Any electronics engineer or technical person you speak to will know about Hewlett-Packard (HP) test equipment. And many of them will talk nostalgically of a certain item they have owned or worked with. I’m certainly like that. Whenever I see or hear of HP test equipment I get a kind of warm fuzzy feeling. When you used a piece of HP gear, you knew it would do its job superbly, and usually be easy to get to grips with. And most techie tragics like me will know the story of how Bill Hewlett and Dave Packard started off in a garage in Palo Alto in California. There’s even been a book about it: Bill and Dave: How Hewlett and Packard Built the World's Greatest Company by Michael S. Malone. Max Maxfield has done an excellent review of it. I’m ashamed to say I have not read it yet, but it is on my “must read before I die” list.
Anyway, I saw an article recently with a link to the Antiques Roadshow website, about a guy who picked up an original HP 200D audio oscillator, one of HP’s first products, for $25 at a Santa Cruz flea market – it doesn’t say when but must have been the early ‘90s. He had worked at HP and managed to get it signed by both the great men. There’s a couple of pics and a video of the show segment (in 2009) where he had it valued – at $7000 to 9000. Not a bad return, if he wanted to sell it, though it does not say whether he did. I don’t think I would have done. Although some of the screws are showing a bit of rust, you can see the legendary build quality of HP equipment in this simple oscillator. The knobs are all solid and the frequency scale and switches look as if they were custom made for it.
There’s another interesting site which has a bit of a “potted history” of HP, along with a photo and a circuit diagram of the original 200A oscillator. Bill Hewlett came up with the idea of using an incandescent light bulb in the feedback path as a variable resistance to stabilise the output amplitude of the oscillator, a technique which you can see used in almost any audio oscillator circuit you can find now.
HP’s line of engineering calculators in the 80s were also legendary. I had the good fortune to own a 45 and later a 33E programmable. In true HP fashion they did things differently, using Reverse Polish Logic (RPL) to enter and operate on numbers. But once you got used to it, you realized how powerful it was, and how easy it made some tricky calculations.
I was recently given an HP RF signal generator model 8640B. It goes up to 512 MHZ and has a built in frequency counter which can either read the generator or an external frequency. When I fired it up everything appeared to work perfectly but it had no output. I suspect someone has transmitted into it in the past. It’s in my list of things to fix on rainy days…
Another one of my favourite HP stories is about a guy who worked at Monash University in Melbourne, Australia and found a 50-year old HP counter in a dumpster in the rain. He dried it off, powered it up….and it worked! The counter is of 1963 vintage, almost entirely made with discrete transistors, and yet has a plug in that enables it to work up to 3 GHz, and BCD outputs for interface to a computer. In 1963! Nothing illustrates HP quality, reliability and innovation better than this story I think. There are plenty of pictures for those of you who (like me) get off on stuff like this (one included below). And if you are, be warned, this guy is a tinkerer and has a very distracting web site…. I did post this link in Max’s book review as a comment, so forgive me if you have seen it before.
Max’s “That was tricky:” series recently had an article about two guys who managed to get the use of the faculty’s HP logic analyser for their undergraduate project. This had a touch screen based on x-ray finger detection!
Max’s article also has a story about his first contact with HP, and some comments from people who worked at HP. It sounds like it would have been a great place to work. Bill and Dave’s style of Management by Walking Around (MBWA) is a far cry from today’s lean mean enterprises run by greedy idiots with MBAs. And HP itself is a different company now from the one that built all that great test equipment. HP now makes computers and the test equipment is now made by Agilent. Nice stuff, but “Agilent” doesn’t have the same ring as “HP” did. Ah, the good old days….. I hope some of you with good HP stories (about working there or about their equipment) will post them below.
About the Author David Ashton on David Ashton: I’m not sure what I am….. I was born in London, UK, raised and trained and worked in Rhodesia, then Zimbabwe, and I now live in Australia. (So I’m a Pom-Rhodie-Zimbo-Aussie??) Work-wise it's much the same. I have run electronics labs and managed telecoms centres, run my own comms business, and I am now working as a telecoms specialist keeping a large comms network going. I’m a jack of all trades, and yes, admit I’m master of none, but I kinda like it that way. It makes it difficult to get bored.
I had a problem once - I got a design for a sine wave generator using an 8-bit shift register that has inverted feedback - ie it fills up with 1's then fills up with 0's. You dimension the resistors off the outputs so that at each point the resistors divide the 1's and 0's to the right voltage at that point on the sine wave. Only problem was, I wanted a 10-bit shift register. So had to redimension all the resistors. I worked out a program to do it on my 33E. It involved quadratic equations but with RPL and the stack they are easy. I was sorting thru some old articles the other day and came across my original hand written notes on this. The program only just fitted into memory (think it was max 50 steps?) but it worked just fine.
Like David I have a Zimbabwean accent. My favourite story was back in 1992 I phoned someone in California to mail me some data (no email, web sites and fax wasn't really clear). I gave my name and address and finished off with "Ontario, Canada". The voice on the other side countered with
"well, that explains the accent"!
@"...dating from the mid-1050s"
Goodness - I didn't know they'd been going THAT long... ;-)
Typos aside, another good story illustrating the quality of the old HP stuff. Sorry, I'm not clear, which one did you sell, the HP or the 465? I have fond memories of the 465...the first scope I ever used...as a radio tech in the Rhodesian police. Our comms were 40 MHz AM, so you could look at the TX output directly on a sniffer port of our dummy load. Damn good scopes, Tektronix is a close second to HP in my opinion, but they only really made scopes in those days, unlike HP who made pretty much everything.
Oh, goodness, too many HP test equipment stories to tell but here is just one. I am now retired and I have a number of old'ish HP test equipment around. A couple of months ago, I pulled an HP-120B oscilloscope off the shelf where it had been languishing for 20+ years.
I had a two fold objective: get it working so I could use it to fix my Tektronix 465 o'scope and then to be able to sell it. The HP120B is a (mostly) vacuum tube beast dating from the mid-1050s. I put it on the bench and used a variac to bring it up over a 12 hour period. I rotated the controls and spritzed them with suitable cleaner. As the variac reached 90V, the old HP120 started to come to life and, after more than 20 years, it was soon working much it did '..back in the day..' After using it to find my problem, I then sold it to another electronics guy down south. Fantastic but not totally unexpected. They build them good!
Re the calculators: When I was in Jr. High, I wanted an HP-35. In High school, I wanted the 45, and when it came out, the 55. When I was a freshman in college, I actually bought a 29C from an ad in Scientific American. I really loved that calculator, but I had difficulty (several failed attempts) replacing the battery, and eventually sold it to a collector on eBay for about 50% more than I paid for it in the first place.
Today I have a 48G on my desk. Unlike the 29C, which I knew backwards and forwards, I can only use about 10% of the capabilities of this amazing machine. I just wish the build quality matched the 29C...
Anyone who has an interest in HP calculators might enjoy a trip to www.hpmuseum.org. There's even sections on slide rules and the Curta "pepper grinder".
I have several pieces of late 60's through end of 1970's HP equipment. I call them "infinitely repairable" instruments because they generally used discrete transistors, or at most complex, very basic op amps and TTL chips. I guarantee you this fact alone accounts for their longevity and reliability.
Any problem I have ever found in these instruments concerns the silver coloured electrolytic capacitors they used, which short. Sprague was the manufacturer in most cases.
And David, there is likely nothing wrong with your 8640B except a blown fuse on the generator output. A picofuse most likely, they fused the output on many instruments to protect the output stage.
I attribute my engineering degree to the HP-35. While everyone else was pushing their slide rules around, I managed to find an extra 20 minutes in the exam. I still have it and some of the books that described the algorithms to resolve complex (not imaginary) calculations.
When they released the HP35S about 3 years ago, I just had to buy one. It is much closer to the HP61 because of the programmability and key functionality. Sort of resembles the 35 as much as the new Mini car resembles the old one.
I must say though, after my recent acquisitions of HP printers and scanners I don't think the HP quality is still there. See my thoughts here
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