Thursday, July 16, 2015

A first - ordering and using a 3D manufactured item

A Mod for the FT-817nd

As you use the FT-817 (nd) you notice the tuning knob is quite sensitive. You can adjust the steps, but a slightest move of the dial and you're off frequency quite a bit!.... On other products I have, there might be a detent to step you thru. I guess just a matter of taste. One either likes or dislikes a tuning knob with a detent. I have a shortwave radio with a detent and there's a mod to take it out. It seems the preference for fine tuning is a knob without stepping.

So... How to control the tuning to a finer detail, you ask?.... Make a know or modify the knob you have in such a way that it gives you better control....

Such is what a fellow Ham did... A small knob such as this , is a great candidate for 3D printing technology. The latest tech craze, now that low cost 3D printers are being made.

Drawn up and 3D printed on Shapeways, its available and reasonably priced... I'm waiting for mine. Comes in red, green, yellow, blue, purple and orange!... Decisions ! Decisions!

Thursday, July 2, 2015

The satellites are coming! The satellites are coming! Everybody get outside! Part 1

If one can remember a comedy from years gone by "The Russians Are Coming!", when they ultimately landed and tried to invade, the Russians soldier was heard to say... "The Russians are coming, everybody to get from street!"

THe new AmSat satellites are coming! Get out in the backyard! Our new generation of amateur satellites are being made with the hopes of being launched  (one this year) soon. As costs rose for everything so did the price of a launch....based on size!!! So it precipitated a new generation of small satellites... the CubeSat and none too soon! The Amateur  world is picking up on it too with the design and development of three CubeSats, the first SO-1, being 4 inches square.

AmSat Fox-1

Not that amateurs haven't communicated by satellite before, even with an HT, but now its with a small CubeSat and a few hundred milliwats. Since I achieved the first level (Technician) back in Dec 2014, its been a plan in my mind to do satellite communications. Sure one can garner a Jigawatt radio and have at it... but we're not doing EME (not yet) it's QRP. And it's been done too many times, as seen here. (Thanks to AE6LX).

An HT and a homemade (or bought) VHF/UHF yagi can get you connected thru an Amsat satellite. A survey of antennas can be found here on YouTube (2011). The idea is to make a homemade satellite antenna and see what I can do. I've seen several designs about....maybe I'll try them all!  One that comes to mind is the tape measure Yagi. Its only a 2 meter antenna, but with a little inventiveness it can be turned into a VHF/UHF antenna. Satcomms with the new CubeSats will cover both  the 2M and 70cm bands at (435.180 uplink CTCSS 67Hz and 145.980 downlink). There's a nice paper on Tape Measure Yagi's here that will help in yagi design. A tape measure style is great for foxhunting.(Can't believe I threw out a broken tape measure about 2 years ago!)
Tape Measure Yagi

A better antenna would be a more permanent solution using stronger elements, coat hanger or welding rod elements. Many designs abound.

A quick search in the net yielded quite a few design ideas.
From WB5CXC - dual band antenna Check the rest of his site for lots of other antenna designs and projects.

Then there's the $4 dual band antenna, a true homemade do it yourself antenna. Parts scrounged, minimal investment... I have a nicely cut piece of PVC (approx 1"x2") looking for some hangers or welding wire. I want to make mine a bit more portable...

$4.00 Ham Radio Satellite Antenna
The $4 dual band satellite antenna

There's also the eggbeater antenna.... for a monoband satellite applications, permanent base or portable. An excellent site for plans and ideas... in English and French. This something for ISS communincations, being omnidirectional it doesn't need to be handheld. ON6WG has lots of antenna information and excellent ideas on portable operations.
The Eggbeater Antenna

A small handheld 70cm antenna for LEO (low earth orbit) satellites, much better than just a rubber duck antenna. Look here. IW5EDI has an excellent page of resources for many topics on ham radio.
70cm antenna

So what will it be, the $4 special, a tape measure yagi or a simple dual band rigid wire yagi? A look through my junk piles and what I might find along the way will dictate the goal. My bets are on a foldable rigid wire dual band design.

But the antenna and radio is only part of the setup. How to find a satellite? A computer will be needed.... Windows, Linux, Android? What's available (and free) That's the discussion saved for Part2!