One of the things I always wanted to play around with was Television Transmitters. In fact that is the reason I originally decided to get my ham radio license.
Time of course is always an issue, cost is another. I acquired on eBay a 10W 70cm ATV Transmitter made by PC Electronics, which pretty much appears to be the only game in town outside of the MFJ model as I am writing this. After doing some initial testing, minor tuning to the best of my abilities, I setup a test. The test pattern you can download in the downloads section of this site if interested and edit to make it your own. In case you are wondering, I simply aimed an old intel webcam that had an composite out plug towards a printout. Yes, I cheated…But it worked! If you look carefully you can see the image is crooked, the printout moved slightly.
Below is the 70cm unit I used for receive and inside the unit you can see the down converter. I made some modifications to it by lining it with metal tape due to the plastic sides having zero RF shielding.
Just for comparison purposes, this is the 33cm (900MHz) AT down converter inside:
One of the first thing any good ham must do of course is open the unit up. I think there is a law about that somewhere. Hopefully even void the warranty, but in this case that was not an issue. I do not recommend transmitting with the unit open normally but I was making some adjustments at the time so I snapped a photo with my phone camera (below). Note the red light. Don’t try this at home.
Here is the unit from the front. 439.25MHz (CATV Ch60) and 434MHz are the two crystal controlled channels. Later models have 5 selectable channels as well as 20W out which is something I am in the market for eventually but interests have shifted for the time being.
In Conclusion, quite nice to have around the shop although at the moment (in 2019) I am not involved in ATV, hoping to get back into it again. Especially the digital aspects of it. If you are hoping to get into ATV, Analog or Digital, hope you find this useful.
If you find something incorrect, have an update, or if there is something you would like to see added to the site, drop me a line here. I like to keep things as up-to-date and as accurate as possible. Thank you! – Lucas / W6AER
