Safely getting the electrical length of a connected antenna feedline
Why is velocity factor an issue? Aren't we only interested in the electrical time from one end of the coax to the other?
Bob
-----------------------------------------------------------------
AE6RV.com
GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info
From: Didier Juges <shalimr9@gmail.com>
To: Bob Albert bob91343@yahoo.com; Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, August 11, 2016 1:20 PM
Subject: Re: [time-nuts] Safely getting the electrical length of a connected antenna feedline
I used the PPS from a Thunderbolt (fast rise lime, low rep frequency, was handy) and a digital storage scope and a couple of resistors to make a reflectometer based on this experiment:
www.ko4bb.com/getsimple/index.php?I'd=coax-cable-impedance-matching
You can very clearly see a 50 ohm/75 ohm mismatch.
The biggest variable will be the velocity factor.
Didier KO4BB
Hi Bob:
I don't think it's so much the stereo microscope as the related equipment. I have a Bausch & Lomb StereoZoom 4 and the
dial is always at the lowest setting (0.7dial * 10X objective = 7 power).
For another reason I got a Nikon SMZ-U microscope and discovered that it's so tall that it can not be used for SMT work.
http://www.prc68.com/I/NikonSMZ-U.html
So an important parameter is is length from the eyepiece to the objective. If that get to be long then you can not
easily use it.
Using an arm type support is very desirable. These have a heavy metal base with an horizontal arm. You can swing the
arm over whatever you're working one and easily move the scope up or down as needed.
This all done while in a standard chair on a work bench/table.
Although an old fashioned illuminator will work, see top photo:
http://www.prc68.com/I/SMT.shtml#Mag
A ring light is much more convenient (scroll down a little).
Also the soldering iron tip to grip distance should be as short as you can get. (1.5" = burned fingers, 0.5" should be
better)
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
-------- Original Message --------
What are the important parameters regarding purchase of a stereo microscope? I see some on ebay for around $50; are those good?
Bob
On Thursday, August 11, 2016 10:00 AM, Didier Juges <shalimr9@gmail.com> wrote:
I concur. I have been using ExpressPCB extensively over the last 2 years
with great satisfaction now that it is possible to get Gerber files from
them.
I typically use the mini board pro service (3 bare boards, 2 sided with
solder mask and silk screen) for prototypes and then buy the Gerbers to
have production quantities done overseas.
The boards are of high quality and the service is very fast at a very
reasonable price.
The only gotcha with regard to Gerber files is that you can only buy
Gerbers for boards that you have actually bought from them, so the process
is to buy the prototypes, then if you are happy with those, buy the Gerbers
for that design.
Didier KO4BB
On Tue, Aug 9, 2016 at 3:06 PM, Brooke Clarke brooke@pacific.net wrote:
Hi:
I've had good luck using any of the the ExpressPCB services that include
solder mask with surface mount parts where the pitch is 0.05" (half normal
DIP) and hand soldering (requires stereo microscope).
http://www.prc68.com/I/BTSG.shtml (battery top signal generator)
http://www.prc68.com/I/Images/ICS525v1o.jpg
http://www.prc68.com/I/SMT.shtml http://www.prc68.com/I/SMT.shtml
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Lots of good suggestions have already been made, but for
me, a boom style stereo microscope, with a distance between
the objective, and the focal point of at least 3 inches works
fairly well...
One other thing that may force your decision, if you are
older, your eyes will likely have lots of "floaters", which
are debris that floats around in your eyeballs. This debris
floats in and out of the center of your field of view, and
looks like a bunch of translucent worms, or shadows.
Your brain, the magnificent organ that it is, tries to compensate
for your eye's degradation, and as long as your eyes can move
about in your field of view, it effectively removes the floaters
from the scenes you are viewing.
However, if you use a stereo microscope, your eye position
is fixed by the very limited amounts of off axis motion
that will allow a through optical channel. This lack of off
axis motion will emphasize your floaters in a great way, and you
will see every single one, clearly, as if it were something
you really wanted to view. Some times, the floaters will cover
the exact thing you need to see clearly, and you will have to
move it off axis by moving it on the microscope stage.
The only answer to this problem, is to either have perfect eyes,
or to use a microscope where you are looking at a screen, rather
than through a pair of oculars. This way, your eyes can dart
around, and inspect what they need to see clearly, and the
floaters will be ignored by your brain.
As far as I know, there is only one optical microscope built this
way, and it is the very expensive Mantis.
Because of the great expense of flat screen optical microscopes,
most modern SMD viewing equipment is going to the trivially cheap
method of using a CCD/CMOS color video camera and an LCD screen.
You can do a lot with a cheap USB camera mounted to a boom, a fiber
optic light source, or a ring light, and a laptop computer to
display the image.
-Chuck Harris
Bob Albert via time-nuts wrote:
What are the important parameters regarding purchase of a stereo microscope? I
see some on ebay for around $50; are those good? Bob
FYI: In Didier's post below, the correct URL is:
http://www.ko4bb.com/getsimple/index.php?id=coax-cable-impedance-matching
I'm guessing a mobile spell checker changed his " id= " to " I'd= " (even though it was part of a URL).
/tvb
----- Original Message -----
From: "Didier Juges" shalimr9@gmail.com
To: "Bob Albert" bob91343@yahoo.com; "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Thursday, August 11, 2016 11:20 AM
Subject: Re: [time-nuts] Safely getting the electrical length of a connectedantenna feedline
I used the PPS from a Thunderbolt (fast rise lime, low rep frequency, was handy) and a digital storage scope and a couple of resistors to make a reflectometer based on this experiment:
www.ko4bb.com/getsimple/index.php?I'd=coax-cable-impedance-matching
You can very clearly see a 50 ohm/75 ohm mismatch.
The biggest variable will be the velocity factor.
Didier KO4BB
On August 8, 2016 2:18:02 PM CDT, Bob Albert via time-nuts time-nuts@febo.com wrote:
I host a group called something like HF Antennas. There I posted a
link to an article on how to measure coaxial cable. The easiest way is
with a spectrum analyzer and a tracking generator.
You connect the generator to the analyzer through a Tee that goes to
the unknown coax. You will see a group of peaks and nulls over the
spectrum. The spacing is a half wave of the cable. The match needs to
not be good to see the nulls best, and you will need to know the
propagation constant of the cable. Chances are, the match won't be
good over the entire range so you are okay with that. Propagation
constant of most coaxial cable runs around 66%.
You can also use a TDR setup but you'll have to make one, with a pulser
and a 'scope. I downloaded a circuit for a pulser that uses one IC. I
have the parts but haven't built it yet, as I am stalled by the problem
of connecting to a 14 pin SMD part. The IC uses one part as an
oscillator and the other 5 in parallel to drive 50 Ohms. Again, you
use a Tee and measure the time for a reflection, bearing in mind that
the trip is two ways over the same cable and the time shown will be
double the time for the calculation.
Bob
On Monday, August 8, 2016 12:00 PM, Bob Stewart bob@evoria.net wrote:
Earlier this year, with some help, I pulled the dish off of an old
DishTV antenna on the roof and put a 5V bullet antenna on the mast. I
also pulled a new cable through by attaching it to the old one. The
problem is that I was not able to measure the new cable. So, the
question is, without going back on the roof in this heat, how can I
measure the electrical length of the line I pulled?
I was thinking of using my 8640B signal generator and sending some RF
back up the line to get a quarter wavelength at the null. But that
assumes a lot, including that the other end is open at 3MHz, or
whatever the frequency works out to be, as well as that the high
voltage on the antenna end won't be high enough to blow the LNA.
So, how much RF I can safely send up the line? I've got an 8558B
spectrum analyzer, but it's not on the bench, and it would be easier to
use my scope, which sadly is a 70s vintage Tek 455. Do I put this all
together with a lead from the generator to a tee at the measuring
device and tune for a null? My experience at getting precise
measurements on anything longer than a few inches is effectively none,
but I'd guess that I want less than 0.5V at the LNA during this test.
Oh, and I do have an 8444A tracking generator that can output -10 dbm
as well as a 10 db attenuator within easy access. That could get a
quick spot on the null point.
Most importantly, of course is the question of whether this will even
work.
Bob -
AE6RV -----------------------------------------------------------------
AE6RV.com
GFS GPSDO list:
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and follow the instructions there.
The best type of stereo microscope to use for SMT assembly is referred to
as an "Inspection Microscope."
Magnification greater than 10 is not needed or desirable for normal
assembly.
Something in the range of 5 to 10 works well.
A wide field of view and a good light source are desirable.
Just as Brooke says, my "zoom" always stays on the lowest setting. (Same as
his, 0.7 times 10x = 7)
--- Graham
==
On Thu, Aug 11, 2016 at 1:57 PM, Brooke Clarke brooke@pacific.net wrote:
Hi Bob:
I don't think it's so much the stereo microscope as the related
equipment. I have a Bausch & Lomb StereoZoom 4 and the dial is always at
the lowest setting (0.7dial * 10X objective = 7 power).
For another reason I got a Nikon SMZ-U microscope and discovered that it's
so tall that it can not be used for SMT work.
http://www.prc68.com/I/NikonSMZ-U.html
So an important parameter is is length from the eyepiece to the
objective. If that get to be long then you can not easily use it.
Using an arm type support is very desirable. These have a heavy metal
base with an horizontal arm. You can swing the arm over whatever you're
working one and easily move the scope up or down as needed.
This all done while in a standard chair on a work bench/table.
Although an old fashioned illuminator will work, see top photo:
http://www.prc68.com/I/SMT.shtml#Mag
A ring light is much more convenient (scroll down a little).
Also the soldering iron tip to grip distance should be as short as you can
get. (1.5" = burned fingers, 0.5" should be better)
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
-------- Original Message --------
What are the important parameters regarding purchase of a stereo
microscope? I see some on ebay for around $50; are those good?
Bob
On Thursday, August 11, 2016 10:00 AM, Didier Juges <
shalimr9@gmail.com> wrote:
I concur. I have been using ExpressPCB extensively over the last 2 years
with great satisfaction now that it is possible to get Gerber files from
them.
I typically use the mini board pro service (3 bare boards, 2 sided with
solder mask and silk screen) for prototypes and then buy the Gerbers to
have production quantities done overseas.
The boards are of high quality and the service is very fast at a very
reasonable price.
The only gotcha with regard to Gerber files is that you can only buy
Gerbers for boards that you have actually bought from them, so the process
is to buy the prototypes, then if you are happy with those, buy the
Gerbers
for that design.
Didier KO4BB
On Tue, Aug 9, 2016 at 3:06 PM, Brooke Clarke brooke@pacific.net wrote:
Hi:
I've had good luck using any of the the ExpressPCB services that include
solder mask with surface mount parts where the pitch is 0.05" (half
normal
DIP) and hand soldering (requires stereo microscope).
http://www.prc68.com/I/BTSG.shtml (battery top signal generator)
http://www.prc68.com/I/Images/ICS525v1o.jpg
http://www.prc68.com/I/SMT.shtml http://www.prc68.com/I/SMT.shtml
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
I've got a great boom Zeiss microscope bought at an estate sale. Right
Place, Right Time.
Before that, I generally used a video camera with some extension tubes, a
USB video capture dongle, and a spare monitor I keep on the workbench. The
monitor and camera are connected with extension cables to the computer
across the room. (ok, 180degree chair swivel way :) )
Getting the lighting right is key. Light ring is good or light close to on
axis helps.
Bob
On Thu, Aug 11, 2016 at 5:06 PM, Graham / KE9H ke9h.graham@gmail.com
wrote:
The best type of stereo microscope to use for SMT assembly is referred to
as an "Inspection Microscope."
Magnification greater than 10 is not needed or desirable for normal
assembly.
Something in the range of 5 to 10 works well.
A wide field of view and a good light source are desirable.
Just as Brooke says, my "zoom" always stays on the lowest setting. (Same as
his, 0.7 times 10x = 7)
--- Graham
==
On Thu, Aug 11, 2016 at 1:57 PM, Brooke Clarke brooke@pacific.net wrote:
Hi Bob:
I don't think it's so much the stereo microscope as the related
equipment. I have a Bausch & Lomb StereoZoom 4 and the dial is always
at
the lowest setting (0.7dial * 10X objective = 7 power).
For another reason I got a Nikon SMZ-U microscope and discovered that
it's
so tall that it can not be used for SMT work.
http://www.prc68.com/I/NikonSMZ-U.html
So an important parameter is is length from the eyepiece to the
objective. If that get to be long then you can not easily use it.
Using an arm type support is very desirable. These have a heavy metal
base with an horizontal arm. You can swing the arm over whatever you're
working one and easily move the scope up or down as needed.
This all done while in a standard chair on a work bench/table.
Although an old fashioned illuminator will work, see top photo:
http://www.prc68.com/I/SMT.shtml#Mag
A ring light is much more convenient (scroll down a little).
Also the soldering iron tip to grip distance should be as short as you
can
get. (1.5" = burned fingers, 0.5" should be better)
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
-------- Original Message --------
What are the important parameters regarding purchase of a stereo
microscope? I see some on ebay for around $50; are those good?
Bob
On Thursday, August 11, 2016 10:00 AM, Didier Juges <
shalimr9@gmail.com> wrote:
I concur. I have been using ExpressPCB extensively over the last 2
years
with great satisfaction now that it is possible to get Gerber files from
them.
I typically use the mini board pro service (3 bare boards, 2 sided with
solder mask and silk screen) for prototypes and then buy the Gerbers to
have production quantities done overseas.
The boards are of high quality and the service is very fast at a very
reasonable price.
The only gotcha with regard to Gerber files is that you can only buy
Gerbers for boards that you have actually bought from them, so the
process
is to buy the prototypes, then if you are happy with those, buy the
Gerbers
for that design.
Didier KO4BB
On Tue, Aug 9, 2016 at 3:06 PM, Brooke Clarke brooke@pacific.net
wrote:
Hi:
I've had good luck using any of the the ExpressPCB services that
include
solder mask with surface mount parts where the pitch is 0.05" (half
normal
DIP) and hand soldering (requires stereo microscope).
http://www.prc68.com/I/BTSG.shtml (battery top signal generator)
http://www.prc68.com/I/Images/ICS525v1o.jpg
http://www.prc68.com/I/SMT.shtml http://www.prc68.com/I/SMT.shtml
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
Can anyone compare the stereo microscope to a camera/monitor for use
with SMT? I have a cheap stereo microscope that I would like to replace
with either a much better stereo microscope or a camera/monitor. Is
there a marked advantage(s) of one versus the other? I have no
"floaters" to contend with.
Steve, K8JQ
On 8/11/2016 4:06 PM, Chuck Harris wrote:
Lots of good suggestions have already been made, but for
me, a boom style stereo microscope, with a distance between
the objective, and the focal point of at least 3 inches works
fairly well...
One other thing that may force your decision, if you are
older, your eyes will likely have lots of "floaters", which
are debris that floats around in your eyeballs. This debris
floats in and out of the center of your field of view, and
looks like a bunch of translucent worms, or shadows.
Your brain, the magnificent organ that it is, tries to compensate
for your eye's degradation, and as long as your eyes can move
about in your field of view, it effectively removes the floaters
from the scenes you are viewing.
However, if you use a stereo microscope, your eye position
is fixed by the very limited amounts of off axis motion
that will allow a through optical channel. This lack of off
axis motion will emphasize your floaters in a great way, and you
will see every single one, clearly, as if it were something
you really wanted to view. Some times, the floaters will cover
the exact thing you need to see clearly, and you will have to
move it off axis by moving it on the microscope stage.
The only answer to this problem, is to either have perfect eyes,
or to use a microscope where you are looking at a screen, rather
than through a pair of oculars. This way, your eyes can dart
around, and inspect what they need to see clearly, and the
floaters will be ignored by your brain.
As far as I know, there is only one optical microscope built this
way, and it is the very expensive Mantis.
Because of the great expense of flat screen optical microscopes,
most modern SMD viewing equipment is going to the trivially cheap
method of using a CCD/CMOS color video camera and an LCD screen.
You can do a lot with a cheap USB camera mounted to a boom, a fiber
optic light source, or a ring light, and a laptop computer to
display the image.
-Chuck Harris
Bob Albert via time-nuts wrote:
What are the important parameters regarding purchase of a stereo microscope? I
see some on ebay for around $50; are those good? Bob
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi Chuck:
The Mantis is very expensive and the arm in the EEVblog review is not as stable as my arm.
https://www.youtube.com/watch?v=a3o0EWHEH08
about US$ 3300 retail, maybe $2000 eBay.
In the review he is confused about 3D vs. perspective.
The working distance does not look as long as the B&L.
http://www.prc68.com/I/SMT.shtml#Mag
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
-------- Original Message --------
Lots of good suggestions have already been made, but for
me, a boom style stereo microscope, with a distance between
the objective, and the focal point of at least 3 inches works
fairly well...
One other thing that may force your decision, if you are
older, your eyes will likely have lots of "floaters", which
are debris that floats around in your eyeballs. This debris
floats in and out of the center of your field of view, and
looks like a bunch of translucent worms, or shadows.
Your brain, the magnificent organ that it is, tries to compensate
for your eye's degradation, and as long as your eyes can move
about in your field of view, it effectively removes the floaters
from the scenes you are viewing.
However, if you use a stereo microscope, your eye position
is fixed by the very limited amounts of off axis motion
that will allow a through optical channel. This lack of off
axis motion will emphasize your floaters in a great way, and you
will see every single one, clearly, as if it were something
you really wanted to view. Some times, the floaters will cover
the exact thing you need to see clearly, and you will have to
move it off axis by moving it on the microscope stage.
The only answer to this problem, is to either have perfect eyes,
or to use a microscope where you are looking at a screen, rather
than through a pair of oculars. This way, your eyes can dart
around, and inspect what they need to see clearly, and the
floaters will be ignored by your brain.
As far as I know, there is only one optical microscope built this
way, and it is the very expensive Mantis.
Because of the great expense of flat screen optical microscopes,
most modern SMD viewing equipment is going to the trivially cheap
method of using a CCD/CMOS color video camera and an LCD screen.
You can do a lot with a cheap USB camera mounted to a boom, a fiber
optic light source, or a ring light, and a laptop computer to
display the image.
-Chuck Harris
Bob Albert via time-nuts wrote:
What are the important parameters regarding purchase of a stereo microscope? I
see some on ebay for around $50; are those good? Bob
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
There is quite a lot to know about stereo microscopes
The first decision is if you want to buy a new Chinese microscope or a
much older used professional grade US made scope. The Chinese units
used to be total junk but not any more, or at least some of them are
good. But at the $50 price point I doubt you are into the better
Chinese brands. That said, inspecting electrical parts does not
require a state of the art microscope. It is an easy task But
can't say much more until you get to talking about exact make and
model.
On Thu, Aug 11, 2016 at 10:24 AM, Bob Albert via time-nuts
time-nuts@febo.com wrote:
What are the important parameters regarding purchase of a stereo microscope? I see some on ebay for around $50; are those good?
Bob
On Thursday, August 11, 2016 10:00 AM, Didier Juges <shalimr9@gmail.com> wrote:
I concur. I have been using ExpressPCB extensively over the last 2 years
with great satisfaction now that it is possible to get Gerber files from
them.
I typically use the mini board pro service (3 bare boards, 2 sided with
solder mask and silk screen) for prototypes and then buy the Gerbers to
have production quantities done overseas.
The boards are of high quality and the service is very fast at a very
reasonable price.
The only gotcha with regard to Gerber files is that you can only buy
Gerbers for boards that you have actually bought from them, so the process
is to buy the prototypes, then if you are happy with those, buy the Gerbers
for that design.
Didier KO4BB
On Tue, Aug 9, 2016 at 3:06 PM, Brooke Clarke brooke@pacific.net wrote:
Hi:
I've had good luck using any of the the ExpressPCB services that include
solder mask with surface mount parts where the pitch is 0.05" (half normal
DIP) and hand soldering (requires stereo microscope).
http://www.prc68.com/I/BTSG.shtml (battery top signal generator)
http://www.prc68.com/I/Images/ICS525v1o.jpg
http://www.prc68.com/I/SMT.shtml http://www.prc68.com/I/SMT.shtml
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/m
ailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Chris Albertson
Redondo Beach, California
This seems totally backwards. Typically a Gerber file is something
you make yourself on your computer then send it in for a prototype.
Seems odd to buy them.
I checked ExpressPCB prices and they are very high. I can get PCBs
made quickly in the US for $3 per square inch, shipping included with
$9 minimum order. And you don't buy the Gerbers.
I notice ExpressPCB offers free software. But it is totally
non-standard and you can't use it for anything other then for their
service. Most people needing free PCB software use Eagle, some use
Kicad or some others. But Eagle seems to be kind of a universal
standard.
On Thu, Aug 11, 2016 at 8:55 AM, Didier Juges shalimr9@gmail.com wrote:
I concur. I have been using ExpressPCB extensively over the last 2 years
with great satisfaction now that it is possible to get Gerber files from
them.
I typically use the mini board pro service (3 bare boards, 2 sided with
solder mask and silk screen) for prototypes and then buy the Gerbers
--
Chris Albertson
Redondo Beach, California