Friday, December 21, 2018

My Favorite Irrational Number


I have always been interested in numbers, especially special numbers like Pi (3.1415. . . ).

Normal whole numbers, like 1, 2, 3, etc (and their negative counter parts) are amazing when you consider there is no end to how far you can go to find a larger number, just by adding one. Within that very large range of numbers, there are many numbers which have their own special properties, for example the "Prime Numbers". As with all whole numbers, there is no Largest Prime Number, there is always a larger one to be found.

The whole numbers (plus/minus) and fractions that can be written using them are known a "Rational Numbers" - meaning that they can be written as a ratio (a fraction), for example:  1/1, 1/2, 1/3, etc.

But there is another class of numbers that can NOT be written as a ratio of two whole numbers, they are called "Irrational Numbers", for example the value of "Pi".  Pi can be written with many-many non-repeating digits without end, but Pi could never be written as an exact fraction (a ratio) of two whole numbers. There are many such "Irrational Numbers", many are used in science and found in Nature.

My favorite Irrational Number can be computed as simple as: (1+sqrt(5))/2

This can be computed with as many digits that you like with a simple Unix command (change that scale as desired for the number of digits):

        echo "scale=1000; (1+sqrt(5))/2" | bc

This is a very special number known as "phi".

A very interesting property of phi is:  1/phi = phi-1

No other number has this simple property.

Phi is found in many places in Nature, for example it is the way seeds are arranged withing a Sun Flower, the size of chambers of the Nautilus fish,  etc.

Phi is the name given to what is also called the "Golden Ratio" or "Golden Rectangle".

Here are the first 1000 digits of Phi:

1.618033988749894848204586834365638117720309179805762862135448622705
26046281890244970720720418939113748475408807538689175212663386222353
69317931800607667263544333890865959395829056383226613199282902678806
75208766892501711696207032221043216269548626296313614438149758701220
34080588795445474924618569536486444924104432077134494704956584678850
98743394422125448770664780915884607499887124007652170575179788341662
56249407589069704000281210427621771117778053153171410117046665991466
97987317613560067087480710131795236894275219484353056783002287856997
82977834784587822891109762500302696156170025046433824377648610283831
26833037242926752631165339247316711121158818638513316203840052221657
91286675294654906811317159934323597349498509040947621322298101726107
05961164562990981629055520852479035240602017279974717534277759277862
56194320827505131218156285512224809394712341451702237358057727861600
86883829523045926478780178899219902707769038953219681986151437803149
97411069260886742962267575605231727775203536139362



-- Home Page: https://WA0UWH.blogspot.com


Wednesday, April 4, 2018

Hands Free Jig

UPDATED:
Added Details and Links


In the past I successfully have used "Hands Free Soldering Jigs", but I wanted more functionality.

I found on ebay Machinist Magnetic Indicator Dial Gauge Holders, with a little 3D Printer Designed Adaptor they could be used as a Hands Free Soldering Jig.

A single Knob adjust and locks all three major joints.


In this case, the yellow alligator clip adapter was 3D Printed.


Also, another adapter (black) was printed, and a "Hat Pin" heated and inserted. This makes for a very nice PCB probe, an Oscilloscope probe can be attached to the top of the pin.



Once adjusted, these Dial Indicator Holders are "Rock Solid", once positioned they stay put, allowing for precise probing.  I use tape to hold board under test to the bench (thanks, Jeff - KO7M).



If used, the Magnet Base needs a stable steel attachment point, in my case, my bench edge is metal and provides as necessary.   The Magnet Base could be abandoned for something that could be attached to a wooden bench.

-- Home Page: https://WA0UWH.blogspot.com


Monday, April 2, 2018

Test Lead Rack - For my eShop

In my Electronics Shop, space and organization is always a challenge.  The following 3D Printed Test Lead Rack will help.

An Interactive Link To The Design

I designed the Test Lead Rack with Fusion 360 as one of my efforts to learn this new (to me) software.  I had been using Sketchup for most of my previous projects, but the lure of Parametric Design is to great to NOT switch to Fusion 360.  Also, a lot of public available designed parts are available from Fusion 360.

Now 6.5 hours later after design, the 3D Printer provides the Results:



And now, it is in use:



-- Home Page: https://WA0UWH.blogspot.com


Sunday, January 7, 2018

3D Printer - MY Noob Mistakes


As posted before, I have been playing with a new TEVO Little Monster 3D Printer, I have made a LOT of Noob mistakes that could have been avoided if I had only knew.

The following are notes to myself.

o. Do not turn off the power to the 3D Printer unless you are certain that the Hot-End has cooled down. if not, removing power to the 3D Printer will cause the filament to melt within the Cold-End and then a complicated repair method will be required to fix the problem.

o. Remember, 3D Printing is very SLOW, it is much slower than waiting for paint to dry.

o. Remember the hot-end is VERY HOT, I have several burns to remind me.

o. Learn how to set the Z zero Height to within a paper thickness of the print bed, or nothing will work correctly until you do, no mater how hard you try.

o. Buy several sets of Print Head replacement parts, for the; Cold-End, Thermal Break, and Hot-End.

o. Consider buying some Tetrahydrofuran (THF) , it is the only effective thing that will dissolve PLA (for Hot-End  clean and repair), and it can be used to glue PLA parts together. Or at least that is what google suggests.

o. Note, MOST often Hot-End repair work will be done while it is HOT (about 210 C, or more), other wise PLA will be hard and not easily removed.

o. For my use, Blue Painter Tape works best for the Printer Bed, it has some texture that will show up on the printed part, but PLA stick very good to it. A roles of Blue Painters Tape (10 inches wide) are available on-line for about $50, and worth every penny, it makes bed prep very easy.

o. If the Hot-End is disassembled, for cleaning or repair, remember it has to be re-assembled and tightened while at intended operating temperature, for me that is about 215C.  If not, it WILL leak.


Note: I will add to this list as I learn more.


-- Home Page: https://WA0UWH.blogspot.com


Wednesday, September 20, 2017

Reduction Gears

Sorry, this is not an Amateur Radio post.

After many months of working with a 3D Printer, I have finally successfully created a working set of interlocking reduction gears, each section provides a 7:1 reduction. This device is about 2 inches in diameter, the total reduction is 14:1.

The original Ring Gear from Thingiverse was modified to create this multi-stage Reduction Gear. My contribution was to modify it as necessary and join two sets together.



Sketchup Model
The transfer plates (with the connecting pins) were assembled by adding the center HEX pin after printing.  Each of the two Reduction Cluster were printer as an assembled single object on the printer. No cleanup or filing was necessary.




Silicon grease is used for lube.

I may increase the size (and with other modification) this could be used as a Light Weight Field Day Antenna Rotor.

-- Home Page: https://WA0UWH.blogspot.com


Wednesday, May 3, 2017

Lost Friends


This week has not been a good week, very sad, two of my Ham Radio Friends have passed away.

Doug Phillips - W7RDP  (SK) a good friend from the local Pacific QRP Group (pQRP).

Don Sehulster - K7QYP / W7LSC  (SK) - a very good Navy Buddy (1968-1972).


73 - My Friends . . .  K



-- Home Page: https://WA0UWH.blogspot.com


Sunday, April 30, 2017

First 3D Printer

I purchased a 3D Printer, and just now learning how to use it, there is a lot to learn.

After many trials and failures, I have successfully printed the equivalent of "Hello World" for 3D Printers, which is the "3DBenchy". This online part was designed to be a torture test for a 3D Printer, with many under-cuts, over-hangs and fills, that are somewhat difficult. This part is about 2.5 inches long.

My Printed 3DBenchy Results
3DBenchy was actually about my 10th attempt at print anything, the first few parts went horribly wrong.

Here are a few of my initial prints of a part of my own design, obviously I did not know what I was doing.





Things got better with practice and understanding of the 3D Print process and control parameters.


The above is a replacement part for an Orbital Sander, this part is no longer available from the manufacture, it will eventually be printed with Black ABS Plastic, which is similar to the original. I designed this part with FreeCAD and used Slic3r for the G-Code output for the 3D Printer.  For me, FreeCAD has a steep learning curve.


And, then . . .

On the next part, a Cable Chain of my own design, I must have lost the magic !!


But finally, things got better with practice.

Cable Chain Links
The First Two Links of a Cable Chain.
I am currently printing four Cable Links with newer/better design, I will report the results. For these link design, I have used Sketchup and Slic3r. For simple designs Sketchup is easy to use, as long as you only need "Union" style of object creation, that is, objects that touch are automatically joined together (union'd) when exported as an STL file. STL files are needed by Slic3r.

Four Cable Chain Links
About 2/3 Complete

This is fun, I think I am going to enjoy my new 3D Printer.


-- Home Page: https://WA0UWH.blogspot.com


Tuesday, March 7, 2017

Esp8266 WebServer Farm - Again

After several long months, I have reactivated my Esp8266 WebServer Farm.

Use this links to all of my Esp8366 project blog posts.

Esp8266 WebServer Farm

Currently, one of my WebServers can be accessed as: http://esp.wa0uwh.com:8154

The main reason that it has be off-line, is lack of interest, and recently, I could only get the code to compile on the old Arduino IDE (Rev 1.6.x).  The code is quite large and I took advantage of many "tabs" for code fragments, which are concatenated before presented to the compiler.  The new Arduino IDE Revision (1.8.1) is much more strict regarding Header Files, code files, and program structure. There were just TOO MANY errors to correct to keep my interest in solving the problem.

Once started to solve the problems and not getting much accomplished, my Friend Jeff - Ko7m, suggest another IDE, he suggested "PlatformIO IDE".

With little work, I found and installed PlatformIO, but alas, I found similar problems and concerns with it.  But little-by-little after much on-line reading, Jeff and I worked out the best file structures that worked with PlatformIO.

I have not moved the new code structure to GitHub, but maybe soon.


-- Home Page: https://WA0UWH.blogspot.com


Saturday, January 14, 2017

My Soldering TIP #1

Several years ago my trusty Weller Soldering Iron failed, knowing that most of my projects were going to use small SMD parts, I ordered a fancy replacement, a Hakko FX-888 Soldering Station (about $90.00) with several assorted tips, some really small tips for SMDs. The tracking information, revealed that it would be in my hands in about three weeks.

But, I needed a replacement Iron NOW, to finish a project. I went to Frys, and found a cheapy Iron that I thought I could use (about $29.00), it was a Hakko Presto 980-V12/P. It had only one smallish chisel tip, but I thought it could be used for some larger SMDs.

Well, now several years later, the expensive Hakko FX-888 with its small tips is VERY seldom used (maybe about 3%), while the cheap Hakko Presto 980-V12/P is used for most (if not all) of my projects, and I am still using the original TIP. If you have seen my projects (typically on a 0.5in x 0.7in PCB boards) you might think the FX-888 would be more appropriate, but I fould it is not.

The following are some of my projects where the Hakko Presto 980-V12/P was used:

HomeBrew Double Sided
Si570 Board
HomeBrew Double Sided Project
These are 0805 Caps, and SOT-223 Voltage Reg
I like and use the Hakko 980-V12/P, it has "Two Temps, 20W normal, and 130W push button switch", very seldom have I used the 130W button.

I have recently purchased a second Hakko 980-V12/P for my tool box.

Today I think the Hakko 980-V12/P is priced about $60.00, if you are interested in online purchase, google is your friend. see: https://www.google.com/search?q=hakko+980

I think you will like it.

BTW: I use a "wall outlet timer" to supply power to my soldering irons, if I forget, the timer turns off power to them after about 45 minutes, which saves the soldering TIPs.


-- Home Page: https://WA0UWH.blogspot.com


Wednesday, December 7, 2016

A Small Experimental Receiver Circuit

I have finally found some time to "melt some solder" at my new location and new eShop bench. The bench is not finished yet, but I needed a Solder FIX.

This, like all of my project, is an attempt to make projects as small as my abilities allow.

New eShop Bench
The project that I am working on is some boards I just received back from OSH Park. The boards are a small and part of an experimental HF Receiver. The boards edge connectors are "Castellated" to allow them to be used within a larger PCB circuit, and with attached Headers, they can be used with/on a Solderless Proto Board.

The size of these boards are:
Left: 0.8x1.0 inch,
Right: 0.5x1.0 inch

This is my experimental design, it is a circuit that contain the:  HF VFO Mixer, Band Pass Filter (BPF, 40MHz), and BFO Mixer.

The bigger boards on the left are similar to those on the right, except they also contains the Oscillators for both the VFO and the BFO, along with the voltage regulator for the oscillator chip.

The components on the lower half are installed
Ready for some testing
Unpopulated is the VFO/BFO and Voltage Regulator
LTSpice suggests this circuit will work, but assessing the actual performance is the real reason for building this experimental circuit.

Additional circuits will be needed, to make this a real receiver, like: Band Select Filters, Automatic Gain Control, Audio Circuit, a Microcontroller, and Display. Likewise, I will make each as small as I can.

Testing will start when I have some (more) time.


-- Home Page: https://WA0UWH.blogspot.com