I would imagine it was much less expensive for HP to gut second hand equipment and re-qualify it than restart a fab or qualify a new design front end. On 25 Jan 2016 16:01, "Bert Kehren via time-nuts" <time-nuts@febo.com> wrote:
> Getting back to the original question, years ago I was told but could not > confirm that HP was buying up 5345's because of a Government commitment to > replace front ends. If they had to go to such matters I doubt we will be > able to find a solution. > In my home counter work I tried but ended up using boards out of 5345's > Bert Kehren > > > In a message dated 1/25/2016 10:01:18 A.M. Eastern Standard Time, > bruce.griffi...@xtra.co.nz writes: > > I've been considering this for some time.The key is the replacement for > the triggered phase locked oscillator based interpolators. > FPGA based TDCs aren't yet quite good enough. > Off the shelf TDC chips are a little better but still fall a little short > in performance. > > Whilst a TAC approach can achieve around 4ps or so (eg various Wavecrest > instruments) a lot of discrete parts are likely to be required. > > My crude testing of a triggered damped sinewave generator sampled by an RF > ADC indicates that an event time stamp noise of 5ps or better appears > feasible. > > The technique of exciting a high Q saw bandpass filter with an impulse and > digitising the output is probably more expensive and complex than > desirable. > > Bruce > > > On Monday, 25 January 2016 6:04 PM, Bob Camp <kb...@n1k.org> wrote: > > > Hi > > Since the front end chips are mixed signal ASIC’s, it will take more than > a bit of time to > replace them directly. Re-doing the entire front panel board is the most > likely way to “fix” > the problem. The question is - why do that at all? Just do a PC instrument > that does the same > thing as the counter with way less effort….. > > Bob > > > > On Jan 24, 2016, at 6:02 PM, Dimitri.p <dimi...@dotp.com> wrote: > > > > Someday , someone will get bored with everything else and give it a try, > you know, in their spare time. > > The time when these counter were new was a long while ago. > > Back then an amplifier chip with 500MHZ BW was a much bigger deal than > it is in 2016. > > ...but spare time is permanently on backorder .... :) > > > > Dimitri > > > > At 06:15 AM 1/24/2016, Bob Camp wrote: > >> Hi > >> > >> Back when these counters (5345, 5370, 5335) all were new, the inputs > were > >> the weak link on all of them. There were known âdonât do thatâ things > on the line > >> that would blow out each of them. Regardless of the level of care and > yelling, inputs > >> blew on a fairly regular basis. Probably 10% of the counters went back > >> for repair over a 5 year period. It was always a âswap out the entire > boardâ sort > >> of repair and never was under $1K. We regularly spent the price of a > new counter > >> each year on repairs. If there had been an easy way to fix them, (or > even to just > >> pay $500 for the chip) we would have done it. > >> > >> Bob > >> > >> > On Jan 24, 2016, at 8:34 AM, Dale Cannon <dalec...@cfl.rr.com> > wrote: > >> > > >> > Funny, > >> > > >> > A friend asked me if I could replicate the front end for a 5370A, a > many > >> > years back. I related to him that replicating the input chip was not > a > >> > trivial task. His 5370A had been used (by someone else) for direct > testing > >> > of controlled-motion DC motors and the front end had obviously been > >> > overstressed by voltage spiking. At the time, I had considered > replicating > >> > the front-end probe circuit of a K100D logic analyzer: FET diff. pair > >> > followed by an ECL 10216 line driver. Obviously most daughterboard or > dead > >> > bug modification approaches have downsides; in the end I just > couldn't cut > >> > up the HP front end and told him to search for a more qualified > repair > >> > facility. > >> > > >> > BAMA boat anchors has the K100D manual and probe schematic. > >> > > >> > Dale Cannon KS4FA > >> > > >> > > >> > -----Original Message----- > >> > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of > Mathew > >> > Breton > >> > Sent: Friday, January 22, 2016 5:15 PM > >> > To: time-nuts@febo.com > >> > Subject: [time-nuts] HP5370B & HP5345B Front-End IC Redesign Effort > >> > > >> > I was gifted an HP 5370B with the usual problem: front-end problems, > >> > probably due to overstress. It is currently up and running again with > a set > >> > of 5345A series A3/A4 boards as I wasn't able to get a cheap pair of > >> > 5088-706x hybrid ICs. > >> > This sounds like a common problem. As a result, I'm designing an > open-source > >> > drop-in (hopefully) replacement. My hat is off to the original IC > designer, > >> > as it is not a trivial effort due to the wide input signal > common-mode > >> > range, and very tight trigger timing requirements. Other items (like > the > >> > E-ECL) output) are also adding a bit of extra effort. > >> > I'm hoping that someone(s) might be interested in working with me on > it. I > >> > would like to have my assumptions and math checked before I start > the > >> > detailed design phase, and perhaps contribute some better ideas. > >> > In addition, it would be really helpful if someone could run a few > rise-time > >> > dispersion tests on an instrument with a working "B"-series A3/A4 PCB > set > >> > (my unit obviously doesn't qualify). > >> > Regards, > >> > Mat Breton > >> > _______________________________________________ > >> > 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. > >> > ----- > >> > No virus found in this message. > >> > Checked by AVG - www.avg.com > >> > Version: 2016.0.7294 / Virus Database: 4492/11420 - Release Date: > 01/17/16 > >> > > >> > _______________________________________________ > >> > 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. > _______________________________________________ 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.