Enhancing portable SSTV
Del Radant, N6JZE
With the advent of the Kenwood VC H1, Visual Communicator unit, there's been much interest in Slow Scan TV. It is now possible to show the NCS of a Public Service event existing conditions at a portion of an activity where additional assistance may be needed.
There was recent discussion in the San Diego section about the possibility of supporting the American Red Cross and the California Department of Forestry with some visual records of the extent of any destruction during any emergency. To prepare for this evolution, several local Amateur Radio operators purchased the Kenwood VC H1 Slow Scan Visual Communicator and the Kenwood THG71A Dual Band Transceiver.
We demonstrated the capability of these units by showing the various members of our local clubs what was possible using this combination. Some of the pictures were not as clearly defined as we would have liked. So a project was instituted to enhance the picture quality by adding a digital source separate from the reproduction device furnished on the VC H1. By adding a digital source with high pixel capability, we did achieve the desired detail in the pictures. Here's how we accomplished our goal of enhancing the video picture.
The digital source
The major restriction in the choice of a digital camera, is that the camera must have a
video output jack. This is necessary for the transfer of the picture to the VC H1, to store it there and, at a later time, send it to the distant receiving office.
Most of the later model camcorders have a "video out" capability to view the picture from the camera on a TV screen.
The choice of the digital camera is of one that has a "VIDEO OUT" port. Most of the better models are so equipped. Digital cameras hold numerous pictures, while a camcorder normally has only one still frame available from the recorded tape (a DVD camcorder can provide a number of pictures from the special DVD tape).
The combination of these devices required a supporting device that was able to accommodate all three items and still be portable and could be mounted on a tripod. This was accomplished by constructing an aluminum and copper mount to hold each unit, provide convenient access to the controls, and also offer application of power from an outside source. I constructed several mounts for various sizes of cameras and camcorders.
Copper was chosen for the construction of supports for the Kenwood units because it's easy to bend and shape for each item. The base support was made from heat-treated aluminum.
The copper mounts are made from 22 gauge material. Ordinary tin snips will cut this material quite easily. (I suggest that a trial form be made of heavy card stock, fit it around your units and see if it satisfies the needs, then transfer these dimensions to the copper stock.) The basic dimensions are 5 1/4 X 2 1/4" for the transceiver and 5 1/2 X 2 1/4" for the VC H1 unit.
All the bending and forming was done using a bench vise with a 3" jaw. A hand-operated electric drill was used to drill the small mounting holes. A floor-mounted drill press was used to drill the larger holes for the VC H1 plug hole in the flat aluminum stock.
The base material used is heat-treated aluminum, specifically chosen for its rigidity. It can be flat or angle shaped, whichever is most readily available. The dimensions are 2 1/2 X 12". The opening for the cable plug can be made by drilling four adjacent 1/2" holes in the chosen position and filing away the excess material. An electric scroll saw with the proper fine tooth blade may also be used to make this hole.
Some care must be taken when drilling the hole for the power plug for each unit. A very small drill must be used to place the hole directly over the pin in the unit (you can see this pin through the small drill hole). Then enlarge it 3/8" for the power plug.
Adjustments can be made to accommodate the available camera and transceiver. The mount for the VC H1 is standard and the hole in the base is required. Sizes of the support can be adjusted. A single slot to admit the plug to enter from the bottom causes the transceiver to be raised upward, hence a modification would be needed in the copper mount construction. The hole for the insertion of the external power cable must be made for the chosen mounting location of the unit.
The dimensions furnished for the copper stock are for a Kenwood THG71A unit, and the Kenwood VC H1. Use a file to remove the small molding nibs, on each side of the Ni-Cad battery case of the Kenwood TH G71A. They prevent the unit from sliding smoothly into the support.
Other handy-talkies work as well, but you must make an adapter to plug into your chosen transceiver to feed the audio and keying circuits. The cable for the THG71A is furnished in the package of the VC H1, and plugs into the Kenwood transceiver (it's much easier to use the Kenwood unit).
The short cable from the video output jack of the camera, to the socket of the VC H1 is also a home-brew cable. When using the digital camera, the viewing head piece on the VC H1 is removed, and the cable plug, takes its place. The plugs and angle adapters are available from RadioShack. Follow the detailed instructions when constructing this cable. The plugs and adapter are tip/ring/sleeve (TRS) devices. (Note plug size and type, on plug-in lens unit.) Ordinary audio plugs WILL NOT work, as one uses the tip and the opposite end uses the ring. The "video out" plug for the camera is also a tip/ring/sleeve unit.
My Olympus C3030 Zoom camera uses NiMH batteries also and it too operates on 6 volts. A home brew cable is required for each 6 volt unit to bring the current from a pair of 6 volt gel cell batteries. They are charged in series as a single 12 volt unit, but provide power as two separate 6 volt power sources. One cable is used for the camera, and one for the VC H1.
The THG71A transceiver has a Ni-Cad battery, and a additional fully charged unit is on hand. A Kenwood PG 3J power cable may be used if operating near an automobile, or from a deep cycle battery. With 12 volt power, they transceiver develops 5+ watts output. (DO NOT use a Kenwood PG 3J cigarette lighter cable as a power source for the VC H1, as it requires 6 volt DC power.)
One of the members uses this setup with a Sony camcorder and an Alinco Dual Band Transceiver. The picture definition with a high pixel count camera produces a much better photo.
Another member also uses an Olympus C3030 Zoom camera, but chose to keep his camera in hand, so an appropriate cable was constructed, to reach the tripod mounted VC H1 and Kenwood transceiver. You can take many pictures, and then transfer up to ten pictures to the storage in the VC H1 unit for later transmission. This action frees space for other exposures on the camera's memory chip.
The cable for the video from the camera to the VC H1 is made from microphone cable. (Follow the drawing for the correct length and connections, using extreme care not to fill the internal lugs with excess solder). If the system does not function correctly try reversing the cable. The end for the VC H1 is using the RING, and my camera uses the TIP. I color code the VC H1 end with red shrink tubing.
Follow the instructions in the booklets that come with each unit. Set up an operation with your friends and practice in the operation of all the controls. Be ready for any emergency within your area. You can also take pictures with the digital camera and, at a later date, display the information at a club or public event.
There is a Kenwood program, KCT24S, that permits a remote unit to receive and transfer your pictures to a computer for processing and printing. Windows 98 is required to use it.
Additional accessories are available for many cameras that permit the transfer of the snapshots into your own computer for printing out the photographs in color. Adobe PhotoShop 5.0 LE was furnished with the Olympus Camera. Other photo processing programs are included within Windows 98, and some programs are furnished with Hewlett Packard products.
A cable is furnished with the Olympus C3030 camera package to view the pictures on the Smart Card in the camera on a color TV. This feature allows you see your work and allows you to experiment with exposures and additional features to improve your skills.
It has been a real pleasure to send photos on any VHF/UHF repeater operation or any amateur frequency using Slow Scan TV. Join in and share the fun!.
Reprinted from WORLDRADIO
HOG HEAVEN (OOPS) HAM HEAVEN
EMMETT H. GOODMAN, WD4GOL
Two farmers were standing over a hog pen watching two fat hogs wallowing in a big mud hole filled with water. One farmer said to the other, “Those two hogs are in HOG HEAVEN!”
Well I’m going to tell you about a Ham, who in 1938, was already in his own HAM HEAVEN!
I was still employed in the auto repair bays of that super dooper automotive repair facility referred to in my last tale, “160 Meters, The Easy Way”. As I walked in about 8:45 AM after dropping off my XYL at the Hudson Hosery Company where she was dragging down over $30 per week, which was very good wages in 1938, why do you think I married her? Anyway, Mac, W4HGV, my boss said, “Since you are interested in ham radio, if we have caught up with our work by lunchtime, why dont you take the afternoon off and go visit a ham station that you will not soon forget.”
So, after lunch, I was following a map supplied by Mac to the 5 acre supply storage yard of the Duke Power Company north of Charlotte (NC) city limit. As I pulled through the gate of the eight foot high chain link fence to find a parking space beroe the little office I was amazed to see the stacks of 20, 30, & 40 foot poles, transformers, automatic and manual switches, rolls of all sizes of wire and cable insulators of all shapes and sizes. Everything necessary to keep the city of Charlotte lighted up!
As I parked my car and got out I looked up and saw a stacked five element 10, 15, & 20 meter beam atop the tallest power pole that I had ever seen running up besides the end of the building. I also saw a lot of two wire ladder lines running out to a lot of 30 foot poles with insulators and wires running between them as far as I could see.
I walked through the door into a large room and met the young ham, a graduate of the University of North Carolina, where he had obtained his Electrical Engineering Degree. He had been hired by the Duke Power Company as a yard clerk to check the supplies going out on the maintenance trucks in the morning and checking them again on their return in the evening. You are right, to ask, what is a college kid, with a degree, doing working as a clerk in a power company supply yard? Well you must remember the time frame that we are talking about. In the late 30’s the country, under FDR, was still recovering from the GREAT DEPRESSION! You were lucky to get any kind of a job. I was just working part-time. But just wait until I tell you of the “perks” that went with the job.
Tom, not his real name, had talked to the powers that be, with the help of his father, who just happened to be a large stock holder of Duke Power, into letting him install his ham station in the office. Reasoning that they could supply communications in the event of an emergency. They bought it!
Over in the corner of the room was, not one, but two homebrew Carolina kilowatts, mounted in two six foot rack & panel cabinets. One xmtr on 10, 15, 20 meters. The other on 75 meter phone. On top of the two desks were two National HRO ham receivers, the kind that had the big bandspread dial in the middle of the front panel that you could spin and just listen to the stations just roll in.
What? You don’t know what a bandspread dial was? Well the ham receivers of that day used either a two-speed planetary drive, the mechanical way or the electrical way of putting a small tuning capacitor in parallel with the main tuning capacitor to cover a 2 to 1 frequency range. I believe the HRO used the mechanical way.
The 10, 15, 20 meter xmtr could either be used to feed the beam antenna with a coaxial cable or feed two rhombic antennas that were feed by those funny looking ladder lines that I had seen going to those 30 foot poles that support those 210 foot legs of the diamonds. One rhombic was directed to Europe and the other to South America.
By means of electrically operated relays he could change the direction of the rhombic facing Europe to work Australia and New Zeland. The 75 meter kilowatt fed a half wave dipole strung between two 40 foot poles.
As I walked in about 1 PM, 20 meters to Europe was wide open and the rhombic antenna had a slight edge over the beam on receiving. On transmitting the two antennas were about equal. He was working an Irish station in Dublin and as soon as he signed with him a station in Oslo called him. I forgot to tell you that the back wall of the room was filled with antenna change-over relays. He could transmit on one antenna and receive on the other. This boy was good!
He signed with the Norwegian station after getting an S9+ report. Then he quickly switched over to the South American rhombic and by golly there were a couple of missionaries in Brazil with traffic to the USA. Tom quickly contacted them and took their traffic. This hamming went on all the rest of the afternoon until the equipment trucks began to return and Tom had to go back to “work”, hi! This was truly HAM HEAVEN!
At contest time he rolled in a cot and set up a hot plate, invited a brother ham to join him and the two of them worked around the clock.
But Tom’s ham heaven was short lived. About eighteen months after my visit Tom was hired by the city of Charlotte as chief engineer to design and supervise the installation of a modern two-way radio system for the police and fire departments. At least he utilize his E.E. How he worked ham radio into his new job is another story. (Watch for it.) WD4GOL
GRUMMAN AMATEUR RADIO CLUB
MINUTES OF GENERAL MEETING – 4/21/04
by Pete, N2PYV
The meeting was called to order by Pat at 5:35 p.m.
All present introduced themselves.
Finances continue to be in good shape.
REPEATER REPORT –
Gordon was absent.
NET REPORT –
The Sunday Morning 40-Meter Net was good after the firs hour. Mike, KJ6XE is doing a good job of coordinating the net.
VE REPORT –
We had three applicants and seven VE’s at the last session. One applicant became a new Technician and one upgraded to General. The other applicant passed the General and Extra written exams, but did not upgrade because he did not want to take the code test.
WAG REPORT –
Bob received one QSL card for a CW contact.
HOUSE REPORT –
Pat stated that we should prepare to change the oil in the generator at the next Executive Committee meeting.
Northrop Grumman is growing rapidly on Long Island. They have filled the third floor of the Briarcliff College building (formerly Plant 35) and are looking for more space. Reopening Plant 5 is being considered.
This is the 60th anniversary year for our club. A discussion was held and it appears most would like to have a luncheon on a Saturday, perhaps in September.
Marty, NN2C, brought a video about the VK9RS DXpeditition to Rowley Shoals in the South Pacific in 1999. On the video you could hear the operator talking to NN2C.