Sunday, January 17, 2021

COVID-19 Masks

UPDATE: Genuine made in USA NIOSH approved N95 masks now available:

  • Direct from the manufacturer: DemeTECH
  • HALYARD (medical grade): Amazon
  • Kimtech (Kimberly-Clark): Amazon
Face masks are a crucial part of minimizing the spread of deadly COVID-19 infection, but poor, fake masks have flooded the market and are a huge problem, thanks to incompetence of the Trump administration, which:
  • Failed to update early temporary mask guidance. (Ordinary cloth masks are not terribly effective.)
  • Provided little guidance to consumers on how to obtain affordable high-quality masks.

The good news is that genuine, affordable, high-quality masks are now readily available. The bad news is that it's hard to distinguish good from bad.

  • The best masks meet the USA N95 standard, but those are still in short supply.
  • Good alternatives are those that meet the comparable Chinese KN95 standard.

How to Tell Genuine KN95 Masks

  1. Manufacturer appears on the FDA PPE EUA list.
  2. Masks (not just packaging) are branded with a China KN95 standard:
    • Medical: GB19083-2010
    • Non-medical (but still effective against COVID-19): GB2626-2006, GB2626-2019

How to Avoid Fake Masks

  1. Manufacturer does not appear on the FDA PPE EUA list.
  2. Masks are not branded with a China KN95 standard (listed above).
  3. Masks claimed to be GB19083-2010 but "non-medical" (since that is a medical standard).


  • Best filtration is melt-blown fabric in a multi-layer sandwich.
  • Carbon filtering is not effective against COVID-19.
  • Avoid masks with valves, because they are less effective against spreading infection.

Genuine KN95 Masks

  1. Powecom KN95 Protective Face Mask (10-Pack) (white)
  2. Chengde Technology KN95 Face Mask 20Pcs (white)
  3. ChiSpi KN95 Face Mask 20Pcs (colors)
  4. ChiSpi KN95 Face Mask 60Pcs (white)
  5. Hotodeal KN95 Face Mask 40 PCs (white)
Disclaimer: Provided as public service, accuracy not guaranteed.

Friday, December 25, 2020

YouTube Music Playlist Shortcut

Google giveth and Google taketh away

Play Music, originally Google Music, was mature and pretty good. There was really no reason for Google to create YouTube Music and shut down Play Music, forcing a painful transition on users, other than its own organizational convenience (but I digress). 

Part of the pain for users is that (as of this writing at least) YouTube Music doesn't work as well as Play Music, particularly for those using it for cloud storage of uploaded music more than for paid streaming. One of the more annoying issues is that some (not all) video playlists get mixed in with audio playlists, making it harder to navigate audio playlists.

The YouTube Music app for Android, which suffers from annoying pauses even with strong mobile signal, makes things worse by having no way to create Home screen icons for specific playlists, either by widget or by shortcut. (The Play Music app had a widget for a specific playlist.) Fortunately, there is a way to work around this limitation, but it's not obvious. On Android:
  1. Install the Website Shortcut app.
  2. Open YouTube Music in Chrome browser (not the app), and navigate to a desired playlist.
  3. Scroll up to 3 dot overflow menu at right end of Chrome navigation bar to Share that page to Website Shortcut:
    1. Add the Playlist name in the Label field.
    2. Select a custom icon (e.g., artist photo) if desired (otherwise it will be the YouTube Music icon).
    3. Create Shortcut, and install the icon on a Home screen.
Now that Home screen icon can be used to launch the specific playlist (in the app if it's installed rather than in Chrome).
  • A good way to organize these playlist icons is to create a Playlist folder on the Home screen.
  • Another way is to add a Home screen just for music playlist icons.
  • This same technique works for artist, album, contributed playlist, search, anything that can be shared.
The reason for using Website Shortcut is that Add to home screen in Chrome just creates an icon that launches the app, not the desired playlist.


Monday, December 14, 2020

Message Not Delivered

Message Not Delivered error with alias in Gmail 'send mail as' feature

In Gmail,

  • if you use the 'send mail as' feature to send mail from a different address (account),
  • and you have recommended two-factor authentication (aka 2-Step Verification) enabled,
then you may eventually get this Message not delivered error:

Unfortunately, the error message is written in confusing technical jargon that makes it hard for ordinary people to figure out (a) what's causing the problem and (b) how to correct it.

The clue is the "out of date" phrase. To use 'send mail as' when two-factor authentication is enabled, you have to create and use an app password in order to setup mail sending. What Google doesn't tell you is that there's an expiration on that setup, after which it will no longer work, resulting in the above error message.

It would be much better if Google alerted you to the expiration with instructions on how to renew it, but alas, you have to figure it all out for yourself. Here's how to fix the problem when it occurs:
  1. In Settings > Accounts and Import, find that 'Send email as' address and Delete it.
  2. Then use 'Add another email address' to add that same email address back.
    1. Leave 'Treat as an alias' checked, and click Next Step.
    2. Username is your Gmail address (since you are using a Google SMTP server).
    3. Password can be the same app password as before, or a new app password.
    4. Then Add Account, and follow instructions to Verify it.


Thursday, December 3, 2020

Chrome Sharing Hub

Chrome Sharing Hub

"The road to hell is paved with good intentions."

Sharing on Android

Share functionality on Android has been something of a mess, in that picking a Share target has been clumsy and painful. With Android 10, Google made significant improvements, although it's buggy in that the wrong target app is sometimes launched if you select too quickly (a problem that persists in Android 11).*

Meanwhile, possibly due to that clumsiness, the Chrome team has been working on its own Share solution, called Sharing Hub, and has now rolled it out widely.

What's Wrong with Sharing Hub?

The Sharing Hub provides an array of sharing targets at the bottom of the screen, which sounds like a good idea, except there are a number of problems:

  • The array of targets cannot be customized (as of this writing at least). That's only fine if you just want the sharing target choices made by Google.
  • If you want some other sharing target, you have to first scroll to the right, then select the More overflow menu to open the standard Android Share menu.
  • Opening the standard Android Share menu thus takes two extra selections, which is clumsy and painful, especially if you do it frequently.
  • Opening the standard Android Share menu also takes more time that slows things down, making it doubly clumsy and painful.

How To Disable Sharing Hub

Fortunately, Chrome Sharing Hub can be disabled, leaving just the standard Android Share menu:
  1. In Chrome, open
  2. Change the option to

* Work-around for the wrong target app bug is to scroll the standard Android Share menu up before making a selection.

Friday, March 13, 2020

Recommended VPN 2020

Update to Secure Wi-Fi with VPN

What is VPN?

A Virtual Private Network (VPN) is a service that allows you to connect to the Internet via an encrypted connection to ensure your online privacy and protect your sensitive data. VPNs are commonly used to secure connections to public Wi-FI hotspots, hide IP addresses and make your browsing private. In addition, VPN can make it possible to get around geographic blocking, such as accessing Canadian and British content from the USA (and USA content from Europe). I strongly recommend use of VPN, particularly on public networks (e.g., Starbucks Wi-Fi).

I had been using and recommending AirVPN, but it has eliminated all but one server local to me, and that server has not always been reliable. (Servers in other locations are not as fast due to extra distance.) So I undertook a through analysis of other VPN providers, and my new recommendation is Surfshark. In addition to excellent service and support, Surfshark is also (currently) a bargain, at only $47.76 for 2 years of service, less than $2 per month, with 30-day full refund.


  1. I get no commission for recommending Surfshark.
  2. During the Olympics, I use VPN to access Canadian coverage (by connecting through a Canadian VPN server), which is far superior to coverage here in the USA. 

Tuesday, January 22, 2019

Choosing a Wireless Router 2019

TP-LINK Archer C8
Checklist for Wireless Networking

Very Important

  1. Don't settle for a "wireless gateway"
    A "wireless gateway" is an all-in-one device that combines a modem (cable or DSL) with a wireless router. They tend to be mediocre, poor performers, especially those supplied by Internet providers.
    1. Insist on a pure modem. Buy your own separate wireless router.
    2. Make sure the modem is configured in "bridge" (not routing) mode. Otherwise you can have "double NAT" problems.


  1. Simultaneous Dual Band
    The low 2.4 GHz band, commonly found in consumer-grade devices, is increasingly crowded, which can severely limit performance. The high 5 GHz band tends to be much less crowded, and will often provide much better performance. But don't just get a single band 5 GHz device, since some wireless devices only support 2.4 GHz, and avoid dual band devices with a single radio that can only work on one band at a time. In other words, not just dual band, but simultaneous dual band.
  2. AC1750 (Wi-Fi 5)
    The current baseline for good Wi-Fi is AC1750 (Wi-Fi 5), 450 Mbps on the 2.4 GHz band plus 1300 Mbps on the 5GHz band. AC1900 and up can provide improved range and speed, but may not be needed in many cases.
  3. Gigabit Ethernet
    Although Fast (100 Mbps) Ethernet is comparable in real world performance to 300 Mbps wireless (actual wireless performance is usually much less than the advertised maximum), Gigabit (1000 Mbps) Ethernet provides much faster wired networking for not much more money and is otherwise good "future proofing".

Nice To Have

  1. Guest feature
    A guest feature is a separate wireless network for guests that lets them connect to the Internet but not to any of your own networked devices. It's a bad idea to give guests access to your own network.
  2. USB
    USB can be used to attach USB storage or USB printer to the wireless router for network access.


    1. ASUS RT-AC86U
      BestAC2900. Outstanding range and performance. High processing power for gigabit throughput. Excellent support.
    2. ASUS RT-AC68U
      Better. AC1900.
    3. ASUS RT-AC66U B1
      Very good
      . AC1750. B1 is improved over original version. All that most people need.
    4. TP-LINK Archer C8
      Best Buy.
       AC1750. All that most people need. 


    1. Update Firmware
      Check the support website for updated firmware before installing, and regularly thereafter (e.g., quarterly).
    2. Don't "cheap out"
      A cheap wireless router can reduce performance due to poor internal routing speed.
    3. Use WPA2 AES Security
      Identity theft is just one of the risks from getting hacked, and WEP "security" is essentially useless. Use a different (and equally strong) password for a Guest network.
    4. Set a Strong Password
      Use a random combination of 12 or more mixed case letters and numbers that you don't use for anything else, and do not use common words, names, numbers, etc.
    5. Don't fool yourself
      Network name (SSID) hiding and MAC address filtering are too easily circumvented to provide even minimal security, and they can lead to network problems, so don't use them.
    6. Network Backup
      Network storage is an excellent way to keep your devices backed up. Highly recommended. (WD My Cloud is a very good alternative to network storage on the wireless router.)
    7. Mesh wireless
      Mesh wireless is all the current rage, but impairs wireless performance. The better way to increase coverage is with wireless access points connected by Ethernet wiring, or by powerline networking where Ethernet is impractical. If mesh must be used, ASUS AiMesh can work well with a pair of wireless routers.

     See Also

    Tuesday, September 25, 2018

    Memory Card for GoPro

    Samsung EVO Plus microSDXC
    Which memory cards are good for GoPro HERO action cameras?

    Many professional photographers and videographers swear by SanDisk Extreme and Lexar Professional memory cards because they have proven to be tops in reliability and performance.

    But as of September 2018, arguably the best card for GoPro HERO (and for most other devices) is the Samsung EVO Plus (2017 Model). With Class 10 U3 speed (up to 100MB/s Read and 60MB/s Write), the 64GB capacity (with adapter) is widely available for only $21.

    For reliability and performance, format cards with the official SD Association Memory Card Formatter.

    Counterfeit cards are a huge problem. To protect against counterfeits, always (a) buy from a major reputable reseller like B&H, and (b) test before use with H2testw 1.4. Example of testing a 64GB Samsung EVO Plus in a Lenovo ThinkPad T460p:
    Test finished without errors.
    Writing speed: 57.7 MByte/s
    Reading speed: 70.2 MByte/s
    H2testw v1.4
    (After testing with H2testw, be sure to either delete the test files from the card or format the card.)

    Thursday, March 1, 2018

    FZ1000 No Limit Video

    Lumix DMC-FZ1000
    The Lumix DMC-FZ1000 by Panasonic is a terrific digital camera for stills, thanks in part to an amazing Leica branded long zoom lens, but what really sets it apart is excellent 4K video, except for one unfortunate limitation: the length of a video clip is limited to 29:59 (30 minute limit, thanks to an EU tariff, even on a USA camera).

    One way around the limitation is to feed video while monitoring (not recording) over HDMI to an external recorder like Atomos.

    Another way, not documented by Panasonic, is to hack the FZ1000 into service mode with the following procedure:
    1. Start with the FZ1000 turned off, with Drive Mode dial set to Single, and Recording Mode dial set to Program AE (P).
    2. While holding down Right Cursor, DISP, and AF/AE LOCK (yes, all 3), switch the camera on.
    3. Press green Play button to enter Playback Mode.
    4. While holding down Up Cursor and AF/AE LOCK (2 things), switch the camera off.
    5. Switch the camera back on.


    1. PAL cameras must be switched to NTSC frame rates to remove the recording limit. (This is not needed on NTSC cameras.) Format memory cards in the camera after making this switch.
    2. Recording limit is removed only for 4K video, not HD or other video formats.
    3. Yellow exclamation mark that appears when turning off the camera in service mode can be ignored safely.
    4. With this hack, FZ1000 is able to continuously record over 80 minutes of 4K video on a 64 GB SDXC card, ending with 2 of 3 bars battery (when starting with a fully charged battery).
    5. This hack reportedly also works for a number of other Lumix cameras with the 29:59 limit.

    Reset to normal mode:

    1. Start with the FZ1000 turned on, with Drive Mode dial set to Single, and Recording Mode dial set to Program AE (P).
    2. While holding down Right Cursor and MENU/SET (2 things right next to each other), switch the camera off.
    3. When the menu appears, press Right Cursor until the camera actually turns off.
    4. Camera has now been fully reset to normal mode with all settings restored to defaults, so must be initialized again (language, date, time, etc).

    Helpful videos:

    Tuesday, February 27, 2018

    Transcode with VLC

    VLC as a Recorder
    In addition to being a great way to play video and audio content, VLC is also a great way to record Internet streams (e.g., radio) -- see Record Internet Radio.

    MP3 streams are the simplest to record because they can just be dumped to a "raw" file, but that often won't work with other types of streams. The solution is to transcode (convert) streams into MP3 format with VLC before writing them to a "raw" file. It's also a good way to reduce the bitrate of MP3 streams for speech.

    Example of VLC output without transcoding:

    Corresponding example with transcoding for speech
    (bitrate 48 Kbps, stereo, speech sample rate):

    Corresponding example with transcoding for music
    (bitrate 128 Kbps, stereo, music sample rate):

    For the complete recording procedure, see Record Internet Radio.

    Monday, January 23, 2017

    TASCAM DR-40 Input Level

    TASCAM DR-40
    One of the best affordable digital audio recorders is the TASCAM DR-40, capable of producing audio recordings that are far superior to recordings made by most digital cameras and camcorders. Dubbing DR-40 audio into recorded video in post production with software like Adobe Premiere is a great way to produce quality video output.

    One of the keys to making good audio recordings is to set the input level properly. Set it too high and clipping can result in distorted audio. Set it too low and the result can be noisy when amplified to normal listening levels.

    A feature that sets the DR-40 apart from the competition is Dual Recording Mode, which makes a secondary recording at a lower level (at an adjustable difference of -6db to -12db) as a backup in case the primary recording is accidentally clipped into distortion.

    Here's a simple, effective way to set DR-40 input level properly when using Dual Mode:
    1. Set initial input level to 80.
    2. Adjust input level during testing or rehearsal for peak value of -6db (as shown on the display), with an average level of about -12db (triangular hash mark on the display), which will usually provide sufficient headroom (safety margin).
    3. Set Dual Mode at -9db. In the case where input level has accidentally been set too high for the primary recording, that will usually provide proper headroom for the backup recording.
    4. Before dubbing with video in post production, check peak recorded level of the primary recording, and if it did run out of headroom (higher than about -3db), use the backup recording instead.
    General recommendations for quality recordings:
    • Record in (lossless) WAV format.
    • Use a sampling rate of at least 48 kHz, preferably 96 kHz for music.
    • Use 24 bit depth.
    These settings may be more than you need for finished video, but you may well need extra margin in post production, so you should capture as much quality as possible. Because these settings can result in large files, make sure you have a sufficiently large memory card of high quality (e.g., SanDisk, Lexar Professional).