Thursday, September 17, 2009

Firewalls for Windows - Free for Personal Use

I've decided to write in the post about some of my experience with different firewalls for Windows. I needed a firewall with such features as easy and detailed management, possibility to work via remote access with hardware and virtual computers, for both 32- and 64-bit Windows versions, XP and Vista. Here are what I used and my impressions from that.
  1. Windows firewall comes along with both 32- and 64-bit OS versions. XP firewall does not control outbound traffic what is not acceptable for me, Vista firewall does, but its setup is a nightmare - it does not show what process is really sending something out. Since it is not clear what is going on and corresponding rules should be defined manually it appears very difficult to set up the firewall. From what I read, Microsoft put a proper control over the firewall into Windows Live OneCare and there was a hope that soon it would become free of charge, but it is still not - the price is $49.95.

  2. ZoneAlarm is very easy firewall to deal with. I've been using it for a couple of years. It shows outgoing processes and asks whether you want it to be blocked or pass through, once or forever - this is the very right way for firewall to help in setting the rules. At present ZoneAlarm seems to have a free for personal use firewall with both 32- and 64-bit versions for Vista, XP still gets it as 32-bit only: ZoneAlarm disadvantages are:

    1. not very detailed rule settings;

    2. a firewall alert window is not clickable via VNC remote session, what made the remote session very conditional – if firewall shows an alert it is necessary to go to that specific computer and click the firewall pop-up window button.

    Because of those drawbacks I decided to move to another firewall about a year ago.

  3. Comodo - I started using Comodo about a year ago when it was a firewall only (now it comes along with antivirus and defense). I needed more control over the function than I could get from free Zone Alarm and Comodo offered that. Later, when I got a media-PC with Vista x64, Comodo again was one of not many free for personal use supporting 64-bit Windows and the most advanced and rich one among them in features and depth of control. To be honest, at that time Comodo had two main disadvantages from my point of view:

    1. It was too annoying - it required confirmation for every step of a process carrying out. It was educational to see what is going on under the hood, but so many alerts were pretty disturbing (although after setting a permanent rule, of course, it calmed down);

    2. Somehow it blocked remote NX session from one network computer to a virtual Linux computer running on another x64 Vista network machine (pretty specific case I think, but I needed that). Everything like Internet and local network access from the virtual computer was working fine, but not the NX session - and it was the Comodo firewall on the Vista host which blocked the connection.

    That was in the past, the current versions are free from the both of the drawbacks and work very stable on my different Windows computers: 32- or 64-bit OS, different hardware brands; there is no problem with NX or any other type of remote access to hardware or virtual machines I use.

  4. Sphinx - I used it at the time when Comodo had the problems I described above and there were very limited number of available 64-bit firewalls free for personal use. Sphinx was one of them. As its description suggests Sphinx is not a complete firewall, it is a control over the existing Windows firewall and Sphinx compensates the lack of management in it: Sphinx generates pop-up alerts for traffic and sets the firewall rules according to a user choice. It's a pity the rule settings in the free version are very poor: just "Allow" or "Block", all rules are in the same general zone - more detailed control is available only with the commercial version of Sphinx. Nevertheless it did the job.
Nowadays much more firewalls are available for free for personal use: Ashampoo, PCTools, Outpost, etc. - just search. The choice of x64 versions has become better too. Some of them, Comodo, for example, come in a bundle with other protection tools as antivirus and malware defense. At present I put Comodo in charge of security on all of my Windows computers and it seems it's doing the job very well: I have not noticed any system or application slowdown, antivirus is a little bit too alert in "Heuristic" mode (jumps up on some of safe programs), but it's a rare case and it can be easily pacified. Comodo also offers commercial versions of firewalls and many other network security products for different cases - if interested you can check it out following the sponsor link:

Comodo Internet Security Pro

Saturday, September 12, 2009

Add Atom and RSS Feeds to Blogger Template

Atom and RSS are two similar methods of web content syndication. The idea of feeds is not to check all web sites of interest one by one, but automatically collect updates from them with one tool called "feed reader" or "aggregator", so feeds can be considered as an advanced alternative to bookmarks. Subscribing to feeds really helps to save time and stay informed. Blogger supports both Atom and RSS feeds.

The truth is that nowadays web browsers can work directly with feeds, so a special program is not really needed. For example, Firefox shows available feeds as an icon in the end of the address field:and Internet Explorer - in the Command Bar: Click the icon to open available feeds from the web page, choose the one you prefer and that will take you to a subscription page. Firefox can save a feed as a "live" bookmark which references not just a website at whole but each article individually from it. IE puts it under tab "Feeds" in the "Favorites" window.

While it is possible to subscribe to the feeds directly from a web browser it is still can be good for the sake of convenience to add them to a web page. Blogger has some variants of the feeds - Blogger Help describes them in the "Blogger Feed URLs" article.

For instance, I decided to put Atom and RSS full site feeds in the right top column along with the "Bookmark and Share" button. In Blogger layout all the three buttons are sitting inside one HTML/Javascript gadget - you can check the source of the page to see how it looks like as code.

For more information a great description of Atom and RSS can be found in Wikipedia.

Monday, September 7, 2009

Big Green Egg BBQ Rib Eye Steak - For a Few Dollars More

Rib eye is the king of all steaks - great taste and great look, cooking is easy and not very different from, for example, the pork steaks, but result is a true poetry.
Rib eye is the king of all steaks - great taste and great look, cooking is easy and not very different from, for example, the pork steaks, but result is a true poetry.
  1. From what I heard: when you come to a store the best rib eye pieces have been already taken by restaurants and what you can choose from is just remains - but that can be a conspiracy rumor :) This time I've got reasonably good looking chunks.

  2. Wash the chunks gently in cold water, salt and season them.
  3. For cooking rib eye steaks the temperature should be high, so clean up the BGE from ash and small pieces of charcoal which can block air flow to pass through and load it with middle and big size charcoal pieces. Start fire in the center of Big Green Egg.

  4. Let temperature reach 600F

  5. Then drop some smoke chips on the charcoal if you like and put rib eye chunks in the center of the grid right over the hottest area.

  6. Let the meat get nice grid marks on the bottom side and then flip the pieces to another side.

  7. Repeat the step #6 two more times. For the last time place the chunks at periphery of the grid (away from the hottest area) - that will finalize the cooking. I prefer to have a reliable reference for internal meat temperature - cooking thermometer does the job for me.

  8. Close the BGE top cover and wait when the temperature inside the meat get reached a desired value. Cooking thermometers usually have settings for the corresponding tastes, mine has presets for beef as
    Rare      140F
    M. Rare 145F
    Medium 160F
    Well Done 170F
    I prefer medium.

  9. Just great!


Sunday, September 6, 2009

Switching to Netflix

About two months ago when my cable TV bills successfully broke through the $100 barrier and kept climbing up I started thinking about an alternative. I am rather a movie than a TV guy and I don't like to coordinate my time with the TV schedule. For the news I switched to the Internet a long time ago, so I did not really need the TV. Then Netflix caught my attention. I've heard about the company before, but it was mentioned mostly as a "DVDs by mail" service. Now they have a superior addition - internet streaming and that actually turns Netflix into a very attractive choice.

They still define the service as "DVDs by mail" for the first and streaming for the second, but from my interests streaming is the main feature and DVD is a great addition. For about $10 per month Netflix provides unlimited streaming and 1 DVD by mail. Streaming video quality with 5Mb/sec internet connection is on the level of regular standard definition (SD) TV or slightly higher which is satisfactory for me. With faster connection speed, as they say, quality is supposed to be better, but I did not check it. So my approach with Netflix is to order really spectacular movies on DVDs and watch everything else I like via streaming.

I've been with Netflix already for more than a month and my impressions are all positive. I can see many Netflix' advantages over TV:
  1. No schedule - watch when you want and as long or short as you want.
  2. Rich collection of movies and shows for streaming and it keeps growing. I would wish to see everything available via stream and I hope this is the future.
  3. DVD collection is huge.
  4. Both DVD and online collections have many movies from around the world - it's rare when you can catch an interesting non-American movie on American TV.
  5. Getting more for less money: with Netflix it is Internet from an ISP for $30 + Netflix itself for $10 per month; with cable TV and Internet bundle it is more than $100.
From all those above I was pleasantly surprised how rich Netflix's DVD and online collection is. I finally watched the beginning of "The Sopranos" (DVD), TV shows "Weeds" and "Lost" (both via stream), movies like Buñuel's "Un Chien Andalou", Antal's "Kontroll", Tykwer's "Lola rennt"... I'm going to make a list of my favorite movies and shows and indicate their availability at Netfilx.

Subscription to Netflix is very simple, no contract, they offer 2-week trial period for free - just be sure that you have proper equipment ready for streaming. In my case I have a media-PC running Microsoft Vista, I prefer to watch Netflix with MS Media Center, another possibility is MS Internet Explorer (but both work very well).

Saturday, September 5, 2009

Samsung Home Theater HT-X40 - Shut Down on Protection Problem

A couple of days ago my Samsung home theater HT-X40 started periodically shutting down with "Protection" message. Resetting by the "Stop" button pressed for 5 seconds made it forget all settings but did not fix the shut down problem. From the cool start it took about 20 minutes until it switched off for the first time and 2...3 minutes after re-powering while it was still warm. That behavior clearly indicated a problem depended on heating.Disclaimer: Repairing electrical and electronic devices requires corresponding knowledge and skills and should be done by qualified professionals only. Electrical devices are sources of different hazards - electrical shock, skin burn, fire, etc. A DVD laser is a source of different hazards including eye, skin, fire hazards. This post is just a description of the problem in my particular case and not a recommendation for anybody on what to do and how to fix the problem whatsoever. The description is provided for informational purposes only, I bare neither responsibility nor liability and do not accept any claims for any injury and damage on your side.

A couple of days ago my Samsung home theater HT-X40 started periodically shutting down with "Protection" message. Resetting with "Stop" button pressed for 5 seconds made it forget all settings but did not fix the shut down problem. From the cool start it took about 20 minutes until it switched off for the first time and 2...3 minutes after re-powering while it was still warm. That behavior clearly indicated a problem depended on heating.

A promising thing was that all speakers were working fine every time when the theater was on. The fan on the rear side was working OK, air flow was relatively hot, but it was difficult to judge by that. Testing the speakers did not show any problem - each of them had normal resistance about 6 Ohm. Inspecting situation inside the theater I found the following problems on the speaker driver board (marked correspondingly in the following picture - click to see it in whole size):
  1. the output driver heat-sink was very hot,
  2. inductors corresponding to the central speaker were untouchable (burning hot),
  3. 0.47 uF x 100V filtering capacitor in the central speaker channel had a visible crack on its body.
Test of the unsoldered capacitors clarified that 5 out of the 6 caps had good insulation (infinite resistance at 20 MOhm multimiter range) and only the one with visible crack showed 12 MOhm under the same measurement conditions. Each of these capacitors is connected between the two wires going to the corresponding speaker (in parallel to the load). It was probably happening so that under higher temperature insulation resistance significantly dropped down from the 12 MOhm to a value comparable to the main load, in its turn that increased the temperature more. The temperature kept increasing until the protection switched off the power.

For the first step I decided to exchange only that obviously broken capacitor and see if any other problem would surface after. The original capacitor was 0.47uF, 100V, film type:

I was lucky to find a cap of 0.47uF, 250V, same film type in an old modem. This is the board after replacement:

I intentionally distanced cases of the capacitors from the inductors on the board, because the inductors could be that heat source which helps to damage the caps. Since I had assembled everything back together the home theater has been working normally. In addition I increased the gap under the home theater by sticking 4 pads usually used on furniture legs to protect floor from scratches:

Temperature of air flow from the back panel fan has become significantly lower comparing to that time when the home theater was failing.

Technical Note
From many comments I can see that there is an interest in deeper technical details related to the problem. Here are some useful references:
  1. Class D Amplifier describes principals of operation;

  2. Class D Audio Amplifier Output Filter Optimization - the application note explains why output LC filter is required (in the beginning of "Output-Filter Design section). The reason is EMI (electro-magnetic interference).

  3. 2 x 210 Watt STEREO DIGITAL AMPLIFIER POWER STAGE - datasheets for TAS5162, power amplifier from Texas Instruments with examples of typical schematics. It is probably not the exact power amplifier by part number from the Home Theater, but it's of the same class-D.

Long story short: Nowadays most of audio power amplifiers utilize Pulse Width Modulation (PWM), so called class D amplifiers, because of very good about 90% efficiency. PWM uses higher frequency Fpwm (100kHz and higher) comparing to the sound frequencies and the pulses have fast edges. That's why the output signal besides the sound frequencies also has Fpwm and bunch of its harmonics. The output low-pass filter (here built as passive LC) is needed to block Fpwm related frequencies inside the box - without the filter the wires going to speakers will irradiate these frequencies and may interfere with other electronic devices. Say, without such a filter you would still hear correct sound (probably with unnoticeable distortions), but some electronic equipment around can be affected (anything with "wireless", "radio", "sensitive", "low noise" characteristics is in the list).

I hope this technical note can help to understand better what's going on there and how to deal with the problem.

I'll keep updating the post.