September 1, 2011
I recently moved to Lubbock Texas. I’m still in the process of
setting up my new electronics lab in my 30 foot by 40 foot all metal shop. The
shop is some 100 yards from the back of my house. Although I have good cell
phone, WiFi and Cordless phone signal strength over my entire acre lot, all those
signals drop to zero once inside my shop. The metal acts as a large Faraday
shield, blocking nearly all RF. The only radio signal which we can pick up
inside comes from a strong AM station, whose radio tower is close by. Nearly
all other AM and FM stations are useless. I sure wish there were some kind of
broad band antenna system which could route RF signals into and out of a metal shop. |
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Dave's 1200
Square Foot Shop |
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The radio
spectrum of our modern society is vast. AM radio starts at 530KHz and extends
to 1.6MHz. FM radio starts at 88MHz and ends at 108MHz. Then, there is
the 800MHz band needed for many cell phone services. Computer WiFi connections
operate at 2.45GHz. My cordless telephone runs at 5.8GHz. I doubt that
any one antenna would work for all of these signals. I fear that I will have to use
separate antennas for each of the devices I wish to use inside the shop. |
As an example, a
solution which seems to work for the WiFi link to my shop computer was to first buy
a WiFi USB adapter, which contained a SMA external antenna connector. I then
bought a nice high gain WiFi antenna and mounted it outside the shop. Finally,
I punched a hole in the side of my shop and strung a coax cable from the outside
antenna through the metal shop side to the SMA connector on the adapter. That
worked quite well for the computer and I now have Internet access in the shop.
But, what do I do with my cell and cordless phones? Also, my wife often likes
to listen to some talk and oldie AM and FM radio stations while working in the shop.
Perhaps I will have to mount more antennas on the outside and with the aid of some
more coax cables, to bring those signals to the inside. I may have to buy a
good quality radio receiver, which has an external antenna connection. |
Until I have time for some final solutions, I might try some low tech
method for the two telephones. I could mount a box on the outside of the shop,
where they can receive the signals from the house, and develop a beeper system,
which would drive a beeper on the inside of the shop whenever either phone rings on
the outside. We would then have to go outside the shop to pick up the phone.
This would not be ideal but at least we would not miss an incoming call when in the
shop.
If you have any other ideas, I would love to hear about them. |
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Cell Phone |
5.8GHz Cordless Phone
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WiFi Adapter |
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WiFi Antenna |
Coax Cable |
WiFi Antenna Outside Dave’s Shop |
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AM/FM Radio |
External Antenna Connector |
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