New TCVCXO PCB with OnBoard I2C Control

With the very good results of the TCVCXO Propeller Master Clock experiments (see previous post), I decided to rebuild the PCB to include the I2C Pot and Filter Caps on the same board. This is the expected results when produced:

Top

Bottom

Note: This board is very small, it is only 0.365 x 0.650 inches. The above images are local screen prints of DipTrace 3D output.

I often use Homebrew Tone Transfer Method to produce my PCB's, but I use DorkBotPBX to produce my manufactured boards.

Laen (the owner of DorkBotPBX PCB) is now using a new web site: OshPark.com and using a new interactive process for submitting PCP designs. The new web site was introduced at the Bay Area Maker Faire 2012.

The site accepts Eagle and Generic ZIP'd Gerbers (as exported from DipTrace). The interactive process receives the ZIP'd file and renders the design, showing the individual layers and what the board will look like when finished (in Laen's standard Purple color). Very Cool.

The price is the same, $5.00 per square inch for a set of three, two sided boards.

Check it out at: OshPark.com

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TCVCXO Boards Received

Yesterday, I received my TCVCXO PCB back from DorkbotPDX (15 days). These will be used as a stable replacement for the Master Clock on the Propeller USB Protoboard (see several previous posts).






HB 10MHz TCVCXO Propeller Daughter Boards

With a little work two boards were; loaded and initially tested. Jeff - KO7M will receive the second board for his Prop.







Ready to Load Parts

The board size is a little over 0.4 x 0.4 inches, and is made for 0603 and 0805 components. This new board was created to plug into existing hole on the Propeller USB Protoboard.

And of course, More testing is yet to come (although the Homebrew prototype has been doing well, and has be used in my 30m Beacon for the last few weeks).

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UPDATE
Jeff and I have used the TCVCXO sucessfully with our Protoboards, the only difficulty is I miss located the third (single) pin on the PCB, it is slightly left of the of its intend spot.  This mistake makes the board sit slightly crooked on the Protoboard. But, the hole-to-pin slop allows correction (while soldering) for most of the misalignment. The alignment will be corrected on the next boards.

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TCVCXO Boards Are On Order

After a few slight modification, I just placed an order with DorkbotPDX for the 10MHz TCVCXO circuit boards. This is the board that will be used for the Propeller Clock (see previous posts). They should be in my hands in two weeks plus a few days.

Gerber File

Note: The boards will not be Green, DorkbotPDX boards are a very nice Purple !

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DorkBotPDX in Portland

Monday night Jeff - KO7M and I attended the 7-11pm  DorkBotPDX meeting in Portland, there were many projects available to review and interesting people to meet.

An unexpected pleasurable encounter was with Paul - the creator of the "Teensy", which is the cpu board that I have mentioned in previous posts (see search label: Teensy). Paul also, video taped some of the high lights of the meeting. My GUI Development Board and 9 Volt Micro Transmitters can be seen.

http://youtu.be/seyTMkTGZ3E

It was a great meeting, even thought I did not get back to Seattle and home until 3:30am, I plan to attend often.

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Teensy Programming Shield - To FAB Shop

After a little rework on the previous circuit board, we got it working. The +5V trace was broken at the header pin. This type of problem is always a concern with Homebrew Double Sided Boards as they are not through hole plated, and therefore must be soldered on the pads of the two sides. The pad and connecting trace are very fragile.

As Designed and Sent to DorkBotPDX

To make the board more useful (and rugged) we decided to have it sent to my favorite fab shop; DorkBotPDX. The boards should be back (in less than 2 weeks) by Thanksgiving.

The Back Side

The board has been changed a little, as the fab shop can do useful things, that are avoided when doing HB PCB's.


The board is .7'' x 1.8" with 8 mil traces, 6 mil ground grid, and the text font is 3pt.

 I enjoy building very small projects!

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DorkbotPDX PCBs

On a previous post, I reported the results of a test of IteadStudio.com PCB Manufacturing located in China, which is a very good value. My trial of ten 1x2 inch boards was $16.00 and a 22 days wait. That is, the boards cost me $1.60 each.

Recently I found local (US) company "DorkbotPDX" that combines many projects into a full manufacturing PCB panel, and then they send the panel to a Lab for production. The web page can be seen at:

http://www.dorkbotpdx.org/wiki/pcb_order

Update: This manufacture has change their name to OSH Park

First DorkbotPDX Test

For a test, I used the next Revision of the same board used for the previous Production test. I am very impressed with the results. But, in my hast to make the lay up deadline, this Revision of my board did not have the right holes sizes for some of the parts (the results of a multitude of issues; with a new Software Revision and Part Foot Print problems). But, what the heck, . . . this was just a test.

The board is very nicely Gold plated, and as they state on their web page, "You can have any color of Solder Mask that you like, as long as it is Purple".

The price of $5.00 per square inch, which includes shipping and three copies. Once sent to the Lab, the production and shipping time is about 14 days. A collection of projects are combined onto a panel about one each week. Their lay up web site, and Phone App, reports panel lay up progress and shipping status.

For this test, these boards cost me $3.25 each, which is a little more expensive than before, but eight days faster.

The price and turn around time is great for small quantity of prototype boards.

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