[AMRadio] Lowest level modulation

Geoff/W5OMR w5omr at w5omr.shacknet.nu
Thu Dec 23 03:18:38 EST 2004

----- Original Message ----- 
From: "Mike Dorworth, K4XM" <k4xm at arczip.com>
To: "Discussion of AM Radio" <amradio at mailman.qth.net>
Sent: Wednesday, December 22, 2004 8:00 PM
Subject: Re: [AMRadio] Lowest level modulation

> Hi , it is illegal to use a modulated oscillator below about 2 meters. It
> will work but adds FM even to a crystal oscillator. In fact commercial vhf
> equipment using crystals actually phase modulate the crystal oscillator to
> get FM. They of course go through several multiplications to get the plus
> and minus 5 kc deviation.. That's kHz for youngsters!.. The rules simply
> state NO!..hope this helps.. Mike K4XM

You might want to check again, Mike...

10m FM is pretty popular.

As I recall, the rules state that FM is allowed on HF as long as it's no wider
than a conventional AM signal.

That said, if these modern day rice-boxes have FM on 'em, I wonder how 
difficult it would be to check the deviation and modulation index on said
rigs, to keep 'em down to 2.5kc of deviation?  

With the laws now reading that 1500w PEP OUTPUT is the power limit, 
regardless of mode, why not run 1500w Output of FM, at +/-5kc?  ;-)

73 = Best Regards,

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