| Author |
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Dutchman
| | Posted on Tuesday, June 05, 2001 - 10:57 pm: | 
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ok..you have a mobile that has 250 watts capability thru a k40,talking to a base located high on a hill,talking thru a maco 5/8 GP antenna...to get back and forth on a more or less even reading basis,will the base need 250 watts also?? or with the big antenna,can it use less to get the same effect that the smaller mobile needs the higher power to get??
This is the basic setup I am looking at using for now so any info will be REAL helpful!!!
For educational purposes only of course! ha! |
307 (307)
| | Posted on Wednesday, June 06, 2001 - 6:10 am: |
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I would have to say , yes you could. The higher the BASE the better. |
vernonott
| | Posted on Wednesday, June 06, 2001 - 12:35 pm: |
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I believe antenna height has a little to do with it.Running the driver only , dead keying 30 watts and swinging 150 watts from my base I put the same number on my sons s meter as he puts on mine when he is dead keying 50 and swinging 250 from his mobile at a twelve to fifteen mile distance .He uses a Wilson 1000 on his mobile and I use a A99 on the base with the tip at about 72 feet height. |
Dutchman
| | Posted on Friday, June 08, 2001 - 7:07 pm: |
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Vernonott,what is the LONGEST distance you and your son have talked using the setup you describe above with a reasonable good copy??? |
vernonott
| | Posted on Friday, June 08, 2001 - 9:58 pm: |
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We have talked about twenty miles on those nights when the skip is not rolling.I won't have any signal strength on him but can hear him clear as a bell. |
WALTERB
| | Posted on Monday, June 11, 2001 - 10:45 am: |
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Dutchman,
With a Maco5/8 antenna with a good base radio, Cobra 148,ect and same in mobil with the setup you decribed you could talk 7 miles when the skip is in and about 20 to 25 miles when there is no skip if both antenna are on the same plane in most parts of the country. One of the keys is if the antennas can see each other. I talked to an airplane with 4 watts that was 100 miles away from my base station, the plane was at 15000 ft elevation. |
Don
| | Posted on Thursday, July 19, 2001 - 8:38 am: |
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vernonott you dont understand that 75% of your system is in your antenna. If you have an 18 foot antenna you would want it to be at 72ft to the bottom wich is 2 wave lengths above the ground. Or at 36ft wich is at 1 wave length. HEIGHT IS EVERYTHING!!!!! If you dont belive me then put your antenna right at ground level and ask another basestation in the area how good of a signal you give them. Then put it at 36 ft and ask again. And if possible put the BASE at 72ft and ask again. You will notice a difference. You measure the height of your antenna from where the coax screws in and not the top. I think ALL MACO 5/8 antennas are JUNK. In your base setup your antenna is 75% of your system then is your wattage wich is 15% and then modulation wich is 10% |
Don
| | Posted on Thursday, July 19, 2001 - 8:44 am: |
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Vernonott, if your base can only talk 20 miles in good conditions with 150 watts theres somthing wrong. I run an i-max 2000 at 38ft to the bottom and get out 40 miles BAREFOOT. And I run a mobile radio at my base that has been set to run a klv550 base amp. AND I LIVE IN WEST PHOENIX ARIZONA WITH BUILDINGS AND TALL TREES. |
Don
| | Posted on Thursday, July 19, 2001 - 8:47 am: |
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WALTERB, the only reason that is was possible for you to talk to a plane was because it was a line of sight transmission. Radio works by line of sight. |
david
| | Posted on Thursday, July 19, 2001 - 6:59 pm: |
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Don, I think you might have misread vernonott's post. He said his a-99 is 72 feet above ground at the tip, which would put it at 54 feet at the base. That's pretty respectable. :-) The highest I've ever gotton mine is about 45 feet. Doesn't sound like much, but it was a heck of an improvement from the 28 foot or so it was at before I got it higher. I also upgraded from mini-8 coax to RG-8, for the longer run. On SSB, I could get out 50 miles to mobiles running 100 watts or so( me barefoot on galaxy2517), and base to base better than 70 miles a time or two...Usually those stations had beams, though, so they were doing alot of the work for me, but I was happy!!! |
jeremy360
| | Posted on Friday, July 20, 2001 - 11:27 am: |
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better watch out for those k40s mine burnt up because it couldnt handle the watts...the k40 flex can only hold 50watts. Make sure the antenna is rated above what you can put out.oh by the way....a 250hd will get a 4' k40 flex so hot it gets sticky.hehehe |
HAM CBer
| | Posted on Friday, July 20, 2001 - 1:48 pm: |
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Vernon: "I believe antenna height has a little to do with it"
Really? Only a LITTLE?? Beacon AOH only puts out 20 milliwatts and yet it can be heard clearly over 50 miles away at night (no skip). The antenna is 2,500 feet up. In fact, when I was in Las Vegas a couple of months back, I heard it at night trying to pop through the static. That's a distance of over 380 miles. If I mounted the antenna at only 100 feet up or less, do you think I would still hear 20 milliwatts even a few miles away? Doubt it.
When I was hiking in the mountains on the other side of the valley from AOH a few weeks back, I tuned in AOH. The S meter was not pegged, but it was near the top of the scale! I was about 120 miles away from AOH as the crow flies and at about 5,000 feet up, line of sight to AOH. AOH's 20 milliwatts was easily covering up the guys in the valley running power on base stations at my location on the walkie talkie.
Elevation is EVERYTHING. |
vernonott
| | Posted on Saturday, July 21, 2001 - 11:46 am: |
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Exactly what I meant ,just didn't want to shout .73's |
bullet/151 southern Indiana
| | Posted on Sunday, July 22, 2001 - 2:56 pm: |
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on mobile to base communications for cb 20 miles seems to be the norm,some do better some dont.
i talk to a bunch every morning that are from seymore,ind(35+miles),scottsburge ,ind(28miles),lagrange,ky(35-40),clarksville(40+miles),lockport,ky(?)and louisville,ky. im close to madison,in and talk to them on my mobile going to and from work.i run a
modified 2950w/d104 mic and either a wilson 5000
trucker,flatline dual coil antenna.and can talk to them all barefoot almost all the time.
i agree your antenna is a very very important
part of the system that most cb people really overlook its role and how to get the most out of one for the uses you want out of it.short distance sky wave local dx,long distance sky wave dx(dxing to south america,england),ground wave,ground reflected wave,direct wave ect.you must know how to use propogation,and the antennas angle of radiation to set up for these differant types of communications properly.but in doing so you should
go all the way,get rid of that lossy rg58u,mini 8
coax and use beldons 9913 at least.it dont cost that much more to do the job right the first time
and boy will ya see the differance when you use the good stuff and install the antenna at the right height for your intended purpose!
wattage/modulation you got to have enuff power to get ya where you want to go(the better your antenna's installation for its purpose the less youll need to use)modulation enuff to be heard
plainly and clearly but not enuff to become bassy
or over driven.a clean station (90-95% mod.)will be more understandable in a pileup than a 100-150% modulated station and wont bleed 4 channels doing it either.
just my views and experiance from working with it. |
vernonott
| | Posted on Monday, July 23, 2001 - 7:53 am: |
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I like your views and appreciate your experience. |
Hammunition
| | Posted on Wednesday, July 25, 2001 - 3:22 pm: |
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Vernonott, thanks for being open minded and accepting constructive criticism. Your attitude reflects the quality of consumers and employees that Copper attracts. Also a kick a$$ forum master helps. I just set up a mobile rig base station with an IMAX 2000 (ground plane kit). I routinely shoot from Orlando to Daytona (50 to 60 miles as the crow flies). My home sits on a hill, which helps. There is a gentleman who lives in Clermont, Florida who allegedly floats an antenna over 100 feet in the air on a weather balloon and supposedly reaches people in other states(thatsa lotta coax!!). Anyone heard of this practice? |
Don
| | Posted on Thursday, August 09, 2001 - 2:03 am: |
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DUDE U DONT NEED A GROUND PLANE KIT FOR AN IMAX-2000, IF U PUT AN ANTRON PROUND PLANE KIT ON IT ITS GOING TO WORK EVEN WORSE CAUSE THE ANTRON GPK RAIDIALS ARENT LONG ENOUGH AND ARE AT THE WRONG ANGLE.. And hamcber, the only reason your antenna was heard so far away was because it was so high, if your antenna is 18ft it was 138.8 wave lenghts off the ground, compared to most antennas that are about 36ft wich is 1 wave length. then 72ft wich is 2 wave lengths. |
doctor bleedover
| | Posted on Friday, October 05, 2001 - 3:08 pm: |
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if you are talking about ground wave signals, i believe in getting the best antenna you can afford and putting it as high in the air as you can. spend your money on antennas not amplifiers.
height does not seem as important to me if u are talking sky wave or skip' .
i have tried the ground plane kit on one of my a99's but it doesn't seem to do anything at my installation.{36 feet on a tower] |
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