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Quote:
Originally Posted by AntAltMike /forum/post/0


I think that a 1/4 degree difference in beam tilt might make a little difference in transmision at that distance, but I can't imagine it ever having any measurable effect on reception.

It was my understanding that he was referring to transmitter beam tilt, not receiving antenna beam tilt.
 

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Quote:
Originally Posted by AntAltMike /forum/post/0


I like it. I don't have time to develop a price schedule, so when I am drawing up a materials list for a big job, I just go to their site and factor some multiple of their prices.

Mike,


Let me clarify. I do like the fact that they give all the prices, and their selection.

I just wish it were more organized, like warrenelectronics.com is. Having to slide down more than 1 page is a general design no-no in the Web world. And again, their products are great and their service to me has been great. It would make life easier to find stuff that I want if they, for example, had different sections for each category: different pages for Winegard antennas and boosters, etc.

I just want to find what I want quickly.


Gilbert
 

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Gentlemen,


Attached is a chart of a typical UHF transmit antenna and a mid-gain log-periodic antenna. (An 8 dB yagi would have a similar pattern.) The Y-Scale is degrees from horizontal. Negative numbers are to our customers, positive numbers go out into space or, occasionally, getting into a tropoduct.
The X-Scale is gain with 1.0 being maximum signal.


You can see why we have to tilt our beam down to 'see' you from 2000'. You can also see why tilting a consumer antenna does not usually do much good.


By the way, this is not the KHWB antenna. I built this chart by transposing data from a report to excel. It wasn't until I saw the null-fill area on the chart that I realized that it was another stations' antenna. Still, their antenna is more typical of a UHF antenna for a VHF-NTSC station than our antenna would be.


Bob Chase

KHWB-TV

 

Xmit-Recv-El-Chart.pdf 12.8974609375k . file
 

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Quote:
Originally Posted by bobchase /forum/post/0


You can see why we have to tilt our beam down to 'see' you from 2000'. You can also see why tilting a consumer antenna does not usually do much good.

Interesting picture. But it seems to assume a perfect world, and we all know the world isn't perfect. There are things that "scatter" that nice, straight, narrow beam all over the place. Most people who advocate tilters say that tilting only becomes useful when you're over the horizon. It allows you to maximize the gain of the antenna by turning it parallel to the incoming signal - since it is probably "dropping from the sky" rather than coming in nice and straight.


The people who often lose out with reception due to beam angle are those who are "right under" the antenna, say a mile or two away. They often can't get reception with a typical 8db gain antenna (or any of the larger antennas) but they can get rock solid reception from small, indoor antennas like the DB2. I don't know if they're just picking up a reflection, but I've tried to help several people who can't get a blip because they're under the tower's shadow.
 

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Well after following these threads for 80 odd pages, I can say I'm presently confused on a much higher level than I was before I started. Which is a good thing, I guess.


I'm putting in an HD set (finally) and want an OTA antenna to go along with my DirectTV (which I'll up to HD also).


Per www.antennaweb.org , the stations in the general direction I'm aiming are:


yellow PBS TRENTON NJ 295 3.7 43

violet FOX PHILADELPHIA PA 259 35.9 42

green ABC PHILADELPHIA PA 257 36.5 64

green CBS PHILADELPHIA PA 257 36.5 26

ltgrn WB PHILADELPHIA PA 257 36.3 54

red PBS PHILADELPHIA PA 257 36.3 34

red UPN PHILADELPHIA PA 257 36.3 32

blu PAX WILMINGTON DE 257 36.3 31

violet NBC PHILADELPHIA PA 257 36.3 67

violet PBS WILMINGTON DE 257 36.4 55

violet UNI VINELAND NJ 210 38.8 66


I strictly care about all the Philly stations (and not at all about the others)


The one local guy in the Princeton area installs the Winegard 9095 and AP4800 pre-amp; if I want I can buy and he will install anything else.


The antenna will go on the roof of a two story house with a 10' mast.


If I buy the antenna and pre-amp, the installer would be happy to install my choices.


I've been looking at a DB4 or DB8 with a channelmaster 7777 pre-amp.


Can anyone provide me with a pro/con on my choice over the installers?


Cost isn't a consideration ($100 +/- either way doesn't matter here) , I just want rock solid reception without any fuss/muss or rotators.



Thanks in advance.



Andrew
 

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I can't help with the installer question.


I don't think the preamp is needed unless you're running a really long cable or splitting it to multi-sets. I'm 43 miles from Philly, and when I tried a preamp with the CM4228 I lost WHYY.
 

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Is PBS/Trenton up to full power? If not, then when it goes to full powr it might overload a high gain preamp.


Can you get at the amp yourself? If so, then try without the preamp first, but if you think you need one, then you should try a Winegard medium gain preamp (18dB).


Trenton is 30 degrees off your main azimuth, so at UHF frequencies, that should knock it down by a good 20dB. If you had a VHF station that close, then you'd be in trouble.


Philly will have at least two stations going back to VHF highnband, I'm sure. Don't they have a 10 and 12? You'll eventually need to accommodate those somehow, but now is probably not the time to worry about that.
 

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Quote:
Originally Posted by Andy in NYC /forum/post/0


I strictly care about all the Philly stations (and not at all about the others)


The one local guy in the Princeton area installs the Winegard 9095 and AP4800 pre-amp; if I want I can buy and he will install anything else.


The antenna will go on the roof of a two story house with a 10' mast.


If I buy the antenna and pre-amp, the installer would be happy to install my choices.


I've been looking at a DB4 or DB8 with a channelmaster 7777 pre-amp.



Thanks in advance.



Andrew

Hi Andrew,


I can't help with installers either, but my recommendation to you is simple.

At that range, on a 10' mast, assuming no hills between you and the towers,

you don't need a preamp; in fact, as Mike et al have pointed out, it may

overload your signals. BUT, there is one exception: check to see if your

UPN, PAX and WB stations are at full power. The "big 4" stations will be; everybody else doesn't have to be at full until July 1, 2006. Generally, PBS stations will always be at a respectable digital power, so you probably won't have to worry there. Furthermore, I recommend you get the ChannelMaster 4228 8-bay

UHF antenna. It also does a decent job of picking up channels 7-13, so when

a few stations go back to the VHF dial after analog shutdown, you probably

won't have to worry about it. The DB8 from Antennas Direct doesn't pick up VHF

channels 7-13 well at all, and the DB4 is even worse.
 

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Here is something that I would consider useful to see calculated. If you have an antenna with a 300 ohm dipole and, in a given field, it develops 10dBmV of signal power when its output terminals are impressed upon a 300 ohm load, which is what it "sees" when connected to a ferrite balun, then how much power would be developed if the output of that same 300 ohm source were instead impressed upon a 75 ohm load, which is what we appear to be doing when we use a 1/2 wave balun?


If it is less than when impressed upon a 300 ohm load, then that differential must be subtracted in the transmission link calculation just as the calculated or actual loss through the ferrite baluns is. In other words, hypothetically, if a ferrite balun 300 ohm input is the optimal load and if its insertion loss is 1.5dB, but if the use of a 1/2 wave balun results in the development of 1dB less of power because of the impedance mismatch, then the differential in power and therefore S/N present at the tuner is only 1/2 dB. I'd like to see the order of magnitude of the net power differential between the two different transmission links before I spend any time dealing with awkward 1/2 wave baluns.


Your experience with the PR-9032 over the Channel Master 4248 is just that: your experience. Two or three years ago, there were legions of members here who swore that the Channel Master yagi outperformed the Winegard. I told them that the difference couldn't amount to more than a warm pot of spit, and that I used and still use a lot more Winegard PRs than CMs, because they cost less and I have three Winegard stocking dealers within 30 miles of me. But I never outlasted the Channel Master afficianados


You should further contemplate Winegard's channel 69 plot, and notice that it is asymmetrical, which is consistent with my speculation that the mast causes it, because the mast is off to the side of the boom, and should also consider that the effects of a larger mast could well disrupt channels in the 50s. In attic applications, with no internal onstructins and no mast, the plots would look more like they do in the HDTVPrimer site, and I imagine that a plastic mast extension might make the mast disruption negligible as well.


But don't lose sight of what I said in the post in which I criticized the PR series upper UHF performance. I said it wouldn't likely be redesigned because it already seems to do well up to 700 Mz, which is where the band will end when the transition is over.


(Edited to extinguish flame war)
 

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I am getting 5 out of 6 digital OTA channels on a dollars store 99 cent antenna v/s 4 out of 6 from 40+ dollars zenith silver sensor. I am 25 miles from broadcasting tower and out of 6 -- 4 yellow zone, 1 green zone and 1 red zone channels. Zenith SS is going back to sears....
 

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Quote:
Originally Posted by Andy in NYC /forum/post/0


The one local guy in the Princeton area installs the Winegard 9095 and AP4800 pre-amp; if I want I can buy and he will install anything else.


I've been looking at a DB4 or DB8 with a channelmaster 7777 pre-amp.

I, like others, would skip the preamp if you're trying for stations 35 or so miles away. All three antennas you've listed are murder on rotors - the 9095 because all the weight would go on one side - it mounts by the back end to the mast, the DB8 and DB4 because of wind load - bowties really pick up the wind when it blows just right (think wind sail.) But since you won't need a rotor at that distance, it's not really an issue.


In tests I've seen, the Channel Master 4221 and 4228 outperform the AntennasDirect models by a fair bit - especially on high VHF, where the split screen on the DB8 costs it some gain.


WHYY is reverting to channel 12. WCAU is not going to channel 10 because it would conflict with WHTM-DT in Harrisburg. WPVI and KYW are unknowns at this point because their digitals are "out of core" and their analogs are lo-VHF, so neither made a round one election.


If your installer is familiar with the 9095, I'd just go with that. It's more than enough antenna at your distance, and you shouldn't experience any problems with it. (Unless, of course, a station is running at very low power, in which case, you might have trouble with any antenna.) The exotic antennas some of us love are really only necessary for people in difficult/problematic locations, and from what I know of New Jersey topography, your situation wouldn't qualify.
 

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Quote:
Originally Posted by Andy in NYC /forum/post/0


I'm putting in an HD set (finally) and want an OTA antenna to go along with my DirectTV (which I'll up to HD also).

You mean "up to HD-Lite also".....DirectTV doesn't have HD anymore.
 

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Quote:
Originally Posted by sregener
Interesting picture. ....

The people who often lose out with reception due to beam angle are those who are "right under" the antenna, say a mile or two away. They often can't get reception with a typical 8db gain antenna (or any of the larger antennas) but they can get rock solid reception from small, indoor antennas like the DB2. I don't know if they're just picking up a reflection, but I've tried to help several people who can't get a blip because they're under the tower's shadow.
sregener,


The folks close in to a site have a triple whammy coming at them. 1st, gain in that direction is extremely low because the transmitters' energy is focused at the radio horizon. So their tuner or STB is struggling just to make the required S/N (Signal to Noise ratio) to receive a signal. The theoretical limit is 15.2 dB S/N. Anything lower than that and there is no DTV tonight.


2nd, the beam falls apart. The attached PDF is from KHWB's MK-II DTV antenna. (The MK-I died an ugly death.) The beam starts falling apart at 5 deg down angle which is just over 4 miles from the tower. At 7 degrees down (2 miles out) the beam has devolved into a complete mess. (In color, you could see this better.) This phenomenon is called differential gain error because the antenna has different gain on different frequencies within the channel. Every antenna has it, some worse than others. It is hard for a DTV tuner to put this back together because there is not enough equalization available to reassemble the ATSC data. If we were looking at a spectrum analyzer the signal would have huge notches in it like the worst multi-path you ever saw.


3rd, some antennas exhibit deep notches in the signal and sometime the notches will go right down to zero. Take a look at the PDF I sent before showing atypical transmit/receive antenna pair. On the upper side of the antenna those notches exist. That antenna uses specially placed elements called "Null Fill" to make the lower side (customers side) smooth, well, smoother anyway. The amount of 'null fill' used subtracks from the antenna gain, so it is always a trade-off of how much energy to divert to get a decent signal in-close vs. the cost of doing so.


So the folks close in have a tough time getting TV. One of my employees lives right in a another stations null. He can't receive that station unless they are on their auxiliary antenna. This fall we are going to test his attic and his front yard and I'll share the data. My bet is your are quite correct in that low gain antennas will out perform the high gain ones.


Bob Chase

KHWB-TV

 

TFU-18DSC-R CT220SP El Chart1 Diff Gain.pdf 44.7548828125k . file

 

Antenna Depression Angle.pdf 37.9404296875k . file
 

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In response to Post Number 49


A dipole antenna has the electrical equivalent of a series connected Resistance, Capacitance and Inductance. Z = 272+j127Ω is the rectangular values of the polar form of Z = 300∠25°Ω. √(272² + 127²) = 300, Θ = ATAN(127/272) and is = to 25°. The plus value for j means it is inductive (if j were negative, then it would be capacitive). Absolutely nothing vague about it!!!!!


And once again the common 300Ω to 75Ω commercial ferrite balun is a Z of 4:1 or E of 2:1. For an IDEAL balun. If 1V is applied to the 300Ω terminals from a 300Ω source then there will be 0.5V (a drop of 6dB) across the 75Ω terminal when terminated with 75Ω. The source power and the terminated power levels are the same (IDEAL), P = E²/Z. The 4:1, 1/2λ coaxial balun operates the same way, 300Ω to 75Ω. THE DIFFERENCE: a 1/2λ coaxial balun does not have any core IR losses.


The PR-9032 (as most TV antennas and transmissions in the US) is horizontally polarized. Since the E Field is in the H Plane the vertical mast should have little effect on the reception. Most TV antennas I have installed used this form for mechanical mounting.


A search was made for PR-9032 for all AVS Forums, 12 threads were returned. There was only one post that had a negative comment. I know of a few that connected their balun leads to the 300Ω pass thru terminals and posted here their new Channel Master 4248 was no good. I suspect some have done the same with their PR-9032.



In response to Post Number 47


There are only 16 DTV stations in the CONUS that is above Channel 59. There is no channel 66 or 68 on the east coast. Channel 61 is WNET (PBS).



Conclusion:


In certain situations a coaxial balun will help with difficult ATSC channel reception. In most cases it probably will not make any difference in reception. The Winegard PR-9032 is one of the top performing UHF antennas.


To solve for Z and Θ requires only HS level math. A technical person should have answered these questions without any problem. There are no single-wind autoformers baluns, see the schematic I posted. I can only conclude that you are not a technical person and you need to stop trying to pose as one.


07-31-2005 Edited to insert spaces

08-16-2005 Edited to correct notations
 

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OK folks a little background on me. I was a Technical Services Supervisor for 34 years for the statewide public broadcasting system. I have retired and have no ties or connections to any type organization, I do own a small home business. As of June 2007 we have purchased common shares of stock in Dolby Labs. As of March 2008 we have purchased common shares of stock in Netflix and Sirius XM Radio, as of January 28, 2010 Netflix stock was sold. I have a Associates Degree in Electronics Technology, FCC First Class License (in the days before it was a box top) and General Class Amateur Radio License. I was a AES Member for over 20 years.

Attached is a picture of several broadcast or receiving items that I was affiliated with or I was directly responsible for: Left – 300 ft. microwave tower; at the top of the tower are microwave dishes for a 145mb/s payload statewide digital distribution systems. Down the side is a Channel 20 DTV antenna. We went on the air with ATSC Channel 20 in November 1998.

Right Top – A 10 meter satellite dish and a 8.5 meter steerable satellite dish. The 8.5 meter is for receive and Ku up-linking. We had several other small dishes for various applications.

Bottom Right – A 15 ft. Rohn tower on top of the penthouse. We had several channel specific Blonder-Tongue (commerical grade) receiving antennas on this tower.

Bottom Center – Yours truly in Post Audio siting in front of a 96 X 64 Harrison Audio Desk with a Cinema (5.1) Monitor Group. Audio & Video is my true love. I designed and help construct this room and all the loudspeakers (8). I was responsible for most equipment items at the production center and the HD mobile production trailer.

My personal home theater:

Automation: X10, Wink, Echo Dot, Zigbee, Z-Wave, ISY-994i and Harmony Hub
ADC Audio Spectrum Analyzer
Chromecast Audio Model RUX-J42
Crown XLS 1000 for Front Height Speakers
Crown XLS 1000 for Rear Height Speakers
Crown DC-300 for Front Main Speakers
Da-Lite Da-Snap Cinemascope Format, 52" x 122", HD Progressive 1.1 Perf Material***
Da-Lite Pro Imager Horizontal Screen Masking System***
E-SDS 5X1 HDMI Switch
EPVision PHD 205LE ATSC/QAM Tuner
Fluke 8060A Digital Multimeter
FreeSat V7Max DVB-S2 Satellite Receiver
Galaxy CM-140 (Cross Spectrum Labs calibrated) SPL Meter
Hafler DH-120 for Two Back Speakers
Hafler DH-200 for Front Center Speaker
Hafler DH-120 for Two Side Speakers
Heathkit IG-1275 Lin/Log Sweep Generator
HP 400EL dB Meter
HSU (2) VTF-15H MK2 Sub-woofers
JVC HM-DH5U D-VHS Machine
Manhattan DJ-1997 Satellite Receiver
Marantz MKII IR Remote Control
miniDSP UMIK-1 (Cross Spectrum Labs calibrated) Measurement Microphone
Nvidia Shield Pro 2019
Oppo UDP-203 4K/UHD Blu-ray Disc Player
Roku Ultra 2019
Rigol DS1102E Digital Oscilloscope
Sony UBP-X800/BM UHD/4K Blu-ray Disc Player
Sony UBP-X1000ES UHD/4K Blu-ray Disc Player
Sony VPL-VW600ES 4K Video Projector***
Sony ST-SE370 AM-FM Tuner
Sony TC-RX311 Cassette Recorder
TBS 6983 PCIe Satellite Tuner Card
URC MX-980 Remote Control with MRF-260 RF Base***
Yamaha CX-A5100 Dolby Atmos/DTS:X Audio/Video Processor


HTPC with MIT MDP-130 ATSC Tuner Card/DVI Daughter Card,**, Prof 7301 Satellite Tuner Card, Samsung 710n LCD monitor, Aura Vision Keyboard (back lighted) and Mouse. Specialty Software: True Audio 1/24 Octave Analyzer, SpectraPlus 3.0 1/3 Octave Analyzer, TSReader Transport Stream Analyzer, Generic CADD, Visual CADD, Auto CAD lt, Bass Box and Box Plot Speaker Design, Cool Edit 2000 Audio Editor, Electronic Workbench and Display Mate.

Added to other new computer: TBS6983 Satellite Tuner Card, Hauppauge 1196 WinTV-HVR-1250 PCI-E X1 Internal HDTV Card

Antennas: Winegard DS-3100 1M Satellite Dish (used for PBS HD)

Have used the following (now replaced or no longer used or in storage): Winegard PR-9032 UHF Antenna and Winegard VHF Hi-Band YA-1713 with a Channel Master 9521 Rotor, 18 X 24 inch Dish for Dish Network at 110° & 119°, 18" Round Dish for 61.5° for Dish Network, Channel Master 5656 U/V Antenna, Channel Master’s 4408 FM Antenna, 3021 UHF Antenna, 4248 UHF Antenna and a Silver Sensor UHF Antenna.

*Items purchased from Jason Turk right here at A/V Science Inc.
**Items purchased from Digital Connection, a supporter of A/V Science Inc.
*** Items purchased from Mike Garrett at A/V Science Sales

All loudspeakers, 19" Equipment Racks, and HTPC were designed and constructed by me. Several of my hardware items is most likely older than many people on this forum.

12-20-2005: Added HM-DH5U D-VHS Machine
04-26-2006: Added Winegard YA-1713 Antenna
08-01-2006: Removed Dish Network 6000 HD Satellite Receiver and Dish Network 811 HD Satellite Receiver
11-04-2006: Added Tenma, Outlaw & URC
12-01-2006: Added Zektor HDVI5 DVI ? S/PDIF Switcher
01-07-2007: Added Panasonic DMP-BD10
01-07-2007: Removed: JVC HM-DH3000U D-VHS Machine ? Sony EP9ES Dolby Digital Decoder ? NEC AVX-910 Audio/Video Switcher/Selector ? NEC PLD-910 Dolby Pro-Logic Surround Decoder
12-05-2008: Added Panasonic DMP-BD55 Blu-ray Player
12-05-2008: Removed Sony DVP-S7000 DVD Player
02-02-2012: Removed Outlaw Model 970 Processor/Controller/AM-FM Tuner
02-02-2012: Added Onkyo PR-SC-5508P Processor/Controller/AM-FM Tuner
02-21-2012: Added Rigol DS1102E Digital Oscilloscope
08-20-2012: Added Panasonic DMP-BDT220 Blu-ray Player
08-20-2012: Removed Panasonic DMP-BD10 & DMP-BD55 Blu-ray Players
12-24-2012: Added GEOSATpro microHD Satellite Receiver
02-25-2013: Removed JVC DLA-HX1U HD Video Projector*
02-25-2014: Removed Da-Lite Da-Snap 52 X 92 (106 Dia) with Audio Vision material screen*
12-01-2014: Added VW600, Da-Lite screen with mask and MX-980 with base.
09-09-2015: Removed Crown PS-400 for Sub-Woofer and DIY sub
09-09-2015: Added 2 HSU VTF-15H MK2 Sub-Woofers
12/15/2016: Added Yamaha CX-A5100, Oppo UDP-203 and removed Onkyo PR-SC5508P
12/27/2019: Added Nvidia Shield Pro 2019
01/16/2020: Added Roku Ultra 2019





Relocated to the mountains of North Carolina 01/02/2011. In the process of building a new home theater. Will use most of the existing hardware. Will experiment with OTA antennas once the weather warms.

OTA could prove to be difficult, will use QAM for the near term. Update 01-02-2012: Have decided to stay with QAM for the foreseeable future.

11/07/2011 Added a few photos of our Home Theater project on my Facebook page here.

 

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Quote:
Originally Posted by sregener /forum/post/0



9. Now this one is ironic! You think a few inches of plywood and shingles won't kill a signal (real world test suggest 13dB signal loss) but a few extra feet of cable (real world test suggest 3dB/100ft) would?!? :)

I was worried about this, and an extra layer of shingles on my roof might have actually helped me get better reception. I'm not sure yet. I live in the Phoenix area in Arizona, and all the TV stations here put their antennas on top of the same mountain about 11 miles from where I live. I have a Samsung 360 receiver where the OTA meter is pretty useless, and a channelmaster antenna in the attic. I was having trouble losing a couple of stations once in awhile during the last year. They wouldn't always stay locked. Usually during the week during the day. I think it was due to multipath, usually on weekdays when there is more traffic. Just a guess on my part though.


I recently added another layer of shingles on my roof since it was getting old, and I was worried it would cause worse reception. It turns out my reception has been better since adding an additional layer of shingles. It's only been a month since having my roof redone, but I haven't lost a signal yet in that time OTA. I'm wondering if the extra layer of shingles helped block out the weaker multipath signals while the main signal which is stronger still gets through giving me a stronger signal lock? Just guessing and theory on my part which could be wrong, but I hope that's the case. It would make life nicer while waiting for D*TV to get the local HDTV stations up and running in my market which isn't in the top 12.
With my luck though it's probably just coincidence and I'll start losing that signal lock once football season starts.


So in short, if you want to stop multipath problems, try spending $4000 to have an extra layer of shingles installed and see if that helps.
 

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Can't overlook the obvious. Close in to the transmitter site also can have very high signal

levels either from direct signals or backscatter from nearby buildings and/or terrain. Which can overload the HDTV's tuner.


Which would explain why a low gain indoor antenna can sometimes provide better results

than a medium gain outdoor antenna.


Anyone close to a transmitter site should try lowering the signal level by inserting a variable RF Attenuator prior to their HDTV.
 

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Guys I seem to have a problem im about 30 miles from transmittors. I had a small antenna and i started to lose signals from 7 and 10 in miami.. I bout a medium radio shack roof top antenna and things got a bit better but still started to get all over the place readings with 7 and 10.... The thing is right about 200 yards out theres 2 huge palm trees and i have my antenna pointed right in the middle sort of like a fiel goal.. Well I tried placing my antenna real high and it seems that my best signal comes from it being real low.... Well everythign was fine and dandy but today it is a humid really humid night and channel 7 is about 18 decibals lower from normal.... Do you think a signal booster will help me with my up and down readings... I sort fo get the basketball signal readings at times...
 

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im now using the radio shack vu 190.. there biggest antenna.. I have it 3 feet higher than the roof.. I get good readings through out but sometimes like 7 or 10 will get real low .. like for instance on a normal day i get in between 85-89 on these channels but today my channel 7 is from 70-74..... sometimes with dips into 69... Now my run is about 50-70 feet and i have it going into a direct tv multi switch in order to split it to my whole house..... Do you think a signal amp will make a diff and if so which one.. Also the guy from radio shack said that i can put the signal booster to where the cable meets the receiver and plug the power source at the wall...
 

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Quote:
Originally Posted by Eddy13 /forum/post/0


Well everythign was fine and dandy but today it is a humid really humid night and channel 7 is about 18 decibals lower from normal.... Do you think a signal booster will help me with my up and down readings... I sort fo get the basketball signal readings at times...

If your signal strength is varying wildly, the problem is rarely a weak signal - usually this is a sign of multipath. And with VHF, 30 miles is nothing, so you've got more than enough antenna. I'd guess that a signal booster would either make things worse or make no change in your situation.


Two things you can try. One is to bypass the multiswitch and see if that helps at all. Try a direct line to one tuner and see if that makes a difference. Multiswitches are notorious for messing up antenna reception, and they often impact only a small range of channels. I'm not saying it can't work, but if you're trying to troubleshoot, that's something to test for. The other you can try is a variable attenuator from Radio Shack. When the signal is bouncing around, try dialing up the attenuation and see if that helps - an attenuator can knock reflected signals (i.e. multipath) below the tuner's threshold and possibly make things better.


All of this, of course, assumes that you're trying to troubleshoot a problem with your *picture*, not your meter. If the picture is rock solid and breakup-free, don't mess with it no matter what the meter says.
 
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