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Simplest antenna for 5.8GHz 200mW transmitter to allow 100M range

davenn

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Sep 5, 2009
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OK ... thought I better clarify ... since you are considering making a patch antenna
its double sided PCB and the other side is a solid groundplane .... ie ... is not etched


The computer woes ....
It turned out to be the motherboard, which didn't really surprise me, it had been starting to get a bit flaky by not booting up occasionally over recent months
it finally didn't boot up at all

So bought a gigabyte motherboard, i3 CPU, HDD, 4gig ram, case etc to make up a totally new puter also bought Win7 32 bit and got 64bit version thrown in

installed the 32 bit version and all seemed well for a few days or so. but then couldn't get the activation to work and it all started to fall apart. The windows software failures grew more and more till it was useless

I suspect I got a Chinese fake Windows disk ... it looked authentic!
So again had to save all my files off the HDD and I cleared it and installed the 64 bit version. So far all is great and most of my 32 bit progs are running happily

cheers
Dave
 

shumifan50

Jan 16, 2014
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I found this calculator:
Range calculator for transmitter/receivers
I know I have to heed the warning at the bottom that there are many other things that might influence the range, but at least it gives an indication of range.

As a matter of interest; Is it possible to measure the output of a transmitter at home? I found a method on the tektroniks website that uses a scope, but it needs a scope capable of the frequency of the transmitter - in my case 5.8GHz, which I don't have. So is there another way?
 

davenn

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microwave frequency, power meters and spectrum analysers start to get pretty expensive
The total cost of my test gear for that stuff exceeds $5000
and generally would only be found in a hamshack like mine where lots of microwave work has been done or in a commercial radio services workshop

for 200mW I'm surprised you are getting away without a transmitting licence ??
10 - 20mW max is the norm for unlicensed transmitters in the ISM bands

do you know any hams locally that are into the microwave bands ?
go knock on the door and ask for help :)

Dave
 

shumifan50

Jan 16, 2014
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for 200mW I'm surprised you are getting away without a transmitting licence ??

Now that is something I have not investigated. As these are sold locally by hobby shops I thought it was OK. But 'I thought' has got many people into trouble. So maybe the 10mW or 25mW might be legal at least. I will investigate. I don't like breaking any laws as they are normally there for a reason.
Thanks for the warning.

Just ordered the 10mW version. They claim it has a range > 200M.
 
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