transmitter question - Electronic Circuits Projects Diagrams Free

Ashtaroth · 15th June 2003, 11:50 AM

hi!
i was wondering if i need to be heard in an area of 5miles using an AM transmitter in the AM radio band how many Watts should the transmitter be??

i know that it depends from the antenna but i am talking generally.with a normal antenna.

PS:if a have mistakes excuse my english :? :? :?

Dean Huster · 17th June 2003, 01:22 PM

There are so many variables that a good answer for this question cannot be had. At night, our local station at 930KHz which can normally be heard for over 60 miles, can barely be picked up a few miles away. On the other hand, a 50KW station may be able to reach 100 miles in the daytime and "skip" thousands of miles at night due to ionospheric conditions.

For normal daytime operation, I would think that 5 to 10 watts would be sufficient. The antenna is probably the most critical element in the entire system, for no matter how much power the transmitter has, if the signal can't "get out", all that power is wasted.

Ultimately, the power and operation of any transmitter is a legal issue, regulated by your nation's communications regulations.

Dean

**mechie** · 17th June 2003, 03:14 PM

The sensitivity of the reciever (and its aerial) is also important :!:

Take a look at THIS for what can be achieved, look at the powers being used and the distance managed.
OK so this is extreme, but it can be done!

Ashtaroth · 17th June 2003, 10:21 PM

ok
thanks

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15th June 2003, 11:50 AM	(permalink)
Ashtaroth	transmitter question hi! i was wondering if i need to be heard in an area of 5miles using an AM transmitter in the AM radio band how many Watts should the transmitter be?? i know that it depends from the antenna but i am talking generally.with a normal antenna. PS:if a have mistakes excuse my english :? :? :?

17th June 2003, 01:22 PM	(permalink)
Dean Huster	AM Transmitter Power There are so many variables that a good answer for this question cannot be had. At night, our local station at 930KHz which can normally be heard for over 60 miles, can barely be picked up a few miles away. On the other hand, a 50KW station may be able to reach 100 miles in the daytime and "skip" thousands of miles at night due to ionospheric conditions. For normal daytime operation, I would think that 5 to 10 watts would be sufficient. The antenna is probably the most critical element in the entire system, for no matter how much power the transmitter has, if the signal can't "get out", all that power is wasted. Ultimately, the power and operation of any transmitter is a legal issue, regulated by your nation's communications regulations. Dean __________________ Dean Huster, Electronics Curmudgeon Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines). R.I.P.

17th June 2003, 03:14 PM	(permalink)
mechie	Radio The sensitivity of the reciever (and its aerial) is also important :!: Take a look at THIS for what can be achieved, look at the powers being used and the distance managed. OK so this is extreme, but it can be done! __________________ I need a memory upgrade ... My head is full !