ATV projects

What's ATV?
It is an amateur radio activity which consists of transmitting an analog audio/video signal as satellite do (satellite analog video broadcasting).
Audio signal is frequency modulated at 6.5 MHz, combined with the video signal and then the resulting signal is modulated in FM at 1.240 MHz forming a high quality signal 27 MHz wide which can be transmitted to the final receiver directly, or through a repeater.
The repeater I usually use is located on the top of "Monte Pizzoc", a mountain 22km from me: it has several receiver and transmitter in the UHF-SHF bands with a switch matrix remote controlled (using DTMF tones).
Obviously, transmitter is used with a normal camera to transmit audio and video in real time; to receive ATV signal, old analog satellite receivers are used in combination with a preamplifier.

Devices for transmitting audio/video signal

1.2 GHz transmitter - LP5101: The sheet below describe the transmitter I use in the 24cm band: it supply up to 300mW at 13Vdc power supply, with a low current consumption (about 220 mA).

Bidirectional amplifier for 2.4GHz for WiFi and ATV

This project is a bidirection amplifier which permit to achieve 30Bm (1Watt) output power with 15-16dB gain in TX, and more than 20dB filtered gain in RX.
It can be used only in 2400-2480MHz ISM band, due to RX filtering!
Look at thecomplete information about Rast2432 amplifier

Caratteristiche Tecniche
Frequency:	2400-2480MHz (2.4GHz ISM Band)
Supply:	10-14Vdc through external plug or coaxial cable from the access point
Input current while receiving:	80mA
Input current while transmitting:	800mA
Maximum output power:	30dBm (1W)
Maximum TX gain:	15dB
Maximum RX gain:	20dB
RF connectors:	SMA female
Dimensions:	61x92x30mm LxWxH
Case:	Additional PVC watertight box, which can be mounted on the antenna mast, can be supplied at the cost of 5 EUR

More info in the WiFi projects page

Rast2432: Frequently Asked Questions

Can I use this amplifier at 2300 MHz?
Yes, in transmission there are no troubles using the amplifier in the entire range 2300-2500MHz. In RX, consider that the RX section is made by 2 GaAsFet stages within a very selective filter to avoid out-of-band noise, so you need to remove the filter (a copper cube) and short the pads to avoid filtering: note that in this way the receiver connected to the amplifier will receive out-of-band noise which can cause intermodulation
Can I drive this amplifier with a common Audio/Video extender?
Yes, if it uses FM modulation (common situation) in the 2.4GHz ISM band with an output power between 7dBm (5mW) and 24dBm (250mW)
I have several other questions: how can I do?
The fastest way to contact me is entering chat, using skype (nickname iw3grx), or sending an email to iw3grx@ir3ip.net

Information and links

A documenti about italian ATV repeater and band plan, written at the Magenta ATV conference 2005, is available.
Download the italian ATV documentation - Magenta 2005 [712k - 14/04/2005 - OpenOffice.org/impress]

Oct 06, 2008 - 17:42:56 - http://ir3ip.net/iw3grx/atv/
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