this will take a lot of trust on someones part but a i need a part 15 fm tx that i know is near the maximum legal limit but not over it to verify how well part 15 will work here.
this will take a lot of trust on someones part but a i need a part 15 fm tx that i know is near the maximum legal limit but not over it to verify how well part 15 will work here.
i am asking if someone is in the denver area that has a decade ms100 (mono/not stereo) would be willing to loan me their tx to do some testing.
decade is the only one i know of that would be an accurate comparison
i talked to Denver field office and basically my cable modulator idea will not pass muster.
they say for FM it is best to go certified that you are not allowed more than 5ft of coax and antenna in addition to the 250uV/m @ 3m.
they did say that am is not as critical and certified equipment is not really a requirement only compliance.
so basically i have a cable FM modulator that puts out 50dbmV to get rid of.
look in the classifieds. it will be swap only.
well good thing is the existing and mounted antenna will be good for EAS rx deck.
the impression of the denver office is they want to be helpful and keep you out of trouble but have that firm police officer tone.
but as i said he seemed to steer me toward am he said carrier current will be best.
also in his opinion my xft40 was most likely over power even though it was certified. if i hadn't sold it and been paid already i would send it to bill d for evaluation.
Umm...that 5 foot coax thing, where is it written in the rules about that for FM?
Talk to someone other than the front desk receptionist who obviously doesn't know what they heck they are talking about.
RFB
i talked to a man it was rather early so i doubt it was a receptionist. i believe it was a field agent but it was not the office director who is a female. the directors name is nikki p. shears look in the classified im selling and doing an equipment overhaul. i'm not screwing with these people. i am going to head his words and go certified on fm and AM.
It doesn't matter what they tell you, what matters is that they tell you what the law says and what is written in the current rules. They cannot overrule what is clearly written down in the rule book just because one is a director and another is a field agent.
Unless you don't mind them bending their own rules and create their own on the fly.
Put the fear of the boogie man in you is what that was. Just like how they did the same thing with everyone about the boogie man terrorists that don't exist.
And if your really in that much doubt between what someone said and what is written in the law books, consult with an attorney who will go by what the written letter of the law is...not fear mongering.
RFB
i'm getting a decade and putting it in a weather proof box. i will know i'm legal that way. i am not screwing with this guy.
i ordered a pll for my rangemaster to put it on a usable frequency and will also be selling my sstran for my total cost plus shipping so i don't lose any $$$.
my g/f is a very nervous person and i don't need someone showing up badging her and scaring the shit out of her because then it will roll downhill onto me.
no thanks. been there already with then last g/f and the FCC showing up.
§ 15.239 Operation in the band 88–108 MHz.
top
(a) Emissions from the intentional radiator shall be confined within a band 200 kHz wide centered on the operating frequency. The 200 kHz band shall lie wholly within the frequency range of 88–108 MHz.
(b) The field strength of any emissions within the permitted 200 kHz band shall not exceed 250 microvolts/meter at 3 meters. The emission limit in this paragraph is based on measurement instrumentation employing an average detector. The provisions in §15.35 for limiting peak emissions apply.
(c) The field strength of any emissions radiated on any frequency outside of the specified 200 kHz band shall not exceed the general radiated emission limits in §15.209.
(d) A custom built telemetry intentional radiator operating in the frequency band 88–108 MHz and used for experimentation by an educational institute need not be certified provided the device complies with the standards in this part and the educational institution notifies the Engineer in Charge of the local FCC office, in writing, in advance of operation, providing the following information:
(1) The dates and places where the device will be operated;
(2) The purpose for which the device will be used;
(3) A description of the device, including the operating frequency, RF power output, and antenna; and,
(4) A statement that the device complies with the technical provisions of this part.
[54 FR 17714, Apr. 25, 1989; 54 FR 32340, Aug. 7, 1989]
Taken straight from the e-CFR database updated March 09, 2012.
I don't see anything in there about a 5 foot coax and antenna limit. Whomever it was you spoke with must have been referencing that phantom rule book that is like the phantom dictionary with blank lines after every word.
RFB
it matters in theory what the rules say but in practice is another entirely unless you can afford a lawyer.
justice is not cheap or free and neither is so called free speach
With a Part 15 certified FM unit, it is illegal to attach anything to, or use anything but, the original antenna that it comes with.
Right there, you cannot legally add coax and/or another antenna without voiding the certification, no matter how short your coax run is. You're not supposed to be using coax or another antenna at all!
Also, be certain that your Decade transmitter is calibrated to USA (FCC) specs. I've heard of several Decade units being shipped into the US calibrated to Canadian specs, which amounts to about 4 times the signal strength allowed in the US. Be very careful!
Ya well that only applies to certified units carrying an FCC certification number. That does not mean, nor imply that you must only use a certified transmitter.
If you know what your doing, and have adequate testing equipment to do the measurements, and are within a reasonable range of 250uV @ 3 meters from the antenna, there is no violation or need to worry to death.
Again it depends on knowing what your doing, and taking the measurements and keeping things within reason of the rule. Even certified transmitters do not hit 250uV at 3 meters precisely from every installation and from every transmitter. There is what is called tolerance and other factors such as location and things around the setup that will alter that measurement.
They are gonna look for obvious blatant violations, not mess with someone making obvious good engineering practices to keep within the rules.
Experience knows..as I do and have been through inspections and passed and I don't use a certified transmitter.
I don't knock taking the absolute safe route. What else does one do when they either do not have proper test gear to measure, or have no idea how to measure or use the test gear!
RFB