Friday, September 17, 2021

Grounding: Everything a ham almost needs to know



Channeling the strong Long Island roots of some Overlook Mountain Amateur Radio Club members like Neil W2NDG and Steve K2GOG who have transplanted to the Hudson Valley in recent years,  we are proud to bring you a fantastic presentation on grounding by Don Kane WB2BEZ who is a member of the Long Island Mobile Amateur Radio Club (LIMARC).

Enjoy the below presentation and feel free to share questions or comments on the new OMARC YouTube Channel



Thursday, September 16, 2021

Pi-Star: Sharing your public hotspot


Have you noticed that HVDN has not posted much about DMR or even things relating to the different digital voice modes for a while?    Did you look closely at the photo above for some laughs?

Our focus has been on community growth and awareness via the massive June Hudson River Radio Relay event, a mini QRP HVDN field day, helping to support the USMA at West Point triathlon via APRStt this past August and most recently, spending the day at the Old Rhinebeck Aerodrome to support the OMARC K2A effort.

Plus, with a new weekly commitment to support UNDR Net, there has not been much free time to do much else this summer as HVDN prepares for a series of fall season events. 

A reminder from Brian W2BRM today that we have not chatted in a while, made me think I should go find something interesting to write about related to Pi-Star as I try to find the time to do a short video about a duplex hotspot to be included in Pete N2MCI's upcoming presentation about the basics of hotspots to the OMARC club coming up in a few weeks time.

Public Hotspot

Many people are afraid to touch certain buttons in Pi-Star, but I am not one of those.  Most people use a hotspot to just provide communications for themselves which means your hotspot is in private mode and only lets a radio programmed with your DMR ID to use your hotspot.

If you click the button under "General Configuration" from private to public, here is what will happen.

Up until recently, changing to a "public" hotspot would allow for anyone to use your hotspot.  This is helpful at public events as an example if many people have a DMR radio and it makes sense for them to all be on one hotspot for internet communications, while local use can take place via a standard simplex channel.

If you want anyone to be able to use your hotspot, leave the "DMR Access List" box blank.

Alternatively, you can add a list of DMR ID's separated by a comma which would allow only your closest trusted friends to also use your hotspot.

Be sure to remember to hit "apply changes" when adding or deleting DMR ID's. 

Bigger picture use case

Now, lets say your club has a DMR repeater that is managed by a Pi-Star interface on your favorite DMR network like Brandmeister or TGIF.  Using this feature could be helpful to ensure that only members of your club are permitted to use the DMR repeater instead of anyone else.  

While this can be considered exclusionary and not the best way to portray amateur radio, this feature may be helpful to help promote the use of certain talk groups on a repeater rather than a hotspot. Should an issue happen where preventing a specific user is needed, this feature can permit that also.

There are many ways this feature can be used, so feel free to share some comments below on how you may wish to use this or not.

-Steve K2GOG & HVDN Team

Wednesday, September 15, 2021

What's in your kit? + SSTV Enabled Missions


We continue onward with UNDR Net by embracing the National Preparedness Month (NPM) weekly themes by looking at "Build A Kit" as part of this  past Tuesday 8:00 PM EST session.

Following discussion summarized below, another slow scan television (SSTV) over FM test took place.

A total of 10 participants made it to the September 14th UNDR Net and was led by Steve K2GOG, net control and backed up by Jim KD2VAH as alternate net control.

The next UNDR Net taking place on September 21st will focus on "Low-Cost, No-Cost Preparedness" along with another SSTV test, so be sure to tune in to 146.805 MHz repeater WA2MJM thanks to the Overlook Mountain Amateur Radio Club next week.  

Quick Notice:  On September 28th, we will move to testing SSTV over DMR using the Brandmeister Talk Group 31368 which is reserved for Mid-Hudson Valley.   Moving forward, UNDR Net will move one week per month to DMR, so stay tuned for details on that.


be prepared FEME ready.gov  UNDR Net


Summary of "Build A Kit" Discussion

To spur the discussion beyond essentials, here is a great article about "Buy or die:  27 prepper items you need to survive the apocalypse" thanks to Inverse.com

Jumping off of this, our participants shared the top items they think would be useful to have on hand after having the shelter, food, water, fire and security aspects taken care of.

  • KD2GGF - Matt - Kerhonkson - Ulster County (NY) -  Vice grip plyers or pair of forceps
  • KD2TQS - Ken - Rhinebeck - Dutchess County (NY) - Sturdy knife, approximately 4 inch length
  • KD2TLF - Guy - Xena - Ulster County (NY) - Water filtering device
  • KD2QAK - Bob - Red Hook - Dutchess County (NY) - Swiss Army knife or multi-tool
  • WA2RKN - Jerry - Hyde Park - Dutchess County (NY) - Solar battery & E-Reader w/ books
  • KD2TVS - Lou - Hewitt - Passaic County (NJ) - Knowledge on surroundings
  • KD2VAH - Jim - Poughkeepsie - Dutchess County (NY) - Proficiency with a "pew pew" device
  • N2ZFC - Tom - Fishkill - Dutchess County (NY) - A bicycle
  • KD2IWC - Paul - New Paltz - Ulster County (NY) -  Joined later
  • K2GOG - Steve - Poughkeepsie - Dutchess County (NY) - Plastic bags (Net Control)

Lots of great ideas and we hope to release an Amazon.com Smile product list of specific recommendations with the purchase proceeds going direct to OMARC to help support its VHF repeater costs.

SSTV Test #2:  A Real Life Scenario

Our second week of SSTV over FM took on a different approach compared to our first week. This week we created a fictitious scenario involving a MEDEVAC flight looking to understand field landing conditions including obstructions and possible threat actors which may be in the area.


First image sent using PD120 mode this week was of the Old Rhinebeck Aerodrome air field.  The large cluster of buildings in lower left are smaller hangers, gift shops, food stalls and support buildings.  Across the field in lower right are larger hangers and support buildings.  

North of the larger hangers are a cluster of smaller buildings used for entertainment purposes part of the famous air shows conducted at the site.

Sharing an image like this helps provide situational awareness in real time from an aircraft to be shared with users on the ground.  Another option could be using a tethered balloon to continue to provide imagery to ground users who may only have very basic reception equipment such as a handheld two way radio and a smartphone, but with no internet access.

Here is a fun image from the air show story line which you would only understand if you visit this wonderful living history museum in person, but in the case of our example scenario, sharing an image like this with a rescue team could be important to help with some planning needs.

How to use SSTV?

The focus of promoting SSTV over FM is through the lens of a basic user who only has a hand held radio and a smartphone available.  The goal is to not promote the use of this aged technology to users in a fixed home position with more advanced equipment.

Having the most inexpensive FM analog dual band amateur radio which is only capable of voice communications still permits other ways to share narrow band information that can be visual.

Two common applications to explore are the ROBOT36 application for Android or the SSTV Slow Scan TV application for Apple devices.

It is very easy to hold your radio speaker near your microphone on your smartphone to receive an image or to hold your radio microphone while transmitting the sounds of SSTV coming from the speaker of your smartphone to send an image.

Please download the above images and use the great simple conversion tool from https://www.vr2woa.com/sstv/ to experiment with different modes.  

You can simply play the files back over your computer speakers and hold your smartphone nearby to decode them while running the application of choice.

What is next?

Next week we will attempt to play some type of game using images.  it may be simple tic-tac-toe or possibly something more complicated like chess, connect 4 or battleship.

If you did decode images, please share them to get posted in future articles.   Visit hvdn.org/undr for details.

Hope to hear from you all next week

-Steve K2GOG






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