Showing posts with label 70 cm. Show all posts
Showing posts with label 70 cm. Show all posts

December 27, 2020

Earthlings and Astronauts

This is a must-read article for hams, "Earthlings and astronauts chat away, via ham radio" by Samantha Masunaga

No doubt it will inspire you to learn more Amateur Radio on the International Space Station.

Good DX and 73, NJ2X

August 25, 2018

Radio Merit Badge at Camp Lehi

The Radio Merit Badge is earned by approximately 6,500 Boy Scouts in the US each year.  The Radio Merit Badge requirements are demanding and require both classroom learning as well as applied learning in front of a radio.  I really like the design of the merit badge with its hidden Morse code message and lighting bolts.

Radio Merit Badge
I had an opportunity to teach the radio merit badge at a recent Merit Badge Pow Wow at Camp Lehi here in the Bay Area.  My co-instructor for the course was Ray Wentz, W6LPW.

Camp Lehi is a beautiful location in the Santa Cruz mountains

The night before the course the Merit Badge Pow Wow organizer (Jon) and I installed three antennas: a 40 meters home-brew wire dipole, a 20 meters rotatable dipole, and a vhf/uhf antenna.  We setup the radios and class room in the great outdoors under a couple of canopies.  Power was provide a generator.

Rotatable Dipole and VHF/UHF antenna 

Home brew 40 Meters wire dipole between two trees
The 40 Meters wire dipole worked really well for the scouts.  They made contacts with 100W into the North Carolina to the East, Vancouver to the North, San Diego to the South, and Hawaii to the West.  We were using a Kenwood TS-480SAT.  It was a lot of fun to see the scouts make their first radio contacts ever.

Ray tried several times to call on the local repeater using his HT and found no one to talk to.  Fortunately 40 Meters was in good shape and there plenty of hams for the scouts to talk to.

The rotatable dipole was not functioning properly.  I had brought my antenna analyzer and measured SWR exceeding 3.0.  We didn't have time to determine where the failure was occurring in the system.  That will be a job for another day back at the shack.

A big thank you to the patient hams who talked the scouts and helped them log their first contacts.  This event helped create interest in radio.  Several of the scouts mentioned their interest in studying for their own amateur radio licenses.  Support your local scouting organization and radio merit badge, jamboree on the air, and other outstanding programs.

Good DX and 73,

August 16, 2015

Program that HT and get on the air!

An amateur radio HT or handy talkie isn't of much use if you don't use it.  Perhaps it could be an unusual paperweight or interesting desk ornament.  They do look nice sitting on the desk in the shack in a sad inert, powered off, dust-collecting way.  Our two Kenwood TH-F6A HTs were mostly idle due to having relocated across the country to California.

The radio memories had been programmed chock-full-o-stations located on the East Coast (New Jersey, Pennsylvania, New York, and the Eastern Seaboard).  None of the repeaters in the radio memory were accessible from California.  Lack of useful programming was main reason our HTs weren't getting used.  Turn on the radio and there was simply no way to contact anyone other than via simplex communication.

The Kenwood TH-F6A is a compact and very capable radio.  It transmits 5W on 144/220/440 MHz and includes a wide-band receiver.  You can really pack the radio's memory with stations given its 435 PC programmable memories.  The radio has all kinds of really great features, and it has been reliable since purchased back in 2007.
Kenwood TH-F6A HT (Handy-Talkie)

We decided it was time to get our Kenwood TH-F6A radios back on the air and that meant reprogramming them with California stations.  The first thing we needed to do was to locate the radio's programming cable.  If you have ever moved, then you know how much fun it can be to locate a particular item in the new home.  The memory of where it was located at the old residence is usually vivid and the location in the new home tends to be a mystery.  Is it still in a box or in some drawer or perhaps in the attic?  After much searching in all the wrong places we found the cable logically stored on a desk near the computer.

TH-F6A Programming Cable

Lesson learned: always start the search with the most logical place to store the item.

The next step was to load the latest version of the free Kenwood programming software (MCP-F6F7) onto the PC.  This was very easy since the software is available for download on the Kenwood website.

Whenever reprogramming a radio, we always make a backup of the radio's memory first.  You never know when you may need to reference or revert to an earlier memory configuration.  This is very easy with the Kenwood MCP-F6F7 software.  We simply connected the radio to the cable and the cable to the computer and then read the radio's memory (from the menu: Radio --> Read --> All).  Once you have read the memory contents save it as a file on the PC (from the menu: File --> Save-As).

Our next step was to delete all of the undesired East-Coast stations from the memory we just read into the Kenwood MCP-F6F7 software.  It is much easier to delete the stations using the PC software than directly on the radio.  Just click on the memory item then right click and select, "delete" from the from the pop-up menu.  Memory items can only be deleted one memory at a time which worked fine.  It would be nice if you could select and delete a range of memories.  C'est la vie.

Once we had cleaned up our memory, we then resorted the remaining memories by name to organize them and make them contiguous from memory 1 (menu option: Edit --> Memory channel Sort --> Memory Name).  This provides a nice clean set of memories to program in the software.

The next step was to locate California area repeaters on the three bands that the TH-F6A can operate on (144/220/440 MHz).  There are a variety of repeater reference guides available.  We use the website and iPhone app.  The iPhone app is quite handy since it works with or without an Internet connection.  RepeaterBook allows you to search on wide area coverage repeaters.  These are particular useful repeaters, so we targeted these specifically.

Using we searched for repeaters in various areas that we frequent or intend to visit and programmed them each into the Kenwood MCP-F6F7 PC software.  This is really easy to do by double clicking on an empty memory and then filling out a simple form.

MCP-F6F7 PC Software - adding a repeater to memory

The TH-F6A has an LCD screen and allows for station memories to be named.  This is helpful though the real estate for a memory name is limited to eight characters.  Making eight characters understandable requires creativity.  A number of years ago, we came up with a coding standard for our station memories that is surprisingly simple and effective.  After programming, we handed the HT over to another local ham who was able to scroll through the memories and translate (name and city) all but one.
  • 2-digit state code (e.g., CA - California)
  • Use a capital letter to indicate the start of a new word
  • Eliminate vowels since it is proven that people can read most words effectively without them
  • Numerous California cities begin with the word, "San" so abbreviate this to a single letter "S"
  • In this example, "CASFrncs" denotes California, San Francisco
We were rewarded for several hours of station searching and programming with a nice long list of California repeater programmed into the MCP-F6F7 Software.  After programming, we sorted the list again by name so that all memories would be organized logically (menu path: Edit --> Memory channel Sort --> Memory Name).  We then saved the programming on the local PC under a different file name than our backup.  We use a simple and effective file naming convention to organize our files.  Each file name includes:

  • Name of the radio
  • State or location
  • Version (we only use this if there are several versions on a given day)

Applying this naming convention we named our file, "20150815 TH-F6A CA".  A little forethought saves time down the road.

The next step was to load the programming from the Kenwood MCP-F6F7 PC software to the radio.  Turn off the radio before plugging in (or removing) the cable to avoid damaging the radio (power is present on some of the jack connections).  Once the cable is connected to both the radio and computer, turn on the radio.

On the radio, use the menu to find the parameter, "SP/MIC Jack9" and set it to, "PC".  Exit the menu on the radio.

Next, from the Kenwood MCP-F6F7 PC Software select the menu option, Radio --> Write --> Memory.  This will initiate uploading the memories to the radio.  If you get a "Communication Timeout Error" then check your COM port settings on your PC.  The following settings generally work:
  • 9600 Baud Rate
  • 8 Data bit Rate  
  • None Parity
  • 1 Stop Bits
  • Xon/Xoff Flow Control
If you receive an error message, "The radio is invalid please check and try again" then check your cable connection into the radio.  We found that our cheap cable was a little finicky on one of our TH-F6A radios but not the other.  If we angled the connector out at the top a tiny bit it would work better than when fully inserted.  Results may vary.  Remember to power down the radio before inserting or removing the connector.

We gave both newly programmed TH-F6A radios a good testing on our local repeater by cruising around the area on a motorcycle with our HT to see if we could maintain contact through the repeater at various locations.  For safety purposes, we would stop and park the motorcycle before attempting the contact.  Test results:
  • Home - full quieting
  • Local grocery store - full quieting
  • State Park Entrance nearby - full quieting
  • End of the road in the State Park - DEAD SPOT - no area repeaters could be reached and no mobile phone service
  • Fruit stand in neighboring village 17 miles away - full quieting - a happy surprise
2003 Suzuki VL800

We had a lot of fun with our motorcycling HT/repeater coverage test.  We were very pleased to find excellent local repeater coverage at each destination with only one dead spot on the trip.  Most of all, we were thrilled to have our two HT's returned to full operating status instead of sad (though cool looking) inert dust collectors.

Do you have an inert dust collector HT on your desk?  If yes, we hope we have inspired you to take action - charged it up, program it, and get back on the air.  We look forward to our next contact with you either on an HT (or the HF bands).

Good DX and 73, NJ2X

September 28, 2012

FT-8800R Back On The Air

We finished reprogramming our FT-8800R dual band mobile radio tonight.  After installing it we turned it on, hit scan, and immediately found a local net to join in.  Programming software makes the job so much easier than manual entry via the radio controls and menus.  What a bother it would be to upload several hundred frequencies manually.

In this day and age of cheap and plentiful memory and internet enabled devices, it is fairly easy to image radios in the near future coming pre-programmed with software that automatically keeps them synched with all repeater information - anywhere in the world.  Why not?  Since we are dreaming a little.  How about unlimited text labelling for each memory.  6 characters simply doesn't cut it.  Why only 6?  Why not 66, or 266, or even unlimited?  The memory certainly wouldn't add much cost.

September 18, 2012

G4HFQ Software - Excellent Experience

We had a really great experience recently with G4HFQ Software.  We needed a little assistance with a program that we had purchased from Bob back in 2008 for programming our trusty FT-8800.  We sent an email and Bob responded almost immediately with just the right help.  Bob's software works very well and the service is tops.  Highly recommended.

January 29, 2012

Project: Anderson Powerpole to 2.1mm Connector Pigtail

When building our KN-Q7A Single Band SSB Transceiver Kit we realized after starting that we lacked the necessary power 2.1mm connector to supply 12v to the power jack.

From a design standpoint we decided to construct an Anderson Powerpole to 2.1mm connector pigtail.  This was a natural choice since we previously converted our radios and cabling to Anderson Powerpoles.  A 2.1mm connector to Anderson Powerpoles will give us maximum flexibility to move the radio from one power source to the next (e.g. battery, car power, shack power supply, bench power supply, ....).  The commercially available Anderson PowerPole to 2.1mm cable costs at the time of this writing about $5.00 plus shipping. 

We decided it would be more ecconomical and far more fun to build the pigtail cable ourselves.  A home-brew cable would also give us an opportunity to incorporate a few improvements in design over the commercially available cable.
One of the improvements we wanted to include on the cable was an RF choke.  We decided to add a ferrite (from the junkbox) to the pigtail to help minimize RF travelling over the power cable.  This would potentially be useful when running the radio from a car or other noisy source.

Pigtail construction in progress with ferrite bead
To protect the ferrite bead and assure the wire loop would stay nice and tight we added heat-shrink tubing around it.  We also added a section of heat shrink tubing to the end next to the Anderson Powerpole connector as a strain relief and to dress the cable nicely.

Finished 2.11mm to Anderson Powerpole Pigtail with ferrite bead for RF supression
After completing the wiring we ran a quick series of continuity tests with our multimeter to verify that the cable was fully functioning and without any shorts or other defects.  For our project, we needed the 2.1mm center to be positive.
The final product came out really looking and functioning perfectly and cost very little.  Having a completed cable enabled us to continue on building and testing our KN-Q7A Single Band SSB Transceiver Kit - Step 2: Audio Amplifier.

By Michael W. Maher (NJ2X)
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© Michael W. Maher and NJ2X.COM, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.