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 a nice to to have around the shop. I currently do not have a horizontal/yagi 70cm antenna which is what I really should use with this unit. The test was conducted with a 70cm vertical to transmit and the downconverter had rabbit ears. This is enought to shoot the signal accross town with no problems. I also have a 33cm and a 70cm downconverter which I am holding on to for now and hoping to obtain a TV-736 adapted for my Yeasu FT-736r.
If you find something incorrect and/or have an update, I would really appreciate if you could let me know by contacting me. I like to keep things as up-to-date as possible. Thank you! - Lucas / W6AER