C
[email protected]
- Jan 1, 1970
- 0
The January thread on converting a cheap TV to an oscilloscope,
impractical that it was, did recently give me an idea...
What about using a $20 5" portable TV as a display for one of those
cable tuner or comparable homebrew spectrum analyzers?
The key idea would be to rotate the display on its side, so frequency
is on the Y axis and intensity on the X.
- Sweep rate would be fixed at the vertical scanning frequency of the
TV.
- Horizontal scanning frequency would also be normal. Charge a cap
from a current source as the beam scans, and use a fast comparator
(better a window comparator) running against the log detector output to
turn the beam off (or blip it on-off) at the right horizontal position.
- a small fast microprocessor like a PIC could generate the video
timings and also put a reticule on the screen. An FPGA could do that
and aslo add on screen frequency display and range info.
Think it might work?
Might it be possible to use the TV's tuner/IF strip to make a very
crude "toy-grade" swept receiver? These portable TV's are voltage
tuned, right?
impractical that it was, did recently give me an idea...
What about using a $20 5" portable TV as a display for one of those
cable tuner or comparable homebrew spectrum analyzers?
The key idea would be to rotate the display on its side, so frequency
is on the Y axis and intensity on the X.
- Sweep rate would be fixed at the vertical scanning frequency of the
TV.
- Horizontal scanning frequency would also be normal. Charge a cap
from a current source as the beam scans, and use a fast comparator
(better a window comparator) running against the log detector output to
turn the beam off (or blip it on-off) at the right horizontal position.
- a small fast microprocessor like a PIC could generate the video
timings and also put a reticule on the screen. An FPGA could do that
and aslo add on screen frequency display and range info.
Think it might work?
Might it be possible to use the TV's tuner/IF strip to make a very
crude "toy-grade" swept receiver? These portable TV's are voltage
tuned, right?
