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post #7681 of 10986 Old 06-28-2011, 06:31 AM
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Quote:
Originally Posted by Larry Kenney View Post

I'm not familiar with KAZV analog. If it's on 14 it must have a heck of an interference problem from KTNC. I have KAZV listed as a proposed digital station for channel 36 from Modesto. Is that correct?

Larry
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No KTNC this morning. You have the correct info on KAZV but I doubt they're going digital. Channel 36 is a terrible choice for me and I've told them so.

BTW, conditions are awful here this morning. Nearly every station from every direction is 10 dB or more below average. I had to check KMMW again to verify my antennas hadn't broken overnight. KSPX is the only station unaffected.

Chuck
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post #7682 of 10986 Old 06-28-2011, 04:01 PM
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Quote:
Originally Posted by chibi View Post

Anybody else in West San Jose (95129) having problems with KNTV 11? I am getting
signal loss, image breakup etc for the last few days. I never had any problems
with KNTV before.

Thanks

I've been having problems with them too but I'm in at the Santa Clara / Sunnyvale border.
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post #7683 of 10986 Old 06-28-2011, 07:41 PM
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Originally Posted by derekj View Post

I've been having problems with them too but I'm in at the Santa Clara / Sunnyvale border.

Nice to know that I am not the only one with problems. It does not seem to be
a tuner problem because it happens on my Sony TV, digital converter
box and Dish 722k receiver. Wonder what the problems is?
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post #7684 of 10986 Old 06-29-2011, 09:59 PM
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KTNC has returned this evening. BTW, they're only running 12 KW because they are still having interference problems with land mobile services who share the tower they're on. They think they'll have it solved in 6 months with a new filter then they can go up to 40KW.

Chuck
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post #7685 of 10986 Old 06-29-2011, 11:06 PM
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Quote:
Originally Posted by Calaveras View Post

KTNC has returned this evening. BTW, they're only running 12 KW because they are still having interference problems with land mobile services who share the tower they're on. They think they'll have it solved in 6 months with a new filter then they can go up to 40KW.

Chuck

Thanks Chuck, .... 100% before, now 19% signal here.
Indoor double-bow - for Mt. Diablo
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post #7686 of 10986 Old 06-30-2011, 09:34 AM
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Quote:
Originally Posted by chibi View Post

Nice to know that I am not the only one with problems. It does not seem to be
a tuner problem because it happens on my Sony TV, digital converter
box and Dish 722k receiver. Wonder what the problems is?


its been coming just fine down here by metcalfe rd.

but the other vhf ch 7 has been unusually problematic here lately, with pixelation and loss of signal.
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post #7687 of 10986 Old 06-30-2011, 01:36 PM
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Was wondering does anybody know if KMMC 40 is required to ever go digital and if so when? Also are there any other new stations on the horizon or is whats currently out there now basically everything were gonna see from here on out?
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post #7688 of 10986 Old 06-30-2011, 04:34 PM
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I'm now seeing OTA guide info on my Dish 622. Hope it continues. Anyone hear anything from Dish about this? It's not PSIP and I don't subscribe to locals--only use OTA.
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post #7689 of 10986 Old 06-30-2011, 10:13 PM
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Quote:
Originally Posted by PGDave View Post
I'm now seeing OTA guide info on my Dish 622. Hope it continues. Anyone hear anything from Dish about this? It's not PSIP and I don't subscribe to locals--only use OTA.
Locals are now part of every package. They no longer charge extra for them. Both locals and HD are free.

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post #7690 of 10986 Old 06-30-2011, 10:19 PM
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Quote:
Originally Posted by bettygunn View Post
Was wondering does anybody know if KMMC 40 is required to ever go digital and if so when? Also are there any other new stations on the horizon or is whats currently out there now basically everything were gonna see from here on out?
The low power stations will have to go digital or go off the air sometime in the future, but the FCC hasn't set a date yet. Someone suggested that they might set June, 2012, as the deadline, the same time that cable systems no longer have to provide analog signals.

From what I've heard, KMMC is in the process of installing their digital equipment, but the recent financial slowdown caused them to take longer than expected to get everything they need.

As for any other stations, look at all the "possibilities" listed at the bottom of my station list. They have all applied for digital, but haven't shown up yet.

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post #7691 of 10986 Old 06-30-2011, 10:30 PM
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Quote:
Originally Posted by Calaveras View Post
KTNC ... only running 12 KW...
Chuck
KTNC is about 5 dB lower than normal here in San Francisco tonight.

What's happening with KCRA? They're below the cliff edge here... about 14dB SNR instead of the usual 21 to 22 dB. All of the other Walnut Grove stations that I get are at their normal levels.

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post #7692 of 10986 Old 06-30-2011, 11:41 PM
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Quote:
Originally Posted by Larry Kenney View Post
KTNC is about 5 dB lower than normal here in San Francisco tonight.

What's happening with KCRA? They're below the cliff edge here... about 14dB SNR instead of the usual 21 to 22 dB. All of the other Walnut Grove stations that I get are at their normal levels.

Larry
SF
I checked a couple locations here, and KCRA is definitely lower. I'll guess weather due to the heat we have building. With a wrong-facing window, the correct aim and angle indoors here is different for all three of the stations on the KMAX/KCRA/KQCA antenna.
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post #7693 of 10986 Old 07-01-2011, 07:58 AM
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At first I thought KTNC was off again because I couldn't receive them and I did receive KAZV even pointed at Mt. Diablo, but I could see them on the spectrum analyzer. I wonder if they're at very low power after their time off?

All the Walnut Grove stations were normal here last night but all the stations I could possibly receive from Mt. Sutro were coming in, including KCSM which was the first time ever. KGO was SNR 28 dB.

Chuck

Edit: Just checked KTNC late this morning and it seems back to normal.
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post #7694 of 10986 Old 07-01-2011, 10:15 AM
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Quote:
Originally Posted by Calaveras View Post

At first I thought KTNC was off again because I couldn't receive them and I did receive KAZV even pointed at Mt. Diablo, but I could see them on the spectrum analyzer. I wonder if they're at very low power after their time off?

All the Walnut Grove stations were normal here last night but all the stations I could possibly receive from Mt. Sutro were coming in, including KCSM which was the first time ever. KGO was SNR 28 dB.

Chuck

Hi,

I am getting KTNC here in Sunnyvale at 10 AM just fine.

---------------------------------

Should you have a hour and a half, yes it is a lot of time, you might find hope for a faster Internet service for you in the future in this Video Lecture.

http://www.avsforum.com/avs-vb/showt...2#post20636792

I watched the entire Lecture and was amazed by all that he has done and is doing.

Better HTDV than we have in the space used by ~ 10 channels now for all the stations on the air here. The 10 is a wild guess by me, he did not address that possibility.

No more dropped cell phone calls, the list of possibilities goes on and on.

That is in the last 30 minutes, the first part is about what we have now in movie creation and other current applications.

SHF
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post #7695 of 10986 Old 07-01-2011, 12:40 PM
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Quote:
Originally Posted by SFischer1 View Post

Should you have a hour and a half, yes it is a lot of time, you might find hope for a faster Internet service for you in the future in this Video Lecture.

http://www.avsforum.com/avs-vb/showt...2#post20636792

I watched the entire Lecture and was amazed by all that he has done and is doing.

Better HTDV than we have in the space used by ~ 10 channels now for all the stations on the air here. The 10 is a wild guess by me, he did not address that possibility.

No more dropped cell phone calls, the list of possibilities goes on and on.

That is in the last 30 minutes, the first part is about what we have now in movie creation and other current applications.

SHF

It's not practical for me on satellite internet to watch a 90 minute video. Do they explain how they get around the Shannon-Hartley theorem which is used to calculate how much data can be put through a given bandwidth at a given signal-to-noise ratio? This is a time proven mathematically based theorem. Claiming they have done it is one thing, telling us how is another. If they really have then they must have it patented by now so no need to keep it secret.

I can tell you right now how to get more data through a 6 MHz TV channel; up the modulation order to 256 VSB or 256 QAM. The problem with that is the SNR has to be higher. As I remember from testing a PSK demodulator in the lab, 256 QAM needed an SNR of around 30 dB for error-free demodulation. If you think getting better than 15 dB for 8VSB OTA reception is problematic, try 30 dB. Almost no one would receive any stations.

When I read this stuff my skeptical antennas go up. I want to know how something will work in the real world. This reminds me of some guy I read years ago who said that stations on the same frequency don't interfere with each other. Radio waves pass through each other with no interference so there's no reason why you can't have multiple stations using the same frequency. Of course in the real world we have to use actual radio receivers and they have no ability to discriminate between one set of radio waves and another using the same frequency. No receiver exists that I know of that can lock onto one signal and completely ignore the others. If such a receiver could be engineered then there would be no frequency shortage. Maybe Perlman found a way to do this.

Chuck
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post #7696 of 10986 Old 07-01-2011, 02:26 PM
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Quote:
Originally Posted by Calaveras View Post

It's not practical for me on satellite internet to watch a 90 minute video. Do they explain how they get around the Shannon-Hartley theorem which is used to calculate how much data can be put through a given bandwidth at a given signal-to-noise ratio? This is a time proven mathematically based theorem. Claiming they have done it is one thing, telling us how is another. If they really have then they must have it patented by now so no need to keep it secret.

I can tell you right now how to get more data through a 6 MHz TV channel; up the modulation order to 256 VSB or 256 QAM. The problem with that is the SNR has to be higher. As I remember from testing a PSK demodulator in the lab, 256 QAM needed an SNR of around 30 dB for error-free demodulation. If you think getting better than 15 dB for 8VSB OTA reception is problematic, try 30 dB. Almost no one would receive any stations.

When I read this stuff my skeptical antennas go up. I want to know how something will work in the real world. This reminds me of some guy I read years ago who said that stations on the same frequency don't interfere with each other. Radio waves pass through each other with no interference so there's no reason why you can't have multiple stations using the same frequency. Of course in the real world we have to use actual radio receivers and they have no ability to discriminate between one set of radio waves and another using the same frequency. No receiver exists that I know of that can lock onto one signal and completely ignore the others. If such a receiver could be engineered then there would be no frequency shortage. Maybe Perlman found a way to do this.

Chuck

Hi,

It was painfully short on any useful details, there really was NONE!

The worlds reaction will be like the caveman looking up and seeing an airplane overhead, saying nothing about his first ride.

When you go to town take your laptop with you and visit a WiFi hot spot or a local library if text explanations do not suffice.

No patent. They had to use Ham Radio Bands for testing and their testing limit was ~ 30 miles from the transmitter which was as far as they wished to drive. FCC would not grant a testing license. (50 Miles suggested would work)

The first hour part you should be able to prove works by your experience via satellite going to:

http://www.onlive.com/

As far as the BS level, this was a lecture at "Columbia University" and what he has done before was truly well documented by examples in movies.

The limitations of the Shannon-Hartley theorem were explained away by "He asked the wrong question"!

I wish that more could be said, but what you and I want to hear was not in the presentation.

That does not take away from my suggestion to go to town and watch it.


The audio quality is not good so headphones or a very quiet spot is recommended.

The wireless information was mainly in the Q&A at the very end and the audio quality was really bad for the questions from the audience.

I listened to the lecture a second time and the long build up is painful if all you are wanting is the wireless part, but it is necessary to accept his credentials well documented by past successes to just not dismiss the wireless breakthrough.

Redacted, read parts of patent and understood very little but no carrier comment was mis-spoken or not understood in contex by me.

Good luck to anyone reading the patent, the figures are missing and as patents are not meant to be read, few will understand much like me.

Wait for the video that really describes this and what actually is built.

SHF
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post #7697 of 10986 Old 07-03-2011, 12:33 AM
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post #7698 of 10986 Old 07-05-2011, 09:39 AM
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A little while ago Larry asked me if I could ever receive any DTV from Santa Barbara or any other places in that direction. It seemed like it was impossible and now I'm sure it is impossible. I thought the only possibility might be KSBY on RF 15 but it would have stiff competition from KBSV. KSBY is 198 miles from here.

A week ago this morning after the freak late June storm, the 3 stations that transmit from the hills west of Patterson were all off the air at the same time (KBSV, KAZV, KEXT). I figured it must have been a PG&E outage on what's likely the only line that goes up there. KTNC was also off the air at this time so there was nothing on RF 14.

I thought this would be the time to check if I could see any trace of KSBY. I have a 35 dB gain amplifier that I can use with the spectrum analyzer that will make anything down to the noise floor visible. The following images are using the amplifier.

The first image shows the display tuned to RF 15 with the antenna pointed to KSBY (azimuth 182 degrees) last Tuesday morning. That is KSBY but it is very weak, far too weak to receive. The analog signal superimposed on it is K15ET which is listed as an LPTV station in Fresno but its transmitter site is just 55 miles southeast of here. The FCC database shows a measly 2.5 watts in my direction. KSBY shows 200KW in my direction.

The second image is from this morning and shows what I normally see with the antennas pointed at KSBY. That's KBSV and is 15 dB stronger than what KSBY was. The TV showed KBSV had an SNR of 16 dB.

The third image is with my antenna pointed at KBSV and the TV showed an SNR of 28 dB.

So it looks like ducting would have to cause KSBY to come up at least 30 dB to override KBSV. That seems pretty unlikely. If RF 15 was a clear channel then it might be possible.

I think this does show that extremely weak signals that you could never receive could have an impact on the SNR of other weak stations you are trying to receive. Just because a station is too weak to ever receive doesn't mean you're getting no signal at all from it.

BTW, that very weak video carrier on RF 16 seen in images 2 & 3 is likely to be KHSC LP in Fresno. I had a little bit of ducting down that way this morning.

Chuck
LL
LL
LL
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post #7699 of 10986 Old 07-05-2011, 02:06 PM
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KSBY 6-1 is possible in some parts of Monterey County. ( Upper West St. Soledad ) Direct Wave. Not a skip.
110 Miles South of Sutro Tower.
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post #7700 of 10986 Old 07-05-2011, 02:35 PM
 
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I like to ask question about the AD 91xg I'm using one at the moment, i find this aerial under achievin for low uhf bandi like ch20-35 anything higher is ok. I really think this antenna is hyped up. I also use another uhf yagi, similar in size to a rat shack u75, at the same height it does better job at pickin up low uhf channels and its stellar on upper vhf unlike 91xg. does anyone have similar opinion of 91xg?
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post #7701 of 10986 Old 07-05-2011, 04:39 PM
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Originally Posted by nycdigital09 View Post

I like to ask question about the AD 91xg I'm using one at the moment, i find this aerial under achievin for low uhf bandi like ch20-35 anything higher is ok. I really think this antenna is hyped up. I also use another uhf yagi, similar in size to a rat shack u75, at the same height it does better job at pickin up low uhf channels and its stellar on upper vhf unlike 91xg. does anyone have similar opinion of 91xg?

Yagi antennas are inherently a narrow-band structure. When using them in a broad-band application such as the full (original UHF band), they offer peak gain at the design frequency and then drop off very abruptly. On the lower side of the peak performance frequency, gain and directivity build up slowly from the bottom of the response curve up to that peak.

Since the 91XG's gain peaks around 765 MHZ, expecting it to also excel at 470 MHz is not a realistic expectation since no Yagi in this frequency band is going to effectively cover 300 MHz of spectrum uniformly. There's probably a 6 dB difference in gain between the low and high end of its gain curve. Since free-space path loss is less at the lower end of UHF and lower UHF diffracts more readily than higher UHF, the real-world performance differential of the 91XG for low vs high UHF is far less than the numbers on paper would suggest.

The 91XG was never intended for VHF reception, so any expectation that is should do so is misplaced.
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post #7702 of 10986 Old 07-05-2011, 04:44 PM
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Sounds like there is something wrong with your 91XG. I have not heard any bad reports about it and it certainly works well for me although I have not done any A/B tests with other antennas. I have tried other antennas and they have not been better. There have been reports from here in the Sierra foothills that it's the only antenna that works for some people, probably a higher front-to-back ratio than other antennas. Multipath is a very common problem up here.

HDTV Primer shows it to be among the best performers.

http://www.hdtvprimer.com/ANTENNAS/comparing.html

The Radio Shack U-75R is a pretty small antenna and should not be out performing the 91XG.

Chuck

Edit: I misread your comment about upper VHF. The 91XG will not work on high VHF. Any comparison to other antennas on high VHF is not applicable.
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post #7703 of 10986 Old 07-05-2011, 08:35 PM
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Quote:
Originally Posted by Calaveras View Post

Sounds like there is something wrong with your 91XG. I have not heard any bad reports about it and it certainly works well for me although I have not done any A/B tests with other antennas. I have tried other antennas and they have not been better.

I have done such comparisons with the 91XG against these other best-of-breed UHF antennas: The ChannelMaster classic CM-4228a and the Winegard HD-9032.

The short story is that the 91XG beats them both. If there's sufficient interest, I'll post the raw numbers (measuring the POWER LEVEL on a Sencore SLM-1456) and a description of my methodology.
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post #7704 of 10986 Old 07-06-2011, 07:10 PM
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Hi,

I spotted the Bug on a British program on KTEH said "KQED +' and the PBS Logo.

Going to KTEH's TV page I found the following:

"KQED Plus (formerly KTEH) Television Schedule"

http://www.kteh.org/tv/

May KTEH RIP.

Will the transmitter callsign be changed to "KQEP" or ...

SHF
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post #7705 of 10986 Old 07-06-2011, 07:17 PM
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KQEH.

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post #7706 of 10986 Old 07-07-2011, 08:30 AM
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It's not just a call sign change but they want to change the antenna pattern too and give up their construction permit for 1 MW for 310 KW. I wonder why they want to do this? It's good for me because the new antenna would put 6 dB more power in my direction.

I don't suppose they might start airing HD again?

Chuck
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post #7707 of 10986 Old 07-07-2011, 08:31 AM
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The new antenna will be elliptical rather than horizontal, and I'm betting the cost of the new antenna wiped out the funds for a bigger transmitter.

I'm betting Mobile DTV.

- Trip

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post #7708 of 10986 Old 07-07-2011, 08:35 AM
 
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Quote:
Originally Posted by ProjectSHO89 View Post

Yagi antennas are inherently a narrow-band structure. When using them in a broad-band application such as the full (original UHF band), they offer peak gain at the design frequency and then drop off very abruptly. On the lower side of the peak performance frequency, gain and directivity build up slowly from the bottom of the response curve up to that peak.

Since the 91XG's gain peaks around 765 MHZ, expecting it to also excel at 470 MHz is not a realistic expectation since no Yagi in this frequency band is going to effectively cover 300 MHz of spectrum uniformly. There's probably a 6 dB difference in gain between the low and high end of its gain curve. Since free-space path loss is less at the lower end of UHF and lower UHF diffracts more readily than higher UHF, the real-world performance differential of the 91XG for low vs high UHF is far less than the numbers on paper would suggest.

The 91XG was never intended for VHF reception, so any expectation that is should do so is misplaced.

i agree on most of your statement: a logic rhythm antenna with directors getting shorter towards the front of antenna and possibly cut to channel 47 would have a much better uhf lower performance, I been thinkin of drilling new holes on 91xg to space them out and adding a bit of flashing on directors, or I could get band a antenna from uk.
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post #7709 of 10986 Old 07-07-2011, 09:43 AM
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Originally Posted by nycdigital09 View Post

i agree on most of your statement: a logic rhythm antenna with directors getting shorter towards the front of antenna and possibly cut to channel 47 would have a much better uhf lower performance, I been thinkin of drilling new holes on 91xg to space them out and adding a bit of flashing on directors, or I could get band a antenna from uk.

Unless you model the antenna with different sized directors, you'll destroy the antenna performance by making arbitrary changes to it.

In regards to previous comments about antennas like the 91XG being yagi antennas, they are not yagis. They are a hybrid of a corner reflector and a yagi with the corner reflector part designed for the lowest operating frequency and the directors designed for the highest operating frequency. Combining those two together produces a compromise broadband antenna.

I think all of the UHF antennas on the market still cover channels 14 - 69. They all need to be redesigned to cover 14 - 51. That would make them less compromised.

The yagi is one of the best high gain/high front-to-back ratio antennas that there is but it has a very narrow bandwidth; maybe one channel on high VHF and maybe two channels on UHF. A low VHF yagi will not cover one channel without modifying the driven element to be a log periodic.

It seems that every broadband antenna has some sort of compromise.

Chuck
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post #7710 of 10986 Old 07-07-2011, 01:19 PM
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Originally Posted by Trip in VA View Post

KQEH.

- Trip

Hi,

Did I find the correct document, the one that says:

Granted March 28, 2005

For the new name "KQEH"?

If so, then "KTEH"'s demise was planned from the very start of NCPB.

Begin Date KQEH 07/01/2011

SHF
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