In the case of AM transmitters someone who knows how to operate a multi-meter and knows Ohm's Law should be easily able to determine compliance.
... and a tape measure.
That's funny. 🙂
This Spitfire transmitter you speak of. From the UK. Non FCC certified. It's illegal for them to sell them here without certification.
Ha ha! I know! Tell that to eBay! Or 6v6! Get 'em while ya can!
Doug
The Spitfire has been for sale for over 10 years and before that was the Metzo SSTran clone. The Spitfire replaced the Metzo. Obviously eBay doesn't care in the slightest.
Rich correctly stated: "RE: Clips Just Above -- Ohm's Law, multimeters and tape measures existed long before §15.219 was added to FCC Part 15, and before the FCC ever issued NOUOs for non-compliance with §15.219 (including those reporting long ground leads). So apparently those resources were/are not always used by those setting up and operating such unlicensed systems."
Snob DHR commented: "Then those operators should not be operating radio transmitters when these measurements can easily be made."
Not sure what the point of your post is, Rich.
We are all aware that you cannot measure compliance of a Part 15.239, or a Part15.209 transmitter without measuring field strength. And that different environments can cause these transmitters to produce wildly varying field strengths.
But it is also true that with a simple multimeter (and a tape measure), you CAN measure compliance of a Part15.219 transmitter.
I would add that the FCC has an expectation of the field strength of a compliant Part15.219 transmitter - they measure field strength only at first and if a transmitter is obviously above this limit, then they would inspect. I seem to recall a discussion here a few years ago about what that field strength was, but I can't recall if any conclusions were arrived at.
I also don't know what any of this has to do with the Spitfire transmitter.
Ebay is like Amazon, they aren't the sellers so the question is are they partly liable for allowing these to be sold by companies through them?
Mark
(Response to Reply 83 Above)
Not sure what the point of your post is, Rich. ... with a simple multimeter (and a tape measure), you CAN measure compliance of a Part15.219 transmitter.
The point of my post was (is) that meeting, and proving compliance with FCC §15.219 depends upon more than the possession and use of a multimeter and a tape measure.
It also depends on the ethics, knowledge, experience, and website guidance/documentation to such operators available over the years provided by transmitter manufacturers, and others.
Review the case of KENC.
I really don't think the operator will need to prove compliance one way or the other. The FCC will TELL the operator how they're doing.
Especially as Rich pointed out, it doesn't matter if the unit is certified, there are too many variables which could render the unit out of compliance such as whether you have metal piercings or metal cleats on your boots, time of day, time of year, weather conditions, where your vehicle is parked...
Well the list just goes on and on and on...
Question for those of you that physically have a Spitfire...
I see in the specs that the audio frequency response goes to "10K / 25K"
Is the difference accomplished via some sort of switch? If so, how is the audio between the two? Is the 10K steep enough to replicate an NRSC filter? And I'd assume the 25K audio sounds nice and full on a wideband receiver.
Just wondering what your experiences have been with the audio quality of the Spitfire unit. My goal is not to get range, but to get good, solid, full AM audio from my studio to the transmitter, and then to stream that "AM sound" back over my internet station.
Ebay is not the seller, they just provde the medium for sellers and buyers to connect.
I can't use the Spitfire here in Canada at all...meeting the rules or not as ISED(formerly Industry Canada) says any transmitter has to be certified and that is the most important thing they look for. Not approved in their data base, $3000 to get the approval or can't use.
The certification fee is the same for a company and since it comes ready built it could be certified by the manufacturer for legal use in Canada and the USA.
Mark
The SpitFire puts out very good audio. As good as AM gets. What makes mine sound full and punchy is my Orban Comp/Limiter. A 422a is perfect! This one:
My Mackie mixer (1402) has EQ on each channel and I boost the low and high ends a bit. With a GE Super Radio set on "wideband", it sounds like FM...it's all in the receiver after that.
The audio is rolled off at 10K. You cannot get 20-20k frequency response out of AM. Impossible.
Doug
Not "legal" for sale in the United States. You have 2 models of Sstran out there. No comparison in quality. And nothing is "Impossible."