CCTV Cameras

[RandomGrinch]

However, per some of the edits you added after I started writing this

Sorry for the edits!
I had found the diameter of the gold atom, but then came across conflicting information about the number of atoms in a specific layer thickness.
So I stopped short of suggesting what the area would be at 23 atoms thick.

...then I went back to first principles!

Using Avogadro's constant, 1cm³ of gold would have 5.91x10^22 atoms.
...cube rooted = 38'951'946 atoms per side.
...at suggested 23 atoms thick, that would be 1'693'562 cm² slices.
...19.32g (1cm³ of gold) = 169m² at 23 atoms thick.
...8.75m²/g
...Troy ounce = 31.103g

...the area of one Troy ounce of gold at 23 atoms thick = 272m²

...well, that's my guess anyway!

 

[JohnW2]

I had found the diameter of the gold atom, but then came across conflicting information about the number of atoms in a specific layer thickness.
So I stopped short of suggesting what the area would be at 23 atoms thick....

Yes, I realise that, but I 'stuck my neck out' and undertook calculations on the (as I admitted, undoubtedly incorrect) assumption that one could cram the atoms together such that their 'diameters' (which, itself, is a suspect concept) were in contact.

...then I went back to first principles!
Using Avogadro's constant, 1cm³ of gold would have 5.91x10^22 atoms.

Agreed.

...cube rooted = 38'951'946 atoms per side.
...at suggested 23 atoms thick, that would be 1'693'562 cm² slices.
...19.32g (1cm³ of gold) = 169m² at 23 atoms thick.
...8.75m²/g
...Troy ounce = 31.103g
...the area of one Troy ounce of gold at 23 atoms thick = 272m²

Again, I can find no fault with your calculation.

...well, that's my guess anyway!

I would say that 'guess' is somewhat of un understatement!

Kind Regards, John

 

[AstonHill]

I had a go making up the cable, soldering together a coax cable onto a phono cable. I even found a lens from another camera that I swapped over.

I tried it on the TV and I now have a signal comming into the TV. But it is just a fuzz with and with out the lens

 

[JohnW2]

I had a go making up the cable, soldering together a coax cable onto a phono cable. I even found a lens from another camera that I swapped over.
I tried it on the TV and I now have a signal comming into the TV. But it is just a fuzz with and with out the lens

Well done to get a signal - that's certainly an important first step!

Are you sure that the lens is compatible with the camera you swapped it into (and that you have 'installed' it correctly)? Did it come from an identical camera and, if so, why didn't you do your test with camera that already had a lens installed?

Kind Regards, John

 

[AstonHill]

Are you sure that the lens is compatible with the camera you swapped it into (and that you have 'installed' it correctly)? Did it come from an identical camera and, if so, why didn't you do your test with camera that already had a lens installed?

Yes it cam from an identical camera, i tried the other camera first but there was no signal on the screen

 

[JohnW2]

Yes it cam from an identical camera, i tried the other camera first but there was no signal on the screen

Interesting. That, in itself, is a little surprising - I suppose it suggests that the other camera is either ill or dead.

Kind Regards, John

 

[AstonHill]

or it could of all been bad signal from my soldering

 

[DetlefSchmitz]

It could have.

 

[JohnW2]

or it could of all been bad signal from my soldering

... but didn't you use the same lead (soldered together by yourself) for both 'other camera' (when you got no signal) and the one to which you swapped the lens (when you did get a signal)?

Kind Regards, John

 

[AstonHill]

I found this

https://cpc.farnell.com/pro-signal/psg08571/adaptor-phono-skt-to-bnc-plug/dp/CN21115?rpsku=rel3:AV17301&isexcsku=false

Any good?

... but didn't you use the same lead (soldered together by yourself) for both 'other camera' (when you got no signal) and the one to which you swapped the lens (when you did get a signal)?

Kind Regards, John

I ordered the fitting so when it arrives it is just one problem to eliminate, presides I was told on a sound engineering forum that due to the high frequency of the TV signal a proper cable that has good resistance (75 Ohms) will be required to carry the frequency wave

 

[JohnW2]

I ordered the fitting so when it arrives it is just one problem to eliminate, presides I was told on a sound engineering forum that due to the high frequency of the TV signal a proper cable that has good resistance (75 Ohms) will be required to carry the frequency wave

I would have expected you to get some sort of signal with almost any type of (short) cable.

Kind Regards, John

 

[Harry Bloomfield]

I ordered the fitting so when it arrives it is just one problem to eliminate, presides I was told on a sound engineering forum that due to the high frequency of the TV signal a proper cable that has good resistance (75 Ohms) will be required to carry the frequency wave

For the very short cables you are testing with, it will make no difference. It would mostly affect the picture quality anyway, and quality is not important at this stage, just a functional test.

 

[sparkymarka]

I ordered the fitting so when it arrives it is just one problem to eliminate, presides I was told on a sound engineering forum that due to the high frequency of the TV signal a proper cable that has good resistance (75 Ohms) will be required to carry the frequency wave

It’s not transmitting by RF , it’s video 1v peak to peak…….

 

[JohnW2]

It’s not transmitting by RF , it’s video 1v peak to peak…….

I agree with your implied bottom line. As Harry and myself have said, virtually any sort of (short) cable (quite possibly even if there is a small 'air gap' at what should be s 'termination'!) ought to produce a picture of some sort.

However I would say that "not RF" is a little more debatable, since composite TV signals can be anything up to about 6 MHz, maybe even more

Kind Regards, John

 

[DetlefSchmitz]

However I would say that "not RF" is a little more debatable, since composite TV signals can be anything up to about 6 MHz, maybe even more

That is certainly not rf in TV terms.