Started of using one of those CZH-7c 7Watt with a home made dipole that was tuned to the freq 103.8 got me about 2/3 miles away which i thought was a bit low to be honest.
Then i upgraded to a big boy unit 300w Rack mounted transmitter
this was installed inside my old schools boiler tower which has some sort of antenna i believe to be a mobile antenna
There was also a custom built unit by me which was a small Intel atom core based board with a adHoc wireless connection to my studio using YAGI Antennas this works perfect! it also allows to to configure the transmitter from the studio as the transmitter has RS232 configuration.
My issue is this is a 300w transmitter (I'm running it at 260w just to be safe)
The range still seems to be slacking i mean 260w is getting me about 16 - 18 miles at best.
I'm not using the best antenna in the world its an omi-directional 88 - 108 antenna
Would straightening the antenna and cutting it to size solve some of my range issues.
Also could the mobile mast be inter fearing with it?
2/3 mile with 7 watts into a dipole? Something seriously wrong there! Either the VSWR was so high or the CZH unit was not in fact putting out 7 watts.
Now your running 260 into a folded H-Pol with only 16 miles?
What you need is C-POL, or omni. Cutting up that antenna wont help much. At 260 watts you should be hitting 30+ miles easy..that is if the antenna is up in the air enough and not being blocked by those mobile antennas on that tower.
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Yeaa i thought it was a bit odd i gave my freind the 7w but he dosent have the expensive tools to test power output hes mounted it on a 15ft post using the same antenna and hes quite high up to highest point in my whole county to be honest but hes house is sort of in a void (ie hes got hoses all the way around him so i think the signal might be hitting the houses infront of him he uses quite a long standard coax cable to.
Anyways I think i might just shed out more money for a propper antenna spent nearly £2000 already so might aswell spend a little more to make it worth while any suggestions on what antenna would make the most of the power?
With the power level involved, a DC shunt type antenna is best, such as a J-Pole or a Dominator. At power levels above 50 watts it is very easy for the antenna system to attract static buildup simply due to the high RF level on the open radiator element. With nowhere to shunt that static charge to ground, it passes right into your transmitter and POOF! The DC shunt antenna is completely grounded throughout the entire antenna structure and provides the path for static buildup and even lightning strikes straight to ground instead of into your equipment!
To add additional assurance, I would install at least a 300 Watt Low Pass Filter even though the transmitter has one on the final amp module.
Hope that helps!
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
