Televes preamp synopsis

[primestar31]

This post will be a bit long-winded, but I think it all needs to be given for background.

My outdoor antenna system which is at about 25ft at present and installed with all PerfectVision 3Ghz swept RG-6 quad-shield & Thomas & Betts snap n seal connectors, consists of an AntennaCraft Y10-7-13 for my local RF 12 channel. That goes into an MCM Electronics FM filter, then into the non-power passing side of a UVSJ. Then a HDB91x UHF antenna for all my local UHF, went into the 2015 model Kitztech KT-200-Coax preamp, and into the power passing side of the UVSJ. Then, the output of that goes down to the power injector.

After the power injector, I also had a PCT-MA2-4P 4-way powered splitter, though likely overkill, it was there from a previous setup. Off that, I have a Tivo Roamio used for OTA, and 2 tv sets (previously had 3 tv's, but one fried a few months ago).

My house is located at a place where all my DMA's tv towers are in an arc, from North, North-East to slightly West of South. They are also grouped all from around 32 to 52~ miles away. Luckily enough, the highest powered ones are on opposite ends of that arc, and the ONE low power station I want to receive (10KW at 32 miles) is close to dead-center of that arc.

So, my HDB91x UHF antenna is pointed right at that station (WFFC-LD, RF17), and it receives all the other UHF stations acceptably within limits of its beamwidth/sidelobes.

Once I got everything all tweaked and locked down some years ago and finally settled on the KT-200 preamp as being the BEST in my situation out of many that I had tried, I still always felt that there might possibly be more to be gained, and who of us doesn't like to keep playing with antenna setups, lol.

Anyway, I started reading about Televes and their various products this past Winter, and wanted to try one. I finally was able to pre-order a Televes 560483 two-input preamp from Ness Electronics, and got it 3 weeks later. Unfortunately, that was just before Christmas, and Michigan got pounded with too many snow storms to allow me to install it right away, since I had to go on the roof. That's not easy when there's at least two feet of icy snow up there.

I finally was able to install it in February. I eventually did a simple straight-swap of removing the KT-200, and installing the 560483 in its place, along with their power inserter to replace the Kitztech one. I tried various combinations between the antennas/preamp/uvsj while checking it, but NEVER found one that worked even as well as OR better than the KT-200.

In fact, the Televes preamp couldn't even lock WFFC-LD RF17 that the Kitztech could. Locking that station that's only 10KW and 32 miles away, is my gold-standard on MUST HAVES.

Anyway, I thought "Well, that's yet another $70 down the drain, and time wasted trying to beat the Kitztech". I then put the KT-200 back in, and put the Televes preamp into my parts drawer.

That's where it all stood, until a week or so ago after a persons post in the TV and Fm DXing group on Facebook comparing various companies preamps, and I made a reply comment that I also hadn't had any luck with the particular Televes preamp I tried. Javier Ruano of Televes read that comment, mentioned that he didn't think that particular preamp was the best choice for my setup, and offered to swap it out straight-up for the 560383 single input one. I took him up on that offer since I had nothing to lose any way by doing so.

I received a Televes 560383 single input preamp this week Tuesday, and was finally able to install it today in my system, since we've had some bad weather the last few days. I once again did a straight swap for the KT-200, so the preamp is only in the UHF chain. I also of course swapped out the power injector, but initially left everything else the same.

The Tivo Roamio hidden diagnostics screen (which has a LOT of data), showed that Signal strength and SNR on this straight swapout was on average a tad better than the KT-200, but not by much. Since the Televes power injector has TWO outputs and the Televes preamp has a little more juice than the KT-200, I then also decided to remove the PCT powered splitter from the signal chain. I put the Tivo on the injectors main output (since it's my most-watched device) and used a PCT passive two-way splitter on the other output for the two tv sets.

Now, with the Televes preamp, signal strength and SNR readings on average on the Tivo and tv sets are around 4-5 points UP higher than they were with the KT-200, and they appear to be more stable. Also, we are having 30+MPH wind gusts all through this testing today 4/30, and I have lots of trees flapping their leaves starting about 100 to 300 feet away that I have to aim through. Even so, I'm NOT getting any RS Uncorrected errors on my weakest channel, which I was getting a few now and again with the KT-200.

Anyway, I feel that the Televes model 560383 preamp seems to beat the Kitztech KT-200-Coax by a bit, is better built, and I have every intention of keeping it installed. It appears to be built well, has FM & 5G LTE filtering built-in, and I don't think anybody could go wrong in trying them out for themselves.

 

[arlo]

Nice write up. I think that you mentioned noise figures were what turned you off about the Televes unit. In a quick search I couldn't find those specs. I'm glad it works good for you though.
I'm still intrigued about their tunable per channel units. Although the noise figures are higher than your KT-200.
I don't "roll" antenna preamps. So is higher gain or adjustable gain with higher noise figures acceptable over a lower gain with extremely low noise in a deep fringe area? I have a PBS station and one other SW from me and Buffalo ~90 miles north of me. Using a CM-7777 here for some time. The switchable FM trap is important because....I like to receive FM. Even if I need to listen in mono to eliminate MPX hiss.
Thoughts?

 

[Tower Guy]

Hey Arlo,

I think that the takeaway of the layout by Primestar31 is to use a preamp on UHF only and avoid amplification of a second VHF antenna.

Generally, an extremely low noise preamp is helpful on UHF, and either harmful or useless on VHF. (The difference depends on VHF signal strength and local noise levels plus losses due to splitters). Therefore the use of a UVSJ and a new UHF only antenna would avoid over-amplification of a VHF antenna and allow FM signals to be distributed without any strong FM stations causing problems in the preamp.

If you desire optimum FM performance on the same RG-6 as your TV, the best preamp layout can be complicated, and will vary based on location. That said, the filtering in the Televes can improve TV reception. The gain graphs that I’ve seen published suggest the Televes preamp uses an optimum channel 2-6 bandpass filter that will cut off most of the FM band. It doesn’t look like an FM trap that can be bypassed.

 

[televestech]

Nice write up. I think that you mentioned noise figures were what turned you off about the Televes unit. In a quick search I couldn't find those specs. I'm glad it works good for you though.
I'm still intrigued about their tunable per channel units. Although the noise figures are higher than your KT-200.
I don't "roll" antenna preamps. So is higher gain or adjustable gain with higher noise figures acceptable over a lower gain with extremely low noise in a deep fringe area? I have a PBS station and one other SW from me and Buffalo ~90 miles north of me. Using a CM-7777 here for some time. The switchable FM trap is important because....I like to receive FM. Even if I need to listen in mono to eliminate MPX hiss.
Thoughts?

I think there are a lot of misconceptions when it comes to the all around performance of an antenna preamplifier. NF is important but not the end and be all, a half of a dB difference in NF is not as important as the flatness, out of band rejection, and regulation of the preamp, which in the long term is going to in most every case provide more uptime than a fraction of a dB noise margin difference. This is not to justify the way most manufacturers misrepresent the NF value in the specifications.

 

[televestech]

Hey Arlo,

I think that the takeaway of the layout by Primestar31 is to use a preamp on UHF only and avoid amplification of a second VHF antenna.

Generally, an extremely low noise preamp is helpful on UHF, and either harmful or useless on VHF. (The difference depends on VHF signal strength and local noise levels plus losses due to splitters). Therefore the use of a UVSJ and a new UHF only antenna would avoid over-amplification of a VHF antenna and allow FM signals to be distributed without any strong FM stations causing problems in the preamp.

If you desire optimum FM performance on the same RG-6 as your TV, the best preamp layout can be complicated, and will vary based on location. That said, the filtering in the Televes can improve TV reception. The gain graphs that I’ve seen published suggest the Televes preamp uses an optimum channel 2-6 bandpass filter that will cut off most of the FM band. It doesn’t look like an FM trap that can be bypassed.

I do not think that was Primestar31's issue. His problem, as I explained in a different thread, is he was using the dual input 560483 preamplifier for a one feed situation, which is not optimal because it has an input combiner that will lower effective C/N. In a fringe situation, when combining two specific-band antennas, it's always more optimal to diplex the two antennas and hit a one input low noise amplifier such as the 560383, or preamplify the two antennas independently and then combine them, once the NF of the system has been stablished. The 560483 performs broadband combining previous to amplification, which is a great solution to combine two antennas overlapping in frequencies with a minimum cost, but the situation needs to allow for it. I his case, the toll taken by the broadband combination prior to preamplification was not viable.

 

[primestar31]

The 560483 performs broadband combining previous to amplification, which is a great solution to combine two antennas overlapping in frequencies with a minimum cost, but the situation needs to allow for it. I his case, the toll taken by the broadband combination prior to preamplification was not viable.

arlo That's correct. I originally tried the dual-input 560483 preamp, as it was the only one I could find to purchase at the time. It did NOT work as well as the Kitztech KT-200-COAX preamp for my specific application, mostly seen on that low power station it couldn't lock that's only 10kw, at 32 miles from me.

The Televes single-input 560383 preamp works much better for me. It's working better than the KT-200. Signals are a bit more stable, and it seems to have eliminated/alleviated some intermittent multi-path issues that I had.

 

[primestar31]

I have some followup to my original post above. I spent the time in-between, getting my antennas peaked as best I could, using a meter to balance and adjust as best I could for possible multipath. Also I must point out, BOTH antennas are now being combined first with a UVSJ, and then going through the preamps during this test:

My Televes 560383 Kit (560331 preamp) Review and Comparison to the 2015 model Kitztech KT-200, that has NO internal filters.

In my case, I think the Televes 560383 kit (560331 preamp) clearly wins.

Readings are using a Televes H30D3 meter, which is a cable tv meter, so some adjacent channels have the ">" (greater than) symbol as this meter can't demodulate the signal to get MER and BER, but only measure the straight RF. It's a fairly cool night in mid-Michigan, about 50f, but fairly clear, only a little clouds. Maybe 7-10mph steady wind. Readings taken within a short period of time. Just enough to get them for the Televes, swap out the injector and preamp, and take the Kitztech KT-200 readings. NOTHING else in the chain was changed between swapping them.

So, on these readings, BOTH VHF (AntennaCraft Y-10 7-13 aimed at WJRT RF12) & UHF (HDB91x for ALL my UHF stations but aimed at WFFC-LD RF17 (10Kw at 32 miles, I'm about 5 or so miles outside their furthest contour, but it's more or less the center of my UHF station arc, & the lowest power station I actually WANT) antennas are being combined & fed through a UVSJ into the respective preamps. In other words, both VHF & UHF bands are being preamp'ed.

My antennas are up about 25-27ft on a 2" well pipe mast. Everything is properly grounded to the house ground. I do have issues with multipath due to trees and fluttering leaves, but the Televes adjusts for that. First are the newest readings from the Televes;



I'm only allowed to post 20 images, so following post is the Kitztech KT-200 readings

 

[primestar31]

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The following are the 2015 Kitztech KT-200-Coax preamp readings:

 

[videobruce]

Why doesn't the MER show in any of those screen shots??

 

[primestar31]

Why doesn't the MER show in any of those screen shots??

Because I was using a cable tv meter, and it's not capable of demodulating the signal. On OTA signals, it can only show C/N and Power. I'd LOVE to have an actual ATSC meter, but I can't afford one, since they are pushing $400 for a cheap one. This meter was given to me for use right now.

 

[videobruce]

Ok. I'm surprised it doesn't have both 8VSB & QAM. Come to think about it, since it apparently has a OTA channel table/map, one would logically figure it would have that function.

 

[televestech]

Ok. I'm surprised it doesn't have both 8VSB & QAM. Come to think about it, since it apparently has a OTA channel table/map, one would logically figure it would have that function.

The meter shown in those pictures is a P/N 593101 H30 Meter. It's a CATV meter demodulating QAM Annex A/B/C signals. It does not demodulate 8VSB or ATSC 3.0 (there are other part numbers that do), but it is still beneficial that it comes with the OTA channel plan since the C/N and Power readings it provides are perfectly accurate. Of course the spectrum analyzer is valid too for OTA signals.

For antenna work a better choice would be a unit in the H30 Evolution family, which demodulate cable and over the air signals both in ATSC1.0 and 3.0 standards (video attached): H30Evolution - All the functions you need now in your smartdevice