[time-nuts] Good GPSDO?

I am just getting into the precise time and frequency stuff. I thought I should buy a GPSDO. There are quite a few similar-looking ones on eBay, such as eBay number 281802105734 There is also a Trimble at 252162780444 Would either of these be OK for a newbie like me? Richard

Re: [time-nuts] Heliostat

Hi The most common use was to reverse the process …. you used it to obtain local solar time. Bob > On Jul 2, 2016, at 3:12 PM, Brooke Clarke wrote: > > Hi: > > I recently got an Eastern Science Supply Co. demonstration heliostat, that's > to say it's small enough to

Re: [time-nuts] python or matlab/octave for Keysight instruments?

Hiya, > On 3 Jul 2016, at 02:09, jimlux wrote: > > I'm looking for a *simple* *portable* software library to do some > control/data acquisition from either python or octave for Agilent/Keysight > gear, specifically over the USB or Ethernet interfaces. > > [...] Might

Re: [time-nuts] Heliostat

Hi Brooke Primary use of heliostats in astronomy is solar observation Content by Scott Typos by Siri > On Jul 2, 2016, at 3:12 PM, Brooke Clarke wrote: > > Hi: > > I recently got an Eastern Science Supply Co. demonstration heliostat, that's > to say it's small enough to

[time-nuts] Heliostat

Lady Heather can display solar times. Set the time zone name to SST or SDT (there is also a command line option). Heather can also calculate and display the sun and moon positions and moon phase. The next release has some improvements to the equation of time calculation. Also, be aware

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

On Sat, 02 Jul 2016 14:09:44 -0500 David wrote: > If you can find it, "Preventing Emitter-follower Oscillation" by > Michael Chessman and Nathan Sokal has an analysis of negative > resistance oscillation in transistors and why adding dampening to one > lead is often

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

On Sat, 2 Jul 2016 19:00:24 +0200, you wrote: >On Fri, 1 Jul 2016 12:28:44 -0400 >Bob Camp wrote: > >> Real cascode circuits can be built with RF transistors. They also can be >> simulated. >> Simulating them with the “standard” models is a PIA. The issue is that the >>

[time-nuts] Heliostat

Hi: I recently got an Eastern Science Supply Co. demonstration heliostat, that's to say it's small enough to easily hand hold. I've go it working but have some questions. Based on some Waterbury Clock Co. patents I think is was made in the late 1920s or early 1930s. ESSCo was into astronomy.

Re: [time-nuts] Cable length calibration (Brooke Clarke)

Hi, Brooke, Very interesting stuff. Thanks for the link. Question - Is any of the older chirp sounder equipment now available on the surplus market?? Thanks. ... MartinVE3OAT On 02/07/2016 12:00, time-nuts-requ...@febo.com wrote: Hi Mike: For quite a while I was heavily into

Re: [time-nuts] python or matlab/octave for Keysight instruments?

On 7/2/16 10:58 AM, Hal Murray wrote: jim...@earthlink.net said: I'm fine with writing the SCPI commands and parsing the output, I'm just looking for the "glue" between "send_message_to_instrument" or "read_message_from_instrument" and the instrument itself. Why do you need any glue? What

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

I vaguely remember seeing designs where a through hole transistor like a 2N5179 had a ferrite bead slipped over the base to keep it stable. Although this works, it degrades the performance of the transistor. I prefer to put a resistor in series with the collector instead of the base. Since the

Re: [time-nuts] python or matlab/octave for Keysight instruments?

Hi > On Jul 2, 2016, at 1:58 PM, Hal Murray wrote: > > > jim...@earthlink.net said: >> I'm fine with writing the SCPI commands and parsing the output, I'm just >> looking for the "glue" between "send_message_to_instrument" or >> "read_message_from_instrument" and the

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

Hi Yes, you can also look at it as “damping” or" de-Q-ing”. You trade off a bit of isolation for stability. Put another way, the resistor will take the isolation of the stage down a bit. Another practical point on the stage - you want the base bypass as close to the end of that resistor as

Re: [time-nuts] python or matlab/octave for Keysight instruments?

jim...@earthlink.net said: > I'm fine with writing the SCPI commands and parsing the output, I'm just > looking for the "glue" between "send_message_to_instrument" or > "read_message_from_instrument" and the instrument itself. Why do you need any glue? What type of device is it? Why not just

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

On Fri, 1 Jul 2016 12:28:44 -0400 Bob Camp wrote: > Real cascode circuits can be built with RF transistors. They also can be > simulated. > Simulating them with the “standard” models is a PIA. The issue is that the > inductance > of the package is not de-embedded from the test

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

On Fri, 1 Jul 2016 15:45:36 -0400 Scott Stobbe wrote: > If you need higher output resistance you will have to move to a FET based > approach. If you need less than 1 pF of output capacitance you will need a > better transistor and care in how you physically construct

Re: [time-nuts] python or matlab/octave for Keysight instruments?

On Sat, 2 Jul 2016 09:09:49 -0700 jimlux wrote: > Is PyVISA reasonably easy to work with, or is it one of those "once > you've spent 6 weeks recompiling the kernel and finding all the > libraries from 4 different sources, it works great".. About half a year ago, I tried

[time-nuts] python or matlab/octave for Keysight instruments?

I'm looking for a *simple* *portable* software library to do some control/data acquisition from either python or octave for Agilent/Keysight gear, specifically over the USB or Ethernet interfaces. the "Keysight IO Libraries Suite CD " is, I think, Windows only I'm fine with writing the SCPI

Re: [time-nuts] T-Bolt lightning damage

John Do you have a Scope? If so you can confirm its the rs232 chip. See if data is being generated into the chip on the ttl side (I know bad term). If so then perhaps the heat on the other chip is normal. If no data then you most likely have an answer. Good luck Other comment watch for other

[time-nuts] T-Bolt lightning damage

Two weeks ago we had a lightning strike a tree in the backyard, and it coupled energy onto the coax to my 20M dipole. The coax was disconnected from the house, but the energy jumped to another coax running to my FMT setup in the garage. Carnage! The last (I hope) piece of equipment that I am