Hi there i live in the uk i operate a pirate station running on 120w's currently the transmitter is in the studio i want to separate it from the studio i already have a spot on top of a school where the caretaker has agreed to install it for a small fee .
Now im in plain line of sight of the sight where id be transmitting from ive been looking at these links with C&K Horn's and lnb's however i cant find any schematics on how to contstruct a link box.
Does anyone have an links or anything?
I did think that perhabs i could modify a 2.4ghz wireless video sender and replace the antena with the horn and the receiver antenna with the lnb would this work?
Shouldn't have to do much to the wireless video sender other than adapt the horn or a yagi antenna to both the tx and rx. As to using an LNB, those down-convert the signal they receive to a much lower frequency, usually 70Mhz, so that the much higher frequencies do not have to travel down a feed line and loose signal strength due to coax losses. Using an LNB, you would need a up-converter to convert the LNB output of 70Mhz back up to the 2.4Ghz for the receiver to work.
Just try the video sender tx and rx by themselves, and I recommend using yagi antennas as those will provide gain on both the tx side and rx side. Those wi-fi extender yagi antennas should work well for the link.
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Range would depend on the type of gain the yagi or horn antennas provide. I recommend the yagi antennas because with those you can add more passive elements to add more gain, plus they are a bit less wind load factor on the masts than a horn would be. Plus the horn could capture wind and dirt and crap on it's open side, pile up at the end where the emitter element or receiver element is, and clog up the works real quick.
If you want to save some pounds, here is a link to a do it yourself 2.4 Ghz extender yagi and "disc" style antenna system. Will work for both TX and RX.
Remember, the more passive elements (after the driven element) in front, the higher the gain factor. Mount both the TX and RX antenna in the same polarity, meaning if the TX is mounted vertically, the RX must also be mounted vertically.
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
2.4Ghz is a shared part of the spectrum and is used by a lot of devices. Fortunately most of those other devices are operating in "spread spectrum" mode, meaning they use any number of channels within the 2.4Ghz license free band. They bounce around looking for an available channel and lock to that channel, and move around the next time it needs to find another open channel.
Depending upon which type of 2.4Ghz video sender unit you get, it too could also use this method of spread spectrum, hop and bounce approach for the TX and RX to lock to each other. The only real problem I can see is that the RX locks to some other 2.4Ghz signal before seeing the TX it needs to see, unless the video sender units have a special embedded signal like a "key" so that the RX will only lock to a signal it will recognize as being from the video sender TX.
Only way to really know if it is locking to the video sender TX is having someone at the RX end monitor the audio and with a known audio signal on the TX..such as a test tone, the person at the RX end will know if the RX is indeed locked to the correct signal. Once the lock is made, it will follow the TX if the TX ever changes frequency. It follows the same technique that other hop and bop spread spectrum devices use so that everything is looking at the right signal.
If you find you need to move to another band, just follow the same procedures as the 2.4Ghz setup, yagi and all, and you should be fine.
I would think that if the yagi antennas on both the TX end and RX end have sufficient gain, and there is a direct line of sight between them, no trees or other potential obstructions, it should make the trip of .804km (.5mi) just fine.
Hope that helps.
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Thanks mate your advice has probs just saved my station and me a visit from ofcom i'm also a software programmer so i'm debugging the TX/RX firmware it seems it transmits a pulse of data to ensure that the RX locks onto the correct device ive also gutted the RX out of the case put it in a nice case with the transmiter and a few fans and my TX side ive put my RDS Encoder and Limiter and TX in a case and ive hooked up a LED for Lock status
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