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Video Wireless 1240Mhz 1W

Also see the video wireless page if you like.

The 1300MHz band also know as 23cm band is open more or less worldwide for radioamateurs.
Now small and cheap video transmitter equipment can be purchased and used legally with a radio amateurlicence.

Output at 1240 is impressive 31.2dBm 1.3Watt
Audio is 5.6MHz away and in mono, audio RF level is -21dBc
Power supply voltage and RF power out:
12V 355mA +31.2dBm
11V 340mA +30.5dBm
10V 300mA +29.7dBm
9V 280mA +28.9dBm
8V 250mA 27.9dBm
7V unloced dont work
So this unit have less heat loss at lower supply voltage, it's power output drop slightly when supply go down
run this unit near 10V for best power vs heat compromise

The test setup SA Agilent E4443A calibrated attenuator and powersupply

Harmonics at 2480MHz +13dBm this might be a problem !! when people want to use this with 2.4GHz RC equipment !! be warned !!
Harmonics at 4959MHz -23dBm
Harmonics at 6199MHz -13dBm

it is important to mount the TX unit directly on the attenuator to measure correct powerlevel

The switch in the top changes output frequency
1 1240MHz the default powerup frequency, unit do not remember frequency
2 1280MHz
3 1320MHz
4 1360MHz
5 1080MHz
6 1120MHz
7 1160MHz
8 1200MHz


Thomas Scherrer OZ2CPU 2009