[Phillip Beall]

All,

I have the tools and skills to do this, but I simply do not have the time. I want to modify some commercial receivers and change their cheesy little fixed antennas to SMA connections to open up antenna options. Why?

I have more than one of this type project that interests me, but I will limit the post to discussion of just the one item. It is an Interior Wireless Replacement/Additional Driveway Alarm Base Station for Mighty Mule Outdoor Motion Detectors (click here). They have fixed antennas soldered to their respective motherboards. The devices work very well, except that the signal will not penetrate into my shop, which is essentially a windowless faraday cage. These devices operate at 433.92 MHz and are receive only, so I am confident that there are no FCC issues with performing the modification.

What the job will entail is to open the case, either cut the wire and tie onto it or desolder the current connection and then solder on a a new connection. I am figuring on a bulkhead SMA connection. The case may have to be modified, and maybe not, the existing hole may work fine, but at the end of the day there would be an external SMA connection. My plan is to mount the devices to the inside of an exterior wall and pass a cable through the wall to an external antenna. I did a pretty extensive Grok analysis of the project and if you want to read it the link is here (click here).

My preference is to always “go local” if I can do it.  There are places I could ship the devices to and they would perform this task, but I would rather hand a member of the RRVARC, or a non-member in the local community, some cash and have them do it.  If anyone is interested in the project please call me and let’s chat. I can provide the parts or you can source them yourself and I will pay cash per modified device.  I figure if we get it all laid out right you can do 2-3 kind of as a production run. Open them up and do them all together so that lessons learned on one can be applied to the others.

If you are interested, please let me know. Honestly, I think someone could mod these things and sell them on eBay, but who is looking for a job? Not me. So thanks in advance for any consideration you give the request.

73

Phillip Beall (W5EBC)
Cell: 214.729.6182

[Jerry Keisler]

Place a 433mh antenna on roof say mag mount and another identical antenna with short coax run between inside the shop. This is called a passive repeater and will radiate the signal in the shop. This freq. is inside the ham band.

[Jerry Keisler]

another way is to cut a wire 1/2 wave at 433Mh. Put a small insulator in the middle to isolate it from the tin roof.  Stick it thru the roof with the insulator at the roof.

[Phillip Beall]

Jerry,

That’s a genius suggestion! Thank you, I’m off to order the components now and if that works it helps me in a number of ways.

Thanks again!

Phillip

[Jerry Keisler]

In the sixties, TV stations put bill boards on mountain tops to reflect the TV networks over the mountains.  It took 2 bill boards positioned to bounce the signal.

We had a member living in a trailer park with no cell phone signal.  He put a beam cut to the freq. on top of his trailer aimed at a cell tower and a short antenna inside of the trailer. He had service.

[Phillip Beall]

Jerry,

See, I had wondered if that would work, but since I had never heard about anyone trying it I went for the sure thing with my Help Wanted post. I now have Amazon delivering two antennas tomorrow and I will give it a try. Just in the nick of time, we are giving my mom and dad one of the driveway monitors on Sunday. If the passive repeater setup works here tomorrow, I’ll take it to their house on Sunday and install it there and order replacements for us. I do hope it works, that will be very cool.

Thanks again,

Phillip

[Phillip Beall]

All,

On Wednesday I put Jerry’s idea about a passive repeater to the test with mixed results.  As the pictures show I used a magnet on the bracket to hold the exterior antenna on the shop wall.  I routed the cable and interior antenna through the doorway, set it on the metal structure in the wall and tested it out.  No dice.  As I was wrapping it up I had a thought and zip-tied the antenna directly to the antenna on the receiver and – it worked!  😁👌  It is kind of Rube Goldberg looking, but it works.

So, my dad does now get a notice in his shop, but these devices are really range limited.  The one in their house worked when plugged into the outlet on the north end of their kitchen countertop, but moving it ten feet south to where their weather station is plugged in; that was too far away.  So, I’m back to my original plan.

I want to find someone that will mod some of these receivers and change their antenna to an SMA connection.  For something like the one in my parent’s kitchen that would allow me to move it to a different and more convenient location and then I can just add on a larger antenna that will allow it the additional ten feet of range.  And in my dad’s shop setup, I can directly connect that high-gain exterior antenna to the receiver inside.

So, I’m back in the search for someone that wants to take on this project for cash.  I’ll provide the parts and will pay whatever reasonable amount someone wants for their time.  My initial thinking is to do four of them, so someone please shoot me a note (email address here) and tell me what you would charge me to do them.

73

Phillip Beall (W5EBC)

Click any image for a larger view.  Please let me know if you have experience modding these receivers or are interested in the project!

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