[time-nuts] time-nuts conference (was: High rate, high, precision/accuracy time interval counter methods)
A time-nuts conference in Saarbrooklyn - well, I want to register! But I am living in the Rhein Main Area now, I can join if I visit my old home (Neinkerje) BR Hendrik ___ 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] synchronization for telescopes
Its before breakfast for me now, but you could set up a transmitter on a ISM frequency at 5 GHz or 60 GHz, where you have plenty of bandwidth (where plenty means 160 MHz or 2 GHz) and transmit your own clock signal. Either you roll your own by modifying some ham radio open source designs, or try to find some cheap surplus. (A Filter followed by a logarithmic detector might be sufficient for the receiver if you settle for Amplitude shift keying, a oscillator with a amplifier that you switch on during your clock pulse might be sufficient for the transmitter. Greetings, Hendrik ___ 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] help
Hi, about getting time from the Internet to a clockwork: Have a look at the ESP8266, which you can get from china for as low as 4€ in the embodiment of a AMICA board: Its a controller with some GPIOs and WLAN enabled, freely programmable (Either with the ARDUINO IDE, or with a LUA or BASIC Firmware.) Picking up the time from a DAYTIME Server is easier to implement than NTP, these respond just with a string containing date and time. At ~100 mA fully on its a good competitor to the Raspies regarding current consumption. BR Hendrik ___ 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] Monsanto IC
Looks like a rebadged Schlumberger Unit to me. (Case style wise) ___ 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] HP5334A Option 010 replacement connector J8
Hello list, same guy who direct-wired a STP2390C into a HP5334A earlier this year back here again. As a christmas holidays nano-project I made a little PCB to have a nice plug-in module instead of a snake nest. Today the boards arrived from the factory, and it was a lesson in "dont try to design a PCB when 2 little ones are running around you". Swapped two pins. Minor other things. But nothing that a drill press, scalpel and a piece of enameled wire can`t fix. Also users outside germany might want to use the permanent powered +30V rail instead of the +15V I settled for and so far cannot decide if I also change. Besides the STP2390C, it needs to be populated with a 7812 voltage regulator and some chicken food, and with a little cable run a Trimpot on the "OSC ADJ" opening can be connected too. Space for add-ons provided, mine has 1K in series from osc output to PCB output. Details will follow soon, I will post a description with updated eagle files on my website. Now I have some leftovers that I would like to offer time-semi-nuts that want such a OCXO in their beautiful 5334A. €3 for a unmodified buggy board, €5 for a board with the "subtractive corrections", say drill and cut sound about okay? Of course with additional shipping fee from germany that I have to figure out, bare PCB, no other parts. Best regards, Hendrik ___ 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] KS-24361 Output spectrum to 100 MHz
Hi List, here is my example spectrum taken with a Rigol 815, due to inpatience only up to 100 MHz. (I don't know if this was posted yet, but still then it would be a 2nd, 3rd example.) This shows what is meant by "clean 15, dirty 10 MHz." I always use insane pre-attenuation as every beginner should do. But even a dirty 10 MHz can be good, e.g. for driving comb generators =) Hendrik ___ 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] RFTG-u REF 0 Z3812 as cleanup module for FEI5680A
Hello List, having not looked at the spectra yet as I am confined to mobile phone instead of PC often, I had the idea to marry those two well-known devices to get a nice clean reference oscillator. I remember the spectrum of the FEI as not so nice, and the MTI sounds better. My understanding is yet that I would need to emulate the REF1 unit, basically need to look up the "lonely REF" tweak with the bridges in J5, maybe fake valid GPS datagrams with a microcontroller and turn the 1PPS pulse from the FEI into that 2 PPSes expected. Replacing the Lucent Power Brick with a linear supply and bridging the tripler to get 5 MHz out might be tweaks to increase the output spectrum further. This was discussed before, I think, i have to look it up too. (I wonder if the REF0 acts up after complete removal of the source REF1 or keep on doing holdover which would be a nice way to take a good frequency standard to a ham radio repeater side) BR Hendrik ___ 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] Toy Radiolocation
Have a look at Bluetooth low energy. I am working with some nice Modules from Bluegiga (BLE112), they just announced a long-range version. Although they are already very conservative with power and will run for a while even with a button cell, a mercury switch (sorry) could trigger them upon movement. You might be able to read a relative signal strength (RSSI), but dont expect it to be good. Hendrik ___ 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] HP5334A Option 010 replacement connector J8
Dear group, as I just yesterdays implanted a non-original OCXO (C-MAC STP2390C) into a recently ebayed counter, I wanted to share my experience: Swapping C8 to C100 position as per 5334B Service Manual (the B) is fine. J8, the connector for Option 010, is not in the 10811 layout as in the B. As I cannot find a A service manual, I had to poke and trace. This table will give you the pinout of the connector J8, with the lowest row representing the pins that are closer to the front, seen from component side top and the left column closer to the right edge of the PCB: OFF State +30V I +30V GNDI GND I I +15V I +15V I 10 MHz out ON State +29V I +29V GNDI GND I -5V I -5V +15V I +15V I 10 MHz out A 10 turn pot was mounted on the hole on the backside of the unit, connected to the EFC input of the Osc. as a voltage divider of course. All wires are twisted pairs (or twisted triple talking about the EFC.) even the 10 MHz is not a coax - yet. Having the rig open, I discovered burnt resistors at the 50 Ohm Termination of Channel A (only used B terminated so far), where the previous owner even stacked new resistors right on top of the original ones. (both pairs burned). A 619 Ohm Resistor in the ARM Path was also burned but Diodes OK, so I replaced it with a 620 Ohm Resistor, as expected without adverse effects. Counter and OCXO cost me about the price of a single 10811. Greetings Hendrik ___ 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] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE
Good morning Paul, First: I almost spilled my coffe as you bear a similar last name as a guy at a national research lab who does exactly such things :) Even when it makes your ECG preamplifier free for other things, I advise you to use another sensor and put a lot of decoding and interpretation to your brain. ECG is not easy from a safety standpoint, as it connects to the body immediately. The Signal is quite complex as it is composed of not a single but a "burst" of waves during excitation and contains a lot of moving and electrode artifacts, I wouldn't try to count BPM except AD conversion and doing a lot of filtering and preprocessing in software. I would use photoplethysmography instead of ECG, means you shine a little light from a LED thru your finger or ear to a photodiode. Actually a optocoupler with a bit of you inbetween ! The light at the photodiode will fade up and down with the local relative blood pressure in the tissue between the emitter and receiver, and so does the photodiode current. The resulting signal contains way less movement artifacts and less high-frequency parts. to record it on a PC i would say generate a audible AM-modulated tone with the photodiode current (amplified by an TIA) as modulation, when you feed that to the soundcard you can record with audacity and you will see the envelope on screen where you can count the (single) peaks per minute. For a more immediate result without PC, hook the TIA output to a V/F converter in the audible range and hook it up to a speaker, its easier to listen to the pitch changing. At work I am hooked up to heart-signal-analysing thingies quite often and i can tell you that it is easy to change heart-rate and relative blood pressure by will in a certain range. I made it a obligatory task to students, visitors and new co-workers to prove that they have a heartbeat ! :) Best regards Hendrik P.S.1.: My first post at the time-nuts P.S.2.: Don't let the FDA see anything :) ___ 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.
