatible, but it didn't look like it wanted to stay down, so I tacked a wire to the head of the IPX connector put a brass 2-54 nut on a nearby post to ensure mechanical connection. I think this is better than soldering open coax to the connector, but given the short size and low frequency (10 Mhz) it's probably not a concern. So, I probably did something bad to the magic Mu metal annealing by drilling a hole, but it's as far as I could get over on the digital side of the brass divider. At this point I have nothing calibrated that I can measure the device with and see if there's any small magnetic influence, but perhaps someday I will, or maybe someone else would like to compare with another device sometime. It might have been possible to re-purpose a pin from the existing RS232 connector, and perhaps others who buy this same run of device may want to investigate that. Leigh. Bruce Griffiths wrote: Leigh L. Klotz, Jr WA5ZNU wrote: So far I've seen http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%200_4.pdf If the case is Mu metal or similar then the modification shown in the above article will likely destroy its magnetic shielding properties (unless its annealed in a hydrogen atmosphere at 400C for several hours after machining). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A heat sink
Chuck, This device is a pull from a larger system, probably a cell site. It's clearly designed to be mounted on something, as it has lots and lots of holes around the edge. I suspect there's some thermal management that's missing. The FEI sheet gives typical data for the 0-50C range, though presumably that's ambient temperature. I don't want to cool the physics package per se, but I do want to at least approximate what kind of thermal solution ought to be supplied. Quite a few of these have been sold, and I've gotten good advice from others on this list about calibration. I'd hoped that someone would have experience with the thermal management. So far I've seen http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%200_4.pdf which shows (but doesn't describe) a heat sink on the bottom. Leigh. I'm puzzled. I admit that I don't have a lot of experience with Rb standards, but I do have a bit of experience with the HP-5065A Rb standard. In the 5065A, the entire physics package is enclosed in an oven. Assuming that your Rb is the same, and I believe it is, your plan to force the physics package to run at room temperature is just going to make the oven work harder in its never ending quest to maintain stable temperature. If you monitor the current draw of the 5680A, you will probably see that it goes up when you put a fan on it. Sometimes, you just have to let electronics run hot. What did the manufacturer suggest? -Chuck Harris Leigh L. Klotz, Jr WA5ZNU wrote: I've attached an SMA connector to my FE-5680A and built an external linear power supply with a TO-3 7815. I ran the device today for about half an hour, and used an infrared sensing thermometer to measure the external case temperature. It got up to 48 C externally in the physics package area. I put a muffin fan on top and it brought it down to 38C but I don't think this is a good plan because I worry about the effects of the fan's magnetic field on the Rubidium system. I found in my junk box a finned Aluminum heat sink that's exactly the same size as the FE-5680A and plan to tap it around the edges for 4-40 hardware to attach to the many screw holes. Even so, this heat sink will be on the bottom, so the FE-5680A will have to be operated upside down for this to help. Has anybody got good thermal management solution for this device? This is the one currently selling on eBay in the 25x88x125mm chassis. Thanks, Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] FE 5680A supply voltage
Is anyone familiar with the hazards of an undervoltage supply on an FE 5680A? I've seen reports of users running it at a more commonly available 13.2V instead of 15V. What module might be most affected? The lamp? Thanks, Leigh. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
