- June 4, 2019 at 10:43 am #111325
My order has shipped and I have seen the manual. There is no comparison between the original and this version. It appears from the photos to extremely well constructed. The radiating element is similar to the antenna employed on the Procaster. The mounting hardware is sturdy and it comes with 25 feet of RG-6 although one can use up to 100 feet. They make it very clear in the manual to use ONLY 75 ohm coax.
I will post photos when it arrives.
- This topic was modified 1 month, 1 week ago by AMRadiolegend.
- June 5, 2019 at 10:39 am #111335
It has arrived. The construction quality is excellent. Heavy duty! I can’t wait to get this thing tested. I only wish I had Tim-in-Bovey’s FSM LOL!
- June 5, 2019 at 12:20 pm #111336
Good to see the antenna is aluminum like the Procaster is.
I’m also seeing some differences in the way this new ATU looks as well. The old one did not have a see through case and the antenna was a stainless steel whip which does not have the came electrical characteristics as aluminum does. I’m sure that in and of itself will give more Range.
And as we have discussed and some kept saying the height did not matter notice the 20 foot height recommendation. Now if I could get mine up that high I am sure the issue with the Deltaville Market would be eliminated and a straight Tecsun PL-365 could receive this station.
I’d recommend doing a few things in the tests:
1. Tecsun PL-380 or 365 with stock antenna at first to see range.
2. Car Radio such as the ones inside a Toyota Corolla or Delco Radio inside a GM vehicle.
3. Tecsun Radio with Terk AM advantage loop to compare your Range with mine.
4. A video on Youtube similar to my video to show how your station sounds. As you can see if you talk while the music is playing or don’t play Top40 like Black Eyed Pees or Taylor Swift you should be OK. I played CCR and Jefferson Airplane but both songs were not in the Top 40 charts.
Keep us posted I’m really excited to see what this could do. Also I don’t see why you could not use this ATU on an ASMAX2 transmitter as I am using 75 ohm coax and a home made ATU and have no issues at all with the transmitter. So now you folks transmitting in C-Quam AM Stereo and want a professional ATU/antenna can now use it on the ASMAX2.
- June 6, 2019 at 2:13 am #111339
For thought and discussion, below is a NEC4.2 analysis of the AM transmit system described there. The remote ATU is located at the upper end of the 25-ft coaxial cable, at the feedpoint.
The red lines along the conductors of that system show the relative distribution of r-f current along those conductors.
- All of those conductors carrying r-f current and located above the surface of the earth are active parts of the radiating antenna system.
- The total length of that conducting path is limited to 3 meters by FCC §15.219(b).
- The analysis contained in this post is not a matter of opinion, it is a matter of Physics.
- June 6, 2019 at 4:06 am #111341
First of all you have no idea how I am going to install this. We all understand the rules and the manual is very clear on this. Are you going to sleep nights knowing that the extender will be mounted on a fence post about 4 feet above ground. Please stop these unsolicited comments to the same crowd you’ve been preaching to for the last several years. We get it.
And reminder Mr. Physicist: The extender IS the final stage of the transmitter. Since you know everything, you already know that the internal tuner is switched out of the circuit when the external (final stage of the transmitter) is employed.
Now cut back on your sugar intake. 🙂
- This reply was modified 1 month, 1 week ago by AMRadiolegend.
- June 6, 2019 at 4:43 am #111345
RE: “… the internal tuner is switched out of the circuit when the external (final stage of the transmitter) is employed. …”
And that is the configuration of my NEC model.
Also, suggestions have been posted elsewhere that the antenna+ATU should be mounted at least 20 feet above ground level.
- June 6, 2019 at 6:14 am #111349
OK, Maybe I should restrict sugar in my diet. 🙂
- June 6, 2019 at 7:53 am #111351
Lol he just don’t get it. We want to see and HEAR REAL WORLD Range tests as I have described. With and Without the Terk AM Advantage Loop sold on Ebay for $52 as myself has proven time and again your range WILL TRAVEL 2.5 MILES TO A GOOD RECEIVER!! So the first thing we have to get our listeners to understand is that their Radios are the issue not the fault of a legally operated part 15 section 219 compliant transmitter.
A Car Radio with a Steel antenna not that piece of garbage fin antenna should receive further too. I’m sure that the NEC software is for those garbage Emerson or Sound design Radios where as there is no sensitivity 2-3 uV just to receive a station is not good and we the hobby broadcasters need to educate the listeners on how they can receive part 15 stations. The only brands that need to be in their vocabulary are:
Tecsun, Grundig, Sangean, Directed Electronics, Carver, Macintosh. Basically Ebay is your listener’s best friend for a Radio.
When the NEC software can show a Tecsun PL-365 , PL-380, 880, Grundig S350 DL on a Terk AM Advantage loop receiving a part 15 station accurately its a piece of rubbish and quickly disregarded. SHOW THE VIDEO ON YOUTUBE LIKE I DID!!!!!
- June 6, 2019 at 9:21 am #111353
RE: I’m sure that the NEC software is for those garbage Emerson or Sound design Radios …
NEC software analyzes the e-m fields radiated/received by an antenna system, including other conductors in the propagation environment if they are included in the model.
NEC software does not model the performance of receivers, or of complete transmit/receive systems.
- June 6, 2019 at 11:09 am #111357
I’m sure it can give you a guesstimate of what your Range is going to be like. But I say there is nothing morre realistic than a demonstration in particular a video of what your Range is.
Even some folks who wanted to narc on a Pirate used a video on youtube when describing the reception quality of the Pirate Radio station like the one a youtube video had in which the person authoring the video turned in the Pirate in Clearwater, FL. He showed that he was not just doing this as a hobby but rather selling advertising. And the station was off frequency. A video shows a thousand words. The viewer gets to see first hand the experience.
This is why I’m a stickler for those video Range demonstrations because it tells you what your going to sound like to would be listeners. Its really something we need more of.
- June 6, 2019 at 11:30 am #111359
I’m with you on this one, Legacy. If we’re looking for the most listeners, the only test that really counts is the one to see how much turf our usable signal covers.
- June 7, 2019 at 5:40 am #111380
Below are two graphics from NEC4.2 to help understand and compare the performance of two AM transmit system configurations, for the ~similar operating conditions shown for them.
The first one shows the performance with an antenna system having a total radiating length of approximately 3 meters.
The second one shows a system using a remote antenna tuning unit (ATU) with its attached ~3 meter monopole and other conductors, having a total radiating length of about 13.2 meters.
The “bottom line” — the horizontal distance to the 100 µV/m groundwave field intensity contour from the system with a radiating length of 13 meters is about 1.8X greater than from the system with a radiating length of 3 meters.
Although this comparison included no houses, etc along and near the propagation paths, the effect of them is ~negligible, as they are small in terms of wavelength at this 1.65 MHz operating frequency.
- This reply was modified 1 month, 1 week ago by Rich.
- June 7, 2019 at 8:37 am #111387
Or, just plug it in and see how it works…
- June 7, 2019 at 3:24 pm #111407
Part 15.219 doesn’t limit field strength.
The Talking House transmitter, combined with the ATU (and coax) has been FCC certified, and so if you use it as supplied, without adding a long ground lead to the ATU, the field strength (or the fact that the coax may radiate) doesn’t matter.
- June 7, 2019 at 3:50 pm #111410
What does matter is whether or not an FCC equipment certification overrides an FCC Rule applicable to that equipment.
- June 7, 2019 at 5:04 pm #111414
I don’t know. If we think an FCC equipment certification overrides an FCC Rule applicable to that equipment, the Rule probably doesn’t mean what we thought it did…
- June 7, 2019 at 6:34 pm #111417
It wouldn’t be certified if it overrode the FCC rule.
- June 13, 2019 at 4:52 am #111521
That’s because the FCC has rules on how things should be tested – including a 1 meter ground lead attached to a ground plane.
- June 7, 2019 at 6:41 pm #111419
- June 10, 2019 at 4:55 am #111454
Ok Rich, the model with the ATU is irrelevant. Let’s assume the ATU is fed vertically with 25 feet of coax. Only a twit would place the transmitter at the base exposing it to weather. Your modeling does not show a fence mounted (3 feet) ATU with much of the coax horizontal or laying on the ground. As I said, you have no idea how I or anyone else will mount this device.
You have earned the title of “Resident Hobby Agent.” It’s time for you to find some new material.
- June 10, 2019 at 5:14 am #111457
John M. — I did not attempt to model the system you (apparently) are thinking of installing.
In fact, your description of it didn’t appear here until AFTER I posted my graphics.
If you are not installing the system I modeled, then of course your setup will not produce the results shown for the system I modeled.
My model of the system with the ATU shows its radiating components, no matter in what geometric arrangement they are installed.
- June 10, 2019 at 8:34 am #111460
Well for years people thought the final stage of the transmitter meant the final transistor and that was what everyone was going by thus we saw waterproof transmitters with their audio or power lines going up a 20 Ft pole to the transmitter.
Talking Sign had an ATU/transmitter configuration whereas the transmitter was inside the house and the antenna tuner and antenna was mounted on a 20 Ft pole. Many said it was illegal because they counted the 25 Ft of coax as part of the antenna system a ridiculous notion but one that certain hobby hall monitors would drum into our heads.
Then came the Talking House and their transmitter/ATU combo and again the red flag was raised again. But as we see the slew of NOUO’s for FM and the number of NOUO’s for AM which is almost non existent that didn’t really matter to the FCC so the common citizen has to take the facts and examine them. I say the FCC is saying the final stage is what is comming out of the antenna tuner NOT the transmitter which is Good News.
I could say a few things I’ve experienced but then again I’d have to put links up as proof of this so I won’t bother but read between the lines here. Its what is coming out of the ATU that matters. So if the stub of the antenna has 100 mW your legal. Your transmitter could have 1/2 Watt but due to coax loss or whatever as long as that final (in this case the ATU) reads 100 mW (Or Less) its legal. It could be why certain transmitters that were part 15 (and tested elsewhere past 100 mW to the final was allowed to be sold as a kit so long as it was connected to an ATU).
Rounding this back to the topic at hand the Talking House transmitter has not changed its power to get to the ATU although if 10 Watts ever became legal one could slap an amplifier on the back end of the transmitter and there you go 10 Watts. But the point is that as long as you con’t connect a long ground from the ATU to the ground rod your legal. Even then the FCC has seemed to relax that as well as they should AM is a dying band why worry about all of this crap just enjoy the hobby and what you have. Use certified equipment and don’t go overboard and try and blatantly break the rules and you should be fine.
The FCC’s main concern is interference. It was their main concern when they visited me so all the other stuff is icing on that cake.
- June 10, 2019 at 8:41 am #111462
Oh and while I brought up Interference it would not hurt (If you know how to build or where to buy) a filter that goes from 1.8-7 to 10 Mhz. My broadcast engineer friend and I have tested the Talking House and saw plenty of harmonics going into the Ham band and SW bands almost as far as the fundamental frequency. I’ve mentioned this and still no one has offered where to buy or how to build a proper filter for this. If we are to be responsible operators and we know this is the case and we do nothing about we’re willfully knowing about the problem and yet we continue to be on the air why?
Any fine business operator takes care of such issues before continued operations and yet I’ve pointed that out and more concern is being handed to ground lead issues. Fix the real issue here don’t fix what is not broken.
- June 10, 2019 at 10:07 am #111464
Rich, the Talking House plus coax and ATU as an entire configuration was certified under Part 15.219 by the FCC. That means that it complies with those rules, as long as it is installed as supplied with no modifications made (including attaching a long ground lead). I’m struggling as to why you posted those calculations (someone might infer that using it doesn’t fall within the rules), and wanted to make sure that anyone reading this thread understands that it is perfectly legal to use said configuration.
Thelegacy, again, since the Talking House is certified, any spurs or harmonics fall within the parameters allowed by Part 15.219 (if installed and operated as stated in the documentation). No filter is required (but if it makes you feel better, go for it).
- June 10, 2019 at 3:04 pm #111467
Total posts : 20
Can the spanking new Range Extender be set up indoors? Not everybody has tons of front yard or back yard to work with.
- June 10, 2019 at 5:01 pm #111470
Maybe in an attic but I bet it will cut your range back.
- June 11, 2019 at 5:18 am #111480
Earlier today I posted a reply to this thread, then made a small edit to it after it posted. I got a message saying that I already posted this, and it was a duplicate. In that process it did not post my edited version, and it removed the original version.
Here is the final version as a graphic image.
- June 11, 2019 at 5:43 am #111482
I am sorry I ever opened up this topic. My apologies to the group.
- June 11, 2019 at 6:16 am #111486
There’s nothing to apologize for, AMRadioLegend. We all appreciate updates on this highly anticipated device.
Rich, the issue of the legality of the Talking House & Range Extender has been dealt with extensively here in the past.
From the website of the manufacturer:
“When I connect my Talking House Transmitter to a Range Extender (Antenna and Tuner), is the coaxial cable between them considered to be part of the ground?
It is not. FCC approved the Talking House Transmitter for operation with interconnecting coaxial cable and its Range Extender, which is comprised of the 3-meter antenna/ground as a complete system under Part 15.219.”
It is YOU who, by inference, is casting doubt on the legality of this system, and the position of the FCC on its use (even when it’s been certified). That is NOT on topic for this thread. Start a new thread if you must (which people can ignore if they want), but stop immediately in this one.
- This reply was modified 1 month ago by ArtisanRadio.
- June 11, 2019 at 11:38 am #111500
AM Rado Legend I want to see what your tests show in Range. Its a system easily workable and one can easily put the Range Extender in a place with few obstructions and bury the coax if the need to. We need people like you who are willing to do the reports and or videos of the actual Range.
Time to Rejoice.
- June 13, 2019 at 2:20 pm #111523
Total posts : 40
And Mr. Legend:
The laws of physics and where THE ELECTRONS come from and where they go is what determines the results.
The equipment just helps everything go in the right direction.
So take your time and don’t worry about the outcome.
The water table and ground conductivity are probably
unknowns, as well.
- June 13, 2019 at 10:06 pm #111525
Hi everyone .
I have been reading this thread. No one really understood the reason why the FCC did what they did with this transmitter but after going over all the rule it was clear how the company was able to get around the rules. They really did not get around the rules they just read them very carefully and found a way to get the most out of a transmitter that no one had ever thought of before. By the end of this post you will know why they were approved.
I have been license for 40 years and I have worked with the FCC on many occasions.
I am not going to list each and every section of the FCC rules to try and explain this mess but just put it into plain English.
First off the Range Master and Procaster do not fall into this category since their antenna’s are coming straight out of them.
Ok the rules read that your antenna,feed line and Ground shall not exceed a total length of 3 meters.
Let keep this very clear and it has nothing to do with your final stage amplifier that cannot exceed 100mw DC input power.
Ok most the transmitters being made today have the final amplifier and your PI Network all in the same box . Some of the Pi Networks are design to tune your antenna. Keep it in mind you have the entire transmitter in the box. So if you come out of the regular transmitter now you cannot have an antenna that exceeds 3 meters with your feed line.
If you add a ground wire Then you have to subtract that from your feed line and antenna length.
Ok this is not your regular AM part 15 transmitter.
This is how the company was able to get around this rule. They broke their transmitter up in to two sections.
First section being Audio stages,PLL synthesizer for your frequency and your final amplifier with no filtering or tuning section. If it had these then you could not run coax to an antenna.
Company was smart put a tuner that acts like you filter as well antenna Matching section in a separate box.
Now you are not running coax to your antenna but now your final filter and tuning section of your transmitter. This is why the filtering section has an antenna coming out of it. Since the antenna comes out of the filtering section and tuner section the FCC sees no feed line to your antenna.
What they do see is a connection between your final transistor and your filtering section that just happen to have a matching network.
So that coax can be as long as you want because it is not directly hooked up to your antenna but instead to your filtering and antenna network box.
If this transmitter had the feed line coming out of the filtering section and antenna matching network box to your antenna this transmitter would be shut down.
When they design this transmitter they really thought about how to get around the rule that says your antenna cannot exceed 3 meters in length in total length with feed line,Ground wire and your antenna itself.
The FCC could do nothing because it had meet all the current rules of the time this transmitter was being approved . Who to say later down the road there could be a rule added to keep this form ever happening again. I really doubt it will change but this is the First transmitter to ever have two sections to make it work.
Ok here is the big thing how tall is the antenna that come off that box.
If it is 7 FT then you can have a Ground wire 3 FT in length. If it is 8 ft tall then you can have a ground wire that 2 ft in length.
let just say you had this transmitter up 20ft in the air and your antenna is 8 ft tall.
Then you could run a 2 FT ground Wire into a RF Choke then from the RF Choke down to your ground Rod.
This is a legal set up. When I was talking with the FCC this was the only way they said that a transmitter mounted very high up in the air could have a ground wire that long in Length.
I have also been license for around 40 years in radio and I know these rules and I was in Constant communication with the FCC.
Now he bought the transmitter and if he sets it up by the way the instructions say then he will be legal in every way. At least you know how they were able to get the coax to the filter/tuner section. They do not see the coax coming from the transmitter to the Antenna.
They see the coax coming from the final output transistor to the filter/tuner section.
Your antenna comes off the Filter/tuner section box and has no coax between them.
This is the only reason why this transmitter set up was ever approved.
They broke the transmitter up into two separate sections. The coax is not recognized as feed line but instead just a wiring section to connect the entire transmitter together.
Does this now make any sense to everyone.
He still has to figure his ground wire length from the transmitter to the ground rod.
Now one more thing anything buried under the ground does not count as part of your ground wire length. This is why an 8 foot ground pole does not count as your ground wire length. It because it under the ground.
You can run ground radials as long as they are under the ground buried.
If you want to dig a bunch of ditches and bury a bunch ground wires under the ground go right a head . It very legal the FCC will not hold that against you. They look at them the same way as the 8 ft ground pole since they are under the ground.
I hope this is a real help and and clears up why the FCC approved that transmitter setup.
It is very legal by the rules that the FCC had set in place when this transmitter was being approved.
- June 13, 2019 at 11:13 pm #111530
Sorry my post went a way that explain how the ISS Extender works and why it had been approved by the FCC but I am not retyping it all over again.
If it was removed then I am sorry if it offended anyone but I dont see how explaining how this equipment was approved by the FCC.
Anyways Not sure what happen but it been years since I posted anything on this site.
Ok Post has been put back up on thread.
- June 14, 2019 at 10:36 am #111537
Well, I saw the post and it pretty well sums up the situation. I don’t know that I agree that we gain any salvation by using an RF Choke in the ground wire, though. I understand the merits of using a choke, but as a communications attorney I don’t see anything in applicable regulations allowing us to go long with the ground lead by using a choke. Not that it would necessarily hurt anything, either.
I think the real issue with ground leads is how such are defined under the law. There is certainly a lack of definition in the regs, but the FCC is subject to plain writing and plain language requirements. Look up ground lead in the dictionary. Limiting the length may not be nearly as restrictive as some would have us believe…
- This reply was modified 1 month ago by John Sees.
- June 14, 2019 at 1:15 pm #111541
Let’s not make this another long ground lead discussion. We’re wandering far off the intent of the original post.
- June 15, 2019 at 12:19 pm #111546
Well Did I mess up and erase the post by Accident ?
It really was not about the ground wire itself but how the company split the transmitter in to two different sections to allow for a coaxial cable to run between both units.
And was able to keep it legal .
That pretty much it.
- June 15, 2019 at 12:21 pm #111548
Sorry it posted twice on one of my post.
I will let you all get back to your conversation
- This reply was modified 1 month ago by Seankw40.
- June 15, 2019 at 12:33 pm #111551
Well, it was there long enough for me to see it and I didn’t see anything wrong. My only question was if you know something I don’t about the FCC taking an RF Choke into account in the ground lead measurement. I can see why they might, but haven’t found anything to indicate they have or will.
Thanks for your comments.
- June 15, 2019 at 1:13 pm #111560
I have other transmitters as well. The FCC told me if I wanted to place a transmitter up really high then I needed to place an RF choke in line with my Ground Wire to make a DC ground connection for Lighting strikes.
See the rule says that you can only have 3 meter in total length this would count your Antenna,Lead wire(coax), and Ground wire.
In all this cannot be no longer than 10ft in length.
So lets say you have a 8ft antenna coming directly out of your transmitter.
This will only allow you to have a 2 ft ground wire. That 2 ft of ground wire the FCC see’s that as part of your radiated signal.
So if you want to have a longer wire than 2 feet you need to place an RF choke after that 2ft point. Since the RF choke stops all RF from getting through the FCC sees the wire after the choke as a non radiating wire.
Then you can have any length of wire you want after that choke. This is not in the Rules it was what I was told by the FCC and if I mount any of my Part 15 transmitter up very high in the air this would be a way I could provide a ground wire to them.
I really do not think the FCC going to do anything to anyone if you are mounted on a metal fence post and your ground through it.
Since this is very low to the ground. This is more transmitters being mounted very high up in the air.
Now I know of one individual who mounted his transmitter to the chimney of his home.
He had a power outlet added on the top of his home right next to the chimney .Since the Power outlets go to your house ground. He used that ground. He just ran a 10 guage
wire from the transmitter to that out let ground. The wire was bright green and only measure around 18 inches. He Labeled it ground wire. The FCC never gave him any problems since they did not count the house ground . They were not going to tear up his house just to see how long the wires were to the house ground rod. They only counted that short 18 inch bright green wire as his ground wire.
Anyways this was what I was told to do by the FCC on my set up if I need to extend my ground wire for a DC ground.
I hope it helps out a lot.
Ok it looks like my old post came back up.
- June 15, 2019 at 1:43 pm #111565
Ok I said enough and do not want to offend anyone in anyways.
I have only told you the way the FCC told me how to set up my ground system.
This is for anyone who want to know the Choke size I was told to use was a 1 mili henry
or larger should block all RF signal past my ground wire of 2 ft in length.. My ground wire is 2 ft so anything after that 2 ft all RF is being blocked out or reduce to almost zero by the Choke. This just mean any ground wire After the Choke should only pass a DC current to ground which is good for lighting strikes.
If I went by the rules only very strictly, then my transmitter could only be mounted
around 2 feet off the ground. I have 2 transmitter made by different companies and they both use around an 8 ft antenna. That only leave me a 2 ft ground wire to my grounding rod.
This is why I called the FCC on this issue. I think this may be on some of the Manufactures websites of how to use a RF Choke in the ground system.
They may have been told this as well.
I always say when in doubt ask questions.
Well I have said enough and will let everyone get back to their talking.
I will now back out this conversation and let you all have it back
- June 15, 2019 at 2:19 pm #111567
- June 15, 2019 at 2:46 pm #111572
Thank you for sharing that, Sean. I’m sure all here agree that your comments are appreciated and welcome here anytime.
- June 15, 2019 at 4:44 pm #111575
I know you are a Ham Radio operator. Rich keeps referring to W8JI
website but not sure if he is W8JI who has one of the largest ham Antenna
set ups in this country. I am a Ham operator and have been for 4 decades plus
some. I do hold an Extra Class license. Most my receivers and transmitter have been refurbished by me to get them back up on the air. Other I have design and built just to see what they could do. I love tube type radios and transmitters.
Anyways the only reason why I have not designed a part 15 transmitter for the market is that their enough of them on the market already and some are really well design and built.
There really is no reason just to add another one to the market. The transmitter
is really not the Issue. Since if anyone uses a class E type Biasing you will get around 100% output power of the DC input power. The problem is that You only get out as well as your antenna is design.
What have ham radio operators been saying for years. It not the power that gets you out it the Antenna.
So once you have the full 100mw output power then it come down to the Antenna design.
That a whole ball game in itself. And their so many variables that effect part 15 antenna systems. Biggest one is the limit of the 10 FT antenna if you use no feed line or ground connection.
My goal in the future is to introduce a part 15 antenna that has very little loss in the Matching section. I have all the correct test equipment to test antennas.
I did this for a living so I do know this area very well.
Anyways this thread is not about this but I wish you all the best in trying out the ISS extender antenna.
Set up correctly it should perform quite well.
- This reply was modified 1 month ago by Seankw40.
- June 15, 2019 at 9:31 pm #111578
Good post. Especially enjoy your comments regarding Part 15 technology. Are you aware if any of the current transmitters actually getting 100 mw output? I’d heard about the most was around 60 mw out, be that right or wrong. Agree about antennas. I think there’s room for something more efficient.
I’m waiting to hear results of what kind of range people will get with the ISS extended range set up. I was going to go with Rangemasters since those can be networked but I’m thinking if range on the ISS is something approaching a mile, I might not fool around with trying to network several transmitters.
In addition to communications law, my firm (www.seeslaw.com) has several locations here in Indiana where we only handle consumer bankruptcies. I’m thinking of setting up a transmitter at each location to play music and maybe a ten or fifteen second commercial for the firm every 15 minutes. I don’t know how cost effective that will be, but I suppose the costs will be tax-deductable even if it isn’t.
I guess we’ll see how those test results go to determine which kind of transmitters we’ll be deducting for…
- June 23, 2019 at 7:10 pm #111690
I’m assuming the RG6 braid attaches to the chassis at the transmitter end and the chassis at the range extender in the common fashion for coax through connecters. There isn’t any reason this would be different, is there?
I’ll admit I haven’t quite figured out how this got certified, but a local know-it-all (worse than me, even) is spinning a tale about complicated thing that involves the braid not being connected someplace…
I hope he doesn’t know something I don’t about this…
- June 23, 2019 at 9:37 pm #111696
let me see if I understand what you’re saying. What you are suggesting is that somewhere there is no connection to the outer Shield of the coax right? Well if this were true you would have a lot of radiation coming from the output of the transmitter to the range extender but by the time it got to the extender to be tuned you would have lost a lot of power as most of it would be radiating out of the coax.
This really makes no sense if that is what you are saying it would make more sense just to use leaky coax going up to the ATU which then would radiate.
The fact that the coax is well shielded would keep it from radiating until it got to the range extender itself. The shield in this case becomes sort of a block to make sure that the radiation is going out it’s intended place the ATU. I’m quite sure you already know that but just to make sure anyone reading this that doesn’t know now they do know.
As we have also seen Tim in bowlby’s test of his procaster he is getting about 1 1/3 miles before it goes to Fringe area but remember he’s about three stories up so that’s about 30 foot or so give or take from the ground.
I think we really need to see what type of range this thing is actually achieving before we pass any type of judgement and I can’t wait until a real test is done maybe even a video of the range itself. I’m going to stay tuned for this one.
- June 24, 2019 at 4:55 am #111705
Well, yes. I think that is what he was trying to tell me and no, it didn’t make sense to me either.
Thanks for your comments.
- June 23, 2019 at 9:38 pm #111698
I can answer a few of your questions.
The Rangemaster can (and should be) tuned to provide exactly 100mw input to the final. There are two ways to do this. They provide a module that indicates when you are exactly at 100mw, but I’ve never trusted that (the one I had was difficult to read). However, there are also measurement points in the transmitter that allow you to calculate when you reach 100mw (P = I * V).
From what I’ve read in the FCC and Industry Canada databases, most other certified transmitters are approximately 80 mw input to the final (and of course, much, much less output at the antenna, generally less than 1 mw even with the best installation).
As to the Range Extender certification, from what I understand, the manufacturer managed to convince the FCC that the Range Extender was the final stage in the transmitter system. This allows them to connect the Talking House with the Range Extender via coax without violating the ground lead rule. The concept is actually very similar to what radio8z was talking about in one of his posts, and he was postulating connecting the stages via CAT5 cable.
There have been extensive discussions surrounding the Range Extender in this Forum and others for many years. The manufacturer insists that they have the paperwork (and it may well have been published here, I think) that proves that the system is FCC Part 15 certified. I’m too lazy to look it up, but I’m sure that you could find it if you searched. The certification has been treated as fact for many years by virtually everyone in the field, and the FCC has done nothing to dissuade that opinion (i.e., by issuing NOUOs to users of the technology).
I personally believe that the manufacturer managed to pull a fast one on the FCC. A similar type of product for the Talking Sign (the precursor to the ProCaster) was not able to get certified in either Canada or the U.S. and the company was forced to take it off the market. But as I, and I believe you, have stated plenty of times, the Part 15 rules and the rules of physics are not necessarily the same thing. Part 15 rules are open to interpretation (and the FCC has lots of discretion). Physics (ideally) is not. The two are often mixed up, and that’s where some of the heated discussions surrounding this topic originate.
- This reply was modified 3 weeks, 1 day ago by ArtisanRadio.
- June 24, 2019 at 5:03 am #111707
Thanks, Artisan. That sounds right to me.
- June 24, 2019 at 3:53 am #111703
Below is a graphic showing how r-f current can flow on the outer surface of the outer conductor of a coaxial cable.
This occurs even when the termination at the far of that coax exactly equals the characteristic of the coax connected there (often 50 +j 0 ohms).
That current flowing along the outer surface of the coax outer conductor produces e-m radiation into space for the same reason it does when flowing along a conductor leading back to the inner conductor of the coaxial cable.
- June 24, 2019 at 5:11 am #111709
Thanks for your comment, Rich.
So, does that mean:
1. The TH is actually sending RF up that coax and getting another 25 feet of antenna+lead; and,
2. Another 25 feet of ground through the coax braid?
- June 24, 2019 at 5:51 am #111712
With a perfect impedance match between the coax and the load at its far end, the current flowing on the OD of the inner conductor is equal to the current flowing on the ID of the outer conductor, but they are 180 degrees out of phase. Therefore their radiated fields cancel.
But when the current on the ID of the outer conductor reaches the far end of the coax it finds two paths to travel along, one being the OD of the coax outer conductor. The current traveling along that path produces radiation.
Radiation will also occur from any conductor connected to the OD of the coax outer conductor at the tx end, including the path from the transmitter chassis along the “ground” conductor of the a-c mains service until that conductor connects to the ground rod at the service entrance.
- June 24, 2019 at 6:57 am #111714
Indeed, that’s how they’re getting away with it.
- June 24, 2019 at 9:49 am #111716
How much RF is radiated with the cable on the ground. It’s time to drop this subject and move on to newer paranoia.
- June 24, 2019 at 3:56 pm #111720
Well Legend, I think I’ve figured out everything I wanted to know about the grounding of the range extender, anyway. What I’d really like to know is if you have yours operating yet and if so, how does it sound and what kind of range are you getting?
- June 24, 2019 at 10:46 am #111718
If, as the manufacturer claims, and the evidence indicates, the entire system is certified, then the amount of additional radiation introduced by the coax cable is insignificant.
In addition to that, the radiation introduced by coax in a properly matched antenna system is minimal, regardless of whether it is possible or not.
I suggest that if anyone really has their knickers in a twist about the potential radiation the coax, along with the Range Extender, introduces in the Talking House system, they purchase said system and actually measure it (as I’m sure the lab in the certification process did).
If further theoretical discussions along this line are desired, they should be taken to another thread.
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