I have looked at the TalkingHouse wall adapter and it has been specially fabricated (filters added) to reduce conducted emissions down the live and neutral conductors of the house wiring. This transformer adapter is 3-prong and has the ground pin connected to the -ve of the DC output.
When I took the TalkingSign unit in for FCC approval, we failed the conducted emissions at first and had to use a 3-prong switching supply which had commonmode filtering on the line input side which allowed our unit to pass. The problem with both these transmitters is that by their very nature the transmitters are very close to the wall adapter, so its very hard to prevent signals from being conducted down the line.
External tarnsmitters probably don't have these problems because the transmitter is far away. I believe the Rangemaster just has an ordinary transformer wall adapter.
Gerry
Neil said:
With that said, I am not closing our debate and if you want more discussion I am open to that.
By the way, I noted that your writeup on the colinear coil/antenna is on the SSTRAN site.
Actually, I think we have beat this dead horse enough. It seems that just about everyone has expressed their opinion on this topic. Unless something new develops, I'm going to leave it alone.
As to the writeup, Phil posted that several weeks ago. In fact, I had to send him a second version with lower resolution pictures, to accomodate dialup users. It was just my way of contributing.
Here's a quote I found on another board that I though would be interesting to the readers here:
"However, Mr. John A. Reed of the FCC Office of Engineering and Technology wrote the following comment in response to a query: "If the installer/user places the transmitter atop a metal pole or other conducting structure and grounds the transmitter to that structure, the height of that structure also is counted toward the three meters maximum length." (Radio World, August 2, 2000)."
Neil
Unfortunately they don't have that article in the archives:
http://www.rwonline.com/dailynews/archived_issues.html
I'll have to see if there is a way to order a printed archive of that issue.
Neil,
You are a breath of fresh air. Thank you for your historical rundown re: Part 15 rules. Most of the information concerning the citing of the church by the FCC does not let us know if the FCC did an on-site inspection and if it produced a "Notice of Apparent Liability". If it did, the church received a notice that explains what the church can do to ameliorate the "out of compliance" condition and the time necessary to respond. Even the anecdotal responses of the Pastor indicate he has no idea what he is involved with or how to operate in compliance. All the items I have mentioned previously would have helped the church react appropriately to the citation; bringing the station into compliance instead of shutting it down. And as a final note, I have yet to read that excessive field strength played any part in this citation. Maybe someone could find the citation in the FCC enforcement log and publish the link. Then we could know the facts instead of current opinion.
Marshall Johnson, Sr.
Senior Pastor, President
Rhema Christian Fellowship, Inc.
Rhema Radio - The Word In Worship
AM 1660 - FM 93.5
http://www.rhemaradio.org
Before the
Federal Communications Commission
Washington, D.C. 20554
In the Matter of )
) File No.: EB-06-SD-423
Iglesia de Dios Ebenezer )
) Citation No.: C20073294003
Oceanside, California 92054 )
CITATION
Released: January 24, 2007
By the District Director, San Diego District Office, Western Region,
Enforcement Bureau:
1. This is an Official Citation issued pursuant to Section 503(b)(5) of
the Communications Act of 1934, as amended ("Act"), to Iglesia de Dios
Ebenezer for violation of Section 15.219(b) of the Commission's Rules
("Rules").
2. The Enforcement Bureau's San Diego office received a complaint that an
unlicensed AM broadcast station was operating on 1610 kHz at 141
Canyon Drive, Oceanside, California. On November 2, 2006, agents from
the San Diego Office confirmed that an AM broadcast station was
operating on 1610 kHz at 141 Canyon Drive, Oceanside, California, that
did not conform with the requirements of Section 15.219(b) of the
Rules.
3. Section 15.219(b) of the Rules states "[t]he total length of the
transmission line, antenna, and ground lead (if used) shall not exceed
3 meters." The antenna being used by the station appeared to be
approximately 3 meters long, however, the total length of the ground
lead was approximately 30 meters. Consequently, the station is
operating in violation of Section 15.219(b) of the Rules.
4. Violations of the Act or the Commission's Rules may subject the
violator to substantial monetary forfeitures, seizure of equipment
through in rem forfeiture action, and criminal sanctions, including
imprisonment.
5. Iglesia de Dios Ebenezer or their representative may request an
interview at the closest FCC Office, which is Federal Communications
Commission, 4542 Ruffner Street, Suite 370, San Diego, California
92111. You may contact this office by telephone, XXX XXX-XXXX, to
schedule this interview, which must take place within 14 days of this
Citation. Iglesia de Dios Ebenezer may also submit a written statement
to the above address within 14 days of the date of this Citation. Any
written statements should specify what actions have been taken to
correct the violations outlined above. Please reference file number
EB-06-SD-423 when corresponding with the Commission.
6. Any statement or information provided by you may be used by the
Commission to determine if further enforcement action is required. Any
knowingly or willfully false statement made in reply to this Citation
is punishable by fine or imprisonment.
7. IT IS ORDERED that copies of this Citation shall be sent by First
Class U.S. Mail and Certified Mail, Return Receipt Requested, to
Iglesia de Dios Ebenezer at their record of address.
FEDERAL COMMUNICATIONS COMMISSION
William R. Zears Jr.
District Director, San Diego Office
Western Region
Enforcement Bureau
47 U.S.C. S 503(b)(5).
47 C.F.R. S 15.219(b).
47 C.F.R. S 15.219(b).
47 C.F.R. S 1.80(b)(3).
47 U.S.C. SS 401, 501, 503, 510.
47 U.S.C. S 503(b)(5).
See Privacy Act of 1974, 5 U.S.C. S 552a(e)(3).
See 18 U.S.C. S 1001 et seq.
Federal Communications Commission
WDCX AM1610 Part 15
John
Owner-Operator-Chief Engineer-Program Manager
OK, this is obviuosly the first warning or it would have been mentioned in the citation. All the other enforcement statements have referenced any previous dealings with an idividual if there are any. So if he contacted the FCC, he could have said that he turned it off, and that he was following the manufacturers guidelines. Also that it will remain off until such time that he can discuss the situation with the field engineer that did the intial investigation.
Or at least that's what I would have done, and then gathered all the info I could find on the suggested installation from the manufacturer.
A big thank you to you both. Humankind learns from making mistakes and then working to correct the mishap. In this case, bringing the manufacturer and the District Engineer into the picture and having a "sit-down" would have been the logical route. However, for those of you who live in the Southwest and West, you might understand the reluctance on the part of the pastor of the Hispanic church to buck the officials of the Federal Government. The letter's (read citation) tenor is meant to intimidate the recipient. This letter is the equivalent of a "Notice of Apparent Violation". None of the findings in the letter point to actual measurements made of the length of the antenna, transmitter and ground lead. A discussion with the District Engineer could lead to finding the acceptable use of a lightning protection ground for the church and it's equipment. (Editor's note: Adding a high impedance RF choke in the ground lead to protect against a lightning strike is a very small fuse in the case of even a peripheral strike. The nano-second it will take to burn up the choke, will turn the roof into tinder.)
However, this entire situation returns to the point I have been making for some time. Before a person drives a car, performs surgery, goes hunting on public land or operates a transmitter, that person should take the responsibility of knowing how to perform the task legally. Because in this age of litigation, someone is eventually going to "complain". And the government is charged with finding the offender and enforcing the law. However, enforcing the law does not constitute a conviction, even in the case of enforcement of administrative law by the FCC. However, if you poke your finger in the eye of the administrative law judge, THEN he can send the U.S. Marshal's to ensure compliance.
As I suspected, this citation is not the "end-all" to prove compliance or non-compliance with Part 15 AM rules. But, it does bring to light the process that all of us should take responsibility to understand; how the rules and the FCC work. And that we all need to be able to make a technical and political case for our station's operation. Thank you again, John and Greg, for getting it right and doing the foot work to get the train back on the track. BRAVO!
Marshall Johnson, Sr.
Senior Pastor, President
Rhema Christian Fellowship, Inc.
Rhema Radio - The Word In Worship
AM 1660 - FM 93.5
http://www.rhemaradio.org
Marshall Johnson wrote: None of the findings in the letter point to actual measurements made of the length of the antenna, transmitter and ground lead.
Here is a quote from the citation: "The antenna being used by the station appeared to be approximately 3 meters long, however, the total length of the ground lead was approximately 30 meters. Consequently, the station is operating in violation of Section 15.219(b) of the Rules."
The FCC didn't measure the ground lead with any accuracy, but it was clear to them that it greatly exceeded the Rules.
"Editor" wrote: Adding a high impedance RF choke in the ground lead to protect against a lightning strike is a very small fuse in the case of even a peripheral strike. The nano-second it will take to burn up the choke, will turn the roof into tinder.
The purpose of the choke is to supply a DC and low a-c frequency path to ground, while inhibiting the flow of r-f current along the ground wire (which causes it to radiate). The DC path keeps the tx chassis near DC earth potential, rather than let static charges build up on it, which can attract lightning.
If the system receives a direct/near-direct lightning hit with or without the choke, the ground wire could not carry that current anyway, and it would, itself, vaporize along with the rest of the hardware.
An interesting point in this situation is that if r-f chokes or other means were used to prevent the ground/program/power conductors from radiating, then there would be no useful purpose in installing Part 15 AM systems on rooftops, flagpoles, towers, billboards or whatever, because the total radiation then would be worse than if the system was installed with the base of the ~3-meter whip at the surface of the earth using a very short ground lead -- where its chances of getting hit by lightning are much less.
But no matter what the elevation of the tx and whip, and the length of the ground conductor, whether or not the whip has a DC path to the ground conductor/chassis depends on the tx system design. Even if the tx chassis has a good connection to DC earth ground, that may not prevent static charges from building up on the whip, itself -- which of course is the highest point in the system, and the most susceptible to lightning effects.
//
Rich said:
"But no matter what the elevation of the tx and whip, and the length of the ground conductor, whether or not the whip has a DC path to the ground conductor/chassis depends on the tx system design. Even if the tx chassis has a good connection to DC earth ground, that may not prevent static charges from building up on the whip, itself -- which of course is the highest point in the system, and the most susceptible to lightning effects."
I said:
I know the Rangemaster has what appears to be a gas-discharge tube at the feedpoint with one leg tied to ground.
WDCX AM1610 Part 15
John
Owner-Operator-Chief Engineer-Program Manager
John wrote: "I know the Rangemaster has what appears to be a gas-discharge tube at the feedpoint with one leg tied to ground."
Thanks for that info, but a gas discharge tube doesn't provide much of a path either for DC or AC until the potential across it (via lightning strokes) causes it to conduct. Otherwise it is essentially an open circuit, and couldn't provide an efficient way to drain off static charges via the feedpoint of the 3-m whip that could attract destructive lightning damage.
And probably the current rating of the gas discharge tube is not adequate to carry the current induced in the system by a direct/nearby lightning strike, even if the conducting path from the tx ground terminal to a buried earth ground was capable of carrying it.
//
FYI: The Rangemaster antenna loading toroidal coil has separate primary and secondary windings with one end of the secondary 'cold side' being the ground connection. Any static is automatically bled off by the low resistance of the coil. The gas discharge tube installed on the 'hot side' acts as a very fast short to ground if a voltage exceeding the breakdown of the tube is present; a good ground is important for this to work well. Is this gas discharge tube really needed here? I have seen LOWFER transmitter configurations which only use the bleed resistor for keeping static under control and no gas discharge tube at all. Any comments?
Gerry