[AMRadio] Lowest level modulation


Mike Dorworth, K4XM k4xm at arczip.com
Thu Dec 23 16:30:06 EST 2004


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?  ;-)

Narrow band FM has always been allowed.. I take this to be 3 or 6 kc. The
wider band stuff is for above 29 mcs. I guess my old rule book is out of
dade, the original question was about amplitude modulating an oscillator. It
was earlier strictly forbidden. Looks like a rewirte has changed it to good
enginnering practice! Ask Mr Zack Lau, simply " Is it good enginering
practice to modulatate an oscillator for AM". If you really wanna  do it
then there is a dandy 6V6, 813 rig in the RCA tube handbook for 1942 using a
single modulated  B+source for all HV functions and the 6V6 tube drop for
the screen supply. This will give you the TimTron Crappy SBE signal you
desire.. Again 73 and MERRY CHRISTMAS to all like minded Belivers.. Mike
K4XM

Original Message -----
From: "Geoff/W5OMR" <w5omr at w5omr.shacknet.nu>
To: "Discussion of AM Radio" <amradio at mailman.qth.net>
Sent: Thursday, December 23, 2004 3:18 AM
Subject: Re: [AMRadio] Lowest level modulation


>
> ----- 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,
> -Geoff/W5OMR
>
> ______________________________________________________________
> AMRadio mailing list
> Home: http://mailman.qth.net/mailman/listinfo/amradio
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:AMRadio at mailman.qth.net
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Anti-Virus.
> Version: 7.0.298 / Virus Database: 265.6.4 - Release Date: 12/22/2004
>
>



-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.298 / Virus Database: 265.6.4 - Release Date: 12/22/2004




More information about the AMRadio mailing list

This page last updated 19 Oct 2017.