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Post by Deleted on Feb 10, 2017 14:38:30 GMT
PART 1 - How Do You Do. I'll be Your Tour Guide Today As We Tour The Worldround Radio Campus
I'm Carl Blare acting lord here at Home School College and our group of radio stations serving hundreds of square feet.
This transmitter here is an SSTran AMT5000 and by way of our "Wintenna", a metal window-frame serving indoors and out, operates on 1680 kHz serving out to 1,000-feet across the borders of our own nation state of Heaven into The U.S. Homeland. For my own benefit this transmitter serves the home campus with a solid signal receivable on our construction-site Grundig U1 receiver while I'm tending to landscaping chores or seated at the patio.
Please wait here for a couple hours while I listen Cynthia McKinney's "Midnight Oil" from KPFK about the sex trafficking ring connected with the Clintons.
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Post by Deleted on Feb 10, 2017 21:05:34 GMT
Part 2 - A 1680 Backup Site
It's in the planning stage, and eventually will be our first outdoor self-standing tower with AMT5000 and complete ground-radials for what could amount to a few miles in daytime and better signal penetration at night.
We're usually indoors overnight and the fun of DXing our own station from 100-feet away will probably be the biggest thrill provided by this setup.
The big hangup right now is uncertainty of where to route the audio/control cables... underground or on poles along the fence line. I'd hang the wires on the fence but it's not our fence.
Maybe the neighbors will sell us their fence. Smart idea!
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Post by Deleted on Feb 10, 2017 22:21:54 GMT
Part 3 - KDX-FM and FM Plans To Come
We'll get back to the other AM stations in our charge but let's skip ahead to FM since that's a popular topic on the boards.
KDX-FM 89.5 MHz comes from a Ramsey FM30b set on lowest power based on FCC Rule 15.15 (c) Parties responsible for equipment compliance are encouraged to employ the minimum field strength necessary for communications.
The function of KDX-FM 89.5 is to transmit the main programming of KDX over a distance of 35-feet to a Panasonic FM tuner which in turn provides program audio to the AM1680 transmitter described previously, thus comprising an STL (Studio-to-Transmitter Link).
A second instance of KDX-FM is planned to be opened at 106.9 FM which will be a duplicate of the signal heard at 89.5, using a C.Crane FM1 Transmitter.
Utility station FM 89.9 is used for auditioning and editing audio programs prior to airing or distribution, and serves as the back-haul from TeamSpeak for bi-weekly meetings of the ALPB using C.Crane FM2 Transmitter.
A second utility station at 87.7 MHz provides occasional relay of vinyl phonograph recordings over a distance of 30-feet for recording, digitizing and use in KDX programs. Such transmissions last between 5-to-20 minutes via a Scosche FM4TR Certified Transmitter.
Plans are put in the works to obtain an EDM FM Transmitter following the impressive test and review of the unit by Tim in Bovey linked on the two part 15 sites. This new unit will provide backup service to the Ramsey FM30b.
Three spare Scosche FM4TR Transmitters wait in reserve.
Let's get some coffee.
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Post by thelegacy on Feb 11, 2017 19:35:38 GMT
35 Feet on FM for STL purpose is an excellent way to use part 15. Plus at low power like that it's unlikely to cause issues.
I know someone will be unhappy about 87.7 Mhz but again 35 Feet is no threat to anyone.
As for the few mile AM project I'm really interested in the outcome of that experiment. We will stay tuned.
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Post by Deleted on Feb 16, 2017 3:53:03 GMT
Part 4 - KDX Transmitter Tour Continued
We have many more transmitter and antenna sites to visit, but for this stop we are in front of the Internet Building, about 25-feet from the Parade Review Stand (formerly the front porch) a raised section alongside the drive way which is known as "Drive Way" although the postman says it's not found on his GPS Device...
Previously there was a 12-foot 3-legged bamboo tripod tower up here being groomed for a 1550 kHz AM transmitter, hidden by climbing flowering vines but the whole structure blew over in a wind storm and awaits rebuilding with a more firm base.
Because of its accessibility to public access this location would be insecure for an actual transmitter, for which reason we plan to run tests with transmissions lines from a secure location under the Parade Stand, using 15.209 as our safety rule but that's where the problem begins.
Just like 15.239, 15.209 requires expensive measurement equipment and 10-years of engineering school to administer, for which reason we are screwed six ways till Sunday.
Low power radio is no hobby for simpletons.
We also want to experiment with an optical fiber transmission line, which, because it was not a wire, would not violate 15.219.
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Post by Deleted on Feb 18, 2017 1:25:46 GMT
Part 5 - KHZ AM 1640 Experimental Station
An AMT3000 Transmitter dedicated to the KHZ Indoor Antenna Experimental Station will compile information for the many part 15 hobbyists whose only option is to operate an indoor transmitter. This situation most often occurs due to apartment or home owners restrictions on outdoor antenna installations.
Many amateur radio operators experience the same limitations, and have developed innovative ways to obtain good results using indoor transmission systems, and we will delve into their experience to bolster our own studies.
While in operation KHZ will broadcast streams and programming from other part 15 radio stations and will be publicized here on thealpb_com.
We hope to be on the air by spring.
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Post by Deleted on Feb 18, 2017 17:40:00 GMT
Confidential Disclosure
TheLegacy posted: "I know someone will be unhappy about 87.7 Mhz but again 35 Feet is no threat to anyone."
Part of what I said is true. But now that our national role model is a president who doesn't use truth as part of his style we are all freed to stretch or misrepresent the truth.
The true part is that I do have a Scosche FM4TR Certified Transmitter capable of operation at both 87.7 and 87.9 MHz, it's fully installed and tested, and would definitely serve as a utility transmitter as described if there is ever a shortage of other frequencies.
Now the unsaid part of my half-true half-untrue report: Because I use 89.9 as an audition and editing channel coming from a C.Crane FM2, whenever we have need to transmit a vinyl record from another location we close the FM2 and switch to the FM1 sharing 89.9.
As Paul Harvey always said, "And that's the rest of the story."
Those made unhappy by my use of 87.7 can now feel relief in knowing that I am not actually using 87.7 (at this time) and any story to the contrary is fake news.
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Post by Deleted on Feb 20, 2017 0:53:54 GMT
Part 6 -The Present AM 1550 Transmitter
In Part 4 we described a proposed outdoor antenna site for 1550 AM, which will be the backup for the present indoor AMT3000 right over there under the window sill under the big desk.
That transmitter has been modified per the instructions for driving a base-loaded antenna, yet another "Wintenna" as described earlier.
The loading coil is a triangular form made from toot-picks, bamboo corks, and small dowel rods assembled in a triangular form.
The gray hook-up wire of the coil is nothing special, it's just something we had on hand, and I think the total length of the winding that resonates is about 176'.
To get the transmitter to load to the point of resonance it was necessary to attach a strong ground, consisting of a heavy copper wire through the baseboard and clamped to the I-beam in the basement.
The resulting signal is ultra strong everywhere inside the building, but outside it is only strong around the outer skin or "boundary" of the building all the way around front and back. For as yet unknown reasons the signal does not reach very far beyond the building.
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Post by Druid Hills Radio on Feb 20, 2017 15:10:08 GMT
Carl: Have you tested your AMT5000 on 1710? I find it to be a delightful frequency.
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Post by Deleted on Feb 20, 2017 16:16:25 GMT
Part 7 - Ramsey AM25B for 1710 kHz
Druid Hills Radio gives the perfect opportunity to bring it up when he said: "Carl: Have you tested your AMT5000 on 1710? I find it to be a delightful frequency."
Awhile back during a thread on our sister forum part15_us the Resident Agent was defying anyone to dare to operate on 1710 kHz in violation of 15.219 or 15.209, and I reminded that 15.223 DOES allow operation anywhere from 1.705-10 MHz.
At that time I announced plans to set up a station on 1710 under 15.223 using the Ramsey AM25B.
As I recall it the Agent called doubt upon my true intentions based on his claim that the field strength allowed by 15.223 would be so weak as to be "totally in the noise at only a few meters from the antenna".
"That is exactly why I want to do it" I honestly declared, adding: "I like the idea of trying like hell to receive a signal from the far end of the house that is just barely traceable." I believed that it would be as if my transmitter was miles away, and would be a great test for receivers and antennas.
As it was left the Resident Agent seemed displeased that I was going to try it whether legally or illegally. Despite that he is still on my christmas card list.
The Ramsey AM25B Transmitter is ideal for such an application because it isn't the best transmitter for ordinary part 15 use. Unlike Ramsey's fabulous FM transmitters the AM25B was not well designed, which actually presents an interesting challenge to hobbyists like Neil Radio8Z who reviewed its design and did his own re-design with substantial improvements which is documented at part15_us.
The member PhilB, inventor and manufacturer of the world famous AMT3000 and AMT5000, also published a serious overview of the Ramsey AM25B and expressed his curiosity as to why it was released as a part 15 transmitter when in reality it is scaled along the lines of a full power AM transmitter with a 50-ohm output but is not easily compatible with a short (3-meter) antenna. A lot of RF power is lost matching such an antenna.
In my early experiments with the Ramsey AM25B I tried to improve the poor modulation characteristics and did so by using a Nortronics tape recorder BIAS transformer in place of the little toroid with a few wires wound through it in the original design.
Thus KDX Worldround Radio will be dripping at 1710 kHz.
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Post by End80 on Feb 21, 2017 12:20:16 GMT
Carl, you got to be the first legal part 15 broadcaster who's ever desired less range..!
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Post by thelegacy on Feb 22, 2017 2:38:04 GMT
But that is okay if it's only for your personal enjoyment like Broadcasting to a few receivers in your room or even using it as an STL. The old saying goes don't use more power than you need.
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Post by Deleted on Feb 27, 2017 18:19:38 GMT
Part 8 - Transmission on Shortwave
Right downstairs on the workbench are the circuit cards and parts waiting for installation in a metal case as we complete the Big Talker Shortwave Transmitter designed by a committee of Part 15 technicians, including PhilB the inventor of the AMT 3000 & 5000 transmitters, Neil Radio8Z, MRAM 1500, Bruce MICRO1700, Ermi Roos and Carl Blare.
Diagrams and build history is part of the KDX website, except that it hasn't been transferred yet to our new Private Server. Notification will be made.
The final step will be orientation of a new 1/4 wave horizontal Single-Ended Dipole per information from MRAM 1500.
Transmissions will be sent at 13.560 MHz per FCC 15.225, Operation in the band 13.553-13.567, field strength of emissions shall not exceed 15,848 microvolts/meter at 30 meters.
Later, a second Big Talker will operate per FCC 15.227 operation in the band 26.96-26.28 MHz, field strength shall not exceed 10,000 microvolts/meter at 3 meters, antenna undetermined.
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Post by Druid Hills Radio on Feb 27, 2017 20:31:47 GMT
Part 8 - Transmission on ShortwaveRight downstairs on the workbench are the circuit cards and parts waiting for installation in a metal case as we complete the Big Talker Shortwave Transmitter designed by a committee of Part 15 technicians, including PhilB the inventor of the AMT 3000 & 5000 transmitters, Neil Radio8Z, MRAM 1500, Bruce MICRO1700, Ermi Roos and Carl Blare. Diagrams and build history is part of the KDX website, except that it hasn't been transferred yet to our new Private Server. Notification will be made. The final step will be orientation of a new 1/4 wave horizontal Single-Ended Dipole per information from MRAM 1500. Transmissions will be sent at 13.560 MHz per FCC 15.225, Operation in the band 13.553-13.567, field strength of emissions shall not exceed 15,848 microvolts/meter at 30 meters. Later, a second Big Talker will operate per FCC 15.227 operation in the band 26.96-26.28 MHz, field strength shall not exceed 10,000 microvolts/meter at 3 meters, antenna undetermined. DHR asks: Is the transmitter 50 ohms? If so, why not coax feed a half-wave antenna? The approximate length of a center-fed dipole would be 34.5 feet.
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Post by Deleted on Feb 27, 2017 22:03:16 GMT
The Possibilities
Regarding the Big Talker Shortwave Transmitter DHR asks: "Is the transmitter 50 ohms? If so, why not coax feed a half-wave antenna? The approximate length of a center-fed dipole would be 34.5 feet."
Yes, it is 50-ohms output and could indeed feed a half-wave dipole.
I'm the kind of guy who might try both. By the way, when I say "I might try both" I'm only talking about antennas.
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