Thanks for the info, I'll check that.
For the record, promoting kits here is actually OK and folks like Kieth H and Phil B are welcome and expected to be a little bit biased about their own products.
Disagreements are also OK, as long as such disagreements are polite and grow discussions rather that discourage them.
There has been a general increase in rancor over the past few weeks and that shows up in a drop in visitors and a drop in the diversity of participation and that is not OK. You are generally a very good citizen, nothing personal here, this thread just happened to be the one that caught my eye. No problem in talking on the board vs personal messages.
Just so y'all know ... while I want to learn and may read the comments, I'm purposely avoiding participation in threads where members are insulting each other. I'm interested in technical issues, programming, even a little politics and friendly banter ... but none whatsoever in spitting contests.
I echo your thoughts on that Ken. It won't necessarily deter me from posting a comment in a thread just because an insult was thrown in somewhere, but that's not to indicate I consider it condonable.
I like the part Neil put in about the
electron flow. I don't know this
stuff.
Best Wishes,
Bruce, MICRO1690/1700
Looking back to the beginning of this thread I here re-quote the line put into question by Tybee Island:
"For example a pole grounded at the base with a short "ground lead" connected from the top of the pole to the transmitter has been shown to be a solution.
( http://www.am1000rangemaster.com/radiate.html )"
Upon thinking about it, it sounds like a writing error, because I don't think it makes sense no matter what is believed.
Anything new about it?
Upon thinking about it, it sounds like a writing error, because I don't think it makes sense no matter what is believed.
Anything new about it?
Well Ok.. I just discussed this again in a another thread where it really didn't belong to start with.. so lets do it again right here.
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Sent: Tuesday, March 15, 2011 3:21 PM
To: Keith Hamilton
Subject: Non-Radiating ground statement error
Hi Keith, Just a heads up on something you may have missed during past re-editing of your website.. this appears to drastically contradict itself in this statement.. Unless I am ignorantly misreading it:
Avoiding a radiating ground
If you are connected to a ground that looks like an antenna , then you are going to get radiation from the system. Design the ground so that will not radiate, or does not function as an antenna. For example a pole grounded at the base with a short "ground lead" connected from the top of the pole to the transmitter has been shown to be a solution.
( http://www.am1000rangemaster.com/radiate.html)
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From: Keith Hamilton
To: [email protected]
Sent: Wednesday, March 16, 2011 2:05 PM
Subject: RE: Non-Radiating ground statement error
Sorry, I’m not getting your point
Keith Hamilton
RangeMaster Transmitters
(919) 362-9393
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From: Richard Powers [mailto:[email protected]]
Sent: Wednesday, March 16, 2011 2:51 PM
To: Keith Hamilton
Subject: Re: Non-Radiating ground statement error
For example a pole grounded at the base with a short "ground lead" connected from the top of the pole to the transmitter has been shown to be a solution.
Well, maybe I'm misreading it. It sounds to me like it's saying to attach the transmitters ground lead to the top of the pole..
But to do that would just cause the pole to become a radiating conductor, -- and that contradicts the whole subject of the article, which is; to avoid a radiating ground - right?
What am I missing?
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From: Keith Hamilton
To: [email protected]
Sent: Wednesday, March 16, 2011 3:23 PM
Subject: RE: Non-Radiating ground statement error
FCC agents have been passing transmitters on poles after testing them for ground radiation.
Keith Hamilton
Hamilton PCB Design
(919) 362-9393
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From: Richard Powers
To: Keith Hamilton
Sent: Wednesday, March 16, 2011 3:54 PM
Subject: Re: Non-Radiating ground statement error
Keith,
What do you mean "..have been passing transmitters on poles.."
I thought that was just once upon a time.
But still, I'm not comprehending the solution in the statement and how it would keep a pole from radiating-- not that I'm concerned about it in itself, I just want to try to avoid any potential problems should a FCC visit ever occur.
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At this point I guess he got tired of talking about it because he never replied, so I let it drop.
But yeah Carl, it doesn't make sense to me either
Maybe the top of the pole is only a foot or two out of the ground.
And how do you separate ground radiation from reduced ground losses due to a non-radiating ground? Would you disconnect the "ground wire" at the transmitter or to that which is in the ground?
If you did have a ground mounted transmitter connected to a very good counterpoise, which doesn't radiate, the signal would certainly decrease when disconnected from the non-radiating counterpoise as ground losses would increase.
Short of citing theory from reference books about counterpoise, you'd be hard pressed to convince someone that it's not radiating.
If I were in the business of selling pole mounted transmitters, I'd probably avoid the discussion also.
A vertical antenna, no matter how you color it, relies on a simple principle: antenna current = ground current. If you do anything to degrade the ground current, the antenna current will degrade equally. So, lowest ground resistance will maximize the antenna current (good thing).
When you "elevate" a short vertical, the result is exactly the same as if you were to keep the antenna at ground level and lengthen it so the top is at the same altitude as the top of your elevated short vertical, assuming the same resistance to ground is maintained. At the extreme, a 3 meter antenna on top of a 1/4 wavelength grounded tower or pole or wire will perform just like a full 1/4 wavelength vertical antenna.
Elevating a short vertical won't work well unless a low resistance is maintained to ground. So, isolating the elevated antenna from ground in any way (read increase ground resistance) will degrade performance.
Bypassing a grounded pole below the transmitter with a wire from the transmitter to ground will only serve to help reduce ground path resistance and increase the radiation of the whole antenna system.
Inserting an RF choke in the ground lead will increase RF impedance to ground and will be severely detrimental to performance, unless (and this is important) the tuning coil inductance is reduced by the value of the choke inductance to maintain resonance. So you can re-tune to compensate for the choke and end up where you were without the choke, except for the added loss resistance off the choke. If you insert a choke with inductance greater than your tuning coil was without the choke, you won't be able to re-tune, and the antenna will not radiate at all. The concept of a choke in the ground circuit is BOGUS and should never, ever be mentioned again, anywhere!
The reports declaring that a choke in the ground lead actually results in a radiating antenna system can be attributed to one or both of two things: (1) the choke inductance is small enough to allow retuning by changing the tuning inductor to compensate, or (2) there are other lower impedance paths from the transmitter to ground. Namely, the audio and power feed wires.
I believe there is a place for an elevated, well grounded antenna in the Part 15 world. If you operate a "billboard", information or targeted advertising station, the FCC will likely not get complaints from licensed broadcast stations. When you are perceived as being in some sort of threatening competition with licensed broadcast stations, they will lodge a complaint to the FCC and you are busted.
For would-be broadcast stations, the safest bet is a really well constructed ground-level 3 meter antenna. Absolute highest priority should go to a really good ground radial system. From there you can go to some of the enhancements that will increase gain somewhat over the typical base-loaded monopole: top hat, center loading coil, helical antenna, "fat antenna", and a combination of the various types with a top hat. Again, I will emphasize the first priority is a really good ground radial system. That's a lot of work compared to the other enhancements, but none of the enhanced antennas will work worth a darn without a really good, low resistance ground radial system.
"When you are perceived as being in some sort of threatening competition with licensed broadcast stations, they will lodge a complaint to the FCC and you are busted."
That being said, I'm very curious to see how the NPR FM station in California planning to deploy several elevated RangeMaster systems fairs. The station wants to reach inner city minorities and low cost, Part 15 AM radio seems to fit the bill for them.
The article regarding that situation was found in a recent Radio World issue and reference to that article was posted here.
So, they have public promotion and elevated systems presumably grounded to metal structures. All the attributes that should warrant shutdowns.
Having just begun installing a radial ground system with my first tests showing an observable improvement in signal propagation, I feel somewhat "born again" as if I'd just discovered grounding for the first time. I can truly shout, "Hey, it works!"
So with such a clear head I know what PhilB means by lowering the resistance between transmitter and ground. Zero-ohms would be reason to celebrate, but wire and poles add resistance, be it 10-ohms, 100-ohms, and of course we never start with an ideal zero-ohms because connection with ground has imperfections.
But now I understand better than ever PhilB's guidance that ground improvement is the place to invest effort, not raising the antenna higher.
In HAM radio situations, similar problems arise, i.e., poor ground conductivity, so here are a couple of possible artificial ground solutions, but don't use them as a system or safety ground, only as counterpoise:
Homebrew: http://www.remeeus.eu/english/hamradio/artificial_ground.htm
Commercial unit: http://www.mfjenterprises.com/Product.php?productid=MFJ-931
Also, note these may not go low enough to be effective, (but you could add a coil), and the MFJ unit occasionally gets a bad review because of quality problems. All it really is is an antenna tuner simulating ground conductivity, i.e., it does NOT replace a real Earth ground.
One other thing I may not have mentioned ... if Rich chooses to use the 6" metal roof vent, be absolutely sure it goes to Earth ground. Often the roof vents have been left alone because they're harder and less safe to deal with while the lower portions may have been joined to and replaced by PVC ... in which case it's not an Earth ground at all.
One other thing I may not have mentioned ... if Rich chooses to use the 6" metal roof vent, be absolutely sure it goes to Earth ground. Often the roof vents have been left alone because they're harder and less safe to deal with while the lower portions may have been joined to and replaced by PVC ... in which case it's not an Earth ground at all.
Ken it's a old steel pipe that's coming from the bathrooms of the restaraunt( 
),.. but now I do recall about two years ago the owner having plumbing problems and the concrete being busted up in the alley to gain access to the pipes.. so now I am assuming those pipes were probably replaced with pvc - so I guess that idea is out too.
I've never seen or heard of those artificial grounds, but after looking at your links I did a quick search and the results all indicate those are really better for reception and not good for transmission, then found another post that actually said for transmitting "a water pipe or the fire escape would be a better choice." than one of those.
I could not find any positive comments or reviews on it, but found several negative comments.
Now, I have no idea how to go about grounding this thing.. There is some kind of air conditioning return unit at the highest peak of the roof.. I wonder if there's some method of tying into a ground there?
The reason that the quote from the Rangemaster website in the first post in this thread was not understood by RichPowers is because it doesn't make any sense. To get an ideas of what is actually going on, consider the advice given on the same website to Rangemaster users only a few years ago:
A recommended installation was to mount the Rangemaster on a 1 1/4 inch antenna mast that is mounted on top of a roof. A ground wire (for "lightning protection") was to be connected between the ground connection of the transmitter elevated above the roof to an 8' ground rod driven into the earth. The ground wire was to be spaced away from the building.
In my opinion, it is probably because of some FCC enforcement actions relating to long ground wires in recent years that this sort of advice is no longer explicit on the website, and now appears as the double-talk that RichPowers quoted.
A recommended installation was to mount the Rangemaster on a 1 1/4 inch antenna mast that is mounted on top of a roof. A ground wire (for "lightning protection") was to be connected between the ground connection of the transmitter elevated above the roof to an 8' ground rod driven into the earth. The ground wire was to be spaced away from the building. In my opinion, it is probably because of some FCC enforcement actions relating to long ground wires in recent years that this sort of advice is no longer explicit on the website, and now appears as the double-talk that RichPowers quoted.
1. Well... actually, even the Rangemasters new manual still makes this recommendation along with illustrations. http://www.am1000rangemaster.com/ExpandedInstallGuideforInstaller_3_10bw.pdf
2. As so does the Procaster emphasize the same type of install on the front page of their site, along with a very prominent diagram http://www.chezradio.com
3. And to be honest, I still don't understand how it is the I.AM transmitter can be indoors and the external tuning unit on the other end of a 100ft cable can be mounted anywhere you please.
These are all certified transmitters.. It would seem that if the advice given were not a legal method of install, then it couldn't be promoted.
I don't mean to keep on and on rehashing the same thing that many have already beat to death on repeat occasions..
But something just don't make sense here!
And I have no idea how to install my transmitter because of it... I mean if indeed every one of the certified Part15 manufacturers have instructions that are wrong, then.. how the hell are you supposed to install their products?
This is insane.
How do I install this thing??!!
One approach is to try the transmitter in several locations around our property to see what works best for you. Propagating the low power AM signal is art and luck as well as science. Low power AM is an odd duck.
As far as absolute compliance, do your best while you try to get the best signal. If the very worst case scenario unfolds and you are contacted by a field office you could review the KNEC matter for an example of what to expect.
Remember, that operator wasn't fined and no equipment was confiscated (in rem arrest), he just had to change the install. In my opinion that's inconvenient and frustrating but manageable.