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#1
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Folks
So I'm thinking about emergency communications and it seems to me that an 800 Mhz Yagi antenna would be useful. I have one of those old Motorola bag phones which I use when travelling in rural Alberta. It works nice especially when on a 3' mag mount antenna on the vehicle roof but it seems to me a Yagi up 20' might be useful at times. Tony |
#2
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Tony VE6MVP writes:
Folks So I'm thinking about emergency communications and it seems to me that an 800 Mhz Yagi antenna would be useful. I have one of those old Motorola bag phones which I use when travelling in rural Alberta. It works nice especially when on a 3' mag mount antenna on the vehicle roof but it seems to me a Yagi up 20' might be useful at times. Just try it. These things don't cost much, do they? Although you already have a decent antenna. Compared to the built-in antenna of a typical cell phone, it will make a tremendous difference. Here in Norway we have GSM, 900 MHz in rural areas. The signal is very poor at our summer house. So we bought a 40$ 9 el. Yagi at a hardware store and put it in a tree, may be 15 ft up. It's supposed to have 10 dB gain, but it comes with 33 ft of RG-58, so we lose more than half the gain on the way. However, the built-in antenna of most cell phones is unbelievably bad, and getting the antenna higher up makes a lot of difference at our location. I went from 0 bars to 5. The coax is marked "low loss" with nice, friendly letters. I guess that's what does the trick :-) 73 Jon |
#3
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Jon, just think of how many bars you would have had the cable been
marked ULTRA LOW LOSS... denny / k8do |
#4
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Tony, look in the ARRL Antenna Handbook... There will be short yagi
designs for UHF... A Quagi would work well and be easy to match, but not as handy to stow away...I suggest 5 elements as the most bang for the buck between complexity and performance... Just scale to your frequency... Use a small aluminum tube for the boom, and bare welding rods for the elements... Put a decent piece of RG8 or LMR400 on it and it should play well... denny / k8do Tony VE6MVP wrote: Folks So I'm thinking about emergency communications and it seems to me that an 800 Mhz Yagi antenna would be useful. I have one of those old Motorola bag phones which I use when travelling in rural Alberta. It works nice especially when on a 3' mag mount antenna on the vehicle roof but it seems to me a Yagi up 20' might be useful at times. Tony |
#5
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Is there an easy way of coupling the phone to the coax?
Alan WN4HOG -- Windsurfing Club: http://www.ibscc.org "Denny" wrote in message oups.com... Tony, look in the ARRL Antenna Handbook... There will be short yagi designs for UHF... A Quagi would work well and be easy to match, but not as handy to stow away...I suggest 5 elements as the most bang for the buck between complexity and performance... Just scale to your frequency... Use a small aluminum tube for the boom, and bare welding rods for the elements... Put a decent piece of RG8 or LMR400 on it and it should play well... denny / k8do Tony VE6MVP wrote: Folks So I'm thinking about emergency communications and it seems to me that an 800 Mhz Yagi antenna would be useful. I have one of those old Motorola bag phones which I use when travelling in rural Alberta. It works nice especially when on a 3' mag mount antenna on the vehicle roof but it seems to me a Yagi up 20' might be useful at times. Tony |
#6
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On 07 Nov 2006 11:22:53 +0100, LA4RT Jon wrote:
The coax is marked "low loss" with nice, friendly letters. I guess that's what does the trick :-) chuckle Tony |
#7
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On 7 Nov 2006 04:31:37 -0800, "Denny" wrote:
Tony, look in the ARRL Antenna Handbook... Interesting idea. I just received the 16th ediition which I got from someone on Ebay. I Put a decent piece of RG8 or LMR400 on it and it should play well... That LMR400 is fairly stiff stuff. The biggest problem would be locating the end that fits on the Motorala bag phone especially with LMR 400. I have no idea what kind of end it is but I'm sure a commercial radio shop can tell me. Tony |
#8
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In article ,
Tony VE6MVP wrote: Folks So I'm thinking about emergency communications and it seems to me that an 800 Mhz Yagi antenna would be useful. I have one of those old Motorola bag phones which I use when travelling in rural Alberta. It works nice especially when on a 3' mag mount antenna on the vehicle roof but it seems to me a Yagi up 20' might be useful at times. Tony Here in the USA, we are losing our AMPS Network next year, so all the 3Watt AMPS BagPhones will be non-functional. Most of us bush Folks have switched to either Digital BagPhones, or handhelds with external Antenna Ports and 3 Watt Booster Amps. I use a Nokia Handheld with external 10db Panel Antenna, mounted in an Active Cradle that simulates an RJ11 Jack, and has a Cordless Phone plugged into it. I have a "Line of Sight" shot at our local Cellsite, which is 16 miles away, (over water) so I don't need the Booster Amp here. Some of the neighbors need them, however. Bruce in alaska AL7AQ -- add a 2 before @ |
#9
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![]() "Alan" wrote in message m... Is there an easy way of coupling the phone to the coax? I have observed that two of my family's (various) phones have concealed coax fittings. Look for any bit of peelable/liftable plastic trim on or near the top of the phone that might be covering such a jack. Dunno what the connector series would be -- there are more different kinds than I can name by eye. I think I may have observed a coax fitting on the base of one phone. This would be for a unified vehicle adapter, where you slap the phone into a cradle and get power, RF and audio all at once. I hope this helps. |
#10
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Get LMR-400 Ultraflex. Much more flexible.
Adaptor cords are available for most any phone from various suppliers. Try google on "cell phone antenna cord" Bob In article , Tony VE6MVP wrote: On 7 Nov 2006 04:31:37 -0800, "Denny" wrote: Tony, look in the ARRL Antenna Handbook... Interesting idea. I just received the 16th ediition which I got from someone on Ebay. I Put a decent piece of RG8 or LMR400 on it and it should play well... That LMR400 is fairly stiff stuff. The biggest problem would be locating the end that fits on the Motorala bag phone especially with LMR 400. I have no idea what kind of end it is but I'm sure a commercial radio shop can tell me. Tony |