Wireless Camera adjustment pots

[STI2NR]

So I took one of my wireless cameras apart to check out the three adjustment pots in the base. 

One of the pots adjusts for brightness levels.

I cannot seem to figure out what the other 2 do.  I think one of them fine tunes the frequency the transmitter transmits.

As for the third I am not sure.

Has anyone else on here gone as far as I have to "tinker" around with the cameras and actually know for sure what all 3 adjustment pots do??

Any insight would be greatly appreciated.

;-)

[Brian H]

I am not sure if the video boards are shown but there are schematics of the cameras on the FCC web site.
https://fjallfoss.fcc.gov/oetcf/eas/reports/GenericSearch.cfm
Type in B4S in the Grantee tab [B4S is X10s Grantee Code]
Type the rest of the cameras FCC number in the Product Code.
Pick the Details choice for the cameras FCC number.
Many of them have a schematic and other things like internal and external photos in pdf format.
If you save them you will have to rename them as they are all shown as results.pdf.

I looked at one of them. Two of the pots adjust the transmit frequency. One for Ch.1 and the other for Ch.4
The third pot adjusts BaseBand Video to .4 Vpp into the RF modulator. From the video boards 1 Vpp output.

[STI2NR]

.4 Vpp??  Could you please explain this as I do not understand and want to be educated.

Thanks!!

[dave w]

.4 Vpp??  Could you please explain this as I do not understand and want to be educated.

Thanks!!

"Volts Peak to Peak" the pot is adjusting the level of composite video fed from the video board to the RF modulator.

[Brian H]

dave w covered it nicely.
Basically the video board puts out 1 Vpp that is a common baseband video signal level.
It has to be lowered to .4 Vpp so it doesn't over drive the RF modulator and cause the RF signal to distort.

[STI2NR]

So that pot amplifies the video signal sent?

How come when I adjust it the pictures either gets brighter or darker?  It seems to be a lighting adjustment.

[Brian H]

When you adjust it. You modify the modulation of the 2.4GHz signal. The higher the voltage the greater the frequency swings and it makes the picture lighter and darker. It could also make the signal over deviate and against FCC regulations or make it bleed into the next channels space.