|
Ed Price wrote:
Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Ed wb6wsn Imagine your cell phone if it was designed to be repaired, and used only common components. It would be the size of a briefcase. Do you think cell phones would be popular if they had to be briefcase sized? What about spectrum analyzers that needed to be contained in several 6 foot high rack cabinets? Is the world better or worse now that a 100MHz oscilloscope can be made the size of a paper back book? -Chuck, WA3UQV |
Chuck Harris wrote:
Ed Price wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Ed wb6wsn Imagine your cell phone if it was designed to be repaired, and used only common components. It would be the size of a briefcase. Do you think cell phones would be popular if they had to be briefcase sized? What about spectrum analyzers that needed to be contained in several 6 foot high rack cabinets? Is the world better or worse now that a 100MHz oscilloscope can be made the size of a paper back book? -Chuck, WA3UQV Most of the chips in cell phones are off the shelf parts, and there are places that do repair cell phones. RMS Communications in Ocala, Florida rebuilds thousands of pagers and cell phones every week. I know several techs who worked there, and they were telling me about the equipment they had available at each work station. One problem with new RF and test equipment is the firmware programmed into chips isn't readily available to program replacement parts. Another problem is the short production life for some parts. If you build a product for over two years, you either do "Lifetime purchases", or redesign boards to use the next round of parts. What is real fun is a base product with up to 100 different sets of software, depending on the customers specifications. Its hard enough to keep it straight on the factory floor, let alone trying to do it in the field. -- Michael A. Terrell Central Florida |
"Bill Turner" wrote in message ... On Sat, 15 Nov 2003 19:15:09 -0600, "jakdedert" wrote: No, there is no person so named. Would you prefer that he had used the sort of expletives that those symbols generally represent? Have you never seen profanity annotated that way (think: comic strip)? I've never seen "465" included in symbolic profanity before. Remove that and the rest becomes recognizable. Didn't notice that...finger must've slipped off the shift key. The 'Sanford & Son' reference was made by the service rep, apparently referring to the gall of the OP, for wasting the rep's valuable time asking for information about equipment that he (the rep) considered to be nothing but junk (you'll recall the TV series of that name was about a junk dealer). Pretty obscure, but makes sense now. Does that wrap it up for you...or--OP--did I get that right? Got it all, thanks. Plain 'ol English beats speaking in tongues though. Actually, this was kind of fun. Maybe we should all start posting with obscure references and irregular grammar. Not. Glad to be of service. Actually I think the obscure reference was actually a paraphrased quotation of the service rep, which the OP repeated...probably should have used quote marks there to clear it up. jak -- Bill, W6WRT |
Michael A. Terrell wrote:
Most of the chips in cell phones are off the shelf parts, and there are places that do repair cell phones. RMS Communications in Ocala, Florida rebuilds thousands of pagers and cell phones every week. I know several techs who worked there, and they were telling me about the equipment they had available at each work station. Most of the parts in a tek scope are off the shelf too, but like the cell phone, there are one or two show stoppers. For the cell phone, it is the microprocessor with its combination mask and flash programming. I know a guy that repairs pagers, but you cannot convince me that it is a profitable business.... The way he moaned about the cost of my fixing his RF signal generator gives me a clue. One problem with new RF and test equipment is the firmware programmed into chips isn't readily available to program replacement parts. Another problem is the short production life for some parts. If you build a product for over two years, you either do "Lifetime purchases", or redesign boards to use the next round of parts. What is real fun is a base product with up to 100 different sets of software, depending on the customers specifications. Its hard enough to keep it straight on the factory floor, let alone trying to do it in the field. It is even worse in the space field, where by the time a part is qualified, and a satellite is made, the part is stone cold obsolete. -Chuck |
On Sun, 16 Nov 2003 23:30:40 -0800, "Ed Price"
wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Can anyone recommend a decent commercial vector network analyser and spectrum analyser that one can repair oneself if necessary and hopefully keep them up and running for ever? -- "I expect history will be kind to me, since I intend to write it." - Winston Churchill |
Chuck Harris wrote in message ...
Michael A. Terrell wrote: Most of the chips in cell phones are off the shelf parts, and there are places that do repair cell phones. RMS Communications in Ocala, Florida rebuilds thousands of pagers and cell phones every week. I know several techs who worked there, and they were telling me about the equipment they had available at each work station. Most of the parts in a tek scope are off the shelf too, but like the cell phone, there are one or two show stoppers. For the cell phone, it is the microprocessor with its combination mask and flash programming. I know a guy that repairs pagers, but you cannot convince me that it is a profitable business.... The way he moaned about the cost of my fixing his RF signal generator gives me a clue. One problem with new RF and test equipment is the firmware programmed into chips isn't readily available to program replacement parts. Another problem is the short production life for some parts. If you build a product for over two years, you either do "Lifetime purchases", or redesign boards to use the next round of parts. What is real fun is a base product with up to 100 different sets of software, depending on the customers specifications. Its hard enough to keep it straight on the factory floor, let alone trying to do it in the field. It is even worse in the space field, where by the time a part is qualified, and a satellite is made, the part is stone cold obsolete. -Chuck hmm, kind of like buying a computer ...in a few mounths it is obsolete...on the tektroix and hp stuff.......you would think that they would be feeling the heat from asia like everyone else.....just how much profit is there in a unit that sells new for $75,000.00? and why may i ask after 10 to 15 years it still sells for heavy cash.... |
"Ed Price" wrote in message news:nO_tb.9428$cX1.8536@fed1read02...
"gw" wrote in message om... Roy Lewallen wrote in message ... Thanks to Ed for the good advice. I've got an HP 140T. As far as I know, the only difference between it and the 141T is that the CRT in mine is a conventional one with long-persistence phosphor rather than a storage tube. It uses the same plug-in units as the 141T. I find it to be very usable, and don't really miss storage capability at all. I think the tube is a lot more trouble-free than a storage type unit. So I recommend that you don't turn down a 140T if you come across one -- and you might even have a better chance of getting a unit with a working display than with a 141T. Roy Lewallen, W7EL Ed Price wrote: [Lots of good advice] well it is amazing i think how some of these units retain their resale value even though the companies that made them do not service them or back them......man who was the brainiac that thought about how to implement this scam? Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Ed wb6wsn well ed what are your thoughts on a hp 8590? bueno o no bueno? |
gw wrote:
hmm, kind of like buying a computer ...in a few mounths it is obsolete...on the tektroix and hp stuff.......you would think that they would be feeling the heat from asia like everyone else.....just how much profit is there in a unit that sells new for $75,000.00? and why may i ask after 10 to 15 years it still sells for heavy cash.... When you look at the price of a $75,000 unit, consider this: First, the test equipment market is really rather small, nothing like the consumer electronics market, and second, bleeding edge technology test equipment requires some serious money to develop. Tektronix and HP have historically been positioned right in the front of the technology wave. So, a unit that sells for $75,000 may have cost $20 million to develop to where it could be manufactured. It probably only has a market life of 1000 units. Then the actual manufacture of the product costs something. A good round figure is the ratio of parts cost to sale price is 3x to 4x. Labor figures in at about equal to parts cost. -20,000,000 to develop -25,000 x 1000 units = -25,000,000 parts cost -25,000 x 1000 units = -25,000,000 labor cost 75,000 x 1000 units = +75,000,000 sales price of instrument ------------------------------------------------------------- Bottom line +$5,000,000 Take that $5 million, and subtract some for advertising, and service, and you haven't got much left. Granted these numbers are just guesses, but I have been doing small quantity manufacture for a lot of years, and these kinds of ratios come up again and again. As to why the Tektronix and HP stuff commands a high price in the used market, the reason is simple, the gear is high quality, has very high capabilities, and the price of a new replacement is also high. -Chuck |
Chuck Harris wrote:
I know a guy that repairs pagers, but you cannot convince me that it is a profitable business.... The way he moaned about the cost of my fixing his RF signal generator gives me a clue. -Chuck Believe what you want, but the place has around 100 employees, and was looking at buying the old L3-Com/Microdyne complex to expand into its 120,000+ square feet of buildings and acres of land for parking. They are bigger than Microdyne was when it closed the complex and moved to Pennsylvania. If there is no money in repairing pager and cell phones, why do they want to buy property which is priced at 1.6 million dollars? Here is the listing for the complex: http://www.foxfirerealty.com/showlis...tid=17779&id=2 -- Michael A. Terrell Central Florida |
I'm not trying to be difficult Michael. The reason I have trouble
seeing how this is a money making venture is the low price of cell phones and pagers. When a Cell phone lists for $99, how much time can a technician really spend fixing it? In the repair business, the maximum repair price you can charge a customer has to be less than 40% of the cost of new, or they will always walk away. If they walk away, and give you their phones for free, then perhaps you could make a little bit fixing it and selling it, but really, now, tracphone sells refurbished nokia 5185i's for $39. There is not much margine in that. Who pays for the time necessary for the technician to open the phone, diagnose the problem, unsolder the offending module, test the phone, reassemble, and pack? You would have to pay your technicians less than $10 per hour! -Chuck Michael A. Terrell wrote: Chuck Harris wrote: I know a guy that repairs pagers, but you cannot convince me that it is a profitable business.... The way he moaned about the cost of my fixing his RF signal generator gives me a clue. -Chuck Believe what you want, but the place has around 100 employees, and was looking at buying the old L3-Com/Microdyne complex to expand into its 120,000+ square feet of buildings and acres of land for parking. They are bigger than Microdyne was when it closed the complex and moved to Pennsylvania. If there is no money in repairing pager and cell phones, why do they want to buy property which is priced at 1.6 million dollars? Here is the listing for the complex: http://www.foxfirerealty.com/showlis...tid=17779&id=2 |
Chuck Harris wrote:
I'm not trying to be difficult Michael. The reason I have trouble seeing how this is a money making venture is the low price of cell phones and pagers. When a Cell phone lists for $99, how much time can a technician really spend fixing it? In the repair business, the maximum repair price you can charge a customer has to be less than 40% of the cost of new, or they will always walk away. If they walk away, and give you their phones for free, then perhaps you could make a little bit fixing it and selling it, but really, now, tracphone sells refurbished nokia 5185i's for $39. There is not much margine in that. Who pays for the time necessary for the technician to open the phone, diagnose the problem, unsolder the offending module, test the phone, reassemble, and pack? You would have to pay your technicians less than $10 per hour! -Chuck It is run like a factory, not one up repairs. That makes a huge difference. The techs don't disassemble the units. the production people do a quick test, clean up the cases, and send the boards to be repaired. A lot of repairs are new crystals, or reprogramming the synthesizer, or replacing a bad LCD display which is done before a tech sees it. Also, they do large runs of the same unit, then do a different model. Also, some only need a few pieces of the case replaced, and the password cracked so it can be reprogrammed in the field. They have service contracts where someone ships a 1000 pagers or 100 cell phones and they repair what they can in a fixed time. They either return the bad units, or replace them with their own stock of repaired units, depending on the contract. they also repair a lot of older models and sell them overseas. -- Michael A. Terrell Central Florida |
"Chuck Harris" wrote in message ... Ed Price wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Ed wb6wsn Imagine your cell phone if it was designed to be repaired, and used only common components. It would be the size of a briefcase. Do you think cell phones would be popular if they had to be briefcase sized? What about spectrum analyzers that needed to be contained in several 6 foot high rack cabinets? Is the world better or worse now that a 100MHz oscilloscope can be made the size of a paper back book? -Chuck, WA3UQV We were talking about repair and service equipment, not consumer items. A consumer item is expected to have a short life-cycle, and repairability is often not a concern. I never saw "multi-six-foot-rack analyzers"; the oldest & biggest I can recall were Singer FIM analyzers, which were about 24" wide by 30" tall and deep, and took four guys to move them (and the plug-in RF heads were a one-man lift!). OTOH, everything inside was reachable and easily repairable. If that 100 MHz scope can be built to have a reasonable cost to lifetime ratio, then it could be considered a consumer item, and a non-repairable investment. But to me, if I have to pay $10k or more for a piece of test equipment, it had better last quite a few years and allow me to do re-calibration and even moderately severe repair. Ed |
"gw" wrote in message om... "Ed Price" wrote in message news:nO_tb.9428$cX1.8536@fed1read02... "gw" wrote in message om... Roy Lewallen wrote in message ... Thanks to Ed for the good advice. I've got an HP 140T. As far as I know, the only difference between it and the 141T is that the CRT in mine is a conventional one with long-persistence phosphor rather than a storage tube. It uses the same plug-in units as the 141T. I find it to be very usable, and don't really miss storage capability at all. I think the tube is a lot more trouble-free than a storage type unit. So I recommend that you don't turn down a 140T if you come across one -- and you might even have a better chance of getting a unit with a working display than with a 141T. Roy Lewallen, W7EL Ed Price wrote: [Lots of good advice] well it is amazing i think how some of these units retain their resale value even though the companies that made them do not service them or back them......man who was the brainiac that thought about how to implement this scam? Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Ed wb6wsn well ed what are your thoughts on a hp 8590? bueno o no bueno? A very good analyzer series, but generally still priced out of the hobbyist market. Reasonably portable, and ruggedly built. Performance is generally a bit lower than the 856x series, but still very respectable. Much more useful than a hobbyist-affordable 141 analyzer, and easier and more versatile than an older 8569 analyzer. Unless your needs are exotic, the 859x series will be a good industrial choice. Ed wb6wsn |
"Paul Burridge" wrote in message ... On Sun, 16 Nov 2003 23:30:40 -0800, "Ed Price" wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Can anyone recommend a decent commercial vector network analyser and spectrum analyser that one can repair oneself if necessary and hopefully keep them up and running for ever? -- "I expect history will be kind to me, since I intend to write it." - Winston Churchill For the spectrum analyzer part, the best a hobbyist can usually afford is an HP-141, with a few plug-ins (IIRC, they offered a total of 6, collect the whole set!). And you will need the HP manuals (some of which are available free from the US Army LOGSA site). And you will need some other basic and decent lab gear (scope, counter, DMM, sig gens) to do the job right. Sorry, but I can't comment on any Network Analyzers. Ed wb6wsn |
Ed Price wrote:
We were talking about repair and service equipment, not consumer items. A consumer item is expected to have a short life-cycle, and repairability is often not a concern. If you cannot see the relationship, then you need to stretch a bit. Everything in electronics, test equipment especially has grown in complexity and performance, as it has been reduced in size. Some of the reductions are there to make it possible to fit more test equipment in a given space, and some are there because of necessities of the new technology (eg. microwave speeds and low power consumption are better done with tiny sized components.) I never saw "multi-six-foot-rack analyzers"; the oldest & biggest I can recall were Singer FIM analyzers, which were about 24" wide by 30" tall and deep, and took four guys to move them (and the plug-in RF heads were a one-man lift!). OTOH, everything inside was reachable and easily repairable. Was your life, as a technician that is, made better or worse when that same 4 man lift SA was reduced to one that you could carry yourself with one hand, while carrying your 1G scope with the other? How about performance? Did it help you to have the bandwidth limit of your old 4 man lift SA rise from 1GHz to 300GHz? How about your 30MHz scope that is now 1GHz? Did you notice that the prices went DOWN? How about the heat generation? Have you ever worked in a lab that had no effective air conditioning, and also had a herd of Tek 500 series scopes whirring away?.. in the middle of the summer? I have, and I am quite happy not to do it anymore. We saw temperatures as high as 120F at times. No windows, one door, lots of fans. Turn off the equipment, and the AC did quite fine. And finally, how about the space savings? Does it help you or hurt you to recapture that floor space the old SA, and scope, and signal generator used? Tiny little custom component ridden hard to service test equipment made it possible to move away from that kind of scene. If that 100 MHz scope can be built to have a reasonable cost to lifetime ratio, then it could be considered a consumer item, and a non-repairable investment. But to me, if I have to pay $10k or more for a piece of test equipment, it had better last quite a few years and allow me to do re-calibration and even moderately severe repair. All of the $10K+ stuff I have seen from HP or Tek would easily meet your needs. Calibration? You cannot be serious. Most of this stuff is so finely calibrated that it would be beyond the capabilities of anything but an expert calibration lab to accomplish the task. Just having the standards necessary takes a whole lab... and a whole budget. I know this because I tried to set up a NIST traceable cal lab for my business, and eventually concluded that for me to do that, cal would have to become my exclusive business. I still have all the standards and equipment, but no time to put them to use... No money to keep them in cert with NIST. It is FAR cheaper to send the stuff out and get it calibrated. The "consumer grade" goodies in the test equipment market don't really need more than a simple calibration checking. I cannot tell you the last time my little Fluke DVM needed recalibration... Because it is 15 years old, and it has NEVER needed recalibration. Has something to do with the little fidgety custom components that are inside it. Same goes for my Tek 2465 scope. -Chuck |
"Ed Price" wrote in message news:WFoub.16633$cX1.14167@fed1read02...
"gw" wrote in message om... "Ed Price" wrote in message news:nO_tb.9428$cX1.8536@fed1read02... "gw" wrote in message om... Roy Lewallen wrote in message ... Thanks to Ed for the good advice. I've got an HP 140T. As far as I know, the only difference between it and the 141T is that the CRT in mine is a conventional one with long-persistence phosphor rather than a storage tube. It uses the same plug-in units as the 141T. I find it to be very usable, and don't really miss storage capability at all. I think the tube is a lot more trouble-free than a storage type unit. So I recommend that you don't turn down a 140T if you come across one -- and you might even have a better chance of getting a unit with a working display than with a 141T. Roy Lewallen, W7EL Ed Price wrote: [Lots of good advice] well it is amazing i think how some of these units retain their resale value even though the companies that made them do not service them or back them......man who was the brainiac that thought about how to implement this scam? Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Ed wb6wsn well ed what are your thoughts on a hp 8590? bueno o no bueno? A very good analyzer series, but generally still priced out of the hobbyist market. Reasonably portable, and ruggedly built. Performance is generally a bit lower than the 856x series, but still very respectable. Much more useful than a hobbyist-affordable 141 analyzer, and easier and more versatile than an older 8569 analyzer. Unless your needs are exotic, the 859x series will be a good industrial choice. Ed wb6wsn well some guy who has a company that i guess is in the business of buying refurbing and selling electronic equipment has one on ebay for about $2100.00. should i cross my fingers and go for it? he takes credit cards. he says it is working very well, it looks real good according the pics he has of it and it has a fresh calibration. |
Dave Hall wrote:
Ed Price wrote: "Paul Burridge" wrote in message . .. On Sun, 16 Nov 2003 23:30:40 -0800, "Ed Price" wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Can anyone recommend a decent commercial vector network analyser and spectrum analyser that one can repair oneself if necessary and hopefully keep them up and running for ever? -- "I expect history will be kind to me, since I intend to write it." - Winston Churchill For the spectrum analyzer part, the best a hobbyist can usually afford is an HP-141, with a few plug-ins (IIRC, they offered a total of 6, collect the whole set!). And you will need the HP manuals (some of which are available free from the US Army LOGSA site). And you will need some other basic and decent lab gear (scope, counter, DMM, sig gens) to do the job right. Sorry, but I can't comment on any Network Analyzers. This might be a bit off the exact topic but I have a friend who has a HP 141 and the horozontal display scan has shrunk and folded over on top of itself. Having never worked on test equipment, I could only offer generic possibilities, (Voltages, deflection transistors, caps?). Is there are common part failure that can cause this to the best of your knowlege? Thanks, Dave Look at the 2W resistors and the output transistors in the output deflection stages for a start. Andrew |
"gw" wrote in message om... "Ed Price" wrote in message news:WFoub.16633$cX1.14167@fed1read02... "gw" wrote in message SNIP well ed what are your thoughts on a hp 8590? bueno o no bueno? A very good analyzer series, but generally still priced out of the hobbyist market. Reasonably portable, and ruggedly built. Performance is generally a bit lower than the 856x series, but still very respectable. Much more useful than a hobbyist-affordable 141 analyzer, and easier and more versatile than an older 8569 analyzer. Unless your needs are exotic, the 859x series will be a good industrial choice. Ed wb6wsn well some guy who has a company that i guess is in the business of buying refurbing and selling electronic equipment has one on ebay for about $2100.00. should i cross my fingers and go for it? he takes credit cards. he says it is working very well, it looks real good according the pics he has of it and it has a fresh calibration. I can't assess risk for you, but $2k sounds like a fair price for a good condition 8590. Ed wb6wsn |
"Chuck Harris" wrote in message ... Ed Price wrote: We were talking about repair and service equipment, not consumer items. A consumer item is expected to have a short life-cycle, and repairability is often not a concern. If you cannot see the relationship, then you need to stretch a bit. Everything in electronics, test equipment especially has grown in complexity and performance, as it has been reduced in size. SNIP The "consumer grade" goodies in the test equipment market don't really need more than a simple calibration checking. I cannot tell you the last time my little Fluke DVM needed recalibration... Because it is 15 years old, and it has NEVER needed recalibration. Has something to do with the little fidgety custom components that are inside it. Same goes for my Tek 2465 scope. -Chuck You keep mixing the needs of an enterprise with those of a hobbyist. True, many of the people on the groups of this thread are electronics professionals who also have an electronics hobby interest. My comments have all been aimed toward the hobbyist. If you have a 2465B scope (one of the finest analog scopes I have ever used), then you are one extremely wealthy hobbyist, and the economic constraints most everyone else lives by must not apply to you. A hobbyist doesn't send anything "out" for calibration; they rely on the ability to cross-check their various gear with everything else in their collection. Sometimes, they might be able to compare one of their items with a professionally calibrated and traceable item. Or maybe they buy a new DMM, that's rated for 0.1% (whatever) and then proceed to adjust the rest of their stuff into agreement with that one new item. My point is that old equipment is repairable. Your point is that newer equipment is chock full of value, more reliable, and is easier to lift. There's no contradiction between these positions. BTW, your DVM always "needs" calibration, even if it is still within tolerance every time it's checked. Nice to know that it's stable, but nothing lives forever. As for "fidgety little components", should you ever apply a few watts of RF to the input of your 2465, you'll find it very difficult to repair by yourself, and the Tek bill for the job could very well approach the replacement cost. If the same had happened to a 465, then you would just be replacing a few small, precision resistors. Ed wb6wsn |
Ed Price wrote:
"Paul Burridge" wrote in message ... On Sun, 16 Nov 2003 23:30:40 -0800, "Ed Price" wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Can anyone recommend a decent commercial vector network analyser and spectrum analyser that one can repair oneself if necessary and hopefully keep them up and running for ever? -- "I expect history will be kind to me, since I intend to write it." - Winston Churchill For the spectrum analyzer part, the best a hobbyist can usually afford is an HP-141, with a few plug-ins (IIRC, they offered a total of 6, collect the whole set!). And you will need the HP manuals (some of which are available free from the US Army LOGSA site). And you will need some other basic and decent lab gear (scope, counter, DMM, sig gens) to do the job right. Sorry, but I can't comment on any Network Analyzers. This might be a bit off the exact topic but I have a friend who has a HP 141 and the horozontal display scan has shrunk and folded over on top of itself. Having never worked on test equipment, I could only offer generic possibilities, (Voltages, deflection transistors, caps?). Is there are common part failure that can cause this to the best of your knowlege? Thanks, Dave |
Hi Ed,
What I am NOT doing is trying to mix the needs of the hobbiest with the realities of companies that build for professionals. You are lamenting the fact that the newer gear is hard for hobbiests to maintain. That argument will go soft on HP or Tektronix, or any of several dozen other equipment manufacturers that make equipment for professionals. The simple fact that your abilities at repair stop at thru hole, technology, doesn't mean that devices that use hybrids, and surface mount technology are not repairable. The hybrid front end on the 2465 is quite repairable, but requires a little optical help, just like watch repair, an 1800's tecnology. From what I have heard, most of the parts in the hybrid are standard off the shelf surface mount faire... I have no direct knowledge of whether this is actually true. I did find it to be the case with the output hybrid in HP's 86222A sweeper plugin. There would be no more point in taking your busted 2465 to Tek for repair than there would be for your 465, they won't work on either. Checked is not the same as calibration. The case doesn't even get opened for "checked". And to your assertion that I am a rich hobbiest, I am not an electronics hobbiest at all! I am a self-employed electrical engineer, and I use the test equipment I own to earn a living. Sadly, for me electronics died as a hobby when I started getting paid to do it. The happy part is I truly enjoy my work! -Chuck, WA3UQV (I will admit that VERY obsolete electronics retains a hobby sort of thrill for me... Old tube gear, and old minicomputers.) Ed Price wrote: You keep mixing the needs of an enterprise with those of a hobbyist. True, many of the people on the groups of this thread are electronics professionals who also have an electronics hobby interest. My comments have all been aimed toward the hobbyist. If you have a 2465B scope (one of the finest analog scopes I have ever used), then you are one extremely wealthy hobbyist, and the economic constraints most everyone else lives by must not apply to you. A hobbyist doesn't send anything "out" for calibration; they rely on the ability to cross-check their various gear with everything else in their collection. Sometimes, they might be able to compare one of their items with a professionally calibrated and traceable item. Or maybe they buy a new DMM, that's rated for 0.1% (whatever) and then proceed to adjust the rest of their stuff into agreement with that one new item. My point is that old equipment is repairable. Your point is that newer equipment is chock full of value, more reliable, and is easier to lift. There's no contradiction between these positions. BTW, your DVM always "needs" calibration, even if it is still within tolerance every time it's checked. Nice to know that it's stable, but nothing lives forever. As for "fidgety little components", should you ever apply a few watts of RF to the input of your 2465, you'll find it very difficult to repair by yourself, and the Tek bill for the job could very well approach the replacement cost. If the same had happened to a 465, then you would just be replacing a few small, precision resistors. Ed wb6wsn |
Andrew Tweddle wrote:
Dave Hall wrote: Ed Price wrote: "Paul Burridge" wrote in message . .. On Sun, 16 Nov 2003 23:30:40 -0800, "Ed Price" wrote: Designing and building a product to provide many years of use, and then capable of being repaired without access to unique components and/or exotic service equipment, is a concept so rare as to be thought a scam. Can anyone recommend a decent commercial vector network analyser and spectrum analyser that one can repair oneself if necessary and hopefully keep them up and running for ever? -- "I expect history will be kind to me, since I intend to write it." - Winston Churchill For the spectrum analyzer part, the best a hobbyist can usually afford is an HP-141, with a few plug-ins (IIRC, they offered a total of 6, collect the whole set!). And you will need the HP manuals (some of which are available free from the US Army LOGSA site). And you will need some other basic and decent lab gear (scope, counter, DMM, sig gens) to do the job right. Sorry, but I can't comment on any Network Analyzers. This might be a bit off the exact topic but I have a friend who has a HP 141 and the horozontal display scan has shrunk and folded over on top of itself. Having never worked on test equipment, I could only offer generic possibilities, (Voltages, deflection transistors, caps?). Is there are common part failure that can cause this to the best of your knowlege? Thanks, Dave Look at the 2W resistors and the output transistors in the output deflection stages for a start. Andrew Thank you! Dave |
Chuck Harris wrote in message ...
Hi Ed, What I am NOT doing is trying to mix the needs of the hobbiest with the realities of companies that build for professionals. You are lamenting the fact that the newer gear is hard for hobbiests to maintain. That argument will go soft on HP or Tektronix, or any of several dozen other equipment manufacturers that make equipment for professionals. The simple fact that your abilities at repair stop at thru hole, technology, doesn't mean that devices that use hybrids, and surface mount technology are not repairable. The hybrid front end on the 2465 is quite repairable, but requires a little optical help, just like watch repair, an 1800's tecnology. From what I have heard, most of the parts in the hybrid are standard off the shelf surface mount faire... I have no direct knowledge of whether this is actually true. I did find it to be the case with the output hybrid in HP's 86222A sweeper plugin. There would be no more point in taking your busted 2465 to Tek for repair than there would be for your 465, they won't work on either. Checked is not the same as calibration. The case doesn't even get opened for "checked". And to your assertion that I am a rich hobbiest, I am not an electronics hobbiest at all! I am a self-employed electrical engineer, and I use the test equipment I own to earn a living. Sadly, for me electronics died as a hobby when I started getting paid to do it. The happy part is I truly enjoy my work! -Chuck, WA3UQV (I will admit that VERY obsolete electronics retains a hobby sort of thrill for me... Old tube gear, and old minicomputers.) Ed Price wrote: You keep mixing the needs of an enterprise with those of a hobbyist. True, many of the people on the groups of this thread are electronics professionals who also have an electronics hobby interest. My comments have all been aimed toward the hobbyist. If you have a 2465B scope (one of the finest analog scopes I have ever used), then you are one extremely wealthy hobbyist, and the economic constraints most everyone else lives by must not apply to you. A hobbyist doesn't send anything "out" for calibration; they rely on the ability to cross-check their various gear with everything else in their collection. Sometimes, they might be able to compare one of their items with a professionally calibrated and traceable item. Or maybe they buy a new DMM, that's rated for 0.1% (whatever) and then proceed to adjust the rest of their stuff into agreement with that one new item. My point is that old equipment is repairable. Your point is that newer equipment is chock full of value, more reliable, and is easier to lift. There's no contradiction between these positions. BTW, your DVM always "needs" calibration, even if it is still within tolerance every time it's checked. Nice to know that it's stable, but nothing lives forever. As for "fidgety little components", should you ever apply a few watts of RF to the input of your 2465, you'll find it very difficult to repair by yourself, and the Tek bill for the job could very well approach the replacement cost. If the same had happened to a 465, then you would just be replacing a few small, precision resistors. Ed wb6wsn does that mean you still have some use for trash 80's? |
gw wrote:
Chuck Harris wrote in message ... -Chuck, WA3UQV does that mean you still have some use for trash 80's? Way too new! I'm more interested in old PDP 8, stuff, 8/I's in particular. Things that have absolutely no practical use ;-) -Chuck |
Chuck Harris wrote:
gw wrote: Chuck Harris wrote in message ... -Chuck, WA3UQV does that mean you still have some use for trash 80's? Way too new! I'm more interested in old PDP 8, stuff, 8/I's in particular. Things that have absolutely no practical use ;-) -Chuck So Chuck your looking for a Trash 8/E rather than a Trash 80. BTW my Trash 80 was a real Trash 80. R.S said it was uneconomical to repair, read out of warrenty replaced a bad ttl chip and away it went. A friend reworked the firmware to get rid of the infamous keyboard and cassette problems(we rescued 8 of them from that dumpster). Bill |
Bill Higdon wrote:
Chuck Harris wrote: So Chuck your looking for a Trash 8/E rather than a Trash 80. BTW my Trash 80 was a real Trash 80. R.S said it was uneconomical to repair, read out of warrenty replaced a bad ttl chip and away it went. A friend reworked the firmware to get rid of the infamous keyboard and cassette problems(we rescued 8 of them from that dumpster). Bill Snort! That's a good one! I spent too much time using the original TRS-80 to ever really want one. In one of my first consulting jobs I wrote a bunch of drivers for a customer's Z80 controlled instrument using the customer's TRS-80 as the development system. It worked just fine, I guess... it got the job done, but I never did like it all that much. I kind of liked the TRS80 IV, I think it was, that came out much later. -Chuck |
FYI: I still use the Color Computer to do laser light shows.
Steve, k,9,d,c,i "Chuck Harris" wrote in message ... gw wrote: Chuck Harris wrote in message ... -Chuck, WA3UQV does that mean you still have some use for trash 80's? Way too new! I'm more interested in old PDP 8, stuff, 8/I's in particular. Things that have absolutely no practical use ;-) -Chuck |
Steve Nosko wrote:
FYI: I still use the Color Computer to do laser light shows. Steve, k,9,d,c,i Good for you! I really felt stupid seeing mine in the trash can only a year or two after having paid $300 for it. Shoulda kept it? Nah. Still have that little pocket version with 4k RAM, though. It'll come in handy someday :-) -Bill M |
Chuck Harris wrote in message ...
gw wrote: Chuck Harris wrote in message ... -Chuck, WA3UQV does that mean you still have some use for trash 80's? Way too new! I'm more interested in old PDP 8, stuff, 8/I's in particular. Things that have absolutely no practical use ;-) -Chuck perhaps one of you guys can tell me this. when you see a unit on ebay and it says fresh calibration, what exactly does this mean to me as the buyer? does this mean it will probably be operating ok for a few years or is this something that has to be done yearly? for the home shop hobbyist ? thanks. |
"gw" wrote in message om... Chuck Harris wrote in message ... SNIP does that mean you still have some use for trash 80's? Sorry, I never had much use for TRS-80's. But I do have a Commodore PET; a very original one (with the black tape deck). It has an IEEE-488 port, and a Basic that can control any IEEE-488 instrument. And, considering that it has a built-in monochrome monitor, it qualifies as a genuine boat-anchor, since it glows in the dark. g Ed |
"gw" wrote in message m... Chuck Harris wrote in message ... gw wrote: Chuck Harris wrote in message ... -Chuck, WA3UQV does that mean you still have some use for trash 80's? Way too new! I'm more interested in old PDP 8, stuff, 8/I's in particular. Things that have absolutely no practical use ;-) -Chuck perhaps one of you guys can tell me this. when you see a unit on ebay and it says fresh calibration, what exactly does this mean to me as the buyer? does this mean it will probably be operating ok for a few years or is this something that has to be done yearly? for the home shop hobbyist ? thanks. A commercial calibration implies no warranty of future reliability. It just means that the unit was inspected, by a lab with traceable standards (to NIST), and that equipment parameters were found to be within the specified tolerances (or some adjustments we made to allow for proper performance). Every equipment should be on a periodic schedule of calibration, possibly 6 months or 12 months. The interval is determined by the original manufacturer's declaration, or from the class of equipment (is it a resistor or a function generator or an oscilloscope), or from the accumulated record of a device's calibration history. (A Metrology professional can make a case for shorter or longer intervals, based on a review of the calibration history.) The calibration is valid as of that date only, although it's reasonable to expect that the calibration will be valid for some time to come (unless the shipper dropped it as it went out the cal lab's door!). All that said, a traceable calibration is an indication that the equipment has been treated in a professional manner, and I would view that as a definite plus when considering a purchase. Ed WB6WSN |
"Chuck Harris" wrote in message ... Hi Ed, What I am NOT doing is trying to mix the needs of the hobbiest with the realities of companies that build for professionals. You are lamenting the fact that the newer gear is hard for hobbiests to maintain. That argument will go soft on HP or Tektronix, or any of several dozen other equipment manufacturers that make equipment for professionals. That's my opinion. Do I care what Agilent or Tektronix thinks? Gee, do they care what I think? And why are YOU worried about their feelings? Sounds like your nose if pretty far up somebody's butt! The simple fact that your abilities at repair stop at thru hole, technology, doesn't mean that devices that use hybrids, and surface mount technology are not repairable. By the average hobbyist? I don't think so!!!!!!!!!!! The hybrid front end on the 2465 is quite repairable, but requires a little optical help, just like watch repair, an 1800's tecnology. Sorry, I don't do watches. A "little optical help" isn't a magnifying lens in a fluorescent work light. SM work calls for something like a B&L stereo viewer, and that's as expensive as a very decent oscilloscope. BTW, turn on your spell checker, a 1980's technology. From what I have heard, most of the parts in the hybrid are standard off the shelf surface mount faire... I have no direct knowledge of whether this is actually true. Well, don't let lack of direct knowledge slow down your opinions. SNIP And to your assertion that I am a rich hobbiest, I am not an electronics hobbiest at all! I am a self-employed electrical engineer, and I use the test equipment I own to earn a living. Sadly, for me electronics died as a hobby when I started getting paid to do it. The happy part is I truly enjoy my work! I wish you enjoyed reading the thread as well. I said you were either a professional or a very rich hobbyist (as you had declared ownership of some nice gear). OK, you are a professional. Do you hear me now? YOU ARE A PROFESSIONAL! -Chuck, WA3UQV (I will admit that VERY obsolete electronics retains a hobby sort of thrill for me... Old tube gear, and old minicomputers.) Well, that's a good sign, as we have been yakking about this in the boatanchors (and more) group. This is a hangout for hobbyists and very frugal professionals. Ed WB6WSN |
Fresh calibration, should mean that it was fully tested out,
cleaned and calibrated by a technician who knew what he was doing.... What it actually means is anybodies guess. It could be actually calibrated, it could be that the guy bought it surplus, turned it on, and it lit up. The words "fresh calibration" without an express warranty are worthless. Most anything Tektronix or HP made will stay in calibration to close enough for hobbiest use for years. A real bonifide business won't be comfortable using test equipment that is out of calibration for anything very important. It is their assurance that all of the functions should be working properly. -Chuck, WA3UQV gw wrote: perhaps one of you guys can tell me this. when you see a unit on ebay and it says fresh calibration, what exactly does this mean to me as the buyer? does this mean it will probably be operating ok for a few years or is this something that has to be done yearly? for the home shop hobbyist ? thanks. |
Ed Price wrote:
That's my opinion. Do I care what Agilent or Tektronix thinks? Gee, do they care what I think? And why are YOU worried about their feelings? Sounds like your nose if pretty far up somebody's butt! You should care. Unless you suddenly start building your own test equipment, you are going to be "stuck" with using equipment geared toward professionals, and manufactured by companies like HP(Agilent) or tektronix. OBTW, can you think of a less vulgar way of expressing your opinions? I have no financial interest in any test equipment manufacturer. They don't give me special favors, or punishments for stating my opinions. The simple fact that your abilities at repair stop at thru hole, technology, doesn't mean that devices that use hybrids, and surface mount technology are not repairable. By the average hobbyist? I don't think so!!!!!!!!!!! The "average hobbyist" once made complete radios from hunks of rock, metal and wood. A pretty extreme feat for the time. Now if it requires a little study, or the acquisition of some special skill, or tools, it is deemed impossible. The hybrid front end on the 2465 is quite repairable, but requires a little optical help, just like watch repair, an 1800's tecnology. Sorry, I don't do watches. A "little optical help" isn't a magnifying lens in a fluorescent work light. SM work calls for something like a B&L stereo viewer, and that's as expensive as a very decent oscilloscope. BTW, turn on your spell checker, a 1980's technology. At least when I post, my spelling is the result of my own efforts. Yours, apparently, comes from the efforts of a machine. I don't think it hurt your eyes all that much to stumble over one of my very few typo's. When you type at over 100WPM, a few will sneak in now and then. The parts in these hybrids are very large compared with mechanical watch parts. A cheapy stereo dissection microscope works very nicely... easily had for $250 new, or $100 on ebay. Back in the days of yore, adjusted to today's dollar, a soldering gun cost as much. From what I have heard, most of the parts in the hybrid are standard off the shelf surface mount faire... I have no direct knowledge of whether this is actually true. Well, don't let lack of direct knowledge slow down your opinions. You have some direct knowledge that says differently? I know that there will be some parts that are special, but I doubt all are. I have several friends that do a good business repairing these "special" hybrids, they aren't great big companies, just individual hams that saw a market. I haven't needed to go inside the hybrids on my 2465, mostly because I don't put my scope into positions where it is likely it will get zapped. And to your assertion that I am a rich hobbiest, I am not an electronics hobbiest at all! I am a self-employed electrical engineer, and I use the test equipment I own to earn a living. Sadly, for me electronics died as a hobby when I started getting paid to do it. The happy part is I truly enjoy my work! I wish you enjoyed reading the thread as well. I said you were either a professional or a very rich hobbyist (as you had declared ownership of some nice gear). OK, you are a professional. Do you hear me now? YOU ARE A PROFESSIONAL! REALLY? ------ your exact words------------ ..............................If you have a 2465B scope (one of the finest analog scopes I have ever used), then you are one extremely wealthy hobbyist, and the economic constraints most everyone else lives by must not apply to you. ------ your exact words ----------- Stop trying to bend the record to make me look bad, and you look good. (I will admit that VERY obsolete electronics retains a hobby sort of thrill for me... Old tube gear, and old minicomputers.) Well, that's a good sign, as we have been yakking about this in the boatanchors (and more) group. This is a hangout for hobbyists and very frugal professionals. It is a hangout for people with an interest in boatanchors, nothing more, nothing less. -Chuck, WA3UQV |
"Ed Price" wrote in message news:ZX%ub.18357$cX1.8301@fed1read02...
"gw" wrote in message om... Chuck Harris wrote in message ... SNIP does that mean you still have some use for trash 80's? Sorry, I never had much use for TRS-80's. But I do have a Commodore PET; a very original one (with the black tape deck). It has an IEEE-488 port, and a Basic that can control any IEEE-488 instrument. And, considering that it has a built-in monochrome monitor, it qualifies as a genuine boat-anchor, since it glows in the dark. g Ed damn ....commodores.....i almost forgot about them......do you remember the compaq 'portable' that about broke your back when you carried it? |
By the average hobbyist? I don't think so!!!!!!!!!!! I work on SMD all the time. All that's needed is a 40W temperature controlled iron, a roll of good solder braid, and 63/37 solder with internal no-clean flux. I go down as far as 0402 components, which look like sand, and have replaced 100 pin QFP chips without problem. BGAs are where the hobbyist becomes incapable of working on them. (Ball Grid Arrays) |
" damn ....commodores.....i almost forgot about them......do you remember the compaq 'portable' that about broke your back when you carried it? Yes, and I came within one day of throwing one down some stairs to put it out of service so I could get a laptop at work. |
"Ed Price" wrote in message news:tPmtb.4837$cX1.463@fed1read02...
"John Miles" wrote in message ... In article , says... johnm wrote in message ... what is a good spectrum analyzer to have for a home shop in your opinion, and also what is a good scope to have and do you have to break the bank on this stuff? thanks. SNIP how about a 8569b ? some guy has one on ebay now for about $3,000.00......i might pull the trigger on that one.....I would be using it for hf work. I was considering a 141t from tucker . it cost more but at least you know it works. i was going to get the 8552b and 8553b plugins with it. then you have to round up the connecting cables and manuals for them. comments? oh by the way i have read good things about the hp 8569b's. if they work. My guess is that the 8569b would be a very passable unit. Its specs seem competitive with an optioned-out Tek 492 in most respects, except that it only goes down to 10 MHz (perhaps there's an underrange capability that lets it see lower frequencies?) That might be a concern if you're going to be using it mostly for HF work. SNIP The 141Ts at Tucker seem like a pretty good deal. I believe they all come with new CRTs. I personally like to buy broken models on eBay and fix them up. It's cheaper, you get really familiar with the gear inside and out, and you always have spare parts on hand. But that strategy isn't for everybody. -- jm As I have HP-141's, an HP-8569, an 8566B and an 8562A, let me drop a few comments here. The 141's are the best deal for a hobbyist. You can acquire the slightly better 8552B IF section, and then get only the RF plug-in that suits your needs (an 8556, with it's built-in tracking generator, for a few Hz to 300 kHz, or an 8555, for 10 MHz through umpteen GHz, assuming you also get the external mixers). Unfortunately, by the time a hobbyist gets one of these, it has been abused and neglected by its last commercial owner. CRT burns are common, and the flood-gun analog memory may be very quirky. For an advanced hobbyist, either get an associated Polaroid scope camera, or build your own camera hood. You can capture a lot of transient things that way, and you can scan the pixs to input into your computer. Also, HP made a line of oscilloscope plug-ins that fit the 141 mainframe, so you can use the 141 as a multi-channel analog memory oscilloscope too. 141's are a pain in two ways; first, you have to externally store extra plug-ins, and secondly, the hard side handles make carrying one a painful experience beyond about 50 feet. Also, you tend to injure your fingertips sliding those bulky plug-ins in and out past the big metal front handles. The 141 may also be the last of the hobbyist repairable analyzers; newer analyzers use proprietary chips and are built too dense to let you get fingers and probes into them. The 8562A is old (1987) but a superb analyzer, 1 kHz to 18 GHz, all digital and synthesized. This will do everything you want, except drive a parallel or RS-232 printer directly. If you're smart enough to talk to it by IEEE-488, then you can do everything through the computer. Other 856x series units have lesser capabilities, but are still great analyzers, and just might be priced low enough for a very serious hobbyist. Also, the HP-859x series are very good, although some have odd frequency, memory and IO capabilities. All 856x & 859x series units are one-man portables, until your knuckles turn white and numb. The 8569 is, in my opinion, a transitional beast between the analog and digital worlds. It's not as stable and simple as the 8562A, although it's a leap above the 141. Since it's wide, it's also awkward to carry using it's handle. I'm not much of a fan of the 8569. The 8566B is HP's top-of-the-line analyzer. They threw down the benchmark for everyone else to try to meet. Mine is customized a bit, covering 20 Hz to 22 GHz, and with an external tracking pre-selector, optional detectors, programmable attenuators, RF path switching and low-noise pre-amps. My company has a number of somewhat more plain-vanilla 8566B's and 8566A's. There isn't anything I need to do that these units fall short of (uhh, with the help of some external IEEE-488 linked computers). OTOH, these are now obsolete, non-supported by Agilent, and need two guys to carry one. Mine is in a 60" tall dedicated rack. Typical used price is around $20k. Most companies will be better served with one of Agilent's newer EPA or SPA analyzers. Anritsu and Rohde & Schwartz are also making fine analyzers. IIRC, Leader makes an analyzer that a hobbyist may aspire to affording. I would say that a 141 is still the best hobbyist choice. A company needs to be sure that they get a usable item for their money, so buying on eBay is a gamble. A company should buy from some place like Tucker, where they get a warranty backed by a reputable source. Yeah, it initially costs more. But it's a lot safer than having to try to repair an analyzer when you need that analyzer to do the real work of your company. A hobbyist can afford to spend 50 to 100 hours to get something going; in a business environment, where the clock is always ticking, that's unacceptable. Ed wb6wsn ed ...what is a tracking generator and how is it a advantage for a home hobbyist to have one or is it really necessary? also what do you thing about 8565a's also what is the determining factor for pricing on these various units on ebay? does it have anything to do with the options on each unit? sometimes there would appear to be some flucuations on the prices on either the same type unit or a similar unit. |
A tracking generator is a sweep generator calibrated to track
to the center frequency of a spectrum analyzer as it sweeps. Got it? It is used to display the bandpass characteristics of a network using a spectrum analyzer. -Chuck gw wrote: "Ed Price" wrote in message news:tPmtb.4837$cX1.463@fed1read02... "John Miles" wrote in message ... In article , says... johnm wrote in message ... what is a good spectrum analyzer to have for a home shop in your opinion, and also what is a good scope to have and do you have to break the bank on this stuff? thanks. SNIP how about a 8569b ? some guy has one on ebay now for about $3,000.00......i might pull the trigger on that one.....I would be using it for hf work. I was considering a 141t from tucker . it cost more but at least you know it works. i was going to get the 8552b and 8553b plugins with it. then you have to round up the connecting cables and manuals for them. comments? oh by the way i have read good things about the hp 8569b's. if they work. My guess is that the 8569b would be a very passable unit. Its specs seem competitive with an optioned-out Tek 492 in most respects, except that it only goes down to 10 MHz (perhaps there's an underrange capability that lets it see lower frequencies?) That might be a concern if you're going to be using it mostly for HF work. SNIP The 141Ts at Tucker seem like a pretty good deal. I believe they all come with new CRTs. I personally like to buy broken models on eBay and fix them up. It's cheaper, you get really familiar with the gear inside and out, and you always have spare parts on hand. But that strategy isn't for everybody. -- jm As I have HP-141's, an HP-8569, an 8566B and an 8562A, let me drop a few comments here. The 141's are the best deal for a hobbyist. You can acquire the slightly better 8552B IF section, and then get only the RF plug-in that suits your needs (an 8556, with it's built-in tracking generator, for a few Hz to 300 kHz, or an 8555, for 10 MHz through umpteen GHz, assuming you also get the external mixers). Unfortunately, by the time a hobbyist gets one of these, it has been abused and neglected by its last commercial owner. CRT burns are common, and the flood-gun analog memory may be very quirky. For an advanced hobbyist, either get an associated Polaroid scope camera, or build your own camera hood. You can capture a lot of transient things that way, and you can scan the pixs to input into your computer. Also, HP made a line of oscilloscope plug-ins that fit the 141 mainframe, so you can use the 141 as a multi-channel analog memory oscilloscope too. 141's are a pain in two ways; first, you have to externally store extra plug-ins, and secondly, the hard side handles make carrying one a painful experience beyond about 50 feet. Also, you tend to injure your fingertips sliding those bulky plug-ins in and out past the big metal front handles. The 141 may also be the last of the hobbyist repairable analyzers; newer analyzers use proprietary chips and are built too dense to let you get fingers and probes into them. The 8562A is old (1987) but a superb analyzer, 1 kHz to 18 GHz, all digital and synthesized. This will do everything you want, except drive a parallel or RS-232 printer directly. If you're smart enough to talk to it by IEEE-488, then you can do everything through the computer. Other 856x series units have lesser capabilities, but are still great analyzers, and just might be priced low enough for a very serious hobbyist. Also, the HP-859x series are very good, although some have odd frequency, memory and IO capabilities. All 856x & 859x series units are one-man portables, until your knuckles turn white and numb. The 8569 is, in my opinion, a transitional beast between the analog and digital worlds. It's not as stable and simple as the 8562A, although it's a leap above the 141. Since it's wide, it's also awkward to carry using it's handle. I'm not much of a fan of the 8569. The 8566B is HP's top-of-the-line analyzer. They threw down the benchmark for everyone else to try to meet. Mine is customized a bit, covering 20 Hz to 22 GHz, and with an external tracking pre-selector, optional detectors, programmable attenuators, RF path switching and low-noise pre-amps. My company has a number of somewhat more plain-vanilla 8566B's and 8566A's. There isn't anything I need to do that these units fall short of (uhh, with the help of some external IEEE-488 linked computers). OTOH, these are now obsolete, non-supported by Agilent, and need two guys to carry one. Mine is in a 60" tall dedicated rack. Typical used price is around $20k. Most companies will be better served with one of Agilent's newer EPA or SPA analyzers. Anritsu and Rohde & Schwartz are also making fine analyzers. IIRC, Leader makes an analyzer that a hobbyist may aspire to affording. I would say that a 141 is still the best hobbyist choice. A company needs to be sure that they get a usable item for their money, so buying on eBay is a gamble. A company should buy from some place like Tucker, where they get a warranty backed by a reputable source. Yeah, it initially costs more. But it's a lot safer than having to try to repair an analyzer when you need that analyzer to do the real work of your company. A hobbyist can afford to spend 50 to 100 hours to get something going; in a business environment, where the clock is always ticking, that's unacceptable. Ed wb6wsn ed ...what is a tracking generator and how is it a advantage for a home hobbyist to have one or is it really necessary? also what do you thing about 8565a's also what is the determining factor for pricing on these various units on ebay? does it have anything to do with the options on each unit? sometimes there would appear to be some flucuations on the prices on either the same type unit or a similar unit. |
"Chuck Harris" wrote in message ... A tracking generator is a sweep generator calibrated to track to the center frequency of a spectrum analyzer as it sweeps. Got it? It is used to display the bandpass characteristics of a network using a spectrum analyzer. -Chuck Exactly. I found the 8556 plug-in, with a range of 20 Hz to 300 kHz, to be very handy when I was designing lowpass EMI filters (which usually have a cut-off frequency below 10 kHz or so, and increase in loss to maybe 60 dB by 100 kHz. The tracking generator could give me a quick look at the cutoff and slope, so I could tweak the circuit in real-time. It's also handy for acoustics, ultrasonic and vibration testing. And the 141 has a plotter X & Y output, so you can drive an analog plotter to trace the curve using a very slow sweep speed. Ed |
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