Link Checking

Just a quick note to indicate that the links on the engineering site have just been checked and verified. There were a few bad links, but not that many. I still have some sites to check within the next few days, but I need to give the web sites time to come back on-line.

The attached graphic shows the data generated by Xenu. It appears that at a minimum there were 99.29% good links on the site, and that number should increase as I check the rest on the remaining links in the report.

The last time I showed this report was in November 20 2009 as Xenu Report, Statistics for Managers. That report shows 99.25% good links, with a total number of URL links as 6950 URLs

Of course there is one day remaining in the month, but the site numbers look kind of low. Today should not be any different because the site never does well on holidays. This will be the lowest performing month of the year, still better than any month of any previous year. But I should be posting those numbers tomorrow, as my server counter does not up-date until about 5am.

Of course if you have off-page links on your site you should always check them to insure they point to a valid page address. I use a free link checking program called Xenu.

As a side note; the site visits so far this year have past all of the visits for the entire 2005 year.

Mezzanine Buses

There are a great many Mezzanine buses, some more out-dated than others. Mezzanine cards are small form factor boards that reside as a daughter card on a VME or cPCI mother-board to name a few interfaces. Mezzanine cards to not directly interface to the main system backplane as does VME for example. Most of the Mezzanine interface on this site are represented by two separate pages; one page carries the particular board manufacturers and another page covers the description of the electrical interface and mechanical form factor.

The oldest of the current Mezzanine board formats on the market is the IP Card or Industry Pack I/O Modules. Basically a non-intelligent board format used in a number of systems, a bit dated at this point in time, but there are still Companies Producing IP Modules. Page views are almost down to zero for this board format, which seems odd as it was an I/O based module.

The M-Module which is just as old still receives a few page views, but there doesn't appear to be much support in Producing M-Module Cards.

The mezzanine board format that replaced the IP board was the PMC format, or PCI Mezzanine Card. The PMC board added a controller but still allowed for any required I/O, previously handled by the IP card. So there are still many Companies Producing PMC Boards. A variant of the PMC interface is the PMC-X format. Both of these board standards used the PCI bus as the electrical interface, so really they are somewhat out dated [PCI Card Manufacturers].

The follow-on to the PMC standard was the PPMC interface, or Processor PMC format. There are a few companies that Produce PPMC Boards which were true processor based cards, on a PCI bus. Another related was board format is the PTMC Interface, or Telcom PMC standard [still using the PCI electrical interface].

These are all open standards so the board specifications could be used on any carrier card, but some interfaces were designed specifically for the VME bus, others for the cPCI Interface, and still others for the AdvancedTCA Interface. The AMC Mezzanine card was designed to interface to the new ATCA standard, being relatively new there is a small but growing number of Companies Producing AMC Boards.

Additional mezzanine boards include FMC,  and XMC standards.

Search Key Word vs. Search Key Phrase

For a number of years now I've noticed that many of my pages do not do well in a Google search when a one word phrase is used. I've never been able to figure out why my pages do better with two or more key words rather than one key word, but I guess I can't show up first for every key word.

So one example is the search term VME, which would be a one-keyword search. The VME page shows up in the ninth position on the first page. When the phrase is changed to VME Bus, the page shows up in the forth position [same for VMEbus]. When I add another key phrase, VME Bus Pinout, the page shows up as the first listing on the first page. First listing for the key-words VME Backplane, and VME Chassis also. Hmm, looks like VME Connector places first too, in both a text and image search.

I'm using the VME Bus as an example, but I could have used any computer bus because the same thing happens. I just don't under stand how Google determines what page should show up first when only one key-word is used.

Yes I know the rules, those other pages must be using the key terms more often at the beginning of their article. I' don't know, my pages do show up but I would rather have them show up higher for a few one word searches. I guess I need to somehow optimize the VME interface page up that it shows better in a Google search, maybe rewrite some of the text.

Blog Comments change

I made a change to how comments are added to a posting within this blog. Previously there was a 'Leave a Comment' line at the end of the posting. I think that text is gone now and replaced by a '# comments' which needs to be clicked on. So that text needs to be clicked, regardless of the number of current comments, it may say 0 comments. Now this only holds true if your on the main page or some archive page. If your within the posting than you will see the comments, if any, and a comment box.

So that's what I changed, I added the Comment Box to each posting. Now the comment box is within the blog post instead of on a pop-up page. However the comments are still moderated, as they always have been. Some people don't realize the comments need my approval before they get posted, because I see identical redundant comments come in.

Most of the comments in this blog are from me, because I use the comment field to up-date the blog postings. Also, like any other blogger I get comments that say very little but have a link embedded within the comment ~ I don't post those comments. Those comments are just spammers looking for a free link. Anyway it may be a few days before the links gets moderated and posted, or not.

Digital TV Reception

I finally got around to playing with Digital Television [DTV] this week. At first I didn't have a DTV antenna so I just hooked up an old FM dipole antenna I had. The FM antenna worked pretty well, as I was getting around 11 stations [Digital TV Channels]. However there was some interference, or bad reception because a few of the stations would come and go. Any why I went ahead and purchased a Digital Antenna.

I purchased a Omni-Directional Flat Digital Antenna from Best Buy. The digital antenna is a FDTV2 made by Trek. I only just purchased the antenna yesterday so I can't speak to how low it will last, but it comes with a one year warranty.

The antenna was about $55 and was in around the mid price range. There may have been a few both above and below this cost, but never having purchased a DTV antenna I just went with something in the middle price range. No I didn't read any product reviews, it's an antenna, but it is an active antenna. So I take it the only thing that can go wrong would be the internal amplifier, or maybe the attached cable. Anyway I would recommend this antenna because it seems to pick all the stations its supposed to; however I have not tried any other digital antenna.

I was wondering how long the cable from the antenna to the TV could be, but the attached 5 foot coaxial cable answered that question for me [standard BNC connector]. The antenna cable is permanently affixed to the antenna. Although a BNC Barrel [Female-Female] connector could be added to extend the maximum cable length, I wouldn't recommend doing it with out testing first. The antenna itself may be wall mounted, table mounted [comes with a base], or mounted flat on any surface

The attached table is a graphic of the available digital stations in my area from the FCC, showing signal strength, Network Callsign, Virtual TV Channel, and the Frequency band. For many of those stations listed, there are three different channels. That tells me that the stations are transmitting digital TV, but not high definition TV. [a few HD Acronyms].

The attached map is the relative location of the DTV transmitters and the DTV receiver. Although only three antennas are shown to the north many of the antennas are over lapped, with only one antenna being located south of the receiver.
Click either picture to see a larger view.

Related blog postings; HDTV Spectrum,
The TV used with the antenna is a Westinghouse TX-47F430S, 1080p HDTV [with internal digital converter].

Visitor Demographics, Web Site

Here is what Google Analytics has for the Engineering Site visitor demographics [year to date]. The graphic indicates visitors from the United States [US] only. Data is available for many other countries as well, but not all countries display this chart. There are also a number of additional tables of data that go along with graph, but there not as interesting.

Now I did get this chart from the Google Analytics, but it appears that the data was generated by Doubleclick [which Google purchased a year ago]. So I might assume that the data is not as good as if it really came from Google, because they track my visitors. However there are other sites that produce more or less the same data; but they use different methods of producing their data.

For example, Alexa produces some of the same graphs, but you would have to be using an Alexa tool-bar to be counted in their data. They indicate a small amount of Female visitors, while Doubleclick indicates none. Alexa also indicates many more visitors in the age range of 18-24, again doubleclick indicates zero visitors. I just looked at the Alexa data, but I do have a posting from 7/1/09 which shows what their charts look like [Alexa Demographics].

Quantcast also has some of the same data, but I'm not really sure how they get their information [see note below]. Here is another previous posting from 10/2/07 showing one of their charts [Quantcast data]. Their data is also different. I think it's so different I'll post their data to the right.  The time ranges between the two sets of the charts are different, but I'm just working with what I have. Either way, the two graphs show how or what different companies collect and how they display the data.

The point is who do you believe, and why doesn't Google use their own data. I guess Google is using the data from doubleclick because they already had the program. Then why doesn't Google send over the right data, they know every thing about my web site. Then again how would Google know if a visitor was a man or woman ~ there most have been some kind of sigh-up with doubleclick? 

Note: One method to generate information for Quantcast data is to add a small amount of code to your web page(s). For several months I had that code on my home page and a few other high traffic pages [out of 1,300 pages]. However I removed the code to increase page loading time. The real point is before I had added the code Quantcast had my monthly traffic at 9800 visitors, while after I added the code to those few pages the traffic went up to 39000 visitors. Currently it appears to be running around 22000, but that's not the point. How accurate is the data these sites provide.

Of course I don't care what my site's visitor demographics is, unless some company emailed and said they would only advertise if I had a particular kind of visitor ~ which has never happened.

I need to promote a few web pages that are getting no page views [less than 10 this year], sorry;
2N3867 Transistor derating curve............... 2N2944 Transistor derating curve.
2N6762 FET derating curve..................1N4454 Diode derating curve.
PCM Waveforms, IRIG.

Graphic: McDonnell Douglas KC-10 Extender in flight

Page De-listed and not found

I was working on updating a page the other day and I did a Site Search for it, so I could see how it displayed in the Web Browser. Well guess what, the page did not come up in the Google Search bar I have on the site. Two other pages that pointed to it showed up, but not the page it-self.
The page in question shows a Derating Curve for a 2N3762 Transistor, UA Package. However the two pages that showed up in the listing were for a Temperature Derating Curve for 2N3765 Transistor and a list of PNP Transistor Derating Curves. So the assumption is that the page relating to the 2N3762 PNP Transistor was delisted. Now I noticed that there is another related page; the main 2N3762 Transistor Design page and the 2N3762 Transistor in a U4 package which also should have showed up in the search results.

Now if I put a Google Site Search on my Engineering web site, I would expect Google to search my site ~ that's the point of the search bar. What Google does on their own site is up to Google, but my pages should come up on my site.

I was also working on another page [IRIG PCM Waveforms] and I checked Google Analytics stats for that page and only a few page views showed up. So I again did a Google site search and that page does not show as listed either.

These pages exist on the site, but many people may not navigate to the correct page to see the data, they may just use the search engine. I assume they click away when the correct page does not show up in the search.

Attached picture; A-10 Thunderbolt II In-flight, US Air force [USAF].

Page Optimization SEO

Just to follow up with the last posting regarding click-through rates from Google searches ~ I did look at a few of the Google search queries and worked on those related pages. Now I did not update the pages just to optimize them for the search engine. I used the list or my page in question and reviewed the web page to see if any additional work or data could be added to the page.

So in fact I did optimize several pages for the search engine, but only because I added more text to the page. I really just addressed page issues, if the page didn't require any work I left it alone. So I guess it was a good tool to use to find pages that need work. Well there are always many pages that need work, or maybe more detail, but there are always trade offs between what pages get up-dated.

Every Query in the list has a little star which I can high-lite so I'll know which keyword or query I've already worked. Of course there are a few thousand search terms in the list so it might take a little bit of time to work the entire list ~ like I'm going to do that.

Like any page up-date I make, I won't see any response or change in the page visits until the page gets spidered by GoogleBot [which could be a few weeks]. So that fact makes it hard to track page enhancements vs increased page views; as I made 14 page updates today, 30 pages yesterday and 40 pages the day before. What would I do keep a rolling list of page changes for 15 days until Google spidered them. Among other pages I updated include the 7 Segment Driver page and the 15 pin D-sub Connector page to name a few....

Oh, I added a comment to the previous post; I hadn't noticed but many of those numbers in the graph are the same [flat lines]. So the graph must be generalizing data, it's just not possible to have the same click-through rate each day.


Graphic: Iraqi T72 Tank Firing in the Desert [Soviet Designed Main Battle Tank].

Clickthrough Rate

Over the last month or so I've been updating pages to display the new Google Search bar, primarily because it uses 1kB less html code. So far just over a thousand pages have received the up-grade with the new code. But what about all the other page metrics I have to worry about, maybe it's time to work on a few of those; as in:

Page Bounce Rate

Pages with low Pageviews

Pages with a high Exit Rate
And on and on; there's just so many different ways to measure how a page is doing on the internet.

One metric I don't look at that often is search engine Click-Through Rate, or the amount of times a page shows up in a Google search but is not clicked on. Now the search term used or the query could be any term as long as it causes my engineering website to show up in the results returned in a Google search.

Of the 6,091 queries, Google provides no data at all for the lower 4,500 searches. I assume because the page impressions are to low [a percentage] to track; however I really don't know. There are another 1000 queries that display an impression but no Clickthrough data, maybe because the clickthrough rate is below 1%. Because the first term with a clickthrough shows up with a 1% clickthrough rate; which would be the worst search term with any data. The 'worst' Google search term in the report is "DVI" which I assume relates to the page I have on the DVI interface. That DVI page shows up on the first page as #8 out of 32,500,000 results. The DVI search term causes my page to be displayed in the Google search results 6,600 times with only 58 people clicking on the link [over the last month].

So there are thousands more search terms with different impressions and click-through rates. For example the term 'Derating' had only 58 search impressions but 12 click-throughs. So the question is, should I work on pages that have no or low search impression or web pages with a low clickthrough rate? What-ever; working any page based on this data would be Search Engine Optimization [SEO].

Related Blog posts 

[Custom Search Bar 4/2/10]
[Web Site Speed Performance 4/3/10]
[Web Site Speed Enhancements 4/15/10]
[Web Site Performance 4/22/10]

Graphic: Top Search Queries as Page Link Impressions vs. Clickthrough Rate.

Web Browser Usage

I figured I would post which Web Browser people use to visit the web site [the Engineering site, not this blog].
Every now and again I see some news article about how one of the web browsers is doing. Normally the article just posts data for the year, as in how one browser increased by a few percent for the year. In most cases the data is centered around how Firefox gained a percentage as Internet Explorer dropped a percent. Maybe sometimes that Google Chrome increased a percentage as Internet Explorer dropped some amount.

The point is that this chart shows four years of web browser usage for this web site, and not just one year of data.

Chart Data
Explorer; Microsoft Internet Explorer [MS IE]
Firefox; Mozilla Firefox
Chrome; Google Chrome
Opera; Opera Software
Safari; Apple Safari

The two things to note about the graph is that it only covers 2010 up to 5/3/2010, and Google Chrome only started in 2009.

Incoming Visitor Patterns by Month

At first when I saw my stats drop a bit last month I started to think my pages got re-shuffled in Google. Just because they do that ever month. I was also thinking about a few previous post relating to what Google thinks of my page loading times.

But now that I see the data for a full month, the trend appears normal. For the last five years the hits per month have been about the same for Feb and Apr [for the same year]. No they are not identical, but within a few thousand visits, the two months track each other.

Now it could be that more Engineering tasks start in March. Or maybe the jobs start in Jan but March is the month people start looking for parts and start designing the gear ~ I'm not really sure how I would ever know.

But if these trend lines continue I assume I'll see lower page visits for the next four months; although still higher than in previous years.

Taking note of a few pages added in Jan of this year
Power Line Filtering; Visits double each month [but it started at 13 visits]
Panel Mount LEDs; Visits dropped each month
Capacitor Networks; Visits going up a few hits a month
Resistor Networks; Visits are holding steady.
New page never do well the first few months any way.

Click on the graphic to the right to see Number of Visits/Month over the last five years.