An easy to build UHF TV modulator

This analogue audio/video modulator operates in the UHF TV band. Apart from the different type of UHF oscillator, it's schematic, operation and alignment is identical to my other TV modulator, but this one has been made without any PCB, so it can be reproduced easily. Therefore, for alignment, use the instructions provided in that TV modulator page.




+12v


6MHz


5.5MHz


4.5MHz

4.7uF
16v
C1 82pF 100pF 180pF


78L08
C2 220pF 270pF 390pF


1k
C3 330pF 390pF 680pF
100uF
16v
100nF 0.5-8
pF
2turns
3mm
diam.
0.85mm
silver
plated
220k audio
input
4.7k 0.85mm
pitch
100nF

33k

1.5nF 3.3k



56nF
BFR91A 3.3pF 47k

MV209
BC557C
100uF
16v
100nF 4.7k 100uF
16v
BF494 10k
470R 10pF

1k
C2 47k 10uH 39k 470k
BF494 100pF


3.9k
6.8k C3 C1 7-80pF
10k 1nF

3.3k


6.8pF


3.9k
video
input
10k
2turns
3mm
diam.
0.5-8
pF
1N4148
0.85mm
silver
plated
RF
output
0.85mm
pitch
tap at
0.5
turns
from
GND

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