Sunday, November 20, 2016

My new eShop

UPDATED: 11/21/2016

I have NOT posted anything for several (6) months, my life has been in somewhat of turmoil (maybe, I am getting too old for this), but now, maybe things are starting to get back to normal.

Regardless, I have been thinking of many HomeBrew projects that I want to build and blog. But first I have to set up my eShop in this new (and better) location.

This is the beginnings of my new eShop setup:

My new eShop Bench
I just finished building the wooden shelves. My previous eShop shelves were about the same but fixed, these shelves are movable, and therefore this setup should be more effective for varying sized electronic equipment.

Adjacent to that,  is my current MS 10 WorkStation, Raspberry Pi, and Orange Pi set ups:

Computer Workstation
The three bottom screens are connected to the MS WorkStation, and the three uppers are for the PI's.

Note: and the refrigerator is only about 15 feet away, hihi.

Unfortunately, I have not started my Ham Station and Antenna System yet.

I have some small Ham Radio related PC boards out for manufacturing at OSH Park, if they works as expected, I may be blogging about those, soon.

UPDATE:

The day after installing my shelves and turning on the Oscope for the first time in a long while, the (calibration) trace is going bonkers, with a short bright spot at the beginning of the trace. Trace INTEN has little control.  DANG, now something else to repair.
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Tuesday, May 3, 2016

FORD Rant - Oil Cooler Bypass Valve - is a non replaceable part.

UPDATED: Tue May 17 11:19:46 PDT 2016

This is post not about Electronics, it is a RANT about FORD.

For the last few weeks, my Son and I have been working on his F350 6.0L Diesel Engine, to replace; the Exhaust Gas Recirculation (EGR) Heat Exchanger, and the Oil Cooler. This work is a pain because most of the top of the engine, including the Turbo Charger has to be removed to get to the parts being replaced. There are several good Youtube video showing the details.

We ordered parts and gaskets bases on information available. This repair is somewhat of a difficult task due to engine compartment large size and the long reaches necessary to access everything.  There is one very dirty mess when the Oil Cooler cover is removed, where about a quart of oil spills over the engine valley, but that cleanup marked the beginning of the actual part replacement and rebuild.

Most of the previously dis-assembled parts where replaced in the order they were removed without difficulty.

But Then

On top of the Oil Cooler Cover there is a small assemble which is held in place with two screws within the Oil Filter Case (Can). This small assemble is about 3 inches wide.

FORD Failed
Oil Drain Back and Oil Cooler Bypass Valve Assemble
This small assemble holds two valves; one to Drain Back oil from the Oil Filter Case (helpful during oil and filter changes), and the other is the Oil Cooler Bypass Value (OCBV) which opens in case the Oil Cooler get clogged up. These two valves are very simple; the first is held shut by gravity and can pressure; the other is a spring loaded Brass Plunger with a small flat plastic/rubber (of some sort) washer (flapper) that opens at 25lbs of Oil Cooler pressure.

Spring Loaded Oil Cooler Bypass Value
The Brass Plunger shows scoring
The Wood Chip holds open the washer at the failure.


The Problem

According to FORD, these two small values are NOT replaceable parts !!

And therefore, normal Auto Parts stores do not have the parts, nor does FORD.

Our OCBV plastic/rubber seal is damaged, and the Brass Plunger is scored showing that it had failed long ago.

The values can only be replaced with a NEW Oil Cooler Cover, which is about $180.00, the plastic/rubber part, if available, should only cost about $2.00, even though it is about $0.10 worth of plastic/rubber.

My Conjecture

I suspect that the OCBV failure contributed to the EGR Cooler failure and therefore the need to repair this engine - it is a $0.10 part ?

Our Planned Fix

Google searches provided very little help or suggestions of a solution.

Our current plan is to create a new Teflon washer (value flapper). A Teflon rod is now on order. Experiments with different on-hand materials failed to hold up in a gas/oil environment.  Teflon appears to have the right properties; inert and high temperature resistant.

Thanks FORD, my Son's truck has be on blocks for about three weeks now, while finding a workable solution.

End Rant

If this works as planned, I will be selling Teflon washer, and or Teflon Plunger with integrated Teflon Value seat, . . . soon :-).

Teflon Washer
Update:
The engine has now been running with the new Teflon Value Seat for several weeks, when the oil is changed it will be removed and inspected for ware.

Here is a photo of the Bypass Valve Assembly reinstalled ( I had forgotten I took this photo). The Oil Filter Tower and Canister have not been reinstall yet, as can be seen, two screws hold the assembly in place. Inspection for ware at the next oil change, will be easy.


-

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


Monday, February 1, 2016

ASCII Strings within the Largest Known Prime Number


Someone on the Youtube Numberphile Channel was wondering if after converting the Largest Prime Number  to base 26 (see previous post) would there be any interesting ASCII strings within the Number.

I think I have created a Unix Function that will do the conversion.

( echo "obase=16;"; echo "obase=26; 2^74207281-1" | bc | tr -d '\n\\' | sed 's/ /;65+/g' ) | bc | xxd -r -p

This will take a while (maybe several hours, or days), but if I find something interesting, I will report the results.


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

Friday, January 22, 2016

The New Largest Prime Number Found

UPDATED:
Added Details and Links

Recently (Jan 7. 2016) the next and Largest Prime Number has be found (so far), it has about 22 Million Digits long, See, YouTube at: https://goo.gl/C7ngE7.

The number can be expressed as a small-simple math function, that is: "2^74207281-1"

The previous Large Prime Number (17 Million Digits) was found about 3 years ago on Jan 25, 2013, see: http://goo.gl/UbAWK0

Hopefully, and if history hold true, we will see the next Largest Prime sometime within the next 3 to 5 years.

Just for fun, I decided to see how long it would take my 3.4GHz Workstation to perform the calculation and print the full 22 Million Digits to the screen - it took about 154 minutes - it was like watching paint dry.  :-)

Note: To verify that it "is actually prime" would probably take several months (or more actually several years) on my computer.

Here is the linux command that I used to print this New Prime, and a few of the Beginning and Ending Digits of the results:



$ time echo "2^74207281-1" | bc
30037641808460618205298609835916605005687586303030148484394169334554
77232190679942968936553007726883204482148823994267278352907009048364
32218015348199652241372287684310213386284573666361506667532122772859
35986405778025687564779586583214205117110963584426293657265038724071

.
 .  ( 22 Million More Digits )
  .

74801792765597096176486305356033886997788467889060830923906229428002
87770846681535011427622921221836904045477963931367013401448014940470
41169663347456468851607177740147629124621136468794258014451073931002
12927181629335931494239018213879217671164956287190498687010073391086
436351

real 153m50.931s
user 92m34.588s
sys 0m13.496s



Note: To capture the number on the screen, a large display buffer of more than 22 Meg Bytes (of RAM) was necessary.

I need to check with YouTube and/or Numberphile to see if my calculated number is correct  :-)

My computer is current checking four large numbers to see if they are Prime, this consumes about 100% of the Quad Core CPU, but it runs at a very low priority so it does not effect my use of the computer. Each is expected to finish at different times, Below shows the number being tested, and number of days until I should have the results:
As you may have expected, . . . I am a fan of Very Large Numbers !

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

Thursday, January 21, 2016

Simple Complexity - By Proxy

UPDATED:
Added Details and Links

For sometime I have struggled with how to allow public access to my home web servers and Esp8266 modules without opening up my network to abuse. In the past I have managed public access via my Router, by changing its configuration of Port Forwarding and NAT.  This works, but it is a pain to manage and generally requiring a re-boot of the network for each change.

Recently, I have discovered (actually re-discovered) that an Apache2 Web Proxy Server is much easier to manage, but it has a bit of a steep learning curve, with a lot of manual pages to read. One key concept is that Apache2 ReWriteRules are a super-set of the functionality of ProxyPass, each have their own documentation web pages.

After building the Required Config files

Now, on my Router I allow only Ports: http 80, 8040, 8160, and a private ssh port for access from the Internet. Ports 8040, and 8160 are still open for historical reasons, that is, they are used for my published Web Pages at: http://www.WA0UWH.com:8040, and my Esp8266 Server Farm devices.

The Apache2 Web Server supports: Virtual Host Names with Proxy Redirects, ReWriteRules, and ProxPass. By setting up "*.wa0uwh.com" as a CNAME (an aliases) to "www.wa0uwh.com" at my DNS Provider, I can use any "device name" I would like in the config files to initiate a proxy process. For example: I can now use and publish "http://node129.wa0uwh.com" for one of my Esp8266 Web Server modules. The actual connection details and security are all hidden behind the proxy curtains.

The normal web page port 80 is setup with a default virtual host page of; "Error 404", only configured virtual hosts and named devices are let through the proxy.

Note: The service and/or host that is selected is a combination of both Port Number and Host Name (or alias). For an incoming connection, the file is scanned from top to bottom, only the first match is used to select the service.

The following are excerpts from my Apache2 Default Virtual Host configuration file.


ServerName default.wa0uwh.com
LogLevel alert rewrite:trace1

<VirtualHost *:80>

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/DEFAULT/Public

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

</VirtualHost>

# End



The following are excerpts from my Apache2 Named Virtual Host configuration file.


## Main Web Pages

## Loft Raspberry PI
<VirtualHost *:8040 *:80 >

    ServerName  rp21.wa0uwh.com
        RewriteEngine on
        ServerSignature Off
        RewriteRule /(.*)$      http://192.168.___.___/$1 [P,L]

</VirtualHost

## Loft Raspberry PI
<VirtualHost *:8040 *:80 >

    ServerName  rp22.wa0uwh.com
        RewriteEngine on
        ServerSignature Off
        RewriteRule /(.*)$      http://192.168.___.___/$1 [P,L]

</VirtualHost>

# Esp8266 Node on Published Port 8160
<VirtualHost *:8160 >

    ServerName  node.wa0uwh.com
    ServerAlias node*.wa0uwh.*
    ServerAlias localhost
        RewriteEngine on
        RewriteRule /(.*)$    http://192.168.___.___/$1 [P,L]

</VirtualHost>

## Loft Esp8266 Nodes
<VirtualHost *:8040 *:80 >

    ServerName  node.wa0uwh.com
    ServerAlias node*.wa0uwh.com
        RewriteEngine on
        ServerSignature Off
        RewriteCond %{HTTP_HOST} ^node(129|162|164|168|169|170|172)\.wa0uwh\.com [NC]
        RewriteRule /(.*)$      http://192.168.___.%1/$1 [P,L]
        RewriteRule /(.*)$ -  [R=404,L]

</VirtualHost>


## Loft WA0UWH Web Server
<VirtualHost *:8040 *:80>

    ServerName www.wa0uwh.com
    ServerAlias *.wa0uwh.com
    ServerAlias localhost 192.168.__.__ 
        DocumentRoot    /var/www/WA0UWH/Public
        Alias /gallery  /var/www/WA0UWH/Public/Gallery

</VirtualHost>

# End



Note, the above is just an excerpt from my Apache2 Virtual Host config file. For security reasons, the details; actual IPA's (___), BlackListing, Hacker Traps, Web Abuse Traps, and HoneyPots, are NOT included . Google is your friend for suggested configurations.

Now, with simple edits of the Apache2 Virtual Host config file, I can turn ON or OFF, devices and/or services as desired, while leaving only the http and ssh ports open for public access at the router.

Also note: each of my Raspberry PI Web Servers also have similar Apache2 Virtual Host config files, that is: Proxies are serving Proxies, and most often the actual destination is at different physical locations, and on different Networks! All unseen for my Internet users.


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

Monday, December 14, 2015

Got a Round TUIT

UPDATED:

As previously posted, I just needed a Round TUIT.

I receive the replacement CDSH270 Diodes for my Antenna Tuner today, with a little work and with a TUIT they were installed. The Tuner now works as before.

While during the surgery on the tuner, I installed some sharp pointed spark gaps at the SO-239 connectors, and between the Balanced Line Terminals. Maybe they will help save the Diodes the next time I forget to disconnect the Antenna during the an Electric Storm.

For the spark gaps, I soldered one end of a heavy copper wire directly to the SO-239 RF center connector, and then bolted the other end directly to ground (at the connector mount point). After the "Short" was installed, I cut it at the center with dull side-cutters, leaving sharp points on each side. The gap was adjusted to about 1/20 of a inch. The same was done between the Balanced Terminals.

With another TUIT, I installed a 6 AWG ground wire to the Tuner, but waiting for a large spade lug to make the final connection. My available lugs are not big enough for 6 AWG.


Today was nice and sunny, so I also raised the Long Wire Antenna to it normal height. Yesterday when I was repairing it, it was too cold and wet to futz with it to bring it to full height at 90 feet AGL.
 
Two years ago I tried to work on the antenna, but could not get the 3/32 support line to slide back down the tree. I suspected it had "grown" into a limb, or was pitched into a warren slot. My friend Jeff - KO7M and I was able to pull together hard enough to finally break it free. To avoid the same problem again, I slipped the line into a 20 foot piece of 1/4 inch polypropylene ice-make tube. which we pulled up into the tree where the support line goes over the branches.  Now two years later the line was easy to pull down and then back up.

So far I have made a few SSB contacts with the current antenna configuration. Now I am anxious to work some WSPR - but another TUIT is in the way.

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


Sunday, December 13, 2015

Some Antenna Work and Repair

UPDATED: Tue Dec 22 21:38:59 PST 2015

I removed the 9:1 BalBal from my Off-Center-Fed Long Wire Antenna, as described below, it did not work as well as expected. More testing and measurement needed.



There has been a lot of chatter on the local Yahoo pQRP email list about building some 9:1 Ununs as a group project. I already have the Toroids and Wire and had planned to make several of my own - I was just waiting for a Round-TUIT (TUIT).

For the last several (6 or so) years, I have been using a 300 foot Off-Center-Fed (OCF) Long Wire antenna. It is strung up near the top of some nice tall trees with the feed point at about 90 feet AGL. It has worked very well on all bands for WSPR, QRSS, CW, and general Ham use. The antenna is fed with 450 ohm ladder line fed from a Tuner with an internal Balun. I rarely have to provide much L or C adjustment for reasonable performance.

With a crippled antenna (see below), last night I worked Sandy - KG7FFP as she is new General License Ham - Good going Sandy! We were on 80m, 3.885MHz.

There are several things that I have wanted to try, to see if I could improve performance.

The first, is a no-brainer; Ground the Tuner and the Rig, something that has always been waiting for another TUIT.

The second, may be more controversial, I have wanted to put a 9:1 BalBal at the feed point of the OCF Long Wire.  With 450 ohms ladder line in, the output should approximate 4050 ohms, which I think would more closely match typical OCF Long Wire feed impedance. In my case the short end of the Long Wire is about 20 feet. The Feed Line drops straight into my Loft's window, across the celling to the Ham Rig, I think more impedance is desirable, in reality, I thing everything in close proximity becomes the antenna, that is; the long wire, feed line, metal roof, and the moss soaked wet-trees, and I don't think they are typically just 450 ohms  :-)

Another "nit" that I wanted to improve (or remove) is the "egg" insulator at the feed point. I have never really liked this centre point set up, but it is what I had when it was first installed. The new set up is a now a 14 inch long, 3/4 inch PVC (conduit) with three holes in each end. The antenna wire goes through a "Z" bend at each end of the conduit, then "V's" down to my new 9:1 BalBal, which is about 18 inch lower. The antenna wire is standard, solid copper 12 AWG conduit wire.

My antenna tuner is still in my eShop waiting replacement diodes (CDSH270), they are on order and should arrive soon.  The antenna and Tuner took a near hit during one of the last electric storms. I was near the radio and heard a snap or spark across the terminals or somewhere inside, the radio did not suffer any ill effects, the tuner TOOK it ALL.

So, now what?

My newly configured OCF Long Wire Antenna is now up and ready for use, but still waiting tuner repair.

I am expecting some VERY GOOD to EXCELLENT performance from this antenna configuration, because it was installed exactly as per the weather-man specification - that is, it was raining all the time I was outside working with; support lines, antenna wire, BalBal, and feed line. I got soaked ! Everyone knows, that the best antennas always go up during inclement weather.

But, time will tell, I will post my impressions, measurement, and results, when available.


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


Saturday, December 12, 2015

More Fun with Cyclops Numbers

UPDATED:
Added Details and Links


I created a fun function to compute Cyclops Numbers, see previous post.



D=9; C=0; L=27; 
echo "obase=${D}+1;(${D}+1)^(2*${L}-1) -1 -(${D}-(${C}%${D}))*(${D}+1)^(${L}-1)" | bc

Where:
  • D = Is the side Digits, 1 to 9
  • C = Is the single Cyclops Eye Digit, must be < D, or C mod D will be used
  • L = The Cyclops Eye Location (width)

D=8; C=3; L=2; => 838
D=8; C=3; L=3; => 88388
D=8; C=3; L=4; => 8883888
D=4; C=8; L=5; => 444484444
D=9; C=0; L=6; => 99999099999

The results for the above function:

99999999999999999999999999099999999999999999999999999


It is all fun and games, until someone pokes the Cyclops Eye   :-)


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


Wednesday, December 9, 2015

More Large Numbers

UPDATED:
Added Details and Links

Update: Jan 7, 2016 - New Largest Prime found: echo "2^74207281-1" | bc, which is 22 Million Digits, the function takes 77.25 minutes to compute on a 3.4GHz Processor. See, youtube at: https://goo.gl/C7ngE7

See previous post.

The largest known prime number is: 17,425,170 digits long, it can be computed with this very short function:

echo "2^57885161 -1" | bc

On my Workstation (2.2GHz) it takes about 82 minutes to compute, but with more than 17M digits, it takes much longer to display or print.

To print, it would require 7.7 Reams of paper; single sided, 80 character per line, 56 lines to a page, and 500 pages pre ream.

Note: The person that finds the "next" larger prime number will be famous.


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


Large Numbers

UPDATED:
Added Details and LInks

As noted in previous posts, I am a fan of Large Numbers, I am especially interested in small functions that compute Large Numbers.

Recently I watched a Numberphile Youtube video, which captivated my interest. The numbers that I found most interesting are large "Cyclops Numbers".

The following Linux function will compute a large Cyclops:

echo "10^(2*253-1) -1 -9*10^(253-1)" | bc

Can you spot the Cyclops Eye?


99999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999999999999999999999909999999999999999999\
99999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999


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