[BC] AM Radio Kit

[Robert Meuser]

You should re-check that spec. It needs to be 100 mw INPUT power.

Building a GOOD part 15 rig can be a challenge. Small things count a 
lot. I would suggest you research this on the web first.

An antenna could be a CB whip. Rembember you have a 10 foot (aprox) 
limit for the antenna PLUS the ground lead.  A piece of larger diameter 
copper pipe would make a slightly better antenna because of the increase 
diameter.

As you research, you will discover that the biggest challenge is to 
transfer power into the short antenna that has a very low resistive 
component and a very high reactance.  The loading coil is a key 
component. I would look into using litz wire. Also investigate various 
ferrite cores. You need to have the lowest possible resistance in the coil.

You also want to look at some unconventional PA designs so you can 
transfer maximum power into a low impedance load with the highest 
efficiency. Remember you only have 100 mw INPUT power to work with.

Range is often reported to be around 1/4 mile radius but it really 
depends on how much power you can actually transfer into the antenna and 
the quality of your ground.

The FCC does not limit the range, they just set up technical paramters 
that SHOULD limit range. From what I hear, the big issue here is that if 
you have a commercial FCC approved unit and the antenna appears to be 
legal, the inspector will likely leave you alone. On the other hand if 
you have a home brew rig and are operating it as a more or less full 
time operation, you may have some explaining to do if you get out too well.

R

N0JAA at aol.com wrote:

>I just received a Part 15 AM radio transmitter kit from Ramsey.  Spec  sheet 
>states max power output is 100 mW.  Although I know the basics of  
>transmitters (with my ham radio experience) I still thought it would be a good  exercise, 
>especially since one day I would like to try my hand at building a  homebrew 
>ham radio XMTR one of these days.  Any ideas on what I could use  for a simple 
>antenna for it?  I've already wound a coil I can probably use  as a loading 
>coil.
> 
>What is the maximum range I can transmit with while still remaining within  
>the limits of Part 15?
> 
> 
>Paul, N0JAA.
> 
> 
> 
>
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