EMRFD Message Archive 14021

Message Date From Subject
14021 2017-06-16 15:18:03 mosaicmerc Rubidium atomic clock
Picked up a calibrated Rubidium SA22c 10Mhz unit (10 years old) to trim the OXCO unit in my HP 4432B Sig gen and a couple OXCO Trimbles I have on hand.

Thinking of making up a couple standard reference 10Mhz OXCO plus distribution amp units as an exercise. 


Would anyone be interested in such 10Mhz ref.  units after I have calibrated them?


14022 2017-06-16 21:19:49 AncelB Re: Rubidium atomic clock
Any preferences for square wave or sine wave OCXO units?

SC cut has improved long term stability at the oven temps.
14023 2017-06-16 22:36:23 Howie WA3MCK Re: Rubidium atomic clock
I would be most interested in one of your 10 MHz OXCO's.
Thank you,
Howie WA3MCK 

14024 2017-06-16 22:42:44 Howie WA3MCK Re: Rubidium atomic clock
Ancel,
My preference is SC cut.
Howie WA3MCK 

14027 2017-06-17 20:20:27 Bill Carver PCB conversion?
For decades I've been laying mostly-analog PCB's out manually using
old/obsolete Autocad 14. For one-of-a-kind boards of modest dimensions I
printed then onto Mylar and ironed them onto copperclad. Then my HP
lasterjet died. I replaced it with a Brother but found out its toner
won't work to make PCB resist on mylar (for decals, etc). I'm sitting
here with a 5" x 9.5" layout for relay-switched RX antenna filters. Even
if the toner wasn't an issue, ironing it onto copperclad that large is
difficult, and I'm thinking I'd want three boards.

Chinese board manufacture would seem a viable option if I could convert
the Autocad .DWG file to a copper layer. It is single sided, not even a
solder mask is need. There are 40 identical 1/8" diameter holes, and I
could hand drill those if that was the only impediment to making the
boards (If I knew the drill file format maybe could even hand-enter the
coordinates of those 40 holes).

Does anyone have knowledge of, or experience getting boards made from an
Autocad file?
Maybe, somehow,....I could generate a .PDF file from it (version 14 of
Autocad predates the built-in .PDF output option of current versions).

Bill - W7AAZ
14028 2017-06-17 20:24:40 Dave Miller Re: PCB conversion?
Bill
Contact me off list 
Dave
VE7PKE at geeeemail

Sent from my iPhone

14030 2017-06-17 22:12:49 Will Kimber Re: PCB conversion?

Bill try asking this group.

Homebrew_PCBs@yahoogroups.com


Cheers,\Will



14034 2017-06-18 19:38:15 AncelB Re: PCB conversion?
Maybe these links will help u:

https://hackaday.io/project/7938-pcb-smt-maker-lab-home

https://hackaday.io/project/3363-apache-al13p-tl-320b-one-pass-pcb-toner-xfer

They are both my projects, as is the Laminator mod. kit, Ebay item
#132136993019. Most recently sold as far as Russia.

The laminator/toner transfer solution will generate PCBs (double sided
as well) up to 12" wide and as long as you need at home.

I base my PCB designs on EagleCAD , owned by Autodesk, so you should be
able to find an import plugin for AutoCAD files.

https://www.autodesk.com/products/eagle/overview


Ancel
14035 2017-06-18 19:46:04 AncelB Re: PCB conversion?
14036 2017-06-18 22:22:41 Bill Carver Re: PCB conversion?
I had Eagle many years ago but first PCB needed layout for a device not in the library. Just got too complicated too quickly and was never able to get it working.
My Autocad is more than 25 years old, will not make .PDF and attempts at file conversion from multiple vendors were a flop.
So I made only single sided for low-tech projects for many years. then HP printer died, and Brother "replacement" won't print to Mylar. Could have learned that if I had searched internet before purchase, but just assumed that all laser printers were Mylar capable.
There is more to a project that PCBs...design, simulation, breadboard, testing...then chassis/metalwork. It I can use offshore manufacturer for my projects that will be OK with me. Just need Gerbers. And not a $500 conversion program.
W7AAZ


14037 2017-06-18 22:39:17 DuWayne Schmidlko... Re: PCB conversion?

I use a Brother printer for making PCBs using the cold toner transfer method.  I also use the printer for making uv masks for doing solder mask on the boards.  I have had no problem printing on laser overhead projector sheets.  Not quite dark enough to use, so have to print two copies and overlay them to get good results.

DuWayne KV4QB


14038 2017-06-18 23:09:06 Dana Myers Re: PCB conversion?
14039 2017-06-18 23:36:46 Ashhar Farhan Re: PCB conversion?
i went through this two years ago. i had used expresspcb until then. then i decided to invest 2 hours learning the kicad. since then, life has become much simpler. 
kicad is a free software, developed by the guys at CERN. it outputs gerber, it is pretty much a standards driven project. it is not quirky, it is just straightlaced.
you have to stick to the flow : first draw the schematic in eeschema, then, assign the footprints, move over to pcbnew where you drag the footprints around and lay the lines, ground planes. now it appears simple, but then it didn't. VU2SPF helped immensly by being on the phone.
in retrospect, it is always better to invest an hour or two learning a better tool. 

- f

14040 2017-06-18 23:41:01 Bill Carver Re: PCB conversion?
Dana, this is RX BPF board for a homebrew package for Orion-II.  Orion-II is sitting here: I have enough items on my learning curve already!
Bill


14041 2017-06-19 02:24:07 Roelof Bakker Re: PCB conversion?
Hello Bill,

I have been using Sprint-Layout for years. It is not free, but cost
is modest. I also tried high end PCB software, but ran into problems
creating custom symbols. In Sprint-Layout this is very easy to do
and everything can be saved in the library.

I don't quite understand the popularity of the toner transfer
method. I am using a laser printer, calque paper, spray it with
clear lacquer for better contrast and then use a UV source and photo
sensitive board made by Bungard.

You can also export the design in the Gerber format.

http://www.abacom-online.de/uk/html/sprint-layout.html

73,
Roelof Bakker, pa0rdt
14042 2017-06-19 03:15:00 Tony Fishpool Re: PCB conversion?
I have to second Roelof's enthusiasm for Sprint Layout. It is very easy to
use and there is a free utility so that people can use your designs and
print them if you want to share.

For me, the answer to the popularity with toner transfer is that I don't
need to use special PCB stock or mess around with sensitising sprays - and I
don't need a UV light source.

We are lucky now that we have a good range of choices, from home made boards
(via various methods), to cheap far east manufacturing. We've never had
access to so much great technical information.

It's the golden age of home brew my friends!

Kind regards
Tony G4WIF

-----Original Message-----

Hello Bill,

I have been using Sprint-Layout for years. It is not free, but cost is
modest. I also tried high end PCB software, but ran into problems creating
custom symbols. In Sprint-Layout this is very easy to do and everything can
be saved in the library.

I don't quite understand the popularity of the toner transfer method. I am
using a laser printer, calque paper, spray it with clear lacquer for better
contrast and then use a UV source and photo sensitive board made by Bungard.

You can also export the design in the Gerber format.

http://www.abacom-online.de/uk/html/sprint-layout.html

73,
Roelof Bakker, pa0rdt
14043 2017-06-19 06:52:48 Michael Dunn Re: PCB conversion?
Some CAD programs will let you place DXF (and/or other graphic formats) into a design, but you’d still need to manually overlay pads for drilling (and a legend if you want).


I’d suggest redoing the board using one of the many free CAD options. The time spent learning the software will quickly pay back for future projects.


Check out my freeCAD summary:


http://www.edn.com/electronics-blogs/all-aboard-/4441802/Free-PCB-ECAD--The-Ultimate-list


I’ve also run across one or three really simple PCB packages that were too primitive for that article, but might fit your needs. Unfortunately, I can’t recall any names.


You may be able to find PCB shops that can accept DXF/DWG, but probably not in China! Check out PCB Shopper for ideas.


Michael Dunn










1a. PCB conversion?
    Posted by: "Bill Carver" bcarver@safelink.net billw77aaz

    Date: Sat Jun 17, 2017 8:20 pm ((PDT))


For decades I've been laying mostly-analog PCB's out manually using 
old/obsolete Autocad 14. For one-of-a-kind boards of modest dimensions I 
printed then onto Mylar and ironed them onto copperclad.  Then my HP 
lasterjet died. I replaced it with a Brother but found out its toner 
won't work to make PCB resist on mylar (for decals, etc). I'm sitting 
here with a 5" x 9.5" layout for relay-switched RX antenna filters. Even 
if the toner wasn't an issue, ironing it onto copperclad that large is 
difficult, and I'm thinking I'd want three boards.


Chinese board manufacture would seem a viable option if I could convert 
the Autocad .DWG file to a copper layer.  It is single sided, not even a 
solder mask is need. There are  40 identical 1/8" diameter holes, and I 
could hand drill those if that was the only impediment to making the 
boards (If I knew the drill file format maybe could even hand-enter the 
coordinates of those 40 holes).


Does anyone have knowledge of, or experience getting boards made from an 
Autocad file?
Maybe, somehow,....I could generate a .PDF file from it (version 14 of 

Autocad predates the built-in .PDF output option of current versions).
14044 2017-06-19 07:10:55 Bill Carver Re: PCB conversion?
Thanks for another push toward Kincad. My plate is full, but I downloaded tutorial and current version and it's on my "to do" list. Might take a while to get to it.
Bill


14045 2017-06-19 08:10:55 AD7ZU Re: PCB conversion?
I've also moved to KICAD, not bad, but I end up making new KICAD parts for practically everything.  The library structure seems to trip up some users but having been in the S/W business for 40+yrs or so I find it operates much like an integrated development systems I have used in the past.

I could create a book of features id like to see .. first among them would be a direct import of footprints and a standardized schematic form from major manufacturers.  The KICAD PCB layout tool doesn't think like i do.. (that might be a good thing?) so it was challenging.

overall i give KICAD a B+  if they get to a database oriented parts library management i could up that score.  I know im not the only one out there making my own parts.  The price is right!

i had one simple board done at oshpark so far..  took about a week.  no problems.  

Randy
AD7ZU

14046 2017-06-19 09:00:20 ad7jt Re: PCB conversion?
Hi Randy et al.,

I too have started using KiCad and I highly recommend it.  After you adjust your thinking a little bit, it becomes fairly intuitive and the documentation is pretty extensive.  It is also open source and free to all users without restrictions on board sizes and number of layers.

I have also used OSH Park a few times and have had very good luck with them and the service and support has been great.  The cost for three prototypes is $5 per square inch including shipping.  

Recently I have found another great source for prototypes:


Their cost for 5 or 10 boards, 100mm x 100mm or smaller, is only $5.  No setup charge and no hole counting.  Shipping with DHL is $21 (2-3 days).  They offer other shipping options too (e.g., E-Packet, $12, 10-15 days).  I have used DHL for my orders and always received my boards in less than one week from the time they accept the order.  (They do an audit on your input before accepting the order.)  They also have on-line chat support which is quite good but the time difference between us and China sometimes means they are sleeping while I am ordering.  

If you play with the numbers and you are only interested in prototype quantities you will find a break-even point between OSH Park and PCBway (depending on the size of your board and how long you want to wait for shipping) at about five square inches (using DHL) or 3.4 square inches (using E-Packet).

For error checking, KiCad's rules checker are very good but I find that selecting the 3-D viewer can reveal a couple other error types.  I also submit my board design to OSH Park just to check the artwork even if ordering from elsewhere.  You can send them your file(s) and they process it to the point where they render views of what the board will look like as well as each of its components (copper, silk screen, routing, drill pattern, etc.).  It only takes a few minutes and errors can be corrected and files resubmitted while on line.


73,
Dave Collins - AD7JT