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Video signal amplifier.
Why I said it was solid wire, I am not sure. Definitely stranded and not twisted pair. Foil shield with stranded nickel plated 18ga copper ground wire. -
Video signal amplifier.
Agreed. The circuits showed in your attachment will be my next build. I obtained them from the AD811 data sheets, application notes. -
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Video signal amplifier.
The camera requires a 12VDC supply. A single cable is mandatory. I suppose I could send the 12VDC over the coax, let the signal piggyback on the power line and strip it off, but that may be troublesome, or not. -
Video signal amplifier.
No apologies necessary at all. I have other irons in the fire, plus everyday life events, plus occasional wifi problems. Let me give you some cable numbers. Cable is a 4 conductor shielded type. 18awg solid. Stamped info as follows: E111272 (05-21513) 18AWG SHIELDED CL 3R/FPLR (UL) OR CMR C(UL)... -
Video signal amplifier.
I have a couple AD811s on their way. Haven't gotten back to experimenting but the 811s look like an ideal amp for this app. -
Video signal amplifier.
WHONOES indeed appears to be well acquainted with this subject. When I initially peeked at this project, the mention of baluns came about. I had never used a manufactured balun but deduced that the root of the word was bal, most likely in reference to an act of balancing a supply to a load... -
Video signal amplifier.
I will get the data sheets for the AD811. I am certain that it will be a more appropriate component for my app. Cost is not really a deal breaker but there is no reason for overkill either. Impedance marching of the output to the load allows for maximum power transfer. I'm pretty sure that is... -
Video signal amplifier.
Memory is hazy on this but it seems that when testing for reflected signal values (expressed in db ?) I plugged a watt meter directly into the output BNC connector. I recall that I had to have the proper impedance connector, in this case either a 50Ω or 75Ω connector. I don't recall if I was... -
Video signal amplifier.
I am trying to boost only camera video output information. There is no radio transmission of this data. Video signal to spooled cable (500 feet) to monitor. -
Video signal amplifier.
My understanding is that gain = Rf/Rin. I will look again but a gain of 1 might be maximum gain at ≈ 1MHz. It appears that the horizontal sync pulses are ≈ 15KHz. I'm shooting from the hip here and will later search out actual freqs but 6.45MHz is roughly the dot clock speed. That speed may not... -
Video signal amplifier.
I have placed a balun on each end of my cable. Will that negate reflections? I have forgotten the relationship of ohm value to characteristic impedance. I seem to remember that flat antenna wire was 50Ω and coax was 75Ω or visa versa. I am sure that the ohm value was not per foot of cable but... -
Video signal amplifier.
Thank you for your response AURELZ. There are some elements in this schematic that may prove useful. This circuitry is somewhat more involved than I desire, but may have to resort to. I suspect that somebody has put this entire circuit on a single IC chip and I may have to search for such a... -
Video signal amplifier.
Thank you for your reply and inquiries. I was thinking that the LM747 had a good rail to rail response. I will check my data sheets. My application does not involve signal radio transmission. Merely a CCTV system. The spooled cable is necessary in order to pay out cable length for a travelling... -
Video signal amplifier.
Thank you for your reply. I agree that the LM747 is an unlikely component for successful results in this application. I happen to have a dozen on hand and was hoping to utilize one. This app is merely using what I am guess would be referred to as a CCTV camera. A security camera let's say... -
Video signal amplifier.
I am attempting to construct a video signal booster using an LM747 dual op amp. My cable is a 4 conductor shielded type. Length is 500 feet wound on 6 inch spool. I receive enough signal to produce a black and white image but prefer to have a color image. The op amp is working good but I seem to...