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Discussion Starter · #1 · (Edited)
Back when it was called the 790 I wanted to get one, but I couldn't find any information other than what Solid Signal had. Stuart at SS had a video, but he made it sound like it was such a big and heavy antenna and so hard to put together. As a result, I ended up getting the HDB91X and later the 91XGs. Of course I had to supplement the VHF with the Stellar labs 30 - 2476. But I can't leave anything alone that works. I always wondered -"what if?"

So, I decided to try one out. Assembly is not hard at all. Yes. the instructions would like something from Ikea but they're actually very helpful. Especially the three or 4 bolt lengths. Everything else was a breeze. The only thing that I had to stop for it was the boom separator. With the tri boom Arrangement you need some sort of support and it has a plastic curved piece that can be attempted to be put on upside down which is exactly what I did. When the bolts didn't line up with the holes I just flipped the separator. Done.
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It's a very robust antenna. Sure it's heavier than the Chinese antennas. But not really heavy, I was able to carry it with one hand the ladder and hold it with one hand ( I have no choice) The tilting double clamps are nice.

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Discussion Starter · #2 · (Edited)
I thought I would share this screenshot of the 91XG full power KT-200 compared to what a 5 port splitter does to a signal. Blue= Direct, Green= W 5 port splitter
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Similar but with a 3 way splitter Blue Direct, Green= 3 port splitter:

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Warming up the HDB91X, checking for signal consistency, all good, both traces fairly consistent:
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HDB91X w KT-200 (Green) vs DAT Boss LR Mix (Blue)
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HDB 91X Blue trace, 91XG Green trace both using same KT-200
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Televes DAT Boss LR (Blue trace) Vs. the 91 XG.
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A few minutes later, to be sure. Televes- blue trace, 91XG Green trace.
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Several minutes later,. Televes Vs. 91 XG :
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Here's the one that gets me, My home brew 163XG(Green trace) Vs. the Televes (Blue trace)

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Re-checked my connections and gave it another round, still the Televes is a worth opponent for the 163XG:
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You can't compare these two antennas unless you can get the preamp gains to be the same. It's comparing apples to oranges. Televes has the nasty habit of adding the antenna gain to the preamp gain and then claiming these huge gain numbers for their antennas. This is just marketing and no one else I know of does this. The only thing that really counts is Noise Margin. You need to figure out a way to measure Noise Margin. Simply looking at the amplitude differences on the spectrum analyzer doesn't tell you anything when the preamps have different gains.
 

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Unless one of the preamps controls it’s gain automatically and can’t be removed from the equation because it’s been designed hand in hand alongside the antenna hardware for peak performance.
 

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You can't compare these two antennas unless you can get the preamp gains to be the same. It's comparing apples to oranges. Televes has the nasty habit of adding the antenna gain to the preamp gain and then claiming these huge gain numbers for their antennas. This is just marketing and no one else I know of does this. The only thing that really counts is Noise Margin. You need to figure out a way to measure Noise Margin. Simply looking at the amplitude differences on the spectrum analyzer doesn't tell you anything when the preamps have different gains.
I have to disagree. You are comparing antennas as they are designed. It’s like comparing a bicycle that you add a motor to compared to a crotch rocket that is one complete design. The Televes antennas are designed as a complete unit. You are trying to remove the engine from the crotch rocket and saying including the motor is just marketing and none of the bicycle makers do this. Of course the preamps have different gains. That is, half of the “magic” is the special design of the preamp and the fact that it’s integrated in the antenna which is fairly unique in the market. So bottom line is you should compare things as they are designed to be used and not arbitrarily cripple one to compare to the other. The preamp is the work of PhD’s and university researchers and many years worth of work. Tossing it aside is what does not make sense. To say the only thing that counts is noise margin is simply not correct from an engineering perspective. What matters is to make sure the signal power levels are in the range of the tuner and that the MER in the case of ATSC is maximized.
I hope that helps clarify things from an engineering point of view.
 

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I hope that helps clarify things from an engineering point of view.
The "appeal to authority" argument is not going to work with me. Your post sounds mostly like what the marketing department puts out.

How about some specs on the preamp? What's the noise figure? The gain of your preamp looks like it's 28 dB. I got that from subtracting the antenna gain from the total gain. What's IP3? These 3 numbers would go a long way in evaluating the Televes preamp to other options.

There are no magic preamps. They all have parameters that can be measured and compared. Integrating preamp into the antenna feed is not a new idea. Winegard was doing that back in the 1980's.

If you think your antenna/preamp combo does something special then please tell us what it is and how it's different from anything that came before. So far you haven't explained that.

The best way to maximize MER (aka SNR) is for the preamp to have a low noise figure with enough gain to maximize the System Noise Figure but to minimize the possibility of overload.
 

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The "appeal to authority" argument is not going to work with me. Your post sounds mostly like what the marketing department puts out.

How about some specs on the preamp? What's the noise figure? The gain of your preamp looks like it's 28 dB. I got that from subtracting the antenna gain from the total gain. What's IP3? These 3 numbers would go a long way in evaluating the Televes preamp to other options.

There are no magic preamps. They all have parameters that can be measured and compared. Integrating preamp into the antenna feed is not a new idea. Winegard was doing that back in the 1980's.

If you think your antenna/preamp combo does something special then please tell us what it is and how it's different from anything that came before. So far you haven't explained that.

The best way to maximize MER (aka SNR) is for the preamp to have a low noise figure with enough gain to maximize the System Noise Figure but to minimize the possibility of overload.
First I'm sorry if you took my analogy to be marketing, it was not intended to be and was only meant to explain things without being overly technical. I'll happily help with more technical too, within reason. As far as an "appeal to authority" perhaps I should explain who I am. I am a Sr. Member of the IEEE (Institute for Electrical and Electronics Engineering), a licensed Professional Engineer, a Fellow of the National Society of Professional Engineers, a past instructor for Motorola University (taught introductory RF Communications), and have over 3 decades of engineering design experience, all but a brief period being communications, both terrestrial and satellite. While I am far from "the authority" I am certainly "an authority". BTW the reason I taught intro to RF comms was because of my ability to teach technical things in an easy to understand way and have taught many adult classes over the years. Let's see how I do here though as I'm used to doing this live in front of a class or a group of other folks in person with a more interactive nature.

As far as the gain of the preamp is concerned, it is not fixed, which is the point. When I put "magic" in quotes it's because while nothing is truly magic, this bit of tech seems pretty close though. It's sort of like what folks say FM stands for... F...ing Magic. We have tested the design in the lab with all the apples to apples comparative antennas on the market we could get. We strive to be the best at what we do and if the lab results did not show that, then it would be back to the design to make it better. This is essentially what was done over the years it took to develop this. This is the part I mentioned with all the R&D effort that went in to the design. This is not a basic amp with an AGC but instead is a very complex design AGC with a very large dynamic range. For understandable reasons I cannot give away the exact details. Additionally we have the ability to tune some of the parameters of the MMIC in order to most effectively couple it to the specific antenna it is being installed in. If you want an amp that does take it down to the channel level then we have the Avant X that does that but it costs nearly triple the antenna and TForce (MMIC) preamp we are talking about here.

As far as specs are concerned, we don't hide those, they are readily available on our website. Here is an example though from one of our spec sheets. You'll see we list the gain both with the preamp on and off, though I'm not sure why we bother with off most of the times since we highly recommend everyone use the preamp in the active mode, that is after all what they are paying for. If all they want is a passive antenna, there are plenty out there that don't have the benefits of our antennas. Why would you pay for that amount of tech only to leave it turned off. Please make sure you read the note at the bottom and the fact that the gain with the preamp on is max.

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As far as your comment about "MER (aka SNR)" they are not the same. MER is Modulation Error Ratio and SNR is Signal to Noise Ratio. Those things are not the same though they are somewhat related in much the same way as CNR and Eb/No are related in a communications system. Put simply, SNR is a measurement of the ratio of the over all signal to the noise (pre-modulation) whereas MER is the measure of how far the received symbol is from the ideal (theoretical) symbol and is measured in the form of a vector so the MER effectively measures the ability of the discriminator to determine the correct symbol as visualized in the constellation, in this case 8VSB. The overall MER is put in the form of a ratio (dB) though to represent what is essentially a moving average of how far off the received symbols are from the theoretical construct. MER takes into account additional impairments of the communications system that SNR does not.

To help with an explanation of how noise figure comes in to play in a communications system, here is a white paper that several of us co-wrote within the company. It also addresses why it is important to have the first stage amplification as close as possible to the receive element. Hopefully this will help to dispel some misinformation about NF.
 

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Discussion Starter · #8 ·
You can't compare these two antennas unless you can get the preamp gains to be the same. It's comparing apples to oranges. Televes has the nasty habit of adding the antenna gain to the preamp gain and then claiming these huge gain numbers for their antennas. This is just marketing and no one else I know of does this. The only thing that really counts is Noise Margin. You need to figure out a way to measure Noise Margin. Simply looking at the amplitude differences on the spectrum analyzer doesn't tell you anything when the preamps have different gains.
I agree that Spectrum analyzer doesn't really tell the whole story. And, being a laymen like myself, I don't have the sophisticated equipment to measure noise. All I can really do is offer my screenshots of the Milwaukee Spectrum on my Toshiba TV signal meter which does display SNR:

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I know it's not very scientific, but it's the best I can do with what I have.⁹
 

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Dear Calaveras, this is Javier Ruano, GM with Televes USA. I’ve asked you before both in public and privately through this forum, and I’ll do it again here, do you have personal experience with any Televes antenna products? I’ve read your posts in this forum and others with interest over the years. You seem pretty well set in your opinions about our antennas, seemingly traceable back to incomplete and quite misinformed articles published many, many years ago, but it seems to me, without having first hand knowledge of Televes products. In case you have not had the opportunity and are just putting out opinions based on your interpretation or what you've read in the internet, I'd be happy to provide you with some samples for your perusal. Please, feel free to PM with an address.

Just for context, Televes is a company that has been involved with terrestrial television ever since its foundation in the 1950s. Nowadays we are a multinational covering many different verticals but deeply involved in anything that has to do with DTT (we are, after all, founding members of DVB). From the the design, development and manufacturing of broadcasting transmitters and SFN gap- fillers OEM'd by some of the main brand names in the industry, all the way to professional monitoring and test and measurement equipment, and everything else in between, from aerials and digital processing headends to distribution equipment all the way to the very last outlet in the home. To this day, and as opposed to most of our competitors in the antenna space in the US, we at Televes design, develop, and manufacture all our products in our state-of-the-art facilities located in the Northwest of Spain. When it comes to antennas we roll our elements from raw aluminum, inject our clamps and electronics shielding out of zamak, inject our own plastic parts out of only top performing ABS plastic, and use stainless steel hardware throughout. We make our own printed circuit boards, ensuring the reliability needed to put them inside a dipole on an aerial, all of this with quality assurance and traceability throughout the manufacturing process (for your interest, ISO 9001 and 14001 certifications can be found on the website). All of this manufactured in a 100% robotized Industry 4.0 Manufacturing process paradigm ensuring the most stringent quality control procedures.

We of course have our own certification labs where not only we can approve CE and UL marks, but more importantly subject all our antenna products to extensive EM testing, saltwater and UV resistance, temperature and vibration shock, etc., simulating decades of on the field life for any new products long before they ever reach the market. We actually certify some competitors in these very labs.

The result of this painstaking process are antennas built to quality standards that far exceed what you find in other brand names sourcing their products mostly from the far east these days, or otherwise. I trust you would surely recognize this should you ever be able to experience our products in person.

We currently have subsidiaries in 18 countries, our products are otherwise distributed and sold in over a hundred countries worldwide, and we are, by all accounts, one of the worldwide leading technology companies when it comes to DTT solutions. With regards to the US we've had an office in Denver since the late 90s, but truth be told we have never had a focus on terrestrial television here until fairly recently with the renewed interest in OTA over the last few years. Admittedly our design philosophy is quite different from what you are used to seeing and experience in the US market, flooded with very dated designs and OEM branded far East originated product frequently more concerned with profit margins, marketing and presentation than with quality and performance. As I said, we've watched opinions such as yours in forums from a distance an in amusement for a while, but we believe it's come a time to clarify who we are and what we are all about. I do apologize for this long and winded presentation of who we are as a company, but trust it is pertaining to put these discussions in its adequate context. We are no newcomer to the space, trust me on this.

For many, many years now our antennas have included preamplifiers built in right at the dipole, you will no doubt surely agree with me that this is the optimal location to apply amplification in a signal acquisition system, if amplification is going to be applied. This is rarely seen, and there is a clear business reason for it, it's not cheap to do it right. Sturdy shielding, temp resisting PCBs and quality componentry need to be used throughout. It's far easier to throw a preamp somewhere further down the line, or leave that worry to the customer. Our latest generation of antenna products incorporate what in the marketing literature is known as TForce, our newest iteration of antena pre-amplifiers that automatically adjust their gain to adapt for the conditions of the signal received by the antenna, aiming to deliver an optimum output level for distribution at all times, despite the changes in receiving conditions.

For this the Televes Corporation has designed and manufactures proprietary MMIC chipsets that allow to reach performance parameters not achievable with regular discrete component designs. Some of the key design elements and performance parameters of these solutions are proprietary and we are not at the liberty to share just anywhere, but believe me we have no "nasty habits" or engage in unfounded marketing gimmickry. Quite honestly we have struggled for decades with the US antenna manufacturers tradition of listing the antennas with "miles" ratings. We just develop solutions aimed at covering a wide variety of scenarios, subject to constant improvement and which prove their worth time and time again all over the world.

One should not think of Televes antenna products in terms of a traditional antenna plus a pre-amplifier. From the ground up our antennas and electronics are designed hand in hand to complement each other and provide peak performance, as a system. Of course our hardware antenna designs are fairly unique as well, many times misunderstood and although they've been copied ad nauseam over the years, remain top performing, compact, and imitated time and time again.

Now, going back to your above post if I may, I will be the first one to agree that amplitude differences in a spectrum analyzer plot are not what we should base our opinions on. I have to assume the OP customer posting this review here does not have access to a proper meter that can provide MER per carrier, which is what we would all like to see.

Actually sometimes when such graphs are brought up our antenna performance is often misinterpreted!. Please, allow me to elaborate. I am sure you'll concur with me than in a system comprised by a signal acquisition antenna and an amplifier, the best system is not necessarily that which has the highest gain. The best system will be the one that is able to deliver a larger number of carriers with the best carrier to noise ratio. Of course we have to be mindful that we are using the right tools so the measurement is not altered by noise floor of the measurement equipment itself, as it quite often happens. In a Televes TForce system the gain is variable and it is adjusted automatically. Very seldom the amplifier, which features a vast dynamic range, is applying maximum gain, so when compared to a preamp with fixed gain it will frequently show a lower amplitude, which is not indicative of a worse performance, quite the contrary. Furthermore an automatically self adjusting system such as this provides far greater flexibility for our antenna solutions to adapt to a much wider range of applications and changing circumstances in a particular install. Of course this is not just any AGC, as any adjustments due to energy entering the band for a number of reasons, need to be done carefully as to not induce decoding artifacts or locking issues in the tuning device. All of this is carefully taken into account in the TForce system. The input signal received by the antenna is not as relevant, as the system will adapt and the installation will continue to perform within quality parameters. As a manufacturer of antennas and provider of solutions this is an important parameter, the number of different scenarios where our different antenna models perform equally or better than competing products. Yet another factor, frequently overseen, is the physical volume occupied by the antenna solution. From a design perspective, as any RF engineer can realize, it really has to be a poor design if an antenna that's far larger still underperforms when compared to one of ours, yet it happens time and time again. With all of the above in mind, we trust we provide very flexible, adaptable, and top performing solutions, with a build quality that quite honestly exceeds what can be found in the market nowadays.

You are of course entitled to your opinion sir, but I would like for it to be educated and based on actual user experience. The offer stands if you wish to test any of our products. I trust you will be pleasantly surprised. After all one would think that a company that develops broadcasting exciters, transmitters, and spectrum analyzers, should know how to design and manufacture a decent enough over the air antenna.

Sincerely
 

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Those are awfully impressive SNR figures.
How far away are you from the "Milwaukee Spectrum?"
The fact that the Televes can compete with your very impressive home-made 72 foot long antenna is very impressive! :)
 

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Discussion Starter · #12 ·
Those are awfully impressive SNR figures.
How far away are you from the "Milwaukee Spectrum?"
The fact that the Televes can compete with your very impressive home-made 72 foot long antenna is very impressive! :)
72 FEET LONG?

Milwaukee is not that far, only about 50 miles. That antenna was built to DX but I figured, why not?

The reason I posted the SNR screenshot is simply because I have no other way to check SNR, and the subject came up.
 

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ChiwaukeeOTA, how long is that UHF antenna that you are using there?
 

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I estimated 72 feet. :):D
Or somewhere near that.:unsure:
By far the longest TV antenna I've ever seen by a LOT.
Really, how long is it? Quite a project I would think.
 
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