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Old 13th Nov 2018, 12:10 pm   #91
Ian - G4JQT
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Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,326
Default Re: Building the 'Minimod' AM modulator-questions!

Quote:
Originally Posted by terrykc View Post
A lot simpler than what I was going to suggest - a wire running the length or width of the house, whichever is more convenient...
Careful when significantly extending the MiniMod antenna. A point will be reached where the antenna tuned circuit won't peak unless you reduce the value of L2 and/or C13.

I have not tried the following, and this is only an idea:

The current through L2 is limited by R8 390R to stops it saturating on modulation peaks. If L2 (~90uH) is rewound on a ferrite ring or small rod with a few coupling turns and C13 made variable, it may be possible to get a bit more power out. But it won't be much more; the LM386 is probably already near its maximum output.

Ian
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