Re: [time-nuts] fast edge, rise time.

2014-01-16 Thread Bill Reed
Paul It weighs 30 lbs. Pictures are on face book or I can email with an address. Bill -Original Message- From: paul swed Sent: Wednesday, January 15, 2014 12:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] fast edge, rise time. Bill Interesting

Re: [time-nuts] fast edge, rise time.

2014-01-15 Thread Bill Reed
: Tuesday, January 14, 2014 12:02 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] fast edge, rise time. You might be interested to know this was discussed in a paper by Jim Andrews (founder of Picosecond Pulse Laboratories): http://www.nist.gov/calibrations/upload/im

Re: [time-nuts] fast edge, rise time.

2014-01-15 Thread paul swed
. Thanks, Bill Reed -Original Message- From: Bill Reed Sent: Tuesday, January 07, 2014 7:53 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] fast edge, rise time. Hi, Since you guys are interested in fast pule generators, I have one you may

Re: [time-nuts] fast edge, rise time.

2014-01-14 Thread Mark Kahrs
-Original Message- From: Bill Reed Sent: Tuesday, January 07, 2014 7:53 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] fast edge, rise time. Hi, Since you guys are interested in fast pule generators, I have one you may be interested in. I got

Re: [time-nuts] fast edge, rise time.

2014-01-13 Thread Bill Reed
Reed Sent: Tuesday, January 07, 2014 7:53 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] fast edge, rise time. Hi, Since you guys are interested in fast pule generators, I have one you may be interested in. I got it in govt. auction about 25 years ago

Re: [time-nuts] fast edge, rise time.

2014-01-07 Thread Bill Reed
under Impulse. Bill Reed256 586-3446 -Original Message- From: ct1dmk Sent: Sunday, December 29, 2013 7:36 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] fast edge, rise time. Thank you all for your comments on this subject. Happy new year

Re: [time-nuts] fast edge, rise time.

2013-12-29 Thread ct1dmk
Thank you all for your comments on this subject. Happy new year. Luis Cupido. ct1dmk. ___ 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] fast edge, rise time.

2013-12-27 Thread Attila Kinali
On Fri, 27 Dec 2013 02:16:26 + ct1dmk ct1...@gmail.com wrote: Since the amplitude and timing parameters are to be controlled (pulse timing come from an FPGA) I really need a solution using that trivial switching element fet or bipolar (and can't really do a more exotic scheme if I cant

Re: [time-nuts] fast edge, rise time.

2013-12-27 Thread Attila Kinali
On Fri, 27 Dec 2013 11:30:00 +0100 Attila Kinali att...@kinali.ch wrote: When you have the pulse you can use some standard RF amplifier circuit that drivers your transformer. Setting the amplitude should be easy too. I just reread your first mail and realized that this amplifier might be your

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Jim Lux
On 12/26/13 8:07 AM, ct1dmk wrote: Hello, I'm willing to generate a pulse (of some few hundred volts) by discharging a capacitor into a pulse transformer I'm solely interested is the active edge (call it either rise or fall depending on the wiring of the output of the transformer). ns

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Marek Peca
The target is 4ns, while ideas seemed to be clear at some point, now I'm having doubts if better to use a MOSFET or a bipolar transistor as the switch element. Experiments with MOSFETs presented me some difficulties charging the gate capacitance having some trouble to achieve something in the

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Attila Kinali
On Thu, 26 Dec 2013 16:07:49 + ct1dmk ct1...@gmail.com wrote: The target is 4ns, while ideas seemed to be clear at some point, now I'm having doubts if better to use a MOSFET or a bipolar transistor as the switch element. Experiments with MOSFETs presented me some difficulties charging

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Bob Camp
Hi If you go the Krytron route you probably will need some fairly fancy transformers as well…. Bob On Dec 26, 2013, at 11:19 AM, Jim Lux jim...@earthlink.net wrote: On 12/26/13 8:07 AM, ct1dmk wrote: Hello, I'm willing to generate a pulse (of some few hundred volts) by discharging a

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread David C. Partridge
Look at the Jim Williams application note http://cds.linear.com/docs/en/application-note/an47fa.pdf Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ct1dmk Sent: 26 December 2013 16:08 To: Discussion of precise

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Dr. David Kirkby
On 26 December 2013 16:07, ct1dmk ct1...@gmail.com wrote: Hello, I'm willing to generate a pulse (of some few hundred volts) by discharging a capacitor into a pulse transformer There are probably more modern approaches, but a thryatron is one possibility. Shame I put on in the dump a few

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread J. Forster
Can you say more about your application? What does your load look like? What pulse shape? There are well-known solutiuons for most problems. As Jim said, a lot depends on the energy you need per pulse. What works for a few mJ will not work for MJ BTW, SCRs probably switch a lot faster than

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Al Wolfe
Years ago I had a cousin who ran a civilian calibration lab. For calibrating scopes, etc, for rise time he used a mercury wetted relay which he claimed had nearly instant rise time and no bounce. Seems that he used a resistive divider and the mercury relay shunted a portion of the divider. With

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread J. Forster
There are very fast pulsers, some in NIM, that use a charged coax line and Hg relay to calibrate Pulse Height analyzers. The line length sets the pulse length; the charging voltage, the pulse height. -John Years ago I had a cousin who ran a civilian calibration lab. For

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread cfo
On Thu, 26 Dec 2013 16:07:49 +, ct1dmk wrote: The target is 4ns, while ideas seemed to be clear at some point, now I'm having doubts if better to use a MOSFET or a bipolar transistor as the switch element. Experiments with MOSFETs presented me some difficulties charging the gate

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Gerhard Hoffmann
Am 26.12.2013 17:07, schrieb ct1dmk: p.s. ( I switch a capacitor to GND with a transistor (fet or bipolar). that capacitor has a charging resistor to 48V, transformer has a 9:1 voltage ratio. Pulse average power is quite low a few watt only. At the primary side some 20A of peak current for

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Attila Kinali
On Thu, 26 Dec 2013 19:38:08 + (UTC) cfo xne...@luna.dyndns.dk wrote: Have a look here Jim Williams on eevblog https://tinyurl.com/nhyvtc3 I advice to be cautious with EEVblog. Dave Jones has a lot of half knowledge and presents that like he knew exactly what he is talking about. His

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread ct1dmk
Many thanks to all for the nice tips. I may narrow down by saying a few more specs as suggested. The pulse would see a somehow unknown load but for a start I was suggested to have my source with 50ohm impedance so worst case would be a short circuit and therefore the pulse would be a current

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread J. Forster
Are only the amplitude and rep rate variable, or do you vary the width too? -John = Many thanks to all for the nice tips. I may narrow down by saying a few more specs as suggested. The pulse would see a somehow unknown load but for a start I was suggested to have my source

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread Bob Camp
Hi Unless you want run for 1 second, that rules out a Krytron. Length of operation also impacts some of the other implementations. Bob On Dec 26, 2013, at 9:16 PM, ct1dmk ct1...@gmail.com wrote: Many thanks to all for the nice tips. I may narrow down by saying a few more specs as

Re: [time-nuts] fast edge, rise time.

2013-12-26 Thread bownes
There are some good alternatives to krytrons. Just don't expect to be able to afford or export them. ;) On Dec 26, 2013, at 21:26, Bob Camp li...@rtty.us wrote: Hi Unless you want run for 1 second, that rules out a Krytron. Length of operation also impacts some of the other