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hmm, kind of like buying a computer ...in a few mounths it is
obsolete...on the tektroix and hp stuff.......you would think that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