[Antennas] Cell Phone

2002年12月12日 04:51:02 +0000

Phil,
 I too worked in the NM Oilfields(around Farmington). We used a huge
Dish that we had to build a trailer for. We had to find the sattelite at 
every location we went to.
Not too easy in some of those locations down in between the mountains and 
ridges.
 It was truly a pain in the ^&%&*&)*( to get set up!
73, Tom K5IID
Phil...what outfit were you with? I was with Halliburton Logging.
At 23:25 11-12-02 -0500, n6mly wrote:
>Some years ago I was working for a company doing hydraulic well fracturing
>in the New Mexico Oil Fields (a procedure of pumping fluids under high
>volume (200-4000 gal/min) and pressure (2000-12,000 psi) into new oil wells
>so as to crack the rock open and so get more oil flowing, I ran a computer
>monitoring truck. We had computer programs that would monitor fluid flow
>rates and pressure and would calculate what was happening a mile down in the
>well.
>>Occasionally we would send the live data back to the office via modem
>connected to a Motorola bag phone so they could follow the progress of the
>job. As we were often far out in the desert, far from a cell tower we often
>used a very high gain commercially made beam antenna. I think the
>manufacturer was Antenna Specialists.
>>My experience was that although there was some improvement it wasn't as
>great as you would expect from a 20 element beam. I did a calculation of
>the losses in the coax leading up to the antenna and found, as I expected,
>that it almost equaled the gain of the antenna. Also, they used UHF
>connectors instead of N connectors, giving even more loss.
>>One time when visiting the local cell phone company shop the tech (also a
>ham) showed me an experiment he tried connecting such a beam antenna to a
>UHF portable phone (home phone, not cellular). Said he could access his
>portable phone from several miles away. (Just an experiment, of course, as
>it isn't legal to connect an external antenna to a portable phone.)
>>So, my answer is that yes it will help but you will have to use very low
>loss coax and keep the length as short as possible. Study up on 1.2 gig
>antennas and you will get an idea of what is needed.
>>I also expect you will have trouble locating a modern cell phone that can
>accept an external antenna. All you see in the cellular outlets are
>micro-sized handsets. Offhand I would say you might be best trying an old
>analog 800 MHz unit. I see them dirt cheap at every hamfest. That
>certainly would be a lot cheaper then special ordering a new Motorola. Also
>the bigger units will give the full 3 watts output, which I don't think the
>handsets can do.
>>Phil, n6mly
>>----- Original Message -----
>From: "Merv Stump" <[email protected]>
>To: <[email protected]>
>Date: 2002年12月11日 11:05:37 -0500
>Subject: [Antennas] Cell Phone
>> > Has anyone attempted to extend the range of a cell phone by building a
>gain
>antenna?
>> > I have an older analog only phone which I think operates in the 800 MHz
>range. The antenna is about 3 and 1/2 inches - (1/4 wave on 800 MHz?????).
>I also have a newer phone which operates in either the 800 or 1900 MHz and
>the antenna is approximately 4 and 1/2 inches (3/4 wavelength at 1900????
>and close to 1/4 at 800????)
>> > I like to use the phone from home and sometimes the "cell" is marginal.
>Any
>ideas?
>> > Merv
>>- - -
>>Your moderator for this list is:
>Larry Wilson KE1HZ [email protected]
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