Good Morning all..
I love this place By The way ..
I have learned so much about this Part 15 Stuff here and from you all.
So thanks 🙂
Good Morning all..
I love this place By The way ..
I have learned so much about this Part 15 Stuff here and from you all.
So thanks 🙂
Ok it's time for me to ponder the Antenna for my Talking House 2 that I bought of ebay.
I am going to broadcast at 1610 AM.
So I want to build the antenna to be a close to the 1610 spec as I can.
Goals
1.5 Miles , I know I am dreaming , But hey it's something to shoot for LOL.
What Antenna systems do you folks think is the most efficient for this.
I am leaning towards a J Pole type and looking at a mega ground system.
I have enough land here to do a ground with at least 20' radials.
Thanks again and I will post updates often as the project goes forward.
Since you have a Talking House you can locate the transmitter in the house and use coax to the antenna. They recommend RG-6 which is similar to standard TV cable.
The most common antenna is an 8 to 10 foot radiator, ground mounted. You'll need a loading coil or antenna tuner to resonate the short radiator. There are links to be found with detailed info on how to build such an antenna and loading coil.
If you are lucky enough to find one, the Talking House ATU (antenna tuner) works very well. It's simple to tune and uses a standard 102" CB whip antenna. It's very plug-n-play but more expensive unless you get a good deal. I paid $99 for a used ATU from Ebay. The whip antenna to go on it was another $25.
You could put the Talking House outside in a weather proof box, mount some type of 8 foot radiator to the box and use the "wire antenna" connection point. That way, the Talking House internal antenna tuner will do the rest. Of course you'll have to run power and audio lines to the box.
If you're trying to squeeze out every milliwatt you can, making the loading coil as shown in the SSTRAN plan would be a bit more efficient as the Talking House tuner coils use a very fine wire which would be a little more lossy.
Glad you mentioned radials. Without them, most of your signal will be consumed by ground losses. Your range would be more like 200 to 400 feet. Information Station Specialists (ISS) recommends 62-10 foot radials for frequencies above 900 kHz and 20 foot radials below 900 kHz. Most think that number would be overkill and feel that 15 to 20 radials sufficient. The more the better but at some point the gain flattens out and little more signal is realized.
Now that I've posted, there will be plenty of discussion so hang on.
I'm not sure a TH unit using the external antenna jack connected to a home brew 3 meter antenna setup would be considered as compliant since those TH units were certified with their own specific ATU unit and coax.
It would be interesting to know if there is anyone out there who has a TH unit using an external 3 meter setup that is not the ATU unit certified with the TH, has ever been inspected and passed using that home brew 3 meter system.
RFB
Been reading Part 15 laws and rules.
It seems to me that it is perfectly legal to use your own antenna system provided it conforms to the Part 15 219 & 209 rules.
The FCC Says you must keep the plans for the Antenna on file for inspection propose.
"It seems to me that it is perfectly legal to use your own antenna system provided it conforms to the Part 15 219 & 209 rules."
Do not forget about the rule of using the supplied equipment that comes with certified transmitters. (15.203)
From the FCC Part 15 handbook:
"In order to prevent such interference problems, each Part 15 transmitter must be designed to ensure that no type of antenna can be used with it other than the one used to demonstrate compliance with the technical standards. This means that Part 15 transmitters must have permanently attached antennas, or detachable antennas with unique connectors. A "unique connector" is one that is not of a standard type found in electronic supply stores.
It is recognized that suppliers of Part 15 transmitters often want their customers to be able to replace an antenna if it should break. With this in mind, Part 15 allows
transmitters to be designed so that the user can replace a broken antenna. When this is done, the replacement antenna must be electrically identical to the antenna that was
used to obtain FCC authorization for the transmitter. The replacement antenna also must include the unique connector described above to ensure it is used with the proper
transmitter." 15.203
When the TH unit with the external ATU feature was certified, it was certified using its own ATU and coax. That certainly qualifies to fall under 15.203, and is why I doubt a station would pass using any other type of external antenna system, even one that is documented, and even though the TH unit sports a standard F connector.
The use of an F connector and 75 ohm coax is because that is the most common connector and coax type found in residential homes. The TH unit was designed for selling homes, not broadcasting, though it can be used to broadcast outside of the realm of real estate sales. That does not mean however that its perfectly fine to connect it up to an ATU or antenna system that was not used during certification.
It will be up to the inspecting agent to determine if everything is ok or not. A 50/50 shot in the dark.
Life is fun..but does not have to be risky to be fun.
RFB
A "unique connector" is one that is not of a standard type found in electronic supply stores.
However, fact is not all FCC certified transmitters sport a "unique connector" for the antenna, and do actually use (and call for) a standard type whip antenna connector..
I've mentioned this before..
Just sayin..
"However, fact is not all FCC certified transmitters sport a "unique connector" for the antenna, and do actually use (and call for) a standard type whip antenna connector."
Indeed. Just look at the Rangemaster and its common CB whip mounting stud!
Point however is that no matter what kind of connector is on the equipment, if that equipment is carrying a certification number from the FCC, then that equipped connector, coax or whatever MUST be used and replaced with the same type as when the unit was certified.
I believe that is what their main point is and use of the word "unique" would describe the different types of connectors or antennas used from one piece of gear to another. In other words, TX A certified with an F connector must continue to use that same type of F connector if it needs replacing versus a TX B unit sporting a BNC connector where as that too must also be replaced with a BNC connector if needed.
The two cannot interchange these connector types, thus "unique" would apply.
RFB
Ahh.. RFB, your definition of "unique" makes a clear sense of something that always confused me.
But wait, what about: A "unique connector" is one that is not of a standard type found in electronic supply stores...
I just went looking for a answer and found the following info(edited)described at:
http://www.ce-mag.com/archive/2001/janfeb/Case44.html :
=======================================================================
FCC Part 15.—Intentional Radiators: Updates, Public Notices, and Rule Changes
...If the connector is available at Radio Shack, then it is not considered unique....
FCC Public Notice DA 00-1087 (released May 22, 2000) provided a new definition of unique connector for the industry.1 Some connectors that had previously been ruled as nonstandard were redefined as standard. The public notice also gave a very short time period in which to comply with the new rules. This date has been changed twice due to industry filings, and the implementation date has now been indefinitely rolled back....
Under the new definition, FCC defines readily available as being for sale on the Internet or through catalogs. Whether the requirements of the public notice will be adopted is currently under review at FCC.
=====================================================================
Part15 regulations, it's a mysterious creature
"Part15 regulations, it's a mysterious creature"
Maybe this is their (FCC) attempt at clarifying the Part 15 rules!!
Ain't that a big laugh!!
But even the so called "Super Dooper Committee" couldn't fix the problems they created either even with their law degrees. Makes me wonder where they got them...a Cracker Jack box or from a 25 cent gum ball machine.
The administration levels of government and in all branches of said government are obviously nothing but a collection of lawyers, not engineers or health experts or environment experts or education experts.
Out here amongst the common sense society, when we need a specific thing such as a mechanic..we do not rely on attorneys to change the oil, nor do we rely on attorneys to perform open heart surgery. So why do we rely on attorneys to administer government? Where does it say the administration levels of government and its branches require a law degree to fill the positions?
I think society got fooled some time ago and no one caught it in time to stop the ever faster going down hill snowball.
I am starting to believe the saying that officials should be chosen at random from a phone book than all these fakes running around convincing everyone they have all the answers to the problems they created...they just don't mention they created the problem...boy imagine what would happen if they did admit the truth!
Then again..government admitting truth?!! That's another massive laugh!!
RFB
Even more reading ...
Going though the part 15 rules ..
I am more convinced that if I build the Antenna under the rules the San Francisco field office will pass my system if inspected .
That being said if I could find the values in the Range Extender for IAR I would build an exact copy.
The problem I have with the Factory Range extender is I feel they are vastly over priced.
Thanks for the post guys and keep them coming.
"I am more convinced that if I build the Antenna under the rules the San Francisco field office will pass my system if inspected."
Possibly, possibly not. I do not know of anyone running a TH unit with an external antenna system other than the one that was certified for use with the TH and pass an inspection.
Will be interesting to see what develops.
Good luck!
RFB
Just got my talking house transmitter up and running.
Right now it is on the wire till I figure out how to deal with the Antenna stuff.
I just ran a field test on 1610 KHZ.
On a wire I am getting about 1/4 mile at night.
This thing should rock with a real antenna.
The TH unit works really well, even off its simple "basic" antenna wire. If mounted outside in a weather proof box using that basic wire antenna strung up through a pvc pipe and over a good ground system, it will surprise you how well that signal travels.
And the ATU extender over a good ground system does even better.
I would use my TH and ATU for my 3 meter backup system, but unfortunately the TH does not transmit C-QUAM stereo. 🙁
Modifying the TH for C-QUAM would void its certification as it would require changing out the entire PLL and oscillator and modulation circuit at the final. Basically it would require gutting out the TH board and replacing it with a C-QUAM board. Can't do that if the certification is to be maintained.
So my TH and ATU units sit in the "X" closet. At some point I might set up a second 3 meter system and station using the TH and ATU. But right now there is snow on the ground, very very cold outside and is a project for the summer time!
RFB
Wanna sell a ATU unit ?
"Wanna sell a ATU unit?"
Unfortunately no. Those ATU's are rare to come by at a low price compared to them new from RS.
I was given the ATU from my uncle who owns a Century 21 real estate company in Seattle. He has a bunch of them, both the TH and ATU's. The ATU he gave me was an unused spare and was a gift. The TH unit I purchased from another Part 15 enthusiast from another forum.
I will contact my uncle and see if he might want to get rid of one or two. Even for Century 21, the real estate market is not exactly at a peak these days, though there are a plethora of foreclosures going on and tons of homes up for resale.
RFB