antenna length for video xmtr

That's what I'm afraid of. But it's much easier to keep the camera dry and to maneuver it around if it's only connected by a rope. So I'm gonna try it first. ERS

Yeah Bob, I tried the cable as rope thing and the cable wrapped around the rope and had problems with manipulation and strength problems. I guess I'll lower tthe camera down and if there are problems then go to the extra trouble to make a case with sealed leads coming through. . ERS

If you're going to be lowering the thing down an iron pipe, I would think you would do FAR better simply running the signal over a cable than you ever will with a wireless link.

Bob M.

There's a problem with the "rope" being a coaxial cable, or at least having a mini-coax wrapped around it?

You're going to have REAL problems with an RF link in this case, trust me...

Bob M.

You need to run your video and power over a cable (easy to do using 4 conductor telephone wire). The below cams would be easy and cheap to use with a little tweeking/modding.

Actually, with the transmitter down a metal pipe you could get a wave guide effect, in which case the signal will boom out.

Cap

^^ ?

No, 3e8/9e8 = 1/3m. Thats the wavelength in meters.

Regards, Bob Monsen

Greetyings Bob, It's interesting that the calculations comes so close to the length. Since the thing transmits anywhere in the 900 to 1200 range the antenna being 3.5 inches long would seem to be covering that range. If the antenna needs to be extended and a shielded wire is used until the last 3.5 inches of wire will the effect be the same as the antenna being connected directly to the circuit board as it is now? Thanks, eric

On Friday 17 September 2004 04:53 pm, Eric R Snow did deign to grace us with the following:

What strength problems? If the rope will hold the camera without the cable, what makes the rope becomes weaker when there's a cable dangling alongside it? You leave some slack at the camera end, and let the cable support only its own weight. You could keep them at the same length with some kind of capstan.

Good Luck! Rich

Rich, The video cable by itself was too weak. Wrapped arond the rope it was a mess. ERS

guide

Mea culpa! I thought a foot was a bit long for the frequency! Cap

The camera is small. The casing with batteries and LED lights is the big part. ERS

Cable TV companies use a cable consisting of a coax and a stronger support wire for the drops from a utility pole to a house - perhaps you could use that... (Belden 7983A, for example)

How much weight are you trying to drop down your well? Most cams small enough to drop down the well casing with the pump still installed weigh only a couple of ounces at most. Bullet types of cams usually have a threaded fitting on the rear in which a ~1' length piece of threaded rod can be attached. Tape the cam cable to the threaded rod so all hangs vertically. You can see the threaded hole on the rear of the little IR cam on the below page (this cam is small, but the bullet cams are even thinner). The cable with this cam probably could withstand a 50lb pull if it got stuck. The rear of the cam would need to be tapered to the threaded rod so the edge wouldn't catch on a casing misalignment and such. Sounds like you are trying to put too large a cam setup down your casing.

I've only pulled a couple of well pumps, but I wouldn't be putting all that stuff down the well casing. You are just asking for trouble. Go to google search to see what the well inspectors use. An IR bullet cam on the end of cheap cat5 cable will be plenty strong enough to support the cam and pull back out if it gets in a bind. Below is a cam you might want to look into. YMMV!

On Sunday 19 September 2004 07:42 am, Eric R Snow did deign to grace us with the following:

What part of "alongside" don't you understand?

Thanks, Rich

On Sunday 19 September 2004 12:04 pm, Si Ballenger did deign to grace us with the following:

And leave the batteries topside, of course.

Cheers! Rich