I have this wave amplifier of 64db max and an omnidirectional antenna of 3.2db and I have to transmit a sine wave of 82Mhz, are they suitable for me? What is the maximum gain I can get? I need at least 82db, how can I amplify the signal?

Amplifier: https://www.libertytest.com/store/viewPrd.asp?idCategory=43&opt=2&idProduct=1468

Antenna: https://www.antennakit.it/dipole-omnidirectional-50-87mhz.html

  • \$\begingroup\$ What is the actual purpose of this? What is the source? What will the intended output power level (not gain) be? On what basis are you authorized to do that? \$\endgroup\$ – Chris Stratton Dec 23 '18 at 14:39
  • \$\begingroup\$ It's for a scientific research, anyone can answer please? \$\endgroup\$ – Robert Falco Dec 23 '18 at 15:46
  • 1
    \$\begingroup\$ -1 for not answering the source and power clarification questions. Also "scientific research" does not exclude legality issues, how are you going to prevent this from illegally radiating? With the way you are approaching this, the best you could hope for would be to blow up the amp and your budget before getting in trouble. \$\endgroup\$ – Chris Stratton Dec 23 '18 at 16:19
  • 2
    \$\begingroup\$ You clearly have no idea what you are doing - for example no awareness of how you won't get requisite spectral purity without splitting the gain and putting in good filters. And you don't get authorized to do something like this without passing a licensing exam where you prove knowledge of such issues, thus you are obviously not authorized. \$\endgroup\$ – Chris Stratton Dec 23 '18 at 17:34

64dB(What)? dB is a power ratio so unless you say what your reference is, 64dB is meaningless except as a pure gain.

If your amplifier is good to 64dB reference to whatever and you need 82dB (referenced to the same thing) then you clearly need +18dB of gain (Plus whatever the feedline losses are) from the antenna, at 82MHz that is going to be a physically VERY large antenna.

You amplifier is an INSANELY expensive way to get power there, and looks to be good to about 1500W @ 82Mhz to me, I make 1,500W equivalent to somewhere around +31.7BW, or +61.7dBm (same thing, different reference level) adding 3.2dB of antenna gain gets you an (along the maximum power axis) EIRP of 31.7dBW + 3.2 = 33.9dBW, but you need to allow for feedline and connector losses as well...

Really you need to hire an RF guy, firstly to come up with a system design suitable to do whatever it is you are really trying to do, but also to advise on legal issues and shielding.

Finally you need someone who gets high power RF and how to handle it or you WILL end up either with destroyed equipment, fire or very nasty RF burns.

  • \$\begingroup\$ + 64dBWatt is also +4dB MegaWatt, which will kill you. What is your leeeetle experiment about? \$\endgroup\$ – analogsystemsrf Dec 24 '18 at 0:31

Your Answer

By clicking "Post Your Answer", you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.