Re: [time-nuts] newbie question Thunderbolt supply

Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a

Re: [time-nuts] newbie question Thunderbolt supply

Hi The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out voltage compared to a 1764 (or similar). Stability of any of them will be impacted more by thermal issues than anything else. The colder you can keep the 12V regulator, the more stable it will be. The +12 is by

Re: [time-nuts] newbie question Thunderbolt supply

On 08/26/2012 02:07 PM, Bob Camp wrote: Hi The only real disadvantage of a 7812 / 340-12 is it's relatively high drop out voltage compared to a 1764 (or similar). Stability of any of them will be impacted more by thermal issues than anything else. The colder you can keep the 12V regulator,

Re: [time-nuts] newbie question Thunderbolt supply

Having played with most combinations I could think of including the 1764 there is a lot to be said about the stability of the 7812 and mounting every thing on one plate since power dissipation of the OCXO decreases with increase in ambient temperature and current fluctuation is minimal since

Re: [time-nuts] newbie question Thunderbolt supply

On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter

Re: [time-nuts] newbie question Thunderbolt supply

Hi all: I'm using buck regulators from our ebay friends, e.g. 130704328176 at a little over $1.00 apiece, settable to 5 v or 12 v or whatever, capable of 3 A with good heatsink. Foldback protection. Better than a 3-legged fuse, as my good gaffer Argus calls 'em. Don Bob Camp Hi The only real

Re: [time-nuts] ET-6000 firmware

KO4BB is busy cutting plywood and boarding windows, will be back to fun stuff after Isaac... Didier KO4BB Robert Watzlavick roc...@watzlavick.com wrote: I finally got a flash programmer so I uploaded all three ROM images (TCXO, OCXO, Rub) for the Datum ET-6000 / 9390-6000 to the KO4BB

Re: [time-nuts] ET-6000 firmware

Good luck!! -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Didier Juges Sent: 26 August 2012 19:09 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] ET-6000 firmware KO4BB is busy cutting plywood and

[time-nuts] re ET-6000 firmware

Bob; I have a TCXO version and wonder apart from the ROM change, what recommended hardware is required to install a rubidium osc? Is there a parts list somewhere? I would prefer not to cobble up if I can help it. I finally got a flash programmer so I uploaded all three ROM

[time-nuts] PM6685 GPIB PROM image ?

Hello, I have a GPIB option card (PM9626) from a PM6680 and I would like to use it in a PM6685. Looking at the service manuals, the only difference between the two GPIB cards for the two counters is the FW PROM, so I'm looking for a PM6685 GPIB PROM image or anybody with a PM6685 that could

Re: [time-nuts] PM6685 GPIB PROM image ?

First try if it works as it is. On Sun, Aug 26, 2012 at 11:24 PM, Claudio Girardi claudio.gira...@virgilio.it wrote: Hello, I have a GPIB option card (PM9626) from a PM6680 and I would like to use it in a PM6685. Looking at the service manuals, the only difference between the two GPIB

Re: [time-nuts] re ET-6000 firmware

The manual I have isn't too clear on the differences between the units but the drawing shows an LPRO tucked into the left front of the unit with 2 coax cables going to the PC board (EFC, OSC), and one going to an additional power supply in the right rear. The ET-6000 DAC is 0-5V (actually

Re: [time-nuts] re ET-6000 firmware

Hi; I may have a LPRO unit, if so I will post pictures. Best Wishes; Thomas Knox Date: Sun, 26 Aug 2012 21:08:03 -0500 From: roc...@watzlavick.com To: jleik...@leikhim.com; time-nuts@febo.com Subject: Re: [time-nuts] re ET-6000 firmware The manual I have isn't too clear on the

[time-nuts] Need usb time interval time for portable bullet chrongraph

Hello Folks I have been looking at bullet chrographs and wondering if I could get the a usb module to do a interval measurement and display on my laptop. on a yet to be discovered module to calculate the time interval between the pulses? The bullet travels at approx 1050 feet per second. By

Re: [time-nuts] Need usb time interval time for portable bullet chrongraph

Hi Paul, See http://leapsecond.com/pic/picpet.htm and contact me offline for the USB part. What do you use for sensors: acoustic, optical, seismic? /tvb (iPhone4) On Aug 26, 2012, at 10:48 PM, Paul Cianciolo pa...@snet.net wrote: Hello Folks I have been looking at bullet chrographs and

Re: [time-nuts] Bullet Chronograph

Hi, Paul-- I have several different ballistic chronographs-- only one of the ones I have interfaces to a laptop (Oehler Ballistic Laboratory model). There are inexpensive chronographs available for a little over $100. Some models do provide interface to a laptop as well as a LOT of built-in

Re: [time-nuts] Need usb time interval time for portable bullet chrongraph

Hi Paul: I'm presently adapting a chrony chronograph because I want to use the triggers for timing and other purposes. They've spent a LOT of engineering time to get proper triggering, and the triggers can easily be pulled off without disturbing the basic unit. The triggers are robust and will