Is a FM Radio exciter the same as a FM Radio Transmitter? & can i connect a transmitter to a amplifier?

Question

I am setting up a radio station and want to confirm a few things.

I have a small budget so im trying to get the best value for money...

1. is a Broadcast FM transmitter the same thing as an exciter?

2. can i connect a transmitter to a amplifier or, are only exciters permitted on amps?

The idea behind it is that i buy a 5w transmitter and link it upto a 500w amp. this will then be wired upto the antenna elements... which brings me to the 3rd question if anyone can help!?

3. how does db gain work eg. if i pump 100w into a antenna thats -1.5db what happens? and if i pump 100w into 2 of those antennas what happens and if its 3 and if its 4? how is that calculated? (if anyone knows)

Your helps appreciated! THANKS !!

Answer 1

An exciter is a low power FM transmitter designed to be fed into an amplifier.  Generally it can be directly connected to an antenna or fed into an amplifier to increase power if the matches and power figures are correct..  Your 500 watt amp must be designed to be driven into saturation by the 5 watts, otherwise your signal will be dirty and spaltter, wasting power and interfereing with others.

Sounds like, if you are in the US, you are setting up a pirate station.  Fines begin at $10,000 after confiscation of equipment and civil penalties that could prevent you from ever having a legal station.

  DB is a logarithmic relationship.  3 DB is twice the power (or half if -3db)  5 db is 4 times, 10 db is 10 times, 20 db is 100 times 30 db is 1000 times etc. In your example, 100 watts into an antenna rated at  - 1.5 db would give you maybe 75 watts ERP (Effective Radiated Power) out (I'm to lazy to calculate accurately).  "Stacking " antennas must be done carefully giving consideration to spacing and phase angle but in general the db's don't add, but the gain does go up.  Stacking two 3 db antennas would not give you 6db, but rather a bit less than 5 db (in general) depending on physical relationships..