Dangerous Gmail Phishing Attack

Published January 12, 2017 at 03:02 PM EST
Updated January 18, 2017 at 10:42 PM EST
— Added update notice regarding WordFence’s article.

Hi all.  I wanted to let you know about a dangerous and highly effective Gmail Phishing attack that’s been circulating around.  It’s very tricky and works even on technically savvy users.  Also, even though it’s targeted toward Gmail users, it could probably be adapted to other platforms such as Facebook, etc.

This could apply to you or your friends.  It’s complicated, but as I understand it, you get an email from a friend (who was hacked).  It has a thumbnail image which you click to see.  The image may look familiar and be appropriate to the sender or even be something you know the sender would have.  Your browser pops up and asks you to login to Gmail, which is fake, but you don’t know it.  Even a cursory glance at the address bar shows google.com, as you would expect.  If you complete the sign in procedure, the hackers take over your account.  Then the hackers possibly lock you out of your account and definitely use it to hack your friends as well, using your contact list and your attachments.  They can also access your entire email history and use your Gmail account for password resets on other sites.

Much more detail is shown in the blog post where I got this info over at WordFence.  Even though WordFence is a WordPress specific plugin, this info is relevant to a much wider audience.  WordFence has added an update at 11:30pm on Tuesday January 17th.


If you receive such an email from your friends or associates, be very suspicious.  If something pops up and asks you to login, look for “https://” at the far LEFT of the address bar in your browser, followed by the site name (ie google.com) of the site you’re being asked to login to.  Also, consider whether a login screen is appropriate, ie, are you already logged in?  If you think you’re about to be hacked, do not enter data in the login screen.  Immediately close your browser.  If you think you’ve been hacked, and if you still can, close all your browsers, reopen one, and login to Gmail (or other relevant account) the normal way and immediately change your password.

Consider adding 2 factor authentication to your account.  See other articles on my site about that.:


Good luck and stay safe.


Confusion to Clarity – Raspberry Pi and Arduino Displays

Posted: January 06, 2017 at 01:16 AM EST
Updated: January 18, 2017 at 10:25 PM EST
— Added HMI info in jargon section.
Updated: January 11, 2017 at 08:24 PM EST
— Minor revisions and corrections.
— Added some links.

Hi all.  Welcome to my first post of 2017.  I hope you had a good holiday and will have a happy new year.

I want to share with you my journey from confusion to (some) clarity regarding displays for the Raspberry Pi and the Arduino.  I’m going to do a little raving on about one company.  This does not mean I’m slighting other companies.  I’m just sharing my experience.  I’ll also briefly discuss the concept of marrying the two devices together.  Disclaimer, all this is based only on my research.  I have yet to put most of this into practice.  It’s a work in progress.

Over the last few years I have been increasing my interest in the Raspberry Pi single board computer.  This small Linux based machine allows you to run the types of programs that a normal desktop computer would, and also allows you to do physical computing.  This means that you can control electronic devices with the Pi in the outside world.








Over a period of time, I’ve acquired a Raspberry Pi model b+ and a model 2.  I obtained the usual accessories including a power supply, case, memory card, WiFi dongle, HDMI cable, etc.

My main interest in the topic is to use the device to do scientific experiments.  I would describe the Pi as a general purpose computer with physical computing capability.  It either has, or can have easily added the following: substantial storage, HDMI, video, sound, Ethernet, USB, WiFi, & Bluetooth. It also runs a complete Linux (Debian based) operating system by default called Raspbian.  Other operating systems can be installed.  And, in addition, it has some physical computing capabilities.  It has various electrical pins / signals available to allow it to communicate with other electronic devices like lights, sensors, motors, etc.  It can act as a controller for a large number of projects and has a large following of fans.

One thing I hadn’t gotten for the Pi previously was its own small display, something I’ll discuss in this article.

Some of the experiments I want to run require very precise control of the electrical signals, with millisecond or multi microsecond precision.  I found out one significant limitation of the Pi in this regard.  The operating system is always doing multiple things at once.  It may be writing to the sd card, responding to a mouse or keyboard, sending data over the network, or doing internal “Linuxey” things.  So, it tends to send signals out of the control pins when it gets around to it.  If you need something to happen within 1/2 second (500 milliseconds) of the time you send the command, this is not a problem.  However, for really tight precision, it can be.

So, I started looking around for other options.  The other 800 pound gorilla in the hobby electronics physical computing room is the Arduino.







I would call the Arduino a controller computer which does very little general computing stuff unless you prod it and tweak it and add to it.  By default, most Arduinos do not have substantial storage, HDMI, video, sound, Ethernet, USB, WiFi, or Bluetooth.  They don’t have an operating system.  You load one program, which is far and away less complicated than a web browser or word processor; and it runs THAT program.  Period.  But, what Arduino does have going for it is that it has a perhaps better variety (not necessarily quantity) of electrical pins / signals.  It is lower cost in some cases.  And, for my purposes, because the system is not busy doing all those “Linuxey” or “Windowsey” things, it can just concentrate on getting those signals in and out of those pins.  It can do this more precisely than a Pi can.  The Arduino can also boot quickly and start up it’s designated application, which helps it recover quickly from a power failure.  The Arduino also can act as a controller for a large number of projects and has a large following of fans.

At this point, I’m not concerned with cost cutting or specifying the minimum controller for a project.  I’m only interested in working as a hobbyist and using what’s available at hand that will let me prototype quickly.

I ended up buying some “starter kits” for both the Pi and the Arduino.  Those include accessories like those mentioned before for the Pi.  The one for the Pi also included some components for electronic experiments.  For the Arduino, the kit came with an Arduino Mega 2560 board as well as components for electronic experiments and some sensors.

I also wanted to add a display to the Arduino, and in this case, it’s a bit harder since it has no native video output.  Thus starts my journey into confusion.

I went to a major electronics retailer’s brick and mortar store.  This vendor carries lots of hobby electronics parts including Raspberry Pi products and Arduino products.  I had a shopping list of things I wanted from their website and it said they had the stuff in stock.  I was immediately disappointed.  They DO have a huge selection … everywhere in that part of the store.  Everything was hanging in more or less random order, or so it looked.  Many items did not have any labeling out front where you could identify them.  A sales representative and I searched for one item on my list for half an hour and couldn’t find it even though the computer assured us it was in stock.  He gave up on it.  I looked through ALL their products once more and eventually found it.  While not the retailer’s fault, almost all these products contained NO documentation.  Not even a “getting started” pamphlet.  Some contained a web address on the packaging.  Some did not.  I personally don’t like that.  I’d rather have at least some guidance on or in the package.

I did end up buying a 4.3 inch TFT display which could potentially be used with either the Pi or the Arduino.  I went to their website and the instructions said to contact them after buying and they’d tell me how to connect the thing.  SAY WHAT?  I eventually found some more data by googling around, but I was not impressed.

Let’s take a jargon pit stop.

TFT means Thin Film Transistor and is a type of display technology.


You may also see IPS, which means in plane switching, and is more advanced.


A display is made up of lots of dots, or pixels, which you can see if you get really close or use a magnifying glass to look at it.  Generally, there is a red, a green, and a blue pixel which make up each white “dot” that you see.  Something has to feed these little monsters with the data they’re hungry for to determine which pixels to light up and when.

There are two basic ways to send that data to the display.  First is a parallel interface, where many wires send data at the same time to the display device.  Strictly making this up for an example, you could have 8 wires for red, 8 wires for green, 8 wires for blue, 10 wires for row number, and 10 wires for column number.  Remembering our binary math, assuming each wire is on or off, you could have 256 shades of each of red, green, and blue (24 bit color), and could accommodate up to 1024 rows and 1024 columns.  You could put all the data on the wires and activate a clock signal to tell the display to light up that pixel.  This would be VERY fast.  However, it takes 45 wires, which means 45 connections to your controller.  That’s a problem, since you may not have that many.  There are variations on the theme.  You could use only 10 main wires and a few more to tell the unit whether you want to send it color data or coordinate data.  But, you still need lots of wires.  This is like cars going down a multi lane freeway side by side.

A small caveat.  I’m talking about DIGITAL video signals.  I’m not going to address ANALOG video, like composite or S-Video, or component video, or even VGA, which is still analog.  All these can be used, but they are subject to noise and distortion that digital signals are not.





On the other hand, digital forms of video include:

DVI – https://en.wikipedia.org/wiki/Digital_Visual_Interface

HDMI – https://en.wikipedia.org/wiki/HDMI

Display Port – https://en.wikipedia.org/wiki/DisplayPort

You can even send video over USB.


The Raspberry Pi has a video interface called DSI, as well as supporting composite and HDMI video.


Sending the data bits directly to the target device through wires and with processes that don’t conform to common standards is sometimes called Bit Banging, although that term is frequently used to refer to serial communications.


The alternative to a parallel interface is a serial interface.  This sends data bits out one or a few signal lines one after the other, like cars following along behind each other on a two lane road.  All the digital video signals discussed above are primarily serial, although they may have multiple signal lines.  Serial interfaces are usually, but not always, slower than parallel interfaces.  Serial interfaces have the advantage of not requiring as many signal lines, which means a lot when using up pins on a micro controller.  Yes, you want to drive the display, but you may not need ultra fast refresh rates and you may want to use some of those pins for other things.  It’s not much good to have video and not be able to do the rest of your experiment.

HMI Means Human Machine Interface.  These displays can be used for this purpose.


So, back to the discussion.

I ended up returning the 4.3 inch display (with parallel interface) and decided to look for a serial device.

Here continues the confusion part of my story.  I literally spent a day or two googling every combination of TFT, IPS, display, raspberry pi, and arduino that I could think of.  I found lots of people saying they had displays working, lots of people selling them, and little info on how they worked or how to get it done.  Confusion reigned supreme.

Then, (voices sing) I found one vendor where I could get some clarity.  Again, I’m not slighting others, but I was very impressed with their website.  Hopefully, their customer service will be equally as good.

The vendor is adafruit.


I found all these amazing and sometimes hard to find attributes on their website:

  1. Clear English descriptions
  2. Pricing
  3. Quantity in stock
  4. Specifications
  5. Data Sheets
  6. Instructions
  7. Videos
  8. Tutorials
  9. Suggestions to alternate products
  10. Forums

I was blown away.  They actually go out of their way to provide a wide array of products, tell you what they are, tell you how to use them, tell you how to buy them, and tell you what you can do with them.  IMAGINE THAT!

I haven’t bought anything from them yet, but I anticipate doing so.  I can’t tell you the end of the story, because it’s still going on.

However, here’s their section on displays.  This may change at some point in the future.


I may buy this 5 inch display:


along with its controller:


I still have more research to do before making a final decision though.

For the Pi, I did not buy this type of display.  Because the Pi has its own DSI connector, you can connect to that and use no normal signal pins at all.  Thus, I bought the OFFICIAL Raspberry Pi 7 inch display.





I still may add a TFT display to the Pi like the one I mentioned for the Arduino if I want to run that display separately from the Pi’s main display.  I need to do more research on that too.

Another vendor I’ve heard good things about is SparkFun.  Their website has many, but not necessarily all, of the attributes that adafruit has.


Here’s their display section:


For our fellow makers in the UK, here’s a source in London.  As I mentioned before, I haven’t tried any of these, including this one.




I also mentioned the possibility of marrying a Raspberry Pi to an Arduino.  There are many potential advantages of doing that.  I may get to talk about that in a future article but can’t do so here.  However, here are a couple of options I ran across.



My friend at the Forsyth Makerspace in Cumming, Georgia (USA) mentioned the following to me:





Actually, Lattepanda normally runs Windows 10.  However, I suspect it could run Linux as well.  It’s not the same as a Raspberry Pi though.

Finally, here are a couple of beginner and a few more advanced books.






Well, that’s it for now.  I hope this helps you explore the world of hobby electronics, Arduino, Raspberry Pi, small displays, and physical computing.  While not specifically discussed, if you wanted to use these to build an Internet Of Things thing (IOT), you could.  Have fun.



How To START Securing Your WordPress Site

Updated March 04, 2019 at 16:28 ET.
Minor revisions.
Updated December 09, 2016 at 22:28 ET.
Published December 09, 2016 at 16:02 ET.

If you’re reading this blog, you’re reading a WordPress based site.  WordPress is one of the most popular content management systems, and powers over 18% of all sites on the internet.  ( Source )  Perhaps you run a WordPress site yourself.  If you do, then you need to read this article.

This is about WordPress security.  I’m referring primarily to self hosted sites using software from https://wordpress.org/ rather than sites hosted at https://wordpress.com/ .  (By the way, WordPress.com says WordPress powers 27% of the internet.)

The security plugin I use on my site is Wordfence.  A tech support representative over at Wordfence suggested I write a review during one of our interactions.  He did not say what to put in it, and these are my honest feelings about the product.  I was not compensated for the review.  I decided to expand it and also make it an article about how to secure your WordPress site.

I’ve been running a WordPress based blog for several years.  Over time, I’ve learned a number of things that I didn’t want to know.  One of these is that, if you run a WordPress site, you must … MUST … MUST!!! have security.  The Wordfence security plugin is one of the best options out there.  It’s the only one I’ve tried and I like it very much.

Here’s the deal.

Just a minute ago, I chose a day at random from a few days ago and looked at the Live Traffic display on my blog on my Wordfence control panel (a Wordfence feature).  This shows what IP addresses have been hitting the blog and what URL’s they’re requesting.  On that day, there were about 200 hits excluding the GoogleBot.

The OVERWHELMING number of hits to the blog are attempted attacks!  Most of the rest are search engines.  (Maybe I need to write more and market better.  8-)  )  If you have a WordPress site … YOU will be under attack too, whether you know it or not.

Here’s what I found in the logs.  This is a real geography lesson.

BAD Locations trying to attack me (there may be good queries from these too): Philippines, Ukraine, Malaysia, India, USA, Tobago, Algeria, Bulgaria, Romania, Vietnam, Latvia, Uruguay, unknown, Dominican Republic, Tunisia, Morocco, Venezuela, France.

GOOD Locations sending legitimate queries (there may be bad queries from these too) (includes search engines): China, France, USA.

And, this is just a review of the logs for one day.  My site is REALLY popular … with the AttackBots and malicious Hackers.  Many of those attacks are probably coming from other compromised WordPress sites or IOT (Internet Of Things) things but there’s no way to tell.

Need more proof?

Google search for (hacked or compromised) WordPress sites

Google search for (hacked or compromised) iot things

Here’s an article from my site on IOT security.  A WordPress site is not an IOT thing per se but the principles of attack and compromise and corruption of the site are similar.  Once compromised, your IOT thing or website would be used to attack and terrorize other people.

You should care about IOT security

Bruce Schneier Security Blog

Brian Krebs Security Blog

Here’s what you can do to START securing your WordPress site.

01) Use LastPass or something similar to generate a really long password, say 50 plus characters, for your website for administration.  Do this RIGHT and make sure you have the password saved in LastPass and somewhere else before installing it or you could lock yourself out of your site.  Yes, this is ridiculously long, but nobody will guess it!  And NO … you can’t remember it. You must use a password manager.

02) Install Google Authenticator or something similar on 2 of your devices.  I use my tablets.

03) Install Wordfence on your site.  Make sure you set up the administrative email address so the site can send you notifications.  Test this email.  Make sure messages don’t end up in your junk or spam folder.  GMail is notorious for filtering out messages that IT thinks you shouldn’t see.  Make sure you get them.

04) Upgrade to Wordfence premium.  It’s totally worth the minimal cost.  You get live threat updates, premium support, extra features, and you help fund further product improvements and security research and development.

05) Learn to use the 2FA (2nd factor authentication) features of Wordfence.  They call it cell phone sign-in.  I don’t recommend cell phone text messages for authentication.  They’re not secure.  But, you can use Google Authenticator or similar.  This way, you append a 6 digit changing code to your login credentials.  Install your blog credentials on Google Authenticator on both of your devices at the same time.  If you lose one, you’ll have the other.

06) Scan your site and fix any problems.  Observe the results of scans periodically.

07) Use the Live Traffic feature to see what’s hitting your site.  Check this periodically – say every week.  It may help to only look at one day at a time.

08) Learn to use Country Blocking and use if appropriate.  You have to decide this.

09) Reduce the page access throttling limits if applicable.  See the help file.  I’ve noted that attackers try to hit the site quickly with lots of page accesses, usually for plugins I don’t have, trying to find a weakness.

10) Learn to use the other options in the Wordfence setup.  Click the help icon beside each to find out what it does.

11) Learn to use the Wordfence support ticket system to ask questions when needed.  The staff there are excellent and willing to help.

12) Join the Wordfence mailing list to receive email updates of important security news.

13) Minimize plugin and theme use to the absolute minimum.  Every extra thing you have enabled is a potential attack vector.  Install updates as soon as they come out.

14) Use a hosting provider that provides safe mode or something similar.  1and1.com offers this.  This means they configure and maintain your server including WordPress upgrades and underlying server configuration.  You maintain WordPress and Plugin and Theme updates and configuration.  Do yourself a favor and PAY a nominal fee to get good hosting and support.  Sometimes, free things are the most expensive.

15) PAY a little extra if needed to get an SSL / TLS certificate so you can run your site with https encryption.  Then, use the Force SSL plugin or similar to run your site in https mode at all times.  This encrypts traffic between the user and your site.  This also protects you when you’re administering the site since your login and admin traffic will also be encrypted.  When you login to your site, use https:// in the address bar right from the start.  Preferably, your password manager or the login link on the main page should already do that for you.

If you have full control over your server configuration, https://letsencrypt.org/ might be an option for you to get a free SSL / TLS certificate and use it.  They’re turning to crowd funding to cover operational costs, so who knows how long they’ll stay free or financially stable.  If you’re running the server in safe mode from your ISP, you may not have a choice of using this option.  You may have to get the certificate from the ISP and probably pay for it.

16) You may want to consider other plugins such as these: Disable REST API and Disable XML-RPC to help prevent automated attacks on your site.  This may also prevent automated use of the site, such as blogging from your smart phone.  I always use the web interface to interact with my site, so I don’t need those features.  XML-RPC in particular allows an attacker to quickly try huge numbers of passwords to try to break into your site.  On the Wordfence blog, they point out that there are pros and cons to doing this.  They also point out that their plugin already limits login attempts. Do your homework and understand what you’re doing before implementing these procedures.

17) Hopefully, your site won’t be compromised.  But, if it is, I would wholeheartedly recommend hiring the experts at Wordfence to clean it for you.  That’s what I would do.

The moral of the story is: Yes I strongly recommend Wordfence.  Yes you must actively be conscious of and actively involved in the security of your site.  Yes you WILL be under attack whether you know it or not.

You can get more info about Wordfence at:





42 Things You Need To Know Ultimate LED Light Bulb Buying Guide

Updated June 5th, 2016.

The text of this blog post has been partially modified to facilitate the use of an automated text to speech system to read it.

Here is a link to a text version of the page to load into your text to speech system.

For example, I have taken out almost all symbols, written out everything in text, and spaced out abbreviations.  As with any automated reading system, though, results are not guaranteed.

On Android, you could use a program like At Voice to read it.


If using a text to speech reader, you may wish to edit the text your reader extracts from the web page and remove the hyperlinks, as they are rather annoying to listen to.

One of my favorite topics these days is the ongoing trend of people replacing old style incandescent or Compact Fluorescent ( C F L ) light bulbs with the newer Light Emitting Diode (LED) technology or installing the LED light bulbs from the start of a project.  This trend is in full force and is accelerating.  If you’re dealing with lighting as a consumer, LED is the place to be.  There are several reasons for this.

Compared to incandescent light bulbs, LED light bulbs use much less energy and produce much less heat and last longer.  Compared to Compact Fluorescent light bulbs (or C F L’s), LED light bulbs offer instant on capability and do not contain toxic mercury, which makes disposal easier and reduces risks if a bulb should break.  About the only advantage incandescent light bulbs still have over LED is price, and this advantage is decreasing fast.

This is a topic I’ve been investigating for some time, and I finally decided to do a blog post on it.  So, for the last couple of days, I’ve been investigating the issue more thoroughly.  There’s actually a lot to know about buying and using these things.  And, while the Earth probably won’t end if you miss a few points, the more informed you are, the better shopper you’ll be.

So, here I present my 42 Things You Need To Know Ultimate LED Light Bulb Buying Guide.  My intent here is not to review specific light bulbs, but to give you the information you need to evaluate all the LED light bulbs you come across and make intelligent decisions.  I cover 42 different aspects of LED light bulb technology briefly, all of which are important in different ways, to give you the information you need to become a wise shopper.

In the world of LED light bulb packaging, labeling, and marketing, confusion reigns supreme.  There are many disparate ways the bulbs are labeled and marketed, so much so that you might even think some of it is deceptive.  You could certainly be forgiven for thinking this.  But, rather than making claims of deception or fraud, I leave it to you to make up your own mind.  I’ll just show you how to sort through the mud and get the facts.  For the purposes of this article, I’m discussing only standard traditionally shaped light bulbs, such as you might use in a table lamp or pendant lamp.  I’m not discussing specially shaped bulbs, for example, nor am I discussing reflector bulbs, or smart bulbs, or color changing bulbs.  There are a whole bunch of additional parameters associated with those bulbs beyond the 42 things discussed here.  This information is USA centric, which is the market I live in and know.

If you are considering attaching a smart light bulb or other Internet Of Things ( I O T ) device to your home network, please consider the security.  See this article:


So, let’s get started learning about the parameters of LED light bulbs.

01) LED, Yes LED

For the purposes of this discussion, I’m assuming you want to buy one or more LED light bulbs.  So, you must look for the word LED on the packaging.  There are many light bulbs for sale, and in many cases, you cannot identify whether you’re looking at a LED light bulb.  So, look for this specifically on the packaging.

02) NOT C F L

The package should not say Compact Fluorescent or C F L on it.  A key indicator of this or related technology is the presence of mercury in the bulb.

03) NOT Incandescent or Halogen – Bulb Confusion

There are a number of incandescent bulbs on the market now competing for your attention right beside the C F L and LED bulbs.  I don’t recommend any of them unless you have a specific niche need for the product.  These will universally use more energy and produce more heat than a C F L or LED for the same light output.  Regardless, this can be quite confusing and it can be hard to determine if you’re looking at an incandescent bulb.  By the way, if it says “halogen”, it’s incandescent.

I’m going to go off on a side tangent here and address some packaging of a new breed of incandescent bulbs which I feel is misleading and confusing.

I will talk more about watts versus lumens (power usage versus brightness) below.  But, those of us that grew up in the 1960’s, 70’s, 80’s, and 90’s became accustomed to an incandescent light bulb of a certain wattage having a certain amount of brightness, more or less.

Well, a whole new breed of incandescent light bulbs is on the market, and they’re labeled in a confusing way.

Example 1: Major manufacturer 43 Watt soft white halogen incandescent

It says it replaces a 60 Watt conventional bulb.  WRONG!  It has only 620 lumens of brightness.  This would make a good replacement for a brighter than average 40 Watt light bulb, not 60 Watt.

Example 2: Other major manufacturer 72 Watt clear halogen incandescent

It says it replaces a 100 Watt conventional bulb.  WRONG!  It has only 1,490 lumens of brightness.  This would make a good replacement for a brighter than average 75 Watt light bulb, not 100 Watt.

The entire industry is going down this road, using what I feel to be misleading advertising.  So, buyer beware.

I saw some bulbs which are difficult at first to tell whether they are incandescent or not.

The title for the web page says Incandescent 60 Watt light bulbs.  However the front of the package doesn’t say incandescent anywhere.  However, it does say 60 Watt, not 60 Watt replacement or 60 Watt equivalent.  Also, it says the lifetime is 9/10 year.  (Note: 1 year at the typical 3 hours per day spec equals 1,095 hours.)  No modern LED light bulb designed to replace a 100 Watt or less conventional bulb would have such high power consumption or low life.  So, these may be assumed to be incandescent whether they say so or not.  Note also that they don’t say C F L or Compact Fluorescent or LED.

Here’s another.

Again, the packaging doesn’t say incandescent.  However, it says energy used 150 Watts and life 750 hours.  That equates to 7/10 year at 3 hours per day.  Again, the wattage is actual, not replacement or equivalent.  It does not say C F L, Compact Fluorescent, or LED.  So, this is an actual 150 Watt incandescent bulb.

03 1/2) NOT Mystery Bulb – New Old Kid On The Block

I found this information after writing the initial article.  And, not wanting to mess up the title or the links, I decided to add it here in the middle as bonus content.  So, it’s number 03 1/2.

I was in a local store recently and saw a new light bulb I hadn’t seen before.  The package didn’t say incandescent, LED, C F L, or fluorescent.  I couldn’t figure out what this bulb was.  I started reading the package and found that the bulb contains mercury.  I had to search the fine print to find that.  So, I thought to myself it must be fluorescent.  I went home and started doing some research.

Well, it turns out it’s not a fluorescent, exactly, but it is a very close cousin of one with many of the same shortcomings.  This bulb uses an electromagnetic coil to excite gasses in the bulb, which release UV light, which hits a phosphor coated shell, which produces visible light.  Except for the method of exciting the gas, this essentially works like a C F L bulb.  The technology actually dates back a number of years in history but has been given an update.

As a close cousin of the C F L, it shares many problems with the C F L’s.  Most notably, it has mercury and phosphor.  This requires you to take special care to avoid hazards if the bulb breaks, the same as with C F L’s.  Also, it requires special recycling when you decommission the bulb.  (Of course, it’s best to recycle all electronic gear when its life is over.)  Also, this bulb is not as efficient as a good LED bulb, is not instant on (although it’s close), and has a shorter rated life than a good LED bulb.

So, overall, I would not recommend this bulb either.  In general, I’d say that if the bulb you’re looking at has mercury in it, just move on and find a good LED bulb, since good LED bulbs don’t have mercury.  Here’s a good article from C NET that talks about this mystery light bulb.

C NET article on Mystery Bulb

04) Incandescent Power Versus LED Power

It is useful in this context to think about the actual power usage of incandescent bulbs.  The numbers we are familiar with from the past indicate this power level.  So, in terms of traditional incandescent bulbs:

100 Watt bulbs consume 100 Watts
75 Watt bulbs consume 75 Watts
60 Watt bulbs consume 60 Watts
40 Watt bulbs consume 40 Watts

On the other hand, while not a comprehensive nor conclusive sample, perusing the websites for Walmart and Home Depot for LED bulbs, we find in general:

100 Watt equivalent bulbs consume 14 Watts to 18 Watts
75 Watt equivalent bulbs consume 11 Watts to 13 Watts
60 Watt equivalent bulbs consume 8 Watts to 11 Watts
40 Watt equivalent bulbs consume 6 Watts to 7 Watts

So, in general, one may assume that LED light bulbs consume about 14% to 18% of what a traditional incandescent bulb would of equivalent brightness.

If you’re looking to buy LED light bulbs, and if you don’t need anything bigger than 100 Watt equivalent, and if the actual power consumption is over 20 Watts, then you can probably just move on.

05) Lighting Facts

In the USA, the light bulb package is required to have a Lighting Facts section.  This gives information on Brightness, Energy Cost, Rated Lifetime, Color, and Energy Usage.


06) Replacement Watts / Lumens Chart

The issue I’ve been dancing around above is that we’ve been taught through the history of light bulbs to view brightness in terms of power consumption.  The problem is that the new bulb technologies don’t require as much power as the old technology bulbs.  We must start to think in terms of lumens, which is how brightness is measured.  The following chart shows the conversions for common old incandescent bulb watt values versus their approximate output in lumens.

Lamp Lumens

(Click to enlarge.)

07) Lumens

So, the key determinant as to whether a LED bulb is “equivalent” to a certain traditional incandescent is how many lumens it puts out.

A 40 Watt equivalent LED should put out 450 lumens at least.
A 60 Watt equivalent LED should put out 800 lumens at least.
A 75 Watt equivalent LED should put out 1,100 lumens at least.
A 100 Watt equivalent LED should put out 1,600 lumens at least.

No matter what the packaging says, if a bulb does not put out these minimums of brightness, it is not equivalent to it’s incandescent counterpart.  This refers to non reflector bulbs.

08) Power Confusion

This leads to what I call power confusion, which involves misleading packaging and stating that a LED bulb is equivalent to a certain incandescent, when it is not.

For example:

Example 3: A major manufacturer decorative globe style bulb.

This bulb claims to be a 40 Watt equivalent bulb.  However, it produces only 300 lumens.  According to our chart, a 40 Watt equivalent bulb must produce at least 450 lumens.  Therefore, I would say that this bulb is not, in fact, a 40 Watt equivalent bulb.  According to the chart, it would be a 25 Watt equivalent bulb.

09) Base Size and Configuration

You want to be sure you can actually attach the bulb to your fixture, so you need to know the bulb’s base size and configuration and the configuration of the matching socket in the fixture.  There are a huge number of different bases, and discussing most of them is beyond the scope of this article.  However, the most common in the USA are “medium” or E 26 for a normal traditional light bulb and “candelabra” or E 12 for the smaller base sometimes used in small lamps and chandeliers.






10) Bulb Shape

The traditional bulbs I am discussing are referred to as having an A-shape.



11) Bulb Size

The traditional bulbs also have a size designation, which is 19.  So, the shape combined with the size is A 19, which is 2 3/8 inches wide.



Some LED bulbs, particularly 100 Watt equivalent and larger, may be A 21, which is 2 5/8 inches wide.


Both the shape and the size may become important in determining if the bulb will fit in your fixture with a globe attached.  This may be particularly true with ceiling fan fixtures or enclosed ceiling fixtures for example.

12) Color Temperature

One important spec for the light bulb refers to its color temperature.


This refers to the color tint of the light that it outputs.  Most incandescent bulbs of the past had a yellowish or orange colored light.  Many people find that appealing.  Color temperature is designated in degrees Kelvin and the most traditional incandescent bulbs were 2,700 K.  Light bulbs are usually designated with a (non standard) English phrase to indicate the color temperature.  “Soft White” usually refers to 2,700 K.  Daylight at the horizon is about 5,000 K.  Light bulbs of this color temperature would be more common in office settings.  They are usually referred to as “Cool White” or “Daylight” color temperature.  The convention is to refer to lower numbers as “Warm” and higher numbers as “Cool”, which is completely opposite of physical reality for an object radiating light as a result of heat (like the Sun).

If you are purchasing multiple light bulbs, you should consider matching all of the color temperatures, so they all look the same.  Mismatches are often visible if they are side by side and they bother some people.

13) Color Rendering Index ( C R I )

The Color Rendering Index or C R I refers to how accurately the color spectrum of the light bulb illuminates objects compared to a natural source.


Higher numbers are better, with 100 being the maximum possible.  LED light bulbs for consumers typically have a C R I of around 80.  This is good enough for most people.  If you have specific needs and require high color accuracy, like photography, for example, you may seek bulbs with higher numbers.  This data may not be on the packaging unless the manufacturer wants to brag about it.

14) Light Pattern

The light pattern refers to how much of a complete circle the beam pattern makes around the light bulb.  For standard light bulbs, we can assume they radiate 360 degrees around an axis vertically through the bulb from top to bottom.  In other words, moving horizontally outward from the bulb, and walking around in a circle, you expect to see light all around the room.

However, if the axis is horizontally through the bulb from front to back, and you rotate around that, you will not see equal light in all directions.  You may have lots of light directly to the side, for example, and not much directly to the top or bottom of the bulb.



Some spec sheets may provide a beam width or beam spread number.  360 degrees would mean the bulb radiates light equally 360 degrees around a horizontal axis from front to back through the bulb.  This is impossible, as it cannot radiate light through the bottom structure of the bulb where the base is.  However, they may attempt to get as close to 360 as possible, which would mimic the behavior of a traditional light bulb.  The packaging may say “omnidirectional”, which means they attempt to radiate in all directions.  Whether they achieve it is up for debate, but new bulbs are getting better and better.  Some bulbs do not radiate as well directly on top of the bulb.  See also 40) Shadows below.

15) “Filament” Style

Why on earth am I talking about “filaments” in LED light bulbs?  There are none.  That is absolutely true, which is why it’s in quotes.  However, there are a number of new bulbs on the market with “LED filaments”.  These are strings of LED chips all in a row designed to LOOK like a traditional incandescent bulb with one or more filaments.  If you’re buying one of these, you probably care about the appearance of the filaments.  There are many different styles, so you should find the one that meets your use case and concern for aesthetics.  Googling led filament light bulb will get you huge numbers of results.  These new style bulbs have all the same advantages of other LED bulbs plus the appearance factor.  Note, however, that the rated life of these may be less than others.

16) Frost / Clear / Glass / Plastic / Rubber

What do you want the bulb to look like?  Do you care?  A frosted bulb is more traditional and may create a more even light pattern.  You may prefer clear.  Also, the shell may be made of glass, plastic, or rubber coated glass.  The latter two are more resistant to breakage, which might be important to you.

17) Dimmable

One of the most popular things people do with light bulbs is attach them to dimmers.  C F L bulbs are widely known for having trouble with dimmers.  SOME LED bulbs are dimmable, and cost more.  Other LED bulbs are not, and may cost less.  If you care about such things, you have to check the packaging.  If it doesn’t say dimmable, it most likely isn’t.  Even if it says it is, results can vary widely with different dimmers.  Some bulbs dim down to say 20%.  Others dim down to almost nothing.  Some work with some dimmers and not others.  Look on the packaging for info on this.  Also, many bulb manufacturers have a web page devoted to dimming performance of their LED bulbs.  For example:


18) Enclosures

Do you wish to put the bulb in a FULL enclosure?  This means that it is sealed all around, which is different from having a partial globe around it.  The light bulb may not like or appreciate this treatment, and may throw a temper tantrum to show it’s displeasure, by failing prematurely for example.  The arch enemy of these products is the heat generated in their operation.  While this heat is much less than an incandescent bulb, it is non trivial.  Note that a small soldering iron gets hot enough to melt metal and only consumes 20 Watts or so.  An enclosure makes it harder for the bulb to dissipate this heat, which can cause problems.  If you care about this, look on the packaging for details saying whether the bulb can be enclosed and under what circumstances.  It may say you cannot enclose it, or permit it in some way, or not say at all.

19) Damp / Wet

Will the bulb be in a damp or wet environment?  Damp might be an unenclosed bulb on your porch.  The entire area might be damp during a storm.  WET is a different matter, which would include splashing the bulb with water or submerging it.  Just like a traditional light bulb, most LED bulbs tolerate damp but not wet.

20) Emergency Fixtures

The data on the packaging for most LED bulbs specifically says they are NOT to be used in emergency fixtures, probably because they don’t want the liability if it fails.  If you need a bulb for such a purpose, you should look for one rated for that.

21) Switches / Sensors / Timers

Other than putting a light bulb in an enclosure or attaching it to a dimmer, the other thing people like to do with it is attach it to a control device.  The most common are motion sensors to turn the light on and off, photocells or light sensors to turn the light on and off, and timers to turn the light on and off.  As with dimmers, this may or may not work.  It depends on how the control device actually controls the electricity.  Look on the packaging for the bulb and the control device for info on this.  It may take some research to find a control device to fit your needs which will work with LED bulbs.  You could try googling LED light bulb (sensor OR timer).

22) Longevity Confusion

How long will the light bulb last?  Marketing claims abound about how many years the bulb will last with bigger and bigger numbers.  In the USA, there has been some standardization which helps the situation.  What most people may not know is that they don’t assume you use the light bulb 24 hours per day, or even 12 hours per day.  They assume you use it just 3 hours per day, which is a lot less than some people might expect to see on the labeling.


23) Incandescent Life Versus LED Life

For comparison, incandescent bulbs usually have a rated life of 1,000 to 2,000 hours.  (Note: 1 year at the typical 3 hours per day spec equals 1,095 hours.)  So, that would be 9/10 year to 1.8 years based on the 3 hours per day concept.  LED light bulbs, on the other hand, are usually rated for at least 15,000 hours and up to about 30,000 hours.  This would equate to 13.7 years or 27.4 years based on the 3 hours per day concept.  As you can see, LED bulbs are designed to last much longer than incandescent bulbs.  Whether they actually do last that long is dependent on a number of things.  One of those things is heat build up, as mentioned above.  Another thing is power quality.  If you’re always getting spikes, surges, and brownouts on your power system, your bulbs may last for a much shorter time.  Unfortunately, unlike most electronic equipment, these LED bulbs are not usually attached to a surge protector unless you have a whole house surge protector.

24) Years At Hours Per Day

So, you cannot just think of the bulb’s rated life in years.  You have to think of it in terms of  years at a certain number of hours per day.  If you use the bulb for more hours per day, it will probably last fewer years than the stated number.

25) Total Hours

As a consumer, you really need to know how many hours the bulb is rated for.  Sometimes this is stated on the package, sometimes it is not.  It’s fairly easy to figure out, even though you shouldn’t have to.  Just look at the lighting facts information panel, and, ASSUMING the life is given at 3 hours per day, multiply the number of years times 1,095 to get the rated life of the bulb in hours.

For example, if the lighting facts says the life of the bulb is 22.8 years, the rated life in hours is 22.8 times 1,095 equals 24,966 or about 25,000 hours.

Note that the rated lifespan of these bulbs varies DRAMATICALLY.  So, you should carefully examine the packaging.  In particular, LED filament bulbs may have lower life.

26) Warranty Years At Hours Per Day

The warranty for the bulb is completely separate from the rated lifespan, and will often be much shorter.  Furthermore, the warranty may be tied to hours per day use, or it may be just for a certain number of years.  For example, one bulb I have is rated for a 22.8 year lifespan (at 3 hours per day).  HOWEVER, the warranty is rated for 10 years at 6 hours per day, which does not amount to the same number of hours.  So, check the packaging carefully.

27) Reading Labels

Much of this information will be on the packaging for the bulb, and much will not.  Every maker words things differently.  And every one emphasizes certain things and de emphasizes or hides others.  For example, let’s say they have a 3 year warranty at 3 hours per day.  That’s not very good, and is not much more than a good incandescent bulb.  This may be the case even if the bulb is rated at 20 years of life.  As another example, if the C R I of their bulb is not so great, it may not be on the package.  The package may not talk about dimmers, or enclosures, or sensors, or may have specific criteria for them.  You have to search through the microscopic print.  For a Walmart bulb I bought, I even had to look inside the box to find some of the verbiage, as it was not on the outside.

If you don’t find the info you want on the packaging for the product, you may wish to check the manufacturer’s website and spec sheets for the product.

28) Reading the Bulb

The bulb itself may have valuable information printed on it, so also look there if you can.

29) Volts / Amps / Watts / Frequency

It is common for Volts / Amps / Watts / Frequency to be specified on the packaging or the bulb itself, although not all may be specified. If you are in a retail store, you likely won’t be able to buy any bulbs not compatible with your electrical system.  However, if buying by mail order, you may need to make sure the bulb matches your country’s electrical standards.  In the USA, the most common and important parameters are 120 Volts and 60 Hz (frequency).  Occasionally, you may see products labeled for slightly different voltages, such as 110 Volts or 115 Volts.  However, you should not see anything that says 240 Volts or 50 Hz.

30) Actual Watts Used

One of the important facts you’ll see on the lighting facts panel is the energy used.  This may say 10 Watts for example.  This is the actual energy that the bulb uses.  For some of you, this may be very important.  You may wish, for example, to calculate the actual energy usage or savings.  You may ask, why this is way down at number 30).  Well, for me personally, this is not a big factor.  For one, I have a small house.  But, also, at the risk of making a convoluted sentence, you CAN NOT NOT save energy by switching to these bulbs.  Whether it is worth the cost is another matter.  But, no matter whether you’re switching from incandescent or C F L, you will save energy.  For my own purposes, I don’t bother calculating it.  I banished almost all incandescent bulbs from the house a few years ago.  Now, I’m replacing with LED as the C F L’s burn out.  Anyway, this info is available on the packaging for you to use as you wish.

31) Temperature Limits

Most packages will include temperature limits for the bulb operation.  This won’t be a problem for most people.  However, if you’re running it in a very cold or very hot environment, you may wish to check these numbers.

32) Bulb Weight Caution

The packaging for some bulbs cautions the user about the extra weight these bulbs may have compared to incandescent.  This may cause problems in some fixtures and situations, and is something to consider.

33) Luminous Efficacy

Luminous efficacy is a measure of how many lumens are produced per watt of energy usage.  This is available on some spec sheets and may be useful to users doing energy calculations.  You can determine this number yourself by dividing the bulb’s lumens rating by the watts rating.


34) Energy Cost At Hours Per Day At $ Per kiloWatt hour

The energy cost is printed on the lighting facts panel for a 3 hour per day usage at an energy cost of $ 0.11 per kiloWatt hour.  To find other energy costs, you must consider both the hours per day of use and the cost of energy.

35) Energy Usage Calculations

Here’s an example energy use calculation.  Suppose you use the bulb 7 hours per day, that it draws 18 Watts, and that your energy costs $ 0.15 per kiloWatt hour.

1 kiloWatt hour is 1 kiloWatt for 1 hour or any combination thereof.

Convert the usage of this bulb to kiloWatts.

18 Watts divided by 1,000 Watts equals 18/1000 kiloWatts.

Find how many hours you use the bulb per year.

7 hours per day times 365 days per year equals 2,555 hours per year

Find out how many kiloWatt hours the bulb will use.

18/1000 kiloWatts times 2,555 hours per year equals 45.99 kiloWatt hours per year

Find out how much the bulb will cost you to run.

45.99 kiloWatt hours per year times $ 0.15 per kiloWatt hour equals $ 6.90 per year

And, if you had 1,000 bulbs, then the whole group would cost you $ 6,900 per year to run.

36) Date In Service

It’s a good idea to write the date you put the bulb in service on the bulb with a permanent marker.  That way, if it fails prematurely, and you wish to make a warranty claim, you know how long it lasted.  Also, if the date in service was the same as the purchase date, it will help you find the receipt.

37) Save the Receipt

Save your receipt for purchase.  If it’s on thermal paper, make a photocopy of it.  If you want to make a warranty claim, you may need the receipt years later.

38) Warranty Claims

Different manufacturers have different procedures for warranty claims.  Some require the receipt.  Some don’t.  Some warrant by years.  Some warrant by years at hours per day.  Check the product packaging for details.

39) Brands and Stores

I have not attempted to examine all the myriad online sellers of LED bulbs.  However, I did go into each of several local stores to see what brands they carry.  Note that most stores only carry one or a few brands, and that the brands are different in different stores.  It pays to shop around.  I’m a fan of CREE bulbs.  The only local store that sells them, for example, is Home Depot.  Here is a non exhaustive list of the brands I found in my local stores, which is obviously subject to change.  This is in no particular order.  The websites for these stores may have other brands.

Walmart: sells Great Value, GE, Sylvania

Target: sells GE, Feit, Up and Up

Lowes: sells Cascadia, Feit, Osram, Sylvania, Utilitech

Home Depot: sells Philips, Echosmart, Cree, Feit, GE, Osram, Sylvania

Frys: sells Lenmar, Feit, Energetic Lighting, Kodak, GE, Pro-HT, Whirlpool, Ubrite

Batteries Plus: sells Duracell, Feit, Satco

BJ’s Wholesale Club: sells Sylvania

Costco Wholesale Club: sells Feit

40) Shadows

Note that some bulbs have structure, usually heat sinks, that obstruct the light pattern from going in certain directions, casting shadows.  I don’t generally like those, and recommend bulbs with an omnidirectional light pattern.  See 14) Light Pattern above also.

41) Outdoors

Can the bulb be used outdoors?  The packaging may or may not say.  The bulb’s main enemies are extreme heat, extreme cold, and wetness.  So, if you protect it from these extremes, you may be able to use it outdoors even if the package doesn’t tell you.  If the package does tell you, follow those recommendations.

42) Buying Guides

Here are some other buying guide type documents that I was impressed with.  I have not reviewed these in depth, but they looked good at first glance.  Some of the information may be dated.  The maker of Switch LED bulbs appears out of business as shown in the first link.  This list is not intended to be comprehensive.








This next one has some UK data as well.



Here’s another one with UK info.


Well, there you have it, the 42 most important things you need to know when buying LED light bulbs.  I hope you’ve enjoyed the info and find it helpful.



Carbon Fiber Props At FoxtechFPV or HobbyKing

This page contains a chart of carbon fiber props 12″ inches in diameter and over from 2 common vendors.  I created the page to fill a specific need for a project I was working on.  If you’re reading the blog and have a need for such info, then read on.  If not, feel free to skip it.

This is the cf-props chart.  I hope you find it useful.  This has no guarantee whatsoever.  Use at your own risk.  You are completely and totally responsible for your vendor and product decisions.

Copy the text below the following horizontal line into a separate text file with fixed pitch character spacing so the columns line up.  This may look like gibberish at first since most web browsers use proportionally spaced fonts and / or scrunch the chart to a narrower width.  But, if you copy it into something like notepad (in Windows) in a simple text file with a fixed space font, it should work.  Printing it may be a challenge with notepad, but if your text editor can scale printouts, you should be able to print it on one page.  On my pc, I was able to display the chart all at once on a 1366 x 768 screen, capture a screen image, then print that, just because I didn’t want to worry with other text editors besides notepad (which cannot scale printouts).

The chart shows the results of a simple search through the website inventory of two vendors, on the date listed, for carbon fiber propellers 12″ in diameter and over.  The vendors are http://www.hobbyking.com/, designated by H; and https://www.foxtechfpv.com/, designated by F.  This does not imply an endorsement of these vendors or their products.  They are simply two vendors I’m familiar with.  The chart is not comprehensive nor is it exhaustive.  As soon as you print it, it’s obsolete, like all printed things.  It will likely not be updated as it was created for a specific project.  It lists big props because that’s what I needed at the time.

If you are creating an RC aircraft and need a certain propeller based on your calculations, you may find that the one you want is not readily available on the market.  For example, a 20″ x 4″ carbon fiber prop is not available from either of these vendors.  Keep in mind that this is just a snapshot in time.  The prop could become available tomorrow.  You should not assume that 20″ x 4″ props are not available anywhere on the planet.  What you can assume, if I didn’t make any typos, is that where it says something IS available, that it was available on the date the chart was originated.

NOTE – Pitch numbers are rounded to the nearest .5″.  So, if it says a 22″ x 5.5″ prop is available, it COULD be a 22″ x 5.7″ prop for instance.

To use the chart, find the prop diameter you want to use on the left column of the chart.  Follow that line horizontally to the right until you find the column of the pitch you want.  If the prop is available from Foxtech, you will see an F in the grid where the row and column intersect.  If the prop is available from Hobbyking, you will find an H.  If it was not available from either vendor, the grid will be blank at that point.

Good luck with your design.




Readily available CF prop sizes at or over 12" at (F)oxtech or (H)obbyking.   05/11/16   Pitch rounded to nearest half inch.
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
12": |     |     |     |     |     |     | F H | F H |     | F H | F H |     |     |     |     |     |     |     |     |     |

13": |     |     |     |     |     |     | F H | F   |     | F H |     | F H |     |     |     |     |     |     |     |     |

14": |     |     |     |     |     |     |     | F H | F   | F H |     |     | F   |     |     |     |     |     |     |     |
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
15": |     |     |     |     |     |     | F H |     | F H | F H |   H |     |     | F H |     |     |     |     |     |     |

16": |     |     |     |     |     |     |   H |     |   H | F H | F   |     |     |     |     |     |     |     |     |     |

17": |     |     |     |     |     |     |     |     |   H | F H | F H |     |     |     |     |     |     |     |     |     |
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
18": |     |     |     |     |     |     |   H |     |     | F H |     | F   |     |     |     |     |     |     |     |     |

19": |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |

20": |     |     |     |     |     |     |     |     |     | F H |     |     |     |     |     |     |     |     |     |     |
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
21": |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |

22": |     |     |     |     |     |     |     |     |     | F H |   H |     |     |     |     |     |     |     |     |     |

23": |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
24": |     |     |     |     |     |     |     |     |     | F H |     |     |     |     |     |     |     |     |     |     |

25": |     |     |     |     |     |     |     |     |     |     |     |   H |     |     |     |     |     |     |     |     |

26": |     |     |     |     |     |     |     |     |     |   H |     |     |     |     |     | F   |     |     |     |     |
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
27": |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |

28": |     |     |     |     |     |     |     |     |     |     |     |     |     |     | F   | F   |     |     |     |     |

29": |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |     |
pitch-> 1" | 1.5"| 2"  | 2.5"| 3"  | 3.5"| 4"  | 4.5"| 5"  | 5.5"|  6" | 6.5"| 7"  | 7.5"| 8"  | 8.5"| 9"  | 9.5"|10"  |10.5"|
30": |     |     |     |     |     |     |     |     |     |   H |     |     |     |     |   H |     |     |     |     |     |