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Shot my motion sensor with a blow gun dart (antenna mod)

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hawk1:
Thanks WildBill47!  If anybody does this mod please report back here and let me know how it went!

WildBill47, the helpful post setting is right underneath the users name of the left, not so much for me but for anybody that wants to give a helpful to anyone!  This is just a very simple mod.  I do have another motion sensor mod I will probably post here.

The next mod I will post is one that has already been done with cutting the dusk/dawn sensor.  Actually just the way WildBill47 did, but this is for people that don't know how to solder.

WildBill47:

--- Quote from: hawk1 on April 10, 2009, 09:05:30 AM ---Thanks WildBill47!  If anybody does this mod please report back here and let me know how it went!

WildBill47, the helpful post setting is right underneath the users name of the left, not so much for me but for anybody that wants to give a helpful to anyone!  This is just a very simple mod.  I do have another motion sensor mod I will probably post here.

The next mod I will post is one that has already been done with cutting the dusk/dawn sensor.  Actually just the way WildBill47 did, but this is for people that don't know how to solder.

--- End quote ---

Thanks, I figured out the "helpful" right after I posted that. it was one of those "duh" moments, I had seen the link before and just assumed it told you the guidelines or something, then it dawned on me, hmmmm, this is probably how you do it.

Looking forward to your new mod, I take it this will send on/off based on some criteria and given no soldering you have my interest peaked.

BTW -- I did not use a blow dart since I don't have any :) I used a 9 1/16" piece of solid copper wire, 24 guage. I made it the roughly 9" because that is 1/4 Wavelength of the 310 MHz frequency that X-10 uses in the US to transmit on. You likely already know this but the closer you are to 1, 3/4, 1/2, 1/4, or 1/8 wavelength exactly the more effecient the antenna will be, in many cases like this close is good enough but thought I would add that just for anyone interested.

At 310MHz the ideal length in inches for a vertical antennal is as follows:
Full = 3' 1/4" -- Best you can do, couples the entire wave onto the antenna
3/4 = 2' 3 3/4"  -- odd but at 3/4 why not just go full
1/2 = 1' 6 1/8" -- More common, still a tad long
1/4 = 0' 9 1/16"  -- Very common, very effective
1/8 = 0' 4 17/32" -- Also very common but not nearly as good a 1/4

Thanks,
Bill

PS -- I click on the "helpful for ya"

hawk1:
Thanks for the helpful WildBill47!  The next mod that I mentioned is to use the dusk/dawn sensor lead for a dry contact for about any kind of dry contact switch you can imagine.  The no solder method kind of suprised me too!
More to come!    ;)

dave w:

--- Quote from: WildBill47 on April 10, 2009, 09:57:10 AM ---
At 310MHz the ideal length in inches for a vertical antennal is as follows:
Full = 3' 1/4" -- Best you can do, couples the entire wave onto the antenna
3/4 = 2' 3 3/4"  -- odd but at 3/4 why not just go full
1/2 = 1' 6 1/8" -- More common, still a tad long
1/4 = 0' 9 1/16"  -- Very common, very effective
1/8 = 0' 4 17/32" -- Also very common but not nearly as good a 1/4


--- End quote ---

FWIW

I used a simple 26 ga stranded insulated wire cut to 1/2 wavelength and hot glued to the left side of the xxxeye motion sensor. Most of my Active Eyes are mounted high so I just let the wire hang down like a "dribble" antenna. Ridgid wire like a coat hanger or like 14 ga solid copper in Romex, worked about the same as far as range, but was harder to work with and heavier. I don't think full wave would work well in this application, but didn't try it. ( I thought unless a full wave is "folded" you get signal cancellation along the element(?). )

1/4 wavelength did not work as well as the 1/2 wave since the xxxeye motion sensor has no RF ground plane, but as I recall the actual difference in distance was not appreciable.

I don't know if this old thread is any help or not.

http://forums.x10.com/index.php?topic=12013.0

WildBill47:

--- Quote from: dave w on April 10, 2009, 12:36:15 PM ---
--- Quote from: WildBill47 on April 10, 2009, 09:57:10 AM ---
At 310MHz the ideal length in inches for a vertical antennal is as follows:
Full = 3' 1/4" -- Best you can do, couples the entire wave onto the antenna
3/4 = 2' 3 3/4"  -- odd but at 3/4 why not just go full
1/2 = 1' 6 1/8" -- More common, still a tad long
1/4 = 0' 9 1/16"  -- Very common, very effective
1/8 = 0' 4 17/32" -- Also very common but not nearly as good a 1/4


--- End quote ---

FWIW

I used a simple 26 ga stranded insulated wire cut to 1/2 wavelength and hot glued to the left side of the xxxeye motion sensor. Most of my Active Eyes are mounted high so I just let the wire hang down like a "dribble" antenna. Ridgid wire like a coat hanger or like 14 ga solid copper in Romex, worked about the same as far as range, but was harder to work with and heavier. I don't think full wave would work well in this application, but didn't try it. ( I thought unless a full wave is "folded" you get signal cancellation along the element(?). )

1/4 wavelength did not work as well as the 1/2 wave since the xxxeye motion sensor has no RF ground plane, but as I recall the actual difference in distance was not appreciable.

I don't know if this old thread is any help or not.

http://forums.x10.com/index.php?topic=12013.0

--- End quote ---

One could write tomes on antenna theory, oh wait, they have : ) One of my profressors once said a RF stuff is "FM"....
Dramatic pause... Friggin Magic although he did not use friggin but this seems to be a PG-13 type of forum so O want to respect the theme....

I have added ground planes before, but to your point I don't recall that using a full WL antenna has any drawbacks withouht a ground plain except of course you are not going to get as good coupling. I have not done any true objective testing on X10 antenna's but have found that usually when dealing in omni's, the longer the better, provided you use the right length for each wl you want to match.

I added a very crude stave, 8 stave's 1/8th WL around the base of my CM15A antenna, just soldered the wires at about a 35 degree angle to the vertical, not sure if it made any real differnece but it did not hurt, I did it the same time I had added a 1/4 wave antenna to a motion detector.

I rarely use a full wl antenna for anyrthing, usually too long.

Thanks for the links, it looks like we have many have played X10 Antenna games, another nice trick is to just buy like as Linx although there are a lot cheaper ones out there transmitter and tap that right to the X10 xmit antenna, just get a 310MHz model, hope the FCC looks the other way and actaully unless someone complains no big deal, and then just driver the xmitter to max, you get 1/4 mile easy with 1/4 wl omni.

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