The report is very detailed and useful. My #2 report though more in the relative sense, is forthcoming.
Just out of curiosity I violated my self imposed resolve to never visit the HB site again, and read the review.
I have no beef with the test procedures.
But I have to ask. Can we count on untarnished results when there's an ad for the product being tested right there on the page?
This ad states "A new Range Extender is available that can make a Talking House "talk" a lot farther".
The test results shows an increase in field intensity of 12% (Lord knows we'll never see an actual field intensity number in a HB report). Does an FI increase of 12% translate to "a lot farther". I'm not so sure. Lets say you've determined that your coverage area was half a mile. That's 2640 feet, an increase of 12% is 316 feet. So, all things being equal is it worth over a dollar a foot for the increased range? Obviously this is going to vary greatly depending on your specific location, current range, etc.
And I seek someone with better "book learning" of the science who can tell us if a FI increase equals a linear increase in expected range. In the back of my mind I'm saying no -- e.g. if you double your field intensity you do not double your range.
I'm glad to see Bill at HB did point out that some of this increase may be due to the slightly longer and larger diameter antenna as well. Obviously this would cause SOME increase over the earlier model, just by the change in antenna due to a better match needing less tuning.
At the "System Specifications" part of the Range Extender 2.5 website it states range should be about 2500 feet and that it "varies with mounting height and environment" which is to be expected. They state that recommended minimum height be 20 feet or more.
The lab report at HB says "a ground level Part 15.219 compliant installation was employed for the comparison between both antenna tuners." Not sure if this is implying that mounting it at 20 feet and running a ground lead might not be compliant, but that is what the maker is recommending. It does make me wonder about the legality of mounting it at 20+ feet and installing a ground. Maybe it's fine. Maybe it's not. I would be interested in seeing the same test with the units at 20 feet, and compare FI with and without a 20' ground lead attached. Bet that lead would radiate like crazy!
I would say that the unit does appear to be well built piece of gear. I would have been tempted to install a longer, larger diameter antenna equal to that supplied with the new model on the old one to see what the difference may have been. Maybe you only gain 8%. But 8% gain with a 10 dollar piece of aluminum might be satisfactory compared to a 12% increase for $395 (granted it's cheaper when you bundle with a transmitter if you don't have one already).
So that's my gut reaction to the lab report and the product.
TIB
Regardless of "By The Book Rules" if the FCC certified that ATU at 20 Ft Grounded the previous "Book Rules" are not relevant so long as your running that ATU with their transmitter it was meant to be paired with (or any other for that matter)!
So one could (In theory) connect an ASMAX 2 C-Quam transmitter either with a F connector attached to the board instead of the BNC or use a BNC to F connector converter to do this. My broadcast engineer friend built me an ATU and antenna for mine but say his ATU goes bad for whatever reason. I could pay the $350 and buy the ATU and then hoist it 20 FT with a 10 gauge ground going all the way down. Remember the ATU was certified and the only giveaway is I'm running C-Quam AM stereo which the Talking House obviously isn't C-Quam.
I'd say this is great news for the part 15 community and we need to test this ATU with a Tecsun PL-380, PL-365, PL-880 or High performance receiver as well as a Car Radio such as the Toyota Corolla's Radio because the Toyota Corolla can receive my ASMAX2 2 miles with a very listenable signal. Sometimes I was heard 4 miles but the recording I heard from the Toyota Corolla's Radio I would be tired of it real fast at the level of static I heard. This is what Bill should have done knowing a Kenwood car Stereo or Toyota Corolla Radio is High performance. A Mitsubishi Motors Radio can receive my signal in C-Quam 1.5 miles out (exactly what my agent friend quoted me).
I think this ATU has great possibilities but I'd never go past 100 mW even if it becomes legal with that ATU because of the small gauge of wire it uses. You'll fry it at more than 100 mW because of its low rated parts inside. So this ATU if ever we get our extended part 15 service is not gonna cut it and at almost $400 I'd think they would had made it accept 5-10 Watts knowing that AM Radio is dying and that it will eventually be handed to the Hobby Broadcasters.
RE: ... tell us if a FI increase equals a linear increase in expected range ...
It does, for propagation environments having equal characteristics — as long as...
» the ambient noise and interference present on/near that carrier frequency is the same at all receive locations, and
» the same receive hardware and operational configuration is used at all receive locations, with the receive antenna physically oriented for best reception.
The r-f power radiated from a given configuration of transmit equipment to increase its field intensity by 12% at all receive locations in the far field would need to increase by 1.12² = 25.44%.
TheLegacy wrote "You’ll fry it at more than 100 mW because of its low rated parts inside. "
You may well be right but how do you know this? Is there a published specification from the manufacturer which states the maximum power handling capability? Any documentation regarding maximum power?
Otherwise, it is best if speculation not be used.
If I were an engineer (which I am) and was analyzing the "Range Extender" (which I am not) I would be very interested in measuring the efficiency of the device. What is the loss in the coils and tuning slugs? How much power is lost in driving the metering circuit? Bottom line is how much power is delivered to the antenna system with a given DC input power to the final amplifier?
The primary thing which matters, in my opinion, is how much power, given the input to the final stage is 100 mW, is actually delivered to the antenna system including the radiating element and antenna ground system?
I know of no Part 15 transmitters, except mine which was published here years ago, which state the measured output power to the antenna system. For reference, mine produced a measured power delivered to the actual antenna system I use here of 85 mW with a DC input of 100 mW to the final stage. [Edit to add: To be fair and fully disclose this, my antenna system includes a base loading coil. If the transmitter output is considered to be after the loading coil (as would be the case with those using an internal loading coil) the power delivered to the antenna system (radiator and ground) is 55 mW, 85 mW into the system minus 30 mW being lost in the loading coil. This would then allow comparison to transmitters with an internal loading coil.]
One manufacturer claimed 99 percent efficiency (calculated) but did not include the antenna tuning system (loading coil) so the claim is seriously flawed with regard to assessing the actual performance.
My point here is that in order to assess the effectiveness of any transmitter or tuning arrangement the performance needs to be stated in meaningful engineering terms which can be universally applied and replicated and which can be used as a basis of comparison of the various systems. For example, a bench test using a dummy load negates the real effects of environment which plague "field tests". It provides a repeatable test of different equipment. It negates "weaseling" by just stating your results will depend on your installation...true, but not really useful and all too common.
If any manufacturer chooses to subject their transmitter systems to lab tests using a 30 ohm resistive plus 30 pF reactive load in series to simulate a realistic Part 15 antenna and report the actual power delivered to this load and efficiency this would, in my opinion, do good service in providing a laboratory testable basis of comparison with other devices and can be a meaningful predictor of actual on the air performance...certainly better than what we now have.
"Regardless of “By The Book Rules” if the FCC certified that ATU at 20 Ft Grounded the previous “Book Rules” are not relevant so long as your running that ATU with their transmitter it was meant to be paired with (or any other for that matter)!"
We have no idea if it was certified by the FCC with a 20 foot ground lead with the unit mounted at 20 feet. They recommend this as a minimum height in their specifications. No mention there if that includes a ground. The fact that a ground lug exists does not imply that either. My Procaster is at about 30 feet, and it too has a ground lug, and it too is certified. However, I'm pretty sure if I attached a 30 foot long ground lead I'd be in violation. Can't check on too many certification specs for the Talking House as the certification number they reference goes to an approval from 1997, which obviously doesn't apply to the current Range Extender. In fact the listing at the FCC for this certification number makes no mention of the earlier range extender either.
It also says no license needed if installed according to Part 15.219, which would rule out adding a 20 foot ground lead.
I also can't seem to find any of the certification testing information. For my Procaster not only can I readily find current certification information, but also complete access to ALL the lab work, data, photos, etc from the actual tests as submitted to the FCC. In fact, I could find this information for all the FM transmitters I tested a couple years ago as well.
I can't find a spec of information regarding certification of any Range Extenders.
And there's no documentation on the Talking House site either. Their only manual available is a short manual on the transmitter itself, non a peep about the Range Extender, old or new. The only installation instructions offered say to attach the "indoor antenna" and fully uncoil and extend the antenna wire. And it references details instructions in "this manual" if using an outdoor antenna. I find nothing in this manual about an outdoor antenna.
So, we really don't know much and it appears that details are not available.
TIB
Here is what I can quote legally quote say about how I know about the ATU. My broadcast engineer friend got the schematics of the ATU from a source that is sort of underground. He looked at the ATU and we talked about how if something ever happened to him and there was ever any more legal power allowed could I use that ATU on a more powerful transmitter?
He told me by looking at the schematic that the coil inside that unit was very thin think Dollar Store AM radio here. So you can imagine what would happen if you pumped even 1 watt into it how it could heat up. Now try 10 watts and I guarantee you it would be like lighting a match to paper.
For the price of the ATU I think they could make it much more beefier than that.
The FCC limit is 100 mW input power. Why are we concerned with 1 or 10 watts?
Because "Some" of us (Including Michelle Bradly is working on a New Service or Extended part 15 service (Which most likely we will get as AM is dying as far as a cash cow medium).
How many times do I have to tell everyone this? Again Facebook is your friend start joining the Radio groups, read the writing on the wall AM Radio is dying in several countries. Many stations are going dark, If I sent a link for every dying station I'd have to write a book.
That being said I want a antenna tuning unit that when (Not IF) we get the green light I can buy the higher powered TX (Or create or buy a linear amp and my antenna system doesn't melt away at a $400 price tag).
<b>Many are trying for the restrictive LPAM (A cheap imitation of LPFM).</b>
Now is the time to come to a fair agreement that LPFM laws won't work on AM for a lot of reasons real estate being one. So a 1-10 Watt service for "citizens" or however you want to sugar coat this thing is the magic pill keeping AM alive and separate from FM and the laws should be separate. Please Join the following Facebook groups:
1. Part 15 AM&FM broadcasting.
2. I Love AM Radio
3. AM&FM Hobby Broadcasting (I can hear the moans now).
4. C-Quam AM Stereo (We are fighting to bring back C-Quam and there is a well known broadcast engineer fighting for this on this forum).
Then you will read the links (posted by well known broadcasting engineers and folks in Radio experienced as much OR MORE than that "Other" site we love to hate).
Some folks (Including some FCC agents are starting to take my proposals seriously including easy open source EAS systems as easy as a Kenwood Car Stereo with Bluetooth that has a built in EAS into it and GPS whereas the RAdio breaks in on Bluetooth transmitions. Hint: Do as I do and transmit your station from your bluetooth transmitter into the converted Kenwood car Stereo with EAS and when a weather emergency, Amber alert, comes it breaks into your broadcast and TADA!!! your emergency is broadcasted to the Audio processor (Sean Cuthbert) to the transmitter. When done the music resumes. Very simple easy and not $4G not even close.
Join the "It can happen club" open thy mind.
This thread is supposed to be about the Range Extender, not changing the Part 15 rules.
If you must discuss desired rule changes (which have been discussed ad nauseum in the past), please start another thread.
<p style="text-align: left;">Will getting back to this current ATU that were talking about which is the range extender 2.5 and how it is currently made I would like to see these tests done before winter hits.</p>
Another friend of mine red horse 1620 has done numerous tests with several different types of antennas and different systems out there but this one is a little expensive as he and I talked about.
Maybe you would like to compare the range extender 2.5 with a talking house to the range that I currently get on my system. I had a very dedicated listener who also has a part 15 radio station in Norfolk do some videos in his car and you could hear my signal on an actual car radio that different parts of the Deltaville area. I think this test what awaken some people's mine's about what you can really do if you set your antenna system right and have it in the proper location whereas you don't have a lot of noise on the AM Spectrum band.
I would say that if the range extender 2.5 got nearly the same range or better as I do then it would be worth it but if it got horribly underneath would I get I would say it would just be an overly expensive toy. We'll try and see if one of the folks that I hang with is willing to do the test and if so it will be a video where you can actually hear what's going on no bar graphs no guesstimate an actual sound bite along with the video. This is the kind of range test everyone wants to hear and see.