sept – W9AA HamGab https://hamgab.hamfesters.org Newsletter of the Hamfester’s Radio Club Fri, 28 Aug 2020 02:21:55 +0000 en-US hourly 1 https://wordpress.org/?v=6.6.2 https://hamgab.hamfesters.org/wp-content/uploads/2019/03/favicon.ico sept – W9AA HamGab https://hamgab.hamfesters.org 32 32 194902107 September 2020 – HamGab https://hamgab.hamfesters.org/september-2020-hamgab/ Fri, 28 Aug 2020 02:04:36 +0000 http://hamgab.hamfesters.org/?p=1507 Continue reading "September 2020 – HamGab"

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Next Meeting Sept 4th @ 7:30

  • The meeting will be hosted on Zoom
  • Watch the W9AA website for up to date info

Secretary’s Beat

  • Zoom Meeting

Does Anyone Really Know What Time It Is?

By Gregg Rosenberg (AB9MZ)

Hamfester’s VE Testing

  • APPOINTMENT TIMES ONLY
  • For details click the link above.

Other Club Info

  • Locations, times, dates, nets, and other info!

Photos from the July Meeting

  • Screenshot from our virtual meeting!

PO Box 474
Crestwood, IL
60445-0474

Meets 1st Friday of every month at the
Crestwood Civic Center
14025 S Kostner Ave
Crestwood, IL

August Birthdays
Martin Linke
John Derkacy
John Midkiff
Gary Kole
Charles Zee

Officers
President – Nora KC9MLV
Vice President – Jim W9JPR
Secretary – Patty KC9LYE
Treasurer – ED WA9EOL
Sgt at Arm – Don KC9EQQ
Trustee – Gene W9PNG

Board Members
Steve – W9KXT
Kurt – WB9FMC
Cindy – N9CAS
Don – KC9EQQ
Rich – KB9NTX
John – KB9FQB

HamGab Editor
Gene – W9PNG
hamgab@hamfesters.org

Secretary’s Beat – Meeting Minutes

The Hamfesters Radio Club general meeting for August 7, 2020, was called to order by President Nora Pointer at 1930 hours via ZOOM.

President’s Report: We’ll be having Zoom meetings for the foreseeable future.

Announcements: Brian W9HLQ reported that the QSO Today Ham Expo starts today.

Health & Welfare: Jim W9JPR reported that XYL Judy is still cancer free. Gregg AB9MZ reported that his mother has cancer

Motion to approve the minutes of last general meeting was made by Ed WA9EOL and seconded by Gene W9PNG. All voted to approve.

Treasurer’s Report was given by Ed WA9EOL.

Secretary’s Report: Secretary Patti KC9LYE was unable to attend. Vice President Jim W9JPR took the minutes.

Program: Brian W9HLQ showed a video about working satellites with a handheld by Tim Tucker AE6LS.

Standing Committees

Membership: Brian W9HLQ reported no new member.

Program: AB9MZ will be doing a Zoom program on FT8 tips and tricks in September.

Publicity: No report

Hamfest: No report

Field Day: Jim W9JPR reported FD 2021 will be on June 26-27.

Awards: No report.

Education: Brian W9HLQ reported a possible Tech class in the fall or winter.

Hamgab: Gene W9PNG thanked everyone for last month’s Field Day and VE articles.

Special Committees

Old Business: Cindy N9CAS is looking into new club caps and reported that our new club masks are on the way.

New Business: None.

Motion to Adjourn was made by Dave N9KPD and seconded by Brian W9HLQ. The meeting adjourned at 2013 hours.

Does Anybody Really Know What Time It Is?

The band Chicago once asked the question “Does anybody really know what time it is?”
By Gregg Rosenberg (AB9MZ)

In the early ‘80s My friend Phil Karn KA9Q told me “As technologies becomes smaller and faster their dependance on accurate time and frequencies becomes more and more significant.”

As technologies get smaller and faster their dependance on having an accurate time-base and frequency becomes more and more critical. Many operating modes and protocols have equally become more critical of the accuracy of time and frequency. Most of us don’t think to much about the accuracy of our computer clocks or the stability of the crystal oscillators or frequencies in our radios. For the most part they just work. Those of us that did care typically spent extra money to buy double shielded temperature controlled crystals for our radios. Those that couldn’t afford such a crystal learned to warm our radios up an hour before going on the air or tweaking the RIT / XIT knobs to adjust for what ever frequency error we had. Those that have test equipment understand the importance of having accurate frequency calibration and accuracy. 

You would be amazed how many technologies we have used in our lives depend on the accuracy of time and frequencies. A significant number of technologies depend on time and use what is referred to as time-division multiplexing. When you are traveling in your car and transition from one cellular site to the next you are given a time slice to send your mobile devices identifier, to authenticate to the cellular  network, and the chunks of voice, data, or telemetry that your device sends or receives. Leased lines that interconnect our networks, those that form the backbone of today’s Internet, and that deliver Internet to your home or business dependent critically on the accuracy of time and the accuracy of their transmission frequencies. Today we have many newer protocols evolving that operate using other methodologies which are beyond the scope of this article.

I joined Tuscan Amateur Packet Radio (TAPR) back in the late ‘80s. These guys were all over frequency calibration and accurate time bases. They put out many kits to build time and frequency standards. In the early ‘90s, I built one of their TAC-32 GPS receiver kits. It used a Motorola GPS receiver board pictured below.  which sat on top of an Intel micro 386 board. It was accurate to 1/300ms. It was attached to one of my network time protocol (NTP) servers used to provide a very accurate time base to keep accurate time on my networks. It was connected to the server using a 9-pin RS-232 cable. It used a BNC connected NEMA GPS antenna. On today’s networks, time is critical for encryption, digital certificates, and logging. When we correlate network breaches or attacks on computer services we depend on what is referred to as log correlation. That is, the logs we collect from many systems have to have accurate enough time-stamps so we or our automated security processes can correlate an event on two or more networked devices.
My younger brother Jeff worked at a metal shop and made the box for me. Most of the parts were taken from the junk box besides the parts that came from the TAPR kit. The front of the box has three LEDs to provide status of power, satellite lock, and errors.

At the time we used a ribbon cable to break out the serial port, a BNC connector for the GPS antenna, and a jack for bringing in power.

You can see the TAC-32 board and the Motorola GPS receiver.

Screen shot of the TAPR developed TAC-32 software.

Motorola GPS module that sat atop the i386 micro motherboard.

An example of the NEMA GPS datastrelm.

External frequency references

External frequency reference standards have been around a very long time. Many newer radios have the ability to accept a frequency reference to maintain accurate oscillator frequencies. Several SDR radios, and a few newer amateur radio transceivers have this ability. The IC-R6800 receiver, IC-7610 and IC-7851 transceivers, SDRplay RSP2 and RSPduo, FlexRadio Signature series, and the Expert Colibri receiver, for example, have the ability to lock to an external 10 MHz reference clock.

Frequency drift

Frequency drift is usually caused by temperature variance in the radio. Other factors, such as the DC supply rail voltage changing during transmitting periods, can also have an effect. Frequency drift is not generally a problem at short wave frequencies, or at VHF or UHF frequencies if you are listening to FM signals. But it becomes a big problem at when operating narrowband (<100Hz) digital mode signals (such as FT8), for instance, operating at microwave frequencies, or receiving data signals from a geostationary satellite.  

Wikipedia tells us that Time-division multiplexing is used primarily for digital signals, but may be applied in analog multiplexing in which two or more signals or bit streams are transferred appearing simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel.

A quick peek at a digital mode to understand the importance of time

Lets consider a popular digital mode called FT8. It effectively uses time-division multiplexing to create time slots for radio operators to fill with their exchanged messages. The accuracy of your computer’s clock In order for the your radio to know when to transmit or receive becomes time sensitive. Your radio needs to accurately know when each time slot occurs so you known when it is time to be in transmit or receive mode. Many other digital modes use time windows to coordinate message exchange as well.

If we take a period of time X and divide it into four chunks (A1 through A4) then you or I could take turns sending information in those time slots. 

FT8 makes use of this approach. That is why the accuracy of time and frequency are so important. FT8 takes a minute (maybe longer due to re-tries) and devices it into four 15 second time slices. If your clock or that of another you wish to have a QSO with and your clocks aren’t within one second of each other you will likely get bad decodes or fail to communicate at all.
This isn’t how FT8 works, but for simplicity’s sake, I will use this example. Let’s assume the sender’s clock is reasonably accurate to within a second and the receiver’s clock is off by +3 seconds. You can see below that the receiver’s time-slice is out of sync with the sender’s time-slice. It is far more complicated than that, but I wanted an oversimplified visual to get the point across. 

Here is a typical conversation that might take place over FT8:
“CQ AB9MZ EN61” AB9MZ sends a CQ call with his grid-square location.“AB9MZ G0QQQ IO81” G0QQQ replies with his grid-square location.“G0QQQ AB9MZ -12” AB9MZ responds with a signal report of -12.“AB9MZ G0QQQ R-08” G0QQQ confirms the signal report & replies with his own report R-08.“G0QQQ AB9MZ RRR” AB9MZ says Reception Report Received.“AB9MZ G0QQQ 73” G0QQQ says Best regards.“G0QQQ AB9MZ 73” AB9MZ says Best regards.
Each message of up to 13 characters takes 13 seconds to send. There are four time-slots per minute, and you transmit for one 15 second block, then listen for replies for 15 seconds, and transmit again for 15 seconds. 


So what do we do to get more accurate time

Our software defined radios and more high-end transceivers address the frequency drift issue adequately for most of our needs in Amateur Radio. Our computers, especially those running a Microsoft operating system somewhat fall down on the job. Mac OS and Linux tend to have much more accurate time bases. This is because accurate time was an afterthought on Microsoft’s part. Although Windows 10 has much more accurate time, it still is marginally accurate for protocols like FT8, FT4, …, and other digital mode protocols that use time-division multiplexing that depend on time accuracy of less than a second. 
You can switch from the Microsoft time server “time.microsoft.com” and use the accurate time servers maintained by the U.S. Navy and the National Institute of Science and Technology (NIST). Time servers are generally organized in pools. The U.S. pool of time servers is “us.pool.ntp.org”. You can greatly improve your time accuracy by using the separate sub-pools. 

0.us.pool.ntp.org
1.us.pool.ntp.org
2.us.pool.ntp.org
3.us.pool.ntp.org

Windows time sync command

You can open an elevated command or PowerShell prompt in Windows and use the following command line to setup your list of timeservers.

w32tm /config /manualpeerlist:0.us.pool.ntp.org,1.us.pool.ntp.org,2.us.pool.ntp.org,3.us.pool.ntp.org /syncfromflags:manual /reliable:yes /update

Setup time synchronization on your radio shack’s computer

Even better you can run a time server on your Windows machine. Unlike Microsoft Windows, Mac OS and Linux both have time servers that are very accurate built into their operating systems since their inception. Time servers have been around since the late ‘60s.
For our example we will use the Meinberg server. It is very easy to install, set, and forget. It will start each time you start your computer. 
You can download it from: https://www.meinbergglobal.com/english/sw/ntp.htm#ntp_stable.

Because it is touching sensitive areas of your machine it will ask your permission to make the changes it needs to. Simply click [YES]. Then agree to the license agreement on the next screen.

By default it will install all components. You simply click [NEXT].

On the “Configuration Options” screen we need to change a few things.

  1. Check the “Create an initial configuration file with the following settings.”
  2. Select the United States” from the drop down list.
  3. Type the following “0.us.pool.ntp.org, 1.us.pool.ntp.org, 2.us.pool.ntp.org, 3.us.pool.ntp.org” (without the quotes) in the “You can specify up to 9 NTO servers” text box.
  4. Then check the “Add local clock as a last resource reference” checkbox.
  5. Then click the [Next] button.

You can choose [Yes] to review the changes if you like, or click [No] to continue.

You can take the defaults and click [Next] on the service options screen. 

Then click [Finish] to complete the installation.

Now click your Windows [Start] button and select your list of applications. Scroll down to the M’s and click on “Meinberg”. Since it is a folder it will open up and show you what was installed. Click on the “Quick NTP Status” program.

It will then run a simple diagnostic to show you everything is working.

Computer Time Sync Software Resources from The DXZone:

I have used BktTimeSync, JTSync, and Meinberg time sync software packages. Both are trivial to install and maintain accurate time to within 500ms to 700ms of accuracy. Well below the threshold requirements of modern digital modes. See the link in references.

BktTimeSync by IZ2BKT synchronizes the PC time using an internet time server (NTP server) or a GPS receiver connected to USB, serial port or Bluetooth. Great for use with digital modes like FT8, JT65, JT9, JS8Call and others. For the operation of this program requires an active internet connection or a GPS receiver. This program works on all versions of Windows 32 or 64 bit

Meinberg NTP software to sync your computer clock. NTP client package with IPv4 IPv6 support for Windows XP and newer.

JTSync by UU0JC is a simple utility that provides the ability to synchronize your computer clock over a network with world-wide NTP servers. When the Internet connection is not available, JTSync allows you to make time adjustments based on decoded QSOs within the WSJT-X application. https://www.dxzone.com/dx33937/jtsync.html

TimeSyncTool NetTime is a simple and free software to sync your computer clock via internet. Very useful tool for FT8 FT4 operating modes.

Dimension 4 is Freeware software that synchronize your PC’s clock. Dimension 4 monitor your Internet connection and automatically adjust your PC’s clock when you’re online at an interval you specify.

Reference articles:

How to Sync your computer clock.
https://www.dxzone.com/how-to-sync-your-computer-clock/

Time-Division Multiplexing
https://www.sciencedirect.com/topics/computer-science/time-division-multiplexing

Here are some of my favorite FT8 resources:

Although this article is really about time, since I mentioned FT8 here are some nice resources.
FT8 from SigIDWiki.com
https://www.sigidwiki.com/wiki/FT8#:~:text=FT8%20(%22Franke%2DTaylor%20design,%22ham%20radio%22)%20operators.&text=Transmissions%20occur%20in%2012.6s,entire%20message%20has%20completed%20transmitting.

FT8 – The Basics Explained
https://www.essexham.co.uk/ft8-basics-explained

Tim’s (K3LR) group at DX Engineering has a nice blog post on FT8 on their “OnAllBands” blog site.
https://www.onallbands.com/ft8-what-is-it-and-how-can-i-get-started/

HF Digital Modes Update it is about 43 minutes. This is a very excellent video.
https://youtu.be/tXLXe9C7JX8

Digital Mode Identifiers
https://www.youtube.com/watch?v=nwkz0GNpA0I


This is a very nice series that was used to teach the General License Class. Dave offers great explanations and demonstrations.

2018 JS8CALL Keyboard to Keyboard chatting 
https://www.youtube.com/watch?v=NRCS4nreTA0

2012 Digital Modes history and introduction

VE Testing

Hamfesters VE Testing Report
Al Bukowski N9ZD – VE coordinator

The Hamfester’s VE examinations to Continue on APPOINTMENT TIMES ONLY for the remainder of the year. NO WALK-INS

The Hamfester’s Radio Club VE test session(s) for 7/11 – 8/8 – 9/12 – 10/10 – 11/14 – 12/12  will be Appointment only.

Candidates MUST email to get an appointed time (earliest 8AM), other instructions, and directions to the Exam Location
Liaison Al Bukowski (N9ZD)        ( aln9zd@gmail.com )

TEST Location: TBD – Oak Forest, IL  60452  (will be using a VE’s Garage for now unless Oak Forest City Hall reopens)

VE Stock test material will be in Plastic protective sleeves to protect the next user after disinfectant cleaner applied.

NOTE: Since Hamfester’s average candidate attendance the past years has been average of 4, the 
Appointment times will be 3 candidates 8:00 AM / 3 candidates 9:30AM /  3 candidates 11:00AM  / Flexible as needed

A Special ‘Thank You’ to All the VE’s volunteering there Saturday morning to assist me at the Exam sessions.

Because it is touching sensitive areas of your machine it will ask your permission to make the changes it needs to. Simply click [YES]. Then agree to the license agreement on the next screen.

Club Information

Meetings and VE
Testing

Club meetings are held on the
first Friday of every month at
Crestwood Civic Center
14025 Kostner Ave
Crestwood, IL
Meetings begin at 7:30 PM.
September meetings may vary if our meeting date conflicts with the Crestwood
Flower show.

Board Meetings: 7:30 PM on
the 4th Monday of each month
at the
SouthBridge Community Church
15500 S.73rd.
Orland Park, IL

VE TESTING: Testing currently by appointment only. See details here. Exam fee is now $15.00. Al N9ZD
VE Team Chairman

Special Activities

Hamfester’s Big Peotone
Hamfest:

***Cancelled for 2020****

Field Day:

***Not a public event for 2020***
SouthBridge Community Church
15500 S. 73rd
Orland Park, IL
Field Day Chairman
Jim W9JPR

MAKERS: we participate in the
annual Southwest Chicago
Makers Faire

Community Service: we support
local communities by providing
radio communication for parades
and marathons / walk-a-thons.

Nets/Contact Info
10 METER NET: Every
Sunday Evening at 8:00 PM on
28.410. Tom KA9ZXN is Net
Control

2 METER NET: Every
Monday Evening at 9:00 PM on
146.640. Tom KA9ZXN is Net
Control

WEB SITE: www.hamfesters.org
Webmaster
Brian ,W9HLQ
Granville, W9PNG

Club’s address:
Hamfesters Radio Club
P.O. Box 474 Crestwood, IL 60445
Attn: Patti KC9LYE Sec

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Pics from August Meeting

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