3 Element 2 Meter Yagi Antenna

This is my next Antenna Project

3-Element-2-Meter-Yagi

 

Typically the reflector is 5% longer and the director 5% shorter than the driven element. By spacing elements about 0.15 to 0.25 wavelengths from each other you end up with a beam antenna with about 7dB of gain. (According to the author) To figure out the correct length of the driven element the following simple formula for a half-wave antenna above 30 MHz is used :

Length in feet = 475 / Frequency (MHz)

Construction : 3/4 inch PVC plumber’s pipe is recommended for the supports. Two 18 inch pieces become the boom where the elements are installed. A 36 inch piece is used for the mast. (Although not shown in the original drawing, it is assumed the the T is about 2 inches long.)
The boom and mast pieces are held together with a PVC T joint. Three small holes are drilled in the T as well as the boom and mast pieces. (Look at the T in the drawing for the small black dots. These are the locations of the screws).The boom and mast are inserted into the T and rotated until the holes are aligned. Then the boom is secured with screws…or you may use bolts also if you prefer.

Screws or bolts are used to secure everything in place. Put them just to the side of the elements so as to press against them when tightened. The antenna in the drawing is vertically polarized which is best for FM work.

The director and reflector elements are cut as according to the lengths in the drawing above.

A straight pencil line should be drawn along the boom with an X mark for each hole to keep the holes aligned at the same plane. The hole size chosen should provide a snug fit for the rods when pushed through. After drilling, the reflector and director elements are slid through the holes and adjusted for equal length on each side of the boom. Screws, bolts or epoxy cement is used to hold them in place.
To build the driven element the boom is measured and marked at a distance of about 16 inches from the reflector. Two holes are drilled 1/8 to 1/4 inches apart. Two rods each around 20 inches in length are pushed through the holes until 1/4 inch protrudes from each side of the boom. THE DRIVEN ELEMENT AND MATCHING DEVICE HAS JUST BEEN MADE. Also see “Tuning” below for more info.

The 50 ohm coaxial cable is soldered directly to the protruding stubs. Screws or epoxy is used to secure the rods to the boom but only after swr tuning is done.

Electrical tape or a silicon compound is used to weather proof the solder joints.

It is better to have a little excess length for the driven elements. The antenna should now be hoisted to an elevation of at least 5 feet from the ground and kept away from nearby metal objects or the reflector can be against the ground with the director aimed straight up while braced to prevent it from falling over while tuning. Keep the coax away from the driven element while tuning. See tips below.

Tuning:
With the aid of an accurate 2 meter SWR meter placed in the line between the transceiver and the antenna, the driven element lengths can now be trimmed OR slid in or out of the boom OR both, equally for the lowest SWR at the desired frequency. Remember, start long with the driven element, check swr, and either trim or lengthen each end as needed and or slid the elements in the appropriate direction. Using this method of tuning should yield you a good swr.

After lowest swr tuning is finished use the screws or bolts to secure the elements.
Tips….
Mount the antenna on another suitable support up as high as possible when finished with tuning.
Using the 36″ PVC pipe connected to the boom keeps a metal mast support away from the driven elements which may deform the antenna pattern and create swr problems.
After connecting the coax, it can be taped or secured with UV resistant wire ties to the boom and layed out toward the reflector end while securing it to the boom and then a large loop back down to the mast below the driven element to keep the coax away from the driven element. One other method would be to push the coax from the reflector end of the boom toward a suitable sized hole near the driven element and then make your feed connections. Seal the hole if needed afterwards.

Portability:

The 2 meter beam can be made very portable by removing the 2 18″ boom sections or use your own method to disassemble the antenna.

Windows 10 Editions

windows-10

Microsoft is not yet disclosing the standalone pricing or the detailed feature set and licensing specifics of its Windows 10 SKUs.

As Microsoft said months ago, the company plans to make Windows 10 available as a free upgrade for consumers running Windows 7, Windows 8.x and Windows Phone 8.1 for the first year following availability of the Windows 10 operating system. Some business users — those who want Windows 10 Pro — also will qualify for the first-year-free deal, but enterprise customers will not, Microsoft execs have said.

Here’s the Windows 10 SKU line-up:

Windows 10 – Mobile is designed to deliver the best user experience on smaller, mobile, touch-centric devices like smartphones and small tablets. It boasts the same, new universal Windows apps that are included in Windows 10 Home, as well as the new touch-optimized version of Office. Windows 10 Mobile offers great productivity, security and management capabilities for customers who use their personal devices at work. In addition, Windows 10 Mobile will enable some new devices to take advantage of Continuum for phone, so people can use their phone like a PC when connected to a larger screen.

Windows 10 Pro – is a desktop edition for PCs, tablets and 2-in-1s. Building upon both the familiar and innovative features of Windows 10 Home, it has many extra features to meet the diverse needs of small businesses. Windows 10 Pro helps to effectively and efficiently manage their devices and apps, protect their sensitive business data, support remote and mobile productivity scenarios and take advantage of cloud technologies. Windows 10 Pro devices are a great choice for organizations supporting Choose Your Own Device (CYOD) programs and prosumer customers. Windows 10 Pro also lets customers take advantage of the new Windows Update for Business, which will reduce management costs, provide controls over update deployment, offer quicker access to security updates and provide access to the latest innovation from Microsoft on an ongoing basis.

Windows 10 Enterprise – builds on Windows 10 Pro, adding advanced features designed to meet the demands of medium and large sized organizations. It provides advanced capabilities to help protect against the ever-growing range of modern security threats targeted at devices, identities, applications and sensitive company information. Windows 10 Enterprise also supports the broadest range of options for operating system deployment and comprehensive device and app management. It will be available to our Volume Licensing customers, so they can take advantage of the latest innovation and security updates on an ongoing basis. At the same time, they will be able to choose the pace at which they adopt new technology, including the option to use the new Windows Update for Business. With Windows 10, Enterprise customers will also have access to the Long Term Servicing Branch as a deployment option for their mission critical devices and environments. And as with prior versions of Windows, Active Software Assurance customers in Volume Licensing can upgrade to Windows 10 Enterprise as part of their existing Software Assurance benefits.

Windows 10 Education – builds on Windows 10 Enterprise, and is designed to meet the needs of schools – staff, administrators, teachers and students. This edition will be available through academic Volume Licensing, and there will be paths for schools and students using Windows 10 Home and Windows 10 Pro devices to upgrade to Windows 10 Education.

Windows 10 Mobile Enterprise – is designed to deliver the best customer experience to business customers on smartphones and small tablets. It will be available to our Volume Licensing customers. It offers the great productivity, security and mobile device management capabilities that Windows 10 Mobile provides, and adds flexible ways for businesses to manage updates. In addition, Windows 10 Mobile Enterprise will incorporate the latest security and innovation features as soon as they are available.

There will also be versions of Windows 10 Enterprise and Windows 10 Mobile Enterprise for industry devices like ATMs, retail point of sale, handheld terminals and industrial robotics and Windows 10 IoT Core for small footprint, low cost devices like gateways.

Windows 10 is scheduled for this summer 2015!

Uninstall ForeFront Client Security Script

ForeFront-Client-Security

Here is a script which you can use to uninstall Microsoft Forefront Client Security. In this script you will see functions for removing Microsoft Forefront Client Security Antimalware Service and Microsoft Forefront Client Security State Assessment Service.

Copy and paste this code into notepad then rename to .vbs file.

Option Explicit

const HKEY_LOCAL_MACHINE = &H80000002
Dim SASProductName, SASProductKey, SSSProductName, SSSProductKey, Msg, MsgBoxStyle, RegKey

‘~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sub GetFCSKey()

dim oReg, sPath, aKeys, sName, sKey
Set oReg = GetObject(“winmgmts:{impersonationLevel=impersonate}!\\.\root\default:StdRegProv”)

sPath = “SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall”
oReg.EnumKey HKEY_LOCAL_MACHINE, sPath, aKeys

For Each sKey in aKeys
oReg.GetStringValue HKEY_LOCAL_MACHINE, sPath & “\” & sKey, “DisplayName”, sName
If Not IsNull(sName) Then
if (sName = “Microsoft Forefront Client Security Antimalware Service”) then
SASProductKey = sKey
SASProductName = sName
end if
if (sName = “Microsoft Forefront Client Security State Assessment Service”) then
SSSProductKey = sKey
SSSProductName = sName
end if
end if
Next
end sub

‘~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

sub UninstallFCS(key, name)
dim cmd, objShell, iReturn, oshell

cmd = “C:\windows\system32\msiexec.exe /q/x ” & key
set objShell = wscript.createObject(“wscript.shell”)

objShell.LogEvent 0, “Removing the program [” & name & “] under Product Key [” & key & “]” & vbCrLf & “Executing command: ” & vbCrLf & cmd

iReturn=objShell.Run(cmd,1,TRUE)

if (iReturn = 0) then
objShell.LogEvent 0, “Program [” & name & “] was successfully removed”
else
objShell.LogEvent 0, “Failed to remove the program [” & name & “].”
end if

Set objShell = Nothing
end sub
‘~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SASProductKey = “”
SASProductName = “”
SSSProductKey = “”
SSSProductName = “”
call GetFCSKey()

if Not (SASProductKey = “”) then
call UninstallFCS(SASProductKey, SASProductName)
end if

if Not (SSSProductKey = “”) then
call UninstallFCS(SSSProductKey, SSSProductName)
end if
‘~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

Slim Jim Antenna Project

The Slim Jim Antenna

The Slim Jim is a vertically polarized omnidirectional end-fed antenna having considerable “gain” and this is concentrated almost parallel to ground toward the horizon rather than skyward making it more efficient than a ground plane type antenna by about 50 percent better. It can be built for almost any frequency! ( Below 10 meters it gets VERY tall )
Due to it’s SLIM design, there is very little wind loading. It is fed with 50 ohm coax.

It uses a ‘J ‘ type matching stub (J Integrated Matching = JIM), hense the name SLIM JIM. Credit for the original design goes to F.C. Judd, G2BCX. Since the vertical angle of radiation is so narrow, about 8 degrees toward the horizon, it usually out performs 5/8 λ  or groundplane type construction due to their much higher angle of radiation. It is estimated that the Slim Jim appears to have about 6dB gain over a 5/8 λ  antenna due to the extreme low angle of radiation.

(Most of the radiation is directed toward the horizion making the “gain” appear much greater than other vertical type antennas it has been compared to with A/B testing)
Editor’s note: There are many gain figures quoted for this antenna and also various descriptions of the actual type of antenna on various websites. Some have even stated that, “In fact I found it outperformed a 1/2λ  over 1/2λ  over 1/2λ  colinear!” No matter what you call it, it seems to do an excellent job according to most reports. What have you got to loose? Please let us know your results…..email us! n4ujw AT hamuniverse.com.

Using heavy duty construction would make this a good omni repeater antenna. When correctly matched for lowest swr, it has wide bandwidth.

slim-jim2 slim-jim1

Construction details:

NOTE: NO PART OF THIS ANTENNA SHOULD BE GROUNDED!

It should be totally insulated from it’s mount, mast, tower, etc with at least 1/4 λ length of “freespace” distance. Formulas are provided below for all the measurements including the freespace distance.

The Slim Jim should be constructed from 1/2″ copper pipe. Also old tv antenna elements or aluminum tubing could be used with some ingenuity and would be lighter. Experimentation with heavy guage wire supported inside PVC tubing or attached to insulated material such as wood could also be tried and would probally be successful with some ingenuity. 300 ohm twinlead versions also work great! Using copper pipe, bends are made with soldered 90 degree copper elbows. An adjustable slip sleave made from copper can be added to the element on top above the gap for tuning purposes or possibly some sort of nut, bolt arrangement soldered into the upper end to adjust spacing if needed. (See the 2 meter SSB loop project on this site for better details and pictures of the nut, bolt arrangement.)

Depending on the frequency or band, the average length of the gap and spacing between the elements is 3″ at 72MHz and 1″ at 220MHz. (See updates below) For 2 meter work this would be around 1 1/2 to 2 inches. Some experimenters report about 1 inch or less works well. Experiment with the adjustment for best results. The recommended mount is the use of  PVC pipe and PVC pipe “T’s.”

Testing and tuneup:

Support the antenna as high as possible from the ground and other nearby objects especially metal, and fit the coaxial cable to the antenna with some crocodile (alligator) clips. It is suggested that the center conductor be attached to the longest element, shield to the shortest. See diagram above. Attach about 2 to 4 inches up from the bottom and check the VSWR at the design frequency. USE LOW POWER! Adjust the clips up or down to get the best match, mark where they are to be finally installed, remove the clips, and solder the coax directly or use clamps, screws, etc. Waterproof or seal all connections and the end of the coax. Use the copper sleeve or nut bolt arrangement, if added, for any necessary tuning.

FORMULAS

(For results in inches)

NOTE: Air gap and element spacing may have to be determined by some experimentation for various frequencies.

See new info about gap spacing below.

(Divide results by 12 for feet)

3/4 λ  (longest section)             = 8415 / fMHz = inches

1/2 λ  section                = 5610 / fMHz = inches

1/4 λ  section                = 2805 / fMHz = inches

* 1/4 λ  freespace          = 2953 / fMHz = inches

* This is the distance that antenna should be from mounting  boom, mast or tower.

Note: These formulas are believed to be accurate. Some trimming or tweaking of lengths may be needed with YOUR construction!

Slim Jim Metric Formulas:

(For results in meters)

213.74 / fmhz                            = 3/4 λ  overall length

142.496 / fmhz              = 1/2 λ  length

71.248 / fmhz                            = 1/4 λ  length

Feed point                    = About 10 to 20% of 1/4 λ length (+ – tuning)

75 / fmhz                      = 1/4 λ  “freespace” in Meters

Note: These formulas are believed to be accurate. Some trimming or tweaking of lengths may be needed with YOUR construction!

Some Examples

2 Meters 146.00mhz

3/4 λ  section    8415 divided by 146      = 57.63 inches ( 146.38 m)

1/2 λ  section    5610 divided by 146.00 = 38.42 inches (   97.59 m)

1/4 λ  section   2805 divided by 146.00 = 19.21 inches (   48.79 m)

1/4 λ  freespace 2953 divided by 146.00 = 20.22 inches (   51.36 m)

Feed point about 10 to 20% of 1/4 λ      =    1.9 to 3.84 inches (+ – tuning)

The gap would be a guestimate at about 1 1/2 to 2 inches (+ – tuning)

Remember, the 1/4 λ  freespace is the distance from the mount as a minumum.

6 Meters 50.150mhz

8415 / 50.150mhz                      = 167.79 inches

5610 / 50.150mhz                      =   111.8 inches

2805 / 50.150                            =   55.93 inches

Gap spacing 10 to 20% of 1/4 λ = 8 inches (15%)

Freespace mounting distance 58.8 inches

10 Meters 28.400mhz

8415 / 28.4mhz = 296.30 inches (24.69 feet)

5610 / 28.4        = 197.5 inches   (16.45 feet)

2805 / 28.4        = 98.76 inches   (  8.23 feet)

Freespace mounting distance 103.97 inches (8.66 feet)

17 Meters!

A 52 foot vertical including minimun distance from ground! Hay don’t laugh! It might be worth a try for 6 db more! Please send us your input if you have suggestions for any band using this antenna! The lengths will have to be adjusted slightly for the addition of the top and bottom connection points. See Construction and Testing tips below.

CONSTRUCTION and TESTING TIPS
CONSTRUCTION:
=============
The Slim Jim should be constructed from 1/2″ copper pipe OR near this size of any conductive material but this is not an absolute! The bends are made with soldered 90 degree copper elbows if your using copper tubing.

A slip sleave or other arrangement can be added to the upper or lower part of the gap made from copper, brass or aluminum for adjustment of the gap measurement for swr tuning, although the average length of the gap and spacing between the elements is 3″ at 72MHz and 1″ at 220MHz. Some experimentation may be needed for gap distance.
For 2 meters, this would be about 1 1/2 to 2 inches. Here again, this measurement is not extremly critical and the gap, element spacing and element length all interact.
The total distance from the top of the gap around the entire length and back to the bottom of the gap should equal about 1.5 λ lengths or in the case of the 2 meter example above about 115.26 inches.

No part of the antenna should be grounded to the tower or mast.  The
recommended mount is the use of PVC pipe and PVC pipe “T’s.”   Make sure the space between the tower or mast and the antenna is one “freespace” 1/4 λ length.
TESTING:
========
Stand upright (on a railing or non-conductive object, clear of metal surfaces,
drain pipes, etc.) and fit the coaxial cable to the antenna with some crocodile (alligator) clips.  Attach about 2 to 4 inches up from the bottom (at 2 meters). It is suggested that the center conductor be attached to the longest element, shield to the shortest and using just enough power to get an swr reading, check the VSWR. Adjust the clips up or down to get the best match, mark where they are attached, remove the clips, and solder the coax directly.  Seal connections and end of coax!

Use the copper sleeve, or other spacing adjustment if added, for any necessary tuning. You may not get that perfect 1:1! The air gap, total length and element spacing all interact.

License to Pawn By Rick Harrison Book Review

License-to-Pawn-By-Rick-Harrison

License to Pawn: Deals, Steals, and My Life at the Gold & Silver By Rick Harrison of the popular TV Show on the history channel Pawn Stars was a great book. When I first picked this book up I was afraid that this was going to be an almost 300 page infomercial for the show Pawn Stars boy was I wrong but in a good way.

As well all know from watching the show Rick Harrison loves his history he describes himself in the show as a “Uber History Nerd” and in License to Pawn Rick Harrison gives you his history. He talks a little bit about his life growing and some health issues he has as a kid. Harrison gives an in depth history of his father and his military background. Harrison even goes in depth about his other family members.

Harrison then dives into starting the pawn shop business and how they got started just buying and selling gold and silver to then opening a coin shop then to acquiring a pawn broker license and then struggles to open up a larger store.

Harrison then writes about life before then the show and how the pawn shop business works. Talking about how people use the pawn shop for credit and how people use it to get money to gamble in vegus. Harrison goes into depth telling stories about the kind of customers he services and how the business stay profitable.

Harrison then writes about his real relationship with his father, his son and Chum. He speaks about how sometimes there real feeling for each other does not come out on TV. Harrison writes about working very hard to get a reality TV show and how the original channel that was going to pick it up was HBO but the deal fell through at the end.

Harrison talks about the late nights and long days of recording the show and how they have been forced to close the shop while filming. They then goes on to explain that as much as the show has helped him and his family in the financial area he misses talking to his regular customers at times.

Harrison did admit to family issues between his other son and Corey do the popularity of the show. Harrison goes on to say how the pawn shop is ran mostly by his workers rather than him and Corey cause they are too busy with the show and appearances.

Overall I give this book 5 stars because Rick Harrison wrote this book as a business man not as a television personality. I learned a lot about the pawn business from this book. I would say this book is more of a business manual for a pawn shop owner or someone looking to own or buy a pawn shop. Even though Rick Harrison is main star on Pawn Stars he puts the focus on the Pawn Shop not himself.

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License to Pawn: Deals, Steals, and My Life at the Gold & Silver

TTG 53 – Interview With Joel Richardson

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The Technology Geek Podcast 53

Interview With Joel Richardson

Today in this podcast we are joined by Joel Richardson from Soul Joel Productions on the Podcast. He talks about the comedy business and his work as a producer. Joel tells us about his start in the business and about his great group on comedians he manages. We talk about the venues he runs and about his upcoming performance in my area at Ehrhardts Waterfront Resort. We go into detail about being a headliner vs a producer. We talk about his new website http://sjpcomedy.com. We talk tech news in the beginning and have our interview with Joel at the end.

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TTG 52 – Interview With The Band Reapers

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The Technology Geek Podcast 52

Interview With The Band Reapers

Today in this podcast we are joined by Randy and Onslaught from the band reapers on the Podcast.  They talk about starting there band using myspace and social media. They talk about the equipment they use to record and making money on band camp. They discuss there new songs and the writing process involved. They talk about there song there The Glory and that being there break out hit. I talk with Onslaught about guitars and guitar equipment. We bring up stories about starting out in music as a kid and what bands drew them into the business. We talk about how technology has changed the music business and using live shows to promote new music. We then spin some of there most recent tracks. You can catch there music on http://reapers.bandcamp.com

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Michael Connelly The Reversal Book Review

michael-connelly-the-reversal

The Reversal is the third installment of Michael Connelly’s Mickey Haller (The Lincoln Lawyer) series and is the first time we see Mickey Haller team up with Harry Bosch from New York Times bestselling author Michael Connelly’s flagship Bosch series.

Defense attorney Mickey Haller is recruited to prosecute the high-profile retrial of a brutal child murder. After 24 years in prison, convicted killer Jason Jessup has been exonerated by new DNA evidence. Haller must team up not only Bosch but his ex-wife a full time district attorney to convict Jessup a second time.

Together, Bosch and Haller set off on the case LAPD Detective Bosch must find a runaway eyewitness reluctant to testify after so many years. In the meantime Haller must deal with Jessup being out on bail and trying to put together a case on evidence 24 years old.

During the road to building a case Haller must deal with a sly and crafty defense attorney that loves the media and using the media to his advantage. All this while Harry Bosch must stay on Jessup’s tail using surveillance and his detective skills.

This is my favorite book out of Michael Connelly’s Mickey Haller series having both Haller and Bosch working together on a case pulls you into the book. The other thing that really draws you in is having Haller a veteran defense attorney being the prosecutor gives you insight to how he thinks and his pure skill set for the law.

I would give this book 5 stars it’s a great book I would rate this as best book Michael Connelly has written.

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The Reversal (A Lincoln Lawyer Novel)