A comment on the 13.56 MHz ISM frequency tolerances.
There are allocations in all 3 ITU regions between 13200 and 13360 kHz
for air-ground HF/SSB.
It is quite common in Europe to have to listen at VERY strong hum-modulated
carriers drifting through especially the upper channels in this band.
73/
Karl-Arne
SM0AOM
----- Original Message -----
From: "Tony King - W4ZT" <amps@w4zt.com>
To: <amps@contesting.com>
Sent: Saturday, May 21, 2005 1:30 AM
Subject: Re: [Amps] ARF1505
> Actually 18.301 says the following:
> "ISM equipment may be operated on any frequency above 9 kHz except as
> indicated in Sec. 18.303."
>
> and...
>
> Sec. 18.303 Prohibited frequency bands.
> Operation of ISM equipment within the following safety, search and
> rescue frequency bands is prohibited: 490-510 kHz, 2170-2194 kHz, 8354-
> 8374 kHz, 121.4-121.6 MHz, 156.7-156.9 MHz, and 242.8-243.2 MHz.
>
> It is also interesting to read 18.305 relating to Field Strength Limits,
> especially the following (in part):
>
> (a) ISM equipment operating on a frequency specified in Sec. 18.301
> is permitted unlimited radiated energy in the band specified for that
> frequency.
>
> (b) The field strength levels of emissions which lie outside the
>
> bands specified in Sec. 18.301, unless otherwise indicated, shall not
> exceed the following:<snip>
>
> Industrial heaters and <5,725 MHz Any Power 10 uv/m at 1,600 meters
> RF stabilized arc welders. >5,725 MHz Any Power (\2\)
> <snip>
> \2\ Reduced to the greatest extent possible.
>
> They're all available here:
> <http://www.access.gpo.gov/nara/cfr/waisidx_03/47cfr18_03.html>
>
> 27.1 MHz +/- 163 KHz covers CB channels 1 through 27 almost perfectly.
>
> Just call it a welder! ;-)
>
> 73, Tony W4ZT
>
> Dave Haupt wrote:
>
> >27.12 MHz is one popular ISM frequency.
> >
> >13.56 MHz is probably the most popular. Tune any
> >receiver to 13.56 MHz and you'll always hear a
> >carrier, usually a bit wobbly and often with AC hum.
> >Gigawatts of power are used at 13.56MHz as
> >lumber-drying kilns in the Pacific Northwest, and it
> >is the most-used frequency for plasma etch processing
> >in semiconductor fabrication. There are thousands of
> >50kW 13.56 MHz generators sold every year into the
> >semiconductor industry.
> >
> >The ISM frequencies, per FCC rule 18.301 are:
> >
> >ISM Frequency Tolerance
> >6.78 MHz +/- 15.0 kHz
> >13.56 MHz +/- 7.0 kHz
> >27.12 MHz +/-163.0 kHz
> >40.68 MHz +/- 20.0 kHz
> >915 MHz +/- 13.0 MHz
> >2,450 MHZ +/-50 MHz
> >5,800 MHz +/-75.0 MHz
> >24,125 MHz +/- 125.0 MHz
> >61.25 GHz +/- 250.0 MHz
> >122.50 GHZ +/- 250.0 MHz
> >245.00 GHz +/-1.0 GHz
> >
> >Generally, on an ISM frequency, you can generate as
> >much power as you want, and even radiate it, as long
> >as you are NOT using the energy for communicating.
> >So, you could be doing radar, or you could be drying
> >lumber, searching for cancerous tumors, or other such
> >things, but you can not be sending information (voice,
> >data, CW, RTTY, etc). No license required.
> >
> >Note that 6.78, 13.56, 27.12, and 40.68 are all
> >harmonically related - this is intentional. A "cheap
> >dirty" power generator on 13.56 is likely to generate
> >harmonics, therefore the harmonic frequencies are as
> >legally uncontrolled as the fundamental.
> >
> >Perform a Google search on any of those frequencies
> >(e.g. "27.12 MHz") and you'll come up with lots of
> >links to experiments about using RF energy to weld
> >plastic, seal bags, cure cancer, and so on.
> >
> >73,
> >
> >Dave W8NF
> >Not at Dayton this year....
> >
> >
> >
> >Yahoo! Mail
> >Stay connected, organized, and protected. Take the tour:
> >http://tour.mail.yahoo.com/mailtour.html
> >
> >_______________________________________________
> >Amps mailing list
> >Amps@contesting.com
> >http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> >
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Anti-Virus.
> Version: 7.0.322 / Virus Database: 266.11.14 - Release Date: 2005-05-20
>
>
--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.322 / Virus Database: 266.11.14 - Release Date: 2005-05-20
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|