Wanted - HP 8005A pulse generator UK - Page 1
Forum section: electronics / general

author: woodchips
author_rank: Frequent Contributor
timestamp: October 26, 2015, 12:25:21 pm
content: Does anyone have a HP 8005A, must be the A version, pulse generator gathering dust?I have a B, plus various other pulse gens but the A allows the outputs to be mixed in a way I can't find elsewhere.I am in mainland UK.Thanks

author: woodchips
author_rank: Frequent Contributor
timestamp: November 15, 2015, 06:49:57 pm
content: Bump, must be some different bloggers from first post!

author: TerraHertz
author_rank: Super Contributor
timestamp: November 16, 2015, 02:08:33 am
content: Quote from: woodchips on October 26, 2015, 12:25:21 pmI have an 8005B too, and I'm curious - what is the special feature of the A version?

author: woodchips
author_rank: Frequent Contributor
timestamp: November 17, 2015, 04:17:07 pm
content: The A version allows the two outputs to be mixed to make a composite signal. This signal can be both positive then negative with adjustable delay between, also common settable rise and fall times all at varying frequency. The B version doesn't allow the mixing to make a positive then negative single output pulse. No doubt can use two pulse generators but not sure how to mix the signals.Why? Messing about with ferrite core stores and making my own, this makes the write and read pulses easy to generate.

author: nfmax
author_rank: Super Contributor
timestamp: November 17, 2015, 04:32:46 pm
content: I have a Lyons pulse generator (currently in need of some attention) which I think has that facility as well. I'll check the manual & let you know the model number if it does.

author: nfmax
author_rank: Super Contributor
timestamp: November 18, 2015, 03:53:42 pm
content: I checked: it's a Lyons PG73N, and it does have the facility to combine + and - outputs. However the rise/fall times are not adjustable so it probably won't do what you want. IMHO you might be better off with an AWG for your purposes.

author: woodchips
author_rank: Frequent Contributor
timestamp: November 20, 2015, 03:51:31 pm
content: Hi, thanks for checking.I have one of those and it won't do both a +ve then a -ve, or vica versa, output. There is no individual control of polarity. Similar with the Farnell PG102 etc that they will combine the A and B pulses but not with different polarity. So far the 8005A is the only one I have found, and that only from the data sheet.

author: TerraHertz
author_rank: Super Contributor
timestamp: November 20, 2015, 11:25:37 pm
content: There are three on US ebay now. One is US$75, "untested". 331711035830 Perhaps you should try making a low offer?Another seller has a service manual, $20. 331168524974

author: woodchips
author_rank: Frequent Contributor
timestamp: November 21, 2015, 10:19:35 am
content: Hi, yes, I have seen them, been listed for ages. Doubt they are the world's most popular pulse generator, in fact do they still make general purpose pulse generators? I got a service manual from the late lamented Manuala Plus some months ago. Like the actual generator, postage was greater than the value of the goods!Looking further, the problem seems to be that pulse generators are made for logic use, not analogue, so having a pulse that goes +ve and -ve isn't needed for logic, just blows it up. The reason why the feature was removed from the B version.Perhaps I am needlessly complicating things but how would you combine two outputs to make a bipolar one with, say, 10V drive into 50 ohms?

author: KJDS
author_rank: Super Contributor
timestamp: November 21, 2015, 11:03:23 am
content: Quote from: woodchips on November 21, 2015, 10:19:35 amOver what frequency range?

author: TerraHertz
author_rank: Super Contributor
timestamp: November 21, 2015, 12:14:41 pm
content: Quote from: woodchips on November 21, 2015, 10:19:35 amHP don't make *anything* anymore, as they don't exist. In either name or spirit, despite the frequently renamed golem.QuoteErr... the answer is in that service manual's schematics?Though, summing current sources & sinks to one resistor, possibly with a voltage follower buffer, comes to mind.Now you've talked me into adding an 8005A to my long list of 'things to buy if I can ever afford them.'Curiosity is expensive.

author: woodchips
author_rank: Frequent Contributor
timestamp: November 22, 2015, 04:52:28 pm
content: I have the manual, but it is in storage along with all the others I bought. Will need to try and extract it and have a look.Not really a frequency range. A core store has a cylcle time of around 1us, so need to read and write it over a period of 0.5 to 10us to see what it does. Similarly with drive current levels, rise and fall times etc.There seems to be next to no real engineering information on ferrite cores used in stores around. Possibly in conference papers but they seem near impossible to get hold of, and are expensive when you do find them. There were lots of books written on early computers but little in the way of hard facts, similarly the manufacturers data sheets and applications.

author: woodchips
author_rank: Frequent Contributor
timestamp: November 27, 2015, 08:28:44 pm
content: Been delving into the Farnell PG5222 that I have. Uses an ITT 74124? This is a Universal Pulse Generator, NOT the VCO made by TI. Anyone have a data sheet please?

author: xtech
author_rank: Regular Contributor
timestamp: November 29, 2015, 09:28:37 pm
content: Here is ITT catalogue, datasheet for 74124 is on page 175http://bitsavers.trailing-edge.com/pdf/itt/_dataBooks/1974_ITT_Semiconductor_Product_Catalog.pdf

author: woodchips
author_rank: Frequent Contributor
timestamp: December 01, 2015, 06:17:14 pm
content: Wow, thanks for that, downloaded and printed.Strange, look for circuits on the usual wonderful sites, but never think to use bitsavers, wonder why?Thanks again.

author: woodchips
author_rank: Frequent Contributor
timestamp: December 15, 2015, 04:04:16 pm
content: Well, progress, access to the A and B manuals plus the 8005B I have.The difference between the A and B is that in the dual pulse mode the first pulse can go to the A o/p, the second to the B o/p, this is not possible on the B version. I can't really see why they deleted this function, the ones that are left really don't seem to be of much use. It produces pulses, which is what is needed, but with no subtlety. In dual pulse they overlap to start and then only become two pulses when the delay gets large enough. What is the point of this? It has a bipolar o/p amp but no means of selecting the output channels to be either, they are one or the other.On the 8005A the merging is done simply by shorting the two outputs together. All the clever stuff about the parameters is done earlier so it is buit into the pulse generator, can't easily retrofit it.Looks like an A is needed, but trying to trace a Farnell PG5222 which just uses monostables which might be useful.

author: Astrodev
author_rank: Regular Contributor
timestamp: February 16, 2017, 04:35:59 pm
content: I have just come across this thread while looking for some info on the Lyons PG73N pulse generator, anyway I have several Data General systems that use core memory and have most of the technical documentation that came with them including schematics, but I also just had a look on the bookshelf at an old TI data book I have, entitled 'The Interface Circuits Data Book' which covers their range of core drivers and sense amplifiers it was published in Jan 77, just let me know if any of this may be of help.

author: woodchips
author_rank: Frequent Contributor
timestamp: February 16, 2017, 06:13:50 pm
content: Thank you for that.I do have the same manuals, and similar from other manufacturers.Astonishingly I have recently bought some of these components, new, from Quarndon. They seem to have a few old chips still in stock.