- August 31, 2020 at 9:33 pm #115701
Agree 100% with Tim.
Worry more about the surge in the power supply.
The surge protector you use for your power to the Procaster, computer and any processing gear should not just have a light that tells you if the surge protection is working but if the surge protection is compromised the power bar should shut down instantly cutting power to your stuff like a fast acting fuse.
These are harder to find but are available. These types of power bars would protect you if lightning made a direct hit and it states this on the package.September 1, 2020 at 8:08 am #115704
The one I have has the “Overload” power bar and power bar for battery power. Nice APC Brand.
I guess there is no real protection from lighting. Had a house over the weekend hit by lightning near my area.
I like Tim’s idea, but I’ve worked and been a commercial broadcast station owner. I understand series feed towers and towers with folded unipoles on them. Mine hade a unipole. Rumor was feeding the tower with a unipole was to help with lighting protection. That’s a understatement.
Sonn as I get my Procaster back from the factory, I’m thinking it’s not so much height, it’s the ground, like in commercial ground systems, but on the flip side, the commission hasn’t approved that to my knowledge.October 31, 2020 at 8:45 am #116138
I got my Procaster back from the factory this month. I haven’t done anything with it because I was slow getting it up there. Other stuff at home going on.
Anyhow, this Rule 15.219 about the Ground Lead is “Hog Wash”! The Commission does not give the user a maximum field strength reading not to exceed with Part 15 AM, like they do Part 15 FM.
With talk now about the FCC allowing the Commercial Stations going digital without asking or filing an application, I wonder how many AM’s will do it anyway? What about the TIS Stations?
I thinking protecting your equipment is important, as long as you’re not bothering a Commercial Broadcaster and can prove it. I’ve been a Licensed Commercial Broadcaster on AM. I think I’m right. Thoughts?November 1, 2020 at 3:21 am #116152timinboveyParticipant
Total posts : 719
Actually, they DO give a maximum field intensity. If you check FCC part 15.209.
However, they ALSO have Part 15.219 which takes into account that the average guy can’t measure field intensity without expensive equipment, so they offer the alternative which limits input to the final at 100mw, and 3 meter antenna lead/ground lead combined. Part 15 folks have figured out that the limitations with 15.219 allows you to get a lot more signal out than the field intensity limits.
I have been running a Procaster for over 7 years, elevated install at about 30 feet, with no ground lead attached. No issue with “protecting my equipment”. And we live in “tornado alley” where thunderstorms with plenty of lightning are pretty regular all summer.
I have been a commercial radio engineer since 1973 and hold an FCC First Class license (well, it used to be called First Class when I earned it, now it’s a General Radio Operators License, or “GROL”). Also a certified member of the Society of Broadcast Engineers, and have worked as engineer for commercial AM and FM stations since 1973, and continue to do so today. As long as we’re tossing around credentials.
The FCC is not going to open up a free-for all, where as long as you’re not interfering, you can do what you want.
As for commercial AM’s going digital, I don’t see this happening en mass anytime soon. Why would they give up their listeners to go digital? Most listeners to not have the capability to receive digital AM. It’s going to be a while, or require FCC rule changes to force the issue before this happens. Stations are going to operate in whatever way will gain them the most listenership and thereby most advertising dollars. Switching to all digital is not the way to do that right now.
TIBNovember 1, 2020 at 10:03 am #116154
Agree Tim, about the digital. I don’t care one way or another as long as the band isn’t scrapped and end part 15 and it’s Canadian equivalent.
I think I mentioned before but I use the Procaster and get out nicely to the neighborhood just with a 22 gauge wire exactly 3 meters clipped to the antenna post indoors and no ground, nothing else connected. But you may not be aware but it still gets a ground from the other sources like the computer, processing and the power supply with the Procaster.
An electrical RF ground.
I still find it amazing that with the temperature changes from summer to winter you don’t have to check and retune the antenna or double check you are right on frequency with a counter accurate to at least 6 zeros to be under 10Hz off. You get out better at night if no beating with the skywave stations.
As for the lightning, if you have lots around that would favor lightning strikes the chances are slim your transmitter would be hit. Not only that but that the storm will be right on top of your house.November 1, 2020 at 10:21 am #116156
Oh also, the only way to have truly no ground is to run the Procaster on a 12 volt battery and a wired plug for the jack on the studio part, and a laptop running on the battery. No other processing.
I have yet to try that and see if it makes a difference in performance.November 2, 2020 at 10:45 am #116161AMRadiolegendParticipant
Total posts : 334
I’m glad we haven’t left the Ground Lead discussion LOL!November 2, 2020 at 3:04 pm #116163
To Mark, You didn’t say your transmitter was in the house with a 3 meter wire stretched up along the wall? That’s not going to work.
I kinda tried that with the Chez Procaster. I barley got out if my yard with it! I haven’t taken it outside yet. I did have it in the house with the supplied aluminum antenna attached to it. I couldn’t stand it up straight, but it go two houses down from my house without a ground lead.
I know with AM you have to have some kind of ground system, no matter the power or it won’t work. There is one man that has a “Part 15 Website”.
If he would stop spending disencouragment to Part 15 AM Hobbist and Serious People like churches for example that need it, gee it would be a better world! Man has too much time on his hands scaring people! Go after FM Pirates!November 2, 2020 at 3:06 pm #116165
November 3, 2020 at 12:49 pm #116170
- Sorry for my last rant and a sentence that mad no sense. Get me going, that’s how it is. WHEW!
To Tim, My Procaster power supply does not have a electrical ground. I thought that was unusual! Most electronics have a ground when you plug it in. Wonder if I should call Gerry at the factory and ask him why. The “ONLY” ground I would have in my case would be the electrical bond between the galvanized pole and the transmitter box. I have heard of a few taking a 9 foot wire from the bottom of the box and bonding it to the gavanized pole. The FCC Field Inspector was cool with it. I guess the Inspector felt it was not going to cause any problems. I would love to give you my email address so we could discuss this more!November 5, 2020 at 12:45 pm #116188
Send me a copy of your coverage map to my Yahoo Email Address. It is:
Let me take a look at it. Are you getting at least a block or two. We know what 1/2 mile is in a straight line. I have a TIS 10 watt station in the next town from me going towards I-65 south that goes to Downtown Nashville. I have to go to Vanderbilt University Hospital to see two of my doctors, and at 10 watts with a whip antenna, gets out good!
I was going to Home Depot, but a 8 foot ground rod, attach a 6 gauge wire to it and run the wire into the house. My wife and me was having lunch in the local diner here and a electrican here was on the phone with a customer talking about a computer ground. Maybe the same thing, hun? I told my wife that since she works from home. Anyhow, send me that map. I can get a frequency counter. My consultant engineer has one.November 8, 2020 at 12:09 am #116213
I want to say thanks to Mark! He has gave me some fantastic ideas on the Chez Procaster I have not thought of. One idea is the Chez Procaster comes with that aluminum rod. Copper is a better radiator. The best part of what Mark ìs doing is there is no ground lead needed! I still think the FCC should allow a copper rod into the ground and a longer wire to the transmitter. Just makes sense for AM Part 15!
I should have thought about that being I have had to install a copper ground system for my Commercial AM Station I owned before I retired from that. In plumbing, copper is better than old gavanized pipe!
With that said, and the frequency counter I can buy off eBay for less than $25.00, tune the coil, it’s worth a try to using it in house first before taking it outside. I’m not knocking what Tim is doing, but with the climate change within the country, a person just doesn’t know what to expect where they live.
I learned that the power supply Chez Procaster supplies with their transmitter doesn’t not give you a good electrical ground. They must have bought a surplus of those power supplies at a low cost. Replace it with a power supply that gives you a good electrical AC ground. I know better because I have worked for a Electrical Utility Company. Also, an APC Uninterrupted Power Supply/Surge Protector (which I have a heavy duty one) is nice to have!
Mark’s Range map showed me he was doing better, better range, than a 100 mw FM Transmitter that is FCC Approved!
I got time, this is a hobby now, not a stressful, push to sell advertising and blocks of Sunday Programming Time to make a bank payment on a building and property to stay on the air and in business! That’s over for me. Time to enjoy and mess around with what I enjoy!November 8, 2020 at 1:03 am #116215RichParticipant
Total posts : 195
A few comments about the post first above:
RE: I have had to install a copper ground system for my Commercial AM Station I owned before I retired from that. In plumbing, copper is better than old gavanized pipe!
Just to note that almost all AM broadcast stations use one (or more) galvanized steel towers as radiators. When used with good, buried radial r-f ground systems and low-loss matching networks, those antenna systems radiate over 95% of the available transmitter power. Almost all of the efficiency loss in those antenna systems occurs in their matching networks and buried radials — not in the ohmic r-f resistance of the tower structures.
RE: Mark’s Range map showed me he was doing better, better range, than a 100 mw FM Transmitter that is FCC Approved!
The FCC does not approve Part 15 FM transmitters based on their rated power, but on the field intensity the transmit system produces at a distance of 3 meters from its radiating conductors. The upper limit at a distance of 3 meters from the radiator(s) is defined in 47CFR §15.239 as 250 µV/m.
The amount of transmitter power needed to generate a maximum, free-space field of 250 µV/m when using a 1/2-wave dipole transmit antenna is about 11.43 nanowatts (0.000 000 011 43… watts); far, far less than 100 mW.November 8, 2020 at 1:50 am #116217
That is true on FM. In layman’s terms. say if a FCC Inspector tries to explain it to a Church Preacher, 250 microvolts per meter at 3 meters. I’ve seen some You Tube Videos of Preachers buying those illegal Chinese Transmitters to cover the Church Parking Lot for drive in Sunday “stay in the car” services as the COVID-19 Pandemic came across the country. Texas has now confirmed over 1 Million cases, the most in one state this year.
As we get into colder temperatures, Dr. Anthony Fauci is saying the worse is yet to come, and here people in the rural south are not wear mask. The Commission won’t have enough field inspectors to go to churches because the inspectors don’t want to get sick themselves is my prediction. You may more know more.
I do like your idea for Part 15 AM, with the ground radials, coil, and antenna at the bottom. That makes much more sense to me. AM requires the radials to bring back that lost energy back to the antenna. I’m no expert, but if we could get your idea approved for Part 15 AM, it would have better coverage and maybe educate the small churches and preachers, especially here in the south to get off the FM Band and use the AM Band.
Maybe Digital AM in cars will take a while to get manufactured while the country is going through this pandemic. Your idea by looking at the drawing is a savior! My wife has seen your drawing, but like me, she has no idea how long each radial has to be. She doesn’t want me tearing up the back yard!
What am I doing up? Church is in a few hours for us!November 15, 2020 at 11:43 pm #116300RichParticipant
Total posts : 195
RE: Your idea by looking at the drawing is a savior! My wife has seen your drawing, but like me, she has no idea how long each radial has to be.
Probably you are referring to the drawing in the graphic below.
Please note that the lengths of the buried radials are given as the 4th “bullet” in the list near the top of that page.
- This reply was modified 2 months, 1 week ago by Rich.
- You must be logged in to reply to this topic.