Amateur TV, 70cm video systems.
While researching video systems for a recent project, I stumbled across something I had completely forgotten about Amateur TV systems.
Amateur TV is limited to those who hold a Technician Class or higher amateur radio license. If you don't have a license yet, I highly recommend getting one. ATV comes in several different frequencies; 70cm (420-450 MHz), 33cm (902-928 MHz), 23cm (1240-1300 MHz), and 13cm (2390-2450 MHz). This gives you a wide range of frequencies to choose from to avoid RF interference.
I used the 434 ATV transmitter from www.hamtv.com, which runs about 99$. This can be received on any TV that can receive analog cable signals via channel 59. My receiving system consisted of a 5-element Yagi antenna tuned to 434Mhz connected to an old VCR outputting to a small LCD monitor (the older VCR had better reception than a newer hybrid TV). I tried to use a USB TV Tuner at first, but I could not get a signal unless the transmitter was very close (they have very weak pre-amplifiers) and there was a buffering delay of about 2-3 seconds. Not good for FPV.
My range for the 100mW system ended up to be approximately 2500 feet. Next time I will get the 5 Watt version for another $100 that will give me much more range and will allow me to drop the VCR from the setup and just use a cheap portable LCD TV. Maybe if I am really ambitious, I will even pump the power to 20 watts with an amp.
Overall I was pleased with the system I had slapped together on a tight budget. The transmitter module was easy to use and, thanks to the circuitry being potted, even survived a 70 mph crash into the desert floor.
Amateur TV is limited to those who hold a Technician Class or higher amateur radio license. If you don't have a license yet, I highly recommend getting one. ATV comes in several different frequencies; 70cm (420-450 MHz), 33cm (902-928 MHz), 23cm (1240-1300 MHz), and 13cm (2390-2450 MHz). This gives you a wide range of frequencies to choose from to avoid RF interference.
I used the 434 ATV transmitter from www.hamtv.com, which runs about 99$. This can be received on any TV that can receive analog cable signals via channel 59. My receiving system consisted of a 5-element Yagi antenna tuned to 434Mhz connected to an old VCR outputting to a small LCD monitor (the older VCR had better reception than a newer hybrid TV). I tried to use a USB TV Tuner at first, but I could not get a signal unless the transmitter was very close (they have very weak pre-amplifiers) and there was a buffering delay of about 2-3 seconds. Not good for FPV.
My range for the 100mW system ended up to be approximately 2500 feet. Next time I will get the 5 Watt version for another $100 that will give me much more range and will allow me to drop the VCR from the setup and just use a cheap portable LCD TV. Maybe if I am really ambitious, I will even pump the power to 20 watts with an amp.
Overall I was pleased with the system I had slapped together on a tight budget. The transmitter module was easy to use and, thanks to the circuitry being potted, even survived a 70 mph crash into the desert floor.
Replies to This Discussion
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Permalink Reply by Nathaniel Caner on -
Wayne,
Timing is everything! I am studying for my Technician class now, I hope to take the test in late July, or sometime in August. I would echo your advice about obtaining a Ham license, to anyone interested in transmitting video from their aircraft, FPV or otherwise. The test should not be a challenge for anyone here. I would recommend the ARRL publication, "Ham Radio License Manual", available here form the ARRL web store. Be sure to get the 2nd edition, the question pool changed July 1, 2010 and is good through June 31, 2014. You can also download a copy of the question pool (good to 2014) here. The entire test is only 35 questions and a passing grade is 26. There isn't a code requirement any more, so nothing to be intimidated by. Many of the questions can probably be answered by most people here without any additional studying.
In short what are you waiting for ATV is the way to go!
Nathaniel (no call sign yet.....coming soon)
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Permalink Reply by JOHN PIZZICARA on -
Nate, good luck on your test! One word of warning, there are a couple of tests in the FCC's repertoire that are weighted heavily in the regulations area (i.e. rote memory) so don't take it for granted that it'll be a pushover. I passed the commercial exam and don't think I could have just walked in to the amateur exam and passed without going to a 2-day seminar given by the Navy Post Graduate School Ham Club in Monterey. -KI6OYR-
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Permalink Reply by Nathaniel Caner on
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KI6OYR,
Thanks for the advice! I've got a good "Elmer" to help me when I get stuck.The ARRL License Manual is very good, nice short topics, easy to digest,and if you don't quite understand something you don't have to read through 100 pages to find the answer! Anyway I'll be sure to spend extra time on the FCC regs!!
Nathaniel
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Permalink Reply by Nathaniel Caner on
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Earl,
I was tired when you posted the above reply, at the time I was just happy with the support your reply offered.Now I get it N8TV! Funny LOL!
Nathaniel (aka N8!)
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Permalink Reply by Mike Bakula on -
For folks in the US, the Ham bands are the way to go!
-- Mike (KB9RMK)
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Permalink Reply by Tim McMahan on -
Hooray,, the HAM's are coming out of the woodwork AND talking HAM tv which is hard to get info on. I was thinking about the exact transmitter you mentioned. Thanks guys!
Tim
KCØYOL
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Permalink Reply by Nathaniel Caner on
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Earl,
Leave it to me to over think a simple statement!
Nathaniel
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Permalink Reply by Michael Zaffuto on -
Excellent information and advice Wayne..an inexpensive optimal solution.
Is it legal to attach digital telemetry data into some of the horizontal scan lines?
If not....
Is there an equivalent ham setup that can handle long range telemetry in a similar way?
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