- Posts
My friend who shall remain nameless was inspected by the FCC Langhorne, PA office. He was found to be in violation of part 15.219. They said he would have to disconnect his ground wire or ground mount the transmitter. the FCC agent in charge said since it is not feasable to disconnect the ground since the power leads going up to the transmitter even radiate, and the audio sheild radiates he has to mount it on the ground. He was using a hamilton rangemaster and was inspected by David Dombrowski and 2 other agents accompanied Mr. Dombrowski. I now say that I have sufficient evidence to prove that the FCC is rejecting whip and mast installs now. The guy the FCC inspected is a personal friend of mine and i know all the specifics of his operation.
Total posts : 45366by MRAM 1500 kHz
Did the agent elaborate as to why the friends station was inspected? Was it interference with a licensed service? Did someone simply not like the signal strength or program content? What brought their wrath?Was compliance with the agents request sufficient or will there be other action?
Enquireing minds want to know!
Total posts : 45366I am the manufacturer of the Rangemaster, and it isn’t at all what people seem to think, there is no “rejection of the whip and mast” grounding approach. Many Part 15.219 transmitters are indoor transmitters and can’t even be mounted at the dirt! Or people live in the city or an apartment and have no access to dirt. What is ground isn’t specified in Part 15, just the antenna and ground LEAD length.
In our discussions with the FCC massive metal that is connected to the dirt, such as a water pipe, can serve as an acceptable ground. I have been told that the FCC generally won’t interfere with a site engineers decision (if the site engineer decides to call a water pipe ground) unless the decision seems outlandish. We feel a large piece of wire, coming up from the dirt can also be called ground at the top tip. As long as the wire takes a direct path straight down to the dirt, this is best for lightning protection. We have had this set-up pass FCC field inspection many times. Our transmitter was certified using this configuation.
What is happening with the 2 situations recently where the FCC has cited ground violations has been a bit more complicated then it may appear, someone with a valid concern can contact me directly.
Total posts : 45366Hamilton here again, there really is more then it may seem going on when you hear about a ground violation. If you think about it, it really is the only way the FCC can put a clamp on a problem operator, The ground rule is vauge, I think that may be why it is left so. I spoke with John Reed, the author of Part 15 a couple years ago, he said he was going to clean up some of the vagueness in Part 15 in the last rewrite. But they never did. I think they leave the law vauge to give them some flexibility. For example, from what I understand, the Church in California simply denied access to the FCC, and would not cooperate.
I once heard someone say “situations are usually immensely more complicated then you could ever imagine” that is true or comes close here. It is just not true that as a body the FCC has all of a sudden decided to deny Part 15 transmitters that are grounded with a wire, nothing has changed.
Total posts : 45366Hamilton wrote: “We feel a large piece of wire, coming up from the dirt can also be called ground at the top tip.”
Physics shows that a ground wire or any assembly of “leads” and/or conductors of ANY gauge will radiate when connected together between the tx ground terminal and the true r-f ground reference (ground rod, water pipe, radials etc).
There is abundant evidence in antenna engineering textbooks and elsewhere to show that radiation from a long conducting path to ground is a significant, and often the largest source of radiation from an elevated (whip/mast) Part 15 AM antenna system.
With all due respect, you/Rangemaster may “feel” that the top of a large OD, long, ~vertical conductor to the earth is a true r-f ground, but that concept is not supported by physics.
Furthermore, would you as a circuit designer and manufacturer proceed with a system design, production, and sales for your Rangemaster tx that were based on feelings, rather than the physics involved? Unlikely, no doubt. Yet that is the apparent approach taken with some of the content regarding “official” installation and applications information given on the Rangemaster website, and in your posts.
Even though the top of such a “ground” wire may be near earth potential for direct current, it has considerable impedance to the flow of the r-f energy along it, that results from the coupling of the wire with space, ie, because it is acting as a radiator.
And therefore the top tip of that long “ground” wire is NOT an r-f ground. The whole length of that wire radiates until it enters the physical earth.
This means that a “Part 15” AM tx+3-m whip using such a long, radiating, ground conductor does not meet 15.219, whether or not that is recognized by the tx manufacturer, the “Part 15” operator, or even by every FCC field inspector.
//
Total posts : 45366A local and again unamed station wanted him off the air for some reason. he ran good family friendly programming and served his community well probably better than the unamed station.
he cooperated fully with the FCC field personnel.
Thank You,
Rev. Robert P. Chrysafis
Universal Life Ministries
http://www.ulc.orgModerator Hunterdonfree
http://groups.yahoo.com/group/hunterdonfree
Total posts : 45366“In our discussions with the FCC massive metal that is connected to the dirt, such as a water pipe, can serve as an acceptable ground. I have been told that the FCC generally won’t interfere with a site engineers decision (if the site engineer decides to call a water pipe ground) unless the decision seems outlandish. We feel a large piece of wire, coming up from the dirt can also be called ground at the top tip. As long as the wire takes a direct path straight down to the dirt, this is best for lightning protection. We have had this set-up pass FCC field inspection many times. Our transmitter was certified using this configuation. “
I think the key word in that is “acceptable”. That the Rangemaster was approved with that type of configuration indicates that at least at the height it was mounted at the certification with the guage of wire used, it was found “acceptable enough” in that instance whether or not it constitutes a textbook definition of a “true rf ground”.
In the practical sense, it doesn’t matter what a manufacturer feels, what a website or textbooks says or what anyone thinks.. What it’s going to boil down to is what the inspector looking at it judges as acceptable so far as if one gets written up or is told they can’t do it as they have it currently set up. Not unless you get told it can’t be a certain way or get written up and you officially contest it. Then it may make some difference, but in the sense of avoiding trouble, all the definitions in the world may not keep it from happening. Basically if you’re “pushing the envelope”, then it’s a possibility if a local licensed station or whoever wants you gone. They complain, the FCC will check you out.
But let’s be realistic here, that’s their job. They also check the licensed stations to make sure their tower is properly labelled, their power is in the right range, they’ve been properly keeping the assorted logs including the ones showing how the station does stuff for the local community and so on. They know they have a trained engineer (also licensed by the FCC), that the licensed station was properly set up with a certain number of radials in their grounds system, and on and on. There is also a sizable amount of money/property involved in most licensed stations, so they aren’t usually just going to get annoyed with the biz or move and leave that area without media.
On the other hand, we’re unlicensed, anybody can build a little transmitter, no engineer has to check it out before it goes on the air, no logs are required, and so on. Even if a part15 is doing a really great job of serving a part of the community, there’s no guarantee at all that they’ll still be on the air tomorrow. Heck, we don’t even *have* to identify ourselves on the air with so much as a station name and city.
So why should they favor a part15 station over the licensed stations? They’re licensed and have a considerable number of rules to follow to make sure they operate it right and at least somewhat serve the community. We’re unlicensed and have very few rules, none of which other than “don’t cause interference” actually deal much with how to operate it as a station.
Then consider that, being unlicensed, pretty much the only way they ever run into a part15 station is when there’s a complaint. It’s kind of understandable why they’d be biased towards the licensed stations. Also consider that the FCC historically has generally considered that the public interest on the public broadcast airwaves is best served by big stations rather than small ones. A few big stations is a whole lot easier for them to take care of than a lot of small ones, and we’re even further down the scale than just small. Their manpower and resources are not unlimted, especially in these days of tight budgets.
Now stop and consider that for decades, part 15 stations were at most “yardcasters”.. But with fairly recent innovations, now (at least on AM) they *can* get ranges of a mile or two. I think that Rich said that the theoretical range was between a mile and 2 miles to a good reciever, so well say that 1-2 miles is at least theoretically acheivable by practical means. Maybe it takes a decent receiver to pick it up at that range, but over most of the decades part15 has been around for it would have taken a decent receiver to even pick it up right across the street from the house the xmitter was at. And at least theoretically, a “network” of synched transmitters spread out across a city *could* cover an area well enough that was sufficiently large to possibly challenge a licensed stations for listeners. Ok, much as we *like* those innovations, it is going to result in some of the licensed stations viewing us no better than they do the pirates and filing complaints. Heck, unless they really keep up on recent developments in part15 technology they’d assume that anything with that much range would *have* to be a pirate. So would the FCC until they check it out. But an encouraging point is that even when they’re busting obvious FM pirates, they always look to see if it *could* be a part 15 FM by the field strength, that policy shows right in the wording of those NOUOs. And for part15 AM they certainly seem to be standing by the specs of 15.219(b).
With the licensed stations, you don’t think they report pirates because as licensed stations they stand for truth, justice and the American way (and have to keep away from kyptonite), do you? They report pirates because they are competition. Because pirates could take some of their listener base, which will reduce ad revenues, which will result in loss of money. That’s what it’s going to be about. And they can justify their paycheck to their board of directors or corporate stockholders by saying they eliminated a threat to the station’s income. But so far it *looks* like the FCC won’t just shut down a part15 AM station for just existing, so long as it’s strictly by the provisions of 15.219(b). No guarantees of you’re in a “grey area” on those rules, they might pass it, they might not, but it’s probably best not to count on any slack.
So while this is the way it is, it doesn’t mean it’s the way it always has to be. And what we’re permitted isn’t all that bad. You can bet it’s more then the licensed stations and the NAB wish anybody (other than their people) be allowed to have.
I’m going to be honest on one point, though.. I think that the more we use “grey areas” to push the range, the more chance we have of a new set of part15 regs being drafted that will just outlaw at least some of what we’re definitely permitted now. I also feel that probably using synched multiple transmitters to make a “network” to cover any sizable part of a city is likely to lead to local licensed stations really wanting us just gone. And they’re the ones that pay fees, have big lobby groups, and etc. Underserved areas might get cut a bit more slack, but in areas that already have several or many local stations, that “grey” is going to go to black and white real fast when the licensed stations start viewing you as competition. Or even as something that’s handy for them to justify their paycheck to the stockholders by eliminating.
I checked back on the threads, and Rich calculated the range to a good car radio to be 1.5865 miles. I’d bet the FCC is quite capable of doing the same calculations and already probably has, and anything much over that approximate range is going to get looked over very closely if a local station gets upset over the possibility of losing some listeners to you. But that is *not* a minor amount of range, especially in a town or city. Draw a circle like that on a map around your location and it’s likely to be quite a lot of streets and houses.
Daniel
Total posts : 45366Thanks to kc8gpd for sharing his report on his friend’s experience. Such information illustrates the “gray area” concerning grounds and elevated transmitters.
I would ask two questions which, if answered, could provide more insight to this.
1. kc8gpd: How long was the ground lead or how was the transmitter mounted at the station in your report?
2. Hamilton wrote earlier in this thread:
“We feel a large piece of wire, coming up from the dirt can also be called ground at the top tip. As long as the wire takes a direct path straight down to the dirt, this is best for lightning protection. We have had this set-up pass FCC field inspection many times. Our transmitter was certified using this configuation.”
Hamilton: This implies that the transmitter was certified using either an elevated mount and/or extended ground, or with the intent to be so used. Would you describe the configuration for which your transmitter was certified, particularly the mounting and grounding detalis? Was it certified in an actual “elevated” installation?
Thanks,
Neil
Total posts : 45366Hamilton Rangemaster on a standard factory mount. mounted to a Radioshack 20ft telescoping pole and grounded to the pole. at the base of the pole was a 8ft ground rod attached to pole. this was all installed by an engineer from a local station. the pole was attached to his garage and he had radials going across the top of his garage and attached to the pole and also in the ground at base of pole. he was doing signal levels in the millivolt range at about 1500ft.
Thank You,
Rev. Robert P. Chrysafis
Universal Life Ministries
http://www.ulc.orgModerator Hunterdonfree
http://groups.yahoo.com/group/hunterdonfree
Total posts : 45366Rev. Robert, kc8gpd,
Thank you for your reply. We can add this to our body of knowledge.
Neil
Total posts : 45366What is the FCC ID of the Rangemaster? We should be able to look up the exact test conditions that allowed it to be approved. If it wasn’t approved while operating on a pole mounted installation, then that will be the end of the story!
Sorry I don’t own one, so I can not look it up.
And also note that the key to keeping out of trouble is to comply with the FCC requests immediately and basically shut the transmitter down until you can correct whatever is wrong. No sense making them work harder than they have to. i bet while they were in town the swept every area for cable TV leakage, and may have popped by the station that made a the complaint just to make sure they were in full compliance. If the failed there should be a notice on the FCC website within the next week or two.
Total posts : 45366FCC ID
Found it NWXAM1000
But strangely enough, there are NO public records showing the testing of this device. I find this somewhat odd.
Total posts : 45366Greg,
This is not unusual. The FCC allows manufacturers’ data and other information submitted as part of the certification process to be held confidential upon request. This is to protect proprietary information.
I see nothing wrong with this since it protects the applicant.
Neil
Total posts : 45366My unit bears the ID DLB5LTT98. In the FCC Database that ID Number shows that the unit I bought was manufactuered under the type acceptance that was re-applied for to accomodate the new extended AM band (510 – 1710), but that’s it.
The company that markets the Talking House units also places a high value on restricting information about the units they sell. When I wrote and asked for some info after my ebay purchase the company sent a nice email back that said they can’t provide me with any info because I didn’t buy through their system.
Probably some cost management for user support mixed in with the fact that they use patented technology and generally serve a specific and technically unsophisticated market.
I just get a kick out of using one and unlike the pictures I’ve seen of the Rangemaster, the TH circuitry is pretty low density. Taking the top off and looking at the PCB tells quite a bit about the way it works.
Experimental broadcasting for a better tomorrow!
Total posts : 45366I wonder what the FCC agents would say if an elevated transmitter was supplied with isolated power and audio using transformers? The lines going up to the transmitter would still radiate due to RF coupling even though they are not directly DC connected.
Also if you feed a ground-mounted transmitter with power and audio that is not isolated, the lines would still radiate anyway.
Gerry
- You must be logged in to reply to this topic.
