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Topic: Verizon cell phone external antenna (Read 8 times) previous topic - next topic
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Re: [Life With A Lazy Daze RV] re: Verizon cell phone external ante
Reply #25 –
Yahoo Message Number: 50110
Thanks Barry, Linley, Linda, et al ...  I'm off to buy a Marie Calendar pie -- hmmmm, maybe pecan?!! and then checking out the "Internet by Cell Phone" group.
 Chris, they say great minds travel...., eh?  Maybe we can all pool our resources at LaPaz next month and possibly ditch the pie tin and the mop handle!!
 Any roof jockeys going to attend the February CC outing?  I'll gladly offer Second Wind for a beta version -- this is an inspired idea for those of us who didn't have the foresight to get pre-wired!

Lorna, packing for Hawaii to glide with the turtles
2003 RB
Verizon cell phone external antenna-Question for Linley
Reply #27 –
Yahoo Message Number: 50150
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Apparently the ground plane does not need to be grounded as the antenna works fine on a non-grounded pie pan.

At radio frequencies, "ground" is, uh not really ground (like a chassis ground).  It's a different concept altogether. With antennas fed from coax, ground is the surface that connects to the coax's outer conductor.  As long as that surface is at least roughly a 1/4 wavelength in radius, it will act like "ground" even if it is up in the air.  The longest wavelength of a cell phone signal is about
1.25'(the high band signals are about 0.5').  So a 12" pie tin is
 almost a wavelength in diameter or about 1/2 wavelength in radius;
soit will work fine.

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Another point I have been meaning to raise is that at cell
telephonefrequencies the loss of the cable to the antenna is not neglectable.
 
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Avoid extending the antenna cable where ever possible to avoid reducing the signal amplitudes.  When you do extend the cable,
largercable almost always has lower loss than smaller cable.  This is quiteunhandy considering the tiny connectors that are used on cell

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telephones.

Linley
Linley, thanks for the above info.  Do you know the answer to the question poster earlier:  "If you attach a Wilson Trucker antenna to the TV antenna, will the proximity of both cause any interference to either the TV or the cell phone when either device is in use?"

Chris H
Formerly: 2002 30' IB
Re: Verizon cell phone external antenna-Question for Linley
Reply #28 –
Yahoo Message Number: 50153
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Linley

Do you know the answer to the

question poster earlier:  "If you attach a Wilson Trucker antenna to the TV antenna, will the proximity of both cause any interference to either the TV or the cell phone when either device is in use?"
I would avoid it.
 The advantage of putting the cell phone antenna on the TV antenna is to get it up higher, which is almost always better.  However, there are a couple of issues.

The first is that putting a several hundred milliWatt transmitter outlet right on or next to the TV antenna is likely to cause the preamp in the TV antenna to overload.  The standard cell phone signal (i.e., not the PCS) band is actually the high end of the UHF TV band before everything above channel 65 was given to the cell telephone industry.  The antenna therefore works pretty well to pick up the cell signal.  Overload the preamp enough to damage it? I don't really know but give it an ad hoc chance of perhaps one in four or five.
Note that it may take a while for the damage to accumulate depending on cell phone usage or where you are camped.  Location matters because the phone only uses maximum transmitt power in areas where cell coverage is iffy to reach the cell tower.  If the cell phone does overload the preamp without damaging it, it will interfere with TV signal anytime the phone is turned on.  The phone talks to the cell tower every few seconds even though you are not talking on it.

The second issue is that if the cell antenna is right on the TV antenna, it plus the cable that feeds it will screw up the TV antenna's frequency response. Change like this almost always make it worse so your TV reception in low signal areas may get noticeably poorer.  This effect will be much smaller if the cell antenna is mounted on the TV antenna's support rods, but this will be much harder to accomplish while providing the cell antenna with an appropriate ground plane (i.e., like the metal pie plate) and keeping it vertical for all TV antenna positions.
 All in all, it looks like mounting the cell antenna on the bottom of an upside down aluminum pie plate and then sticking the plate to the top of the roof with sealant sounds looks like an easy way to go.  No holes in the roof and it can be easily removed when times change.  I would mount it a few feet from the TV antenna and that probably will avoid any problems.  On the mid bath, it could be easily put near the refrigerator vent, avoiding the TV antenna that is midway back on the other side.  The refrigerator vent also is an easy way to get the coax cable down into the cabin.

Linley
Re: Verizon cell phone external antenna-Question for Linley
Reply #29 –
Yahoo Message Number: 50162
"All in all, it looks like mounting the cell antenna on the bottom of an upside down aluminum pie plate and then sticking the plate to the top of the roof with sealant sounds looks like an easy way to go.  No holes in the roof and it can be easily removed when times change.  I would mount it a few feet from the TV antenna and that probably will avoid any problems.  On the mid bath, it could be easily put near the refrigerator vent, avoiding the TV antenna that is midway back on the other side.  The refrigerator vent also is an easy way to get the coax cable down into the cabin."

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Linley
Linley, I knew you'd have the answer - and thanks to the others who chimed in.  When camped, I think I'll continue putting the magnetic antenna on the pie tin on the roof, securing it with a piece of duct tape, running the cable through the cab window and usually getting darn good reception.

Chris Horst
30' IB - 2002

Denver (leaving for a month in Arizona Tues. morn.)
Formerly: 2002 30' IB
Re: [Life With A Lazy Daze RV] Re: Verizon cell phone external ante
Reply #30 –
Yahoo Message Number: 50164
Chris,
 If you are going to put the antenna on a Lazy Daze roof, there is no need for the pie plate...the one piece of aluminum they use for the roof is equivalent to the largest pie plate in the world and is a fantastic counterpoise (groundplane).  What I have done to temporarily use magnetic antennas on the Lazy Daze roof (UHF/VHF Amateur, GPS, Cell Phone) is to epoxy small steel plates to the roof (I used painted steel weights from some old vertical blinds...others have used electrical box cover plates) near to the escape hatch.  I just poke my head thru and put the antenna in place..sometimes just run the coax thru the hatch too.

Rich Gort - 2000 MB (Silver) NW Washington State
Former 2000 MB- Now Bullet Crossfire 1800RB trailer pulled by a Chevy 2500HD
 
Verizon cell phone external ante
Reply #31 –
Yahoo Message Number: 50087
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Sounds like a good idea.  Technical questions:  Would either antenna cause any sort of reception interference with the other?

 Chris, that's a good question, and one I don't know the answer to (anyone know?).  However, for us at least, it's a moot point since we rarely, if ever, use the local antenna for TV reception.

Linda & Earl 2004 23.5'  Red TK From Quartzsite, AZ
Linda Hylton