Question: Worst reception higher up

howardc64

DTVUSA Jr. Member
#1
Hi:

My setup is Channel Master 4228 with a Channel Master CM7777 Pre-amp. I get better reception when I lean the antenna against the house on the ground (with a slight upward tilt) than mounting it 30+ feet up on my chimney.

I notice cloudy whether in my area affects my reception quite a bit. I have lots of tall trees in the line of sight to the key stations transmitters.

My question is, does it make sense slight upward tilt should cause a dramatic difference? Here is a link to the tvfool's report on my location

https://picasaweb.google.com/lh/photo/i77chexjK2fosBHijVbb-w?feat=directlink
 

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#2
The antenna works better on the ground because the 7777 amp is likley overloading when the antenna is raised higher. How is reception with the antenna connected directly to one TV?

The 7777 is designed for fringe areas & overloads easily with strong local signals around.
 

howardc64

DTVUSA Jr. Member
#3
The antenna works better on the ground because the 7777 amp is likley overloading when the antenna is raised higher. How is reception with the antenna connected directly to one TV?

The 7777 is designed for fringe areas & overloads easily with strong local signals around.
Interesting. I recall the signal strength got better when I hooked up the 7777 preamp. But I don't recall if I had the antenna on the ground or roof back then. I'll try it without the preamp and report back.

For background info, I only have a single TV hooked up directly to the preamp/antenna. No splitter and under 100 ft of coax cable.
 
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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#4
:welcome: Neighbor!

I also suspect the CM7777 is overloading your tuner and you need to retest your setup after bypassing it or removing it from the coaxial circuit.

Theoretically, tilting a receiving antenna reduces its ability to receive reflections from the ground, such as water saturated earth or a nearby lake that is causing a doubling of the signal from the same direction of the transmitter, which is a version of multipath reception. Also in theory, tilting an antenna can improve 1-edge signal reception from just below the peak of a hill or other physical obstacle.

You're not that far away from our local transmitters and your new or old design 4228 is considered to be a high-gain "near-fringe" antenna. Specifically, which channels do you currently receive and which ones improve when you purposely mis-aim your antenna? Also, what channels would you like to receive but currently cannot?

Jim
 

howardc64

DTVUSA Jr. Member
#5
:welcome: Neighbor!

I also suspect the CM7777 is overloading your tuner and you need to retest your setup after bypassing it or removing it from the coaxial circuit.

Theoretically, tilting a receiving antenna reduces its ability to receive reflections from the ground, such as water saturated earth or a nearby lake that is causing a doubling of the signal from the same direction of the transmitter, which is a version of multipath reception. Also in theory, tilting an antenna can improve 1-edge signal reception from just below the peak of a hill or other physical obstacle.

You're not that far away from our local transmitters and your new or old design 4228 is considered to be a high-gain "near-fringe" antenna. Specifically, which channels do you currently receive and which ones improve when you purposely mis-aim your antenna? Also, what channels would you like to receive but currently cannot?

Jim
Thanks for the note Jim In Seattle. I'm in Sammamish. The stations I want are 4/5/7/9/13 and they are all around 250-260 degrees. If I add about 10 degrees CW, Channel 13.1 and 5.1 comes in better but 4.1 signal strength starts to drop. If I go back to about 10 degrees 7.1, 9.1, 4.1, 16.1 all comes in good but 13.1 and 5.1 weakens.

Since tvfool.com says I'm under 15 miles (except for 13 at 35 miles) and LOS to the transmitter. Perhaps there is a better antenna than my 4228? Maybe omnidirectional?
 
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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#6
Howardc64,

An omnidirectional antenna is the worst choice for OTA HDTV reception, almost anywhere on the planet. You are trying to receive a clean single stream of data to your tuner, without 'hard' wires carrying only those signals to you. Consequently, your antenna choice is very important for its ability to receive strong (but not too strong) signal levels over the natural "noise" that accompanies received signals on their way to you. Both versions (old or new) CM-4228 are good antennas, designed to be able to receive stations from many miles away (as in fringe).

Since you have a 'hyper-directional' antenna that ignores noise and channels from its sides, I suggest you consider using an antenna rotator or rotor to aim your 4228 toward each signal/channel. That's what I have.

*Important question: why did you add the CM7777 pre-amp to your system? Before we continue, I need to know your results before it was added, and what changed after it was added. Also, please post a list of the channels you currently receive.

... Let me blow my own horn a bit, to help everyone reading understand how important a clean signal is compared to a strong signal:

I used to (still) receive K26IC-D, a KIRO-7 translator near Bremerton that had barn-burning power output of 40 watts (yeah, like a porch light bulb) from 27 miles away. They upped their ERP to 900 watts and that is still my main source for KIRO/CBS. KVOS-12 (35) from Bellingham, WA. also split 4-ways using no amplifiers is rock-solid and their transmitter is 75 miles away: that's my source for MeTV and TheCOOLTV.

FYI, FOX-13 can be received from a Capitol Hill translator as an SD subchannel: look at 22 (JoeTV) and rescan for its sub.

I spent the day reworking one of my antenna masts and improved my reception of K62FS (analog) translator for VHF-11 in Port Angeles, WA., and I finally nailed down what it takes to receive all three main network transmitters on top of QA Hill. Also, I changed my rotor to a Channel Master 'remote-controled' unit and now I can redirect my antenna from my chair.
A very productive day and its beer time! :cheers:

Jim
 

Jim1348

DTVUSA Member
#7
Question: Worst Reception Higher Up

By any chance do you have an in-line variable attenuator available to you? I have used one in the past to test some installations and I find them to be handy. For example, if you fear you might be overloading a receiver, attenuate the signal until (or if) the recovered picture improves. Obviously in this scenario I would just take the pre-amplifier out of line and see how that works.
 

howardc64

DTVUSA Jr. Member
#8
Thanks for everyone's note. Up on the roof first thing in this sunny morning. Here is a quick update

- Disconnected preamp
- Found an spool (75-100ft) of RG59. Replaced the current coax cables+connection. Found one of the connections had no contact with the coax shielding
- Found I assembled the antenna to the pole incorrectly. 4228's rear mesh was touching the metal mounting pole. It no longer does now but now sure if this makes a difference.
- Direct connection between antenna to TV. No splitters

I now get 4,5,7,9,11,13,16. 5 and 7 are the weakest according to my Panasonic TV signal meter (30-40% for 5.1, and 40-60% for 7.1). Other channels are between 60-90%.

One of the reasons I put the preamp in is based on what I previously read. After I installed it, i would get nearly 100% signal on some channels but still poor signals on the others. So I thought the preamp is a net gain and I need to figure out why I'm getting hit and miss. Jim In Seattle's comments make sense to me. It probably isn't the strength as much as how clean the signal is.

Today is a sunny day with no wind so we'll see how the signals hold up when it gets cloudy and windy.

I would like to avoid a more complex rotating setup. If I want to improve my reception further, should I consider a multidirectional antenna like Antenna Direct DB2 or DB4? I would guess 4228 being such a long range antenna must have narrower directional lobe? I ask this because as I rotate the antenna 20 degrees CCW, I can get channel 4 or 7 (sorry I couldn't remember) to improvement significantly while channel 5 degrade significantly. tvfool shows the transmitters for 4,5,7 all at 271-2 degrees and all at about 14 miles LOS from me. Not sure why such big difference in my reception for these 3 channels.

Thanks for all the help guys. I'm Computer Science and not EE so this antenna stuff is all new to me :)
 
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Jim1348

DTVUSA Member
#10
Question: Worst Reception Higher Up

.....Found an spool (75-100ft) of RG59. Replaced the current coax cables+connection.....
I feel bad that I didn't mention this earlier. I would suggest that you give some consideration to using RG-6 exclusively in your installation in every piece of feedline that you run, even the short patch cables. The better insulated, lower loss cable can make a huge difference. Granted, RG6 is more expensive than RG59, but I happen to think it is worth the additional cost. (Okay, I am getting off my soapbox now.)
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#11
Howard,

These days, adding an antenna rotator to your system is easier than ever before. I'm currently testing a new Channel Master unit and its small tabletop box displays the compass bearing where the antenna is pointed using bright red LEDs. It has a small remote control unit allowing you to store 69 different (or the same) directions in its memory and after you program it, the rotor will go to that stored compass point when you enter the channel number you want to view. I use 4-wire copper telephone wire between the control box and the rotor although its a 3-wire unit.

I took a second look at your TVFOOL report and receiving KVOS-12 (35) is possible for you. They offer MeTV (old/retro shows) as well as local content on 12.1 and TheCOOLTV on their new 12.2 subchannel which is a 24 hour music film/video channel. Their transmitter is on Mt. Constitution in the San Juan Islands and you would need a rotor and perhaps a couple more feet in antenna height to receive them.

It is well worth trying for, in my opinion. :hippie:

Others above have mentioned RG-6 as the preferred coax: it has about one-half of the signal attenuation over RG-59 and (usually) better shielding. Name brand coax is preferred: one local Broadcast Engineer did a study and he claims Radio Shack coax is "leaky and lossy". Black jacketed coax is preferred for its ability to withstand UV radiation whereas designer-color coax is not.

The multi-directional reception claim for the DB-2 and DB-4 is a marketing ploy, or a play on words. All antennas receive signals from multiple directions and yes, the DB-2 has a wider main lobe. I'm currently testing a DB-2 and its useable main lobe appears to be about 34 degrees wide. This may be exactly what you need to cover the spread of signal directions in your situation. On the other hand, a narrower 'beamwidth' tends to ignore undesireable signals and noise from its sides. The ratio of signal to noise is king, not signal strength. If you go after KVOS, I think you will need the gain provided by your 4228.

Also to clarify a bit of a misnomer, the signal meter in your Panasonic is useful as a reference point to compare signals, but it is not a 'strength meter' as found on a CB radio. It is more accurately called a quality meter, but that's not quite true either. In fact, it uses no specific standard as a reference point so if you tried a Sony TV on the same antenna and compared the results, the numbers would (likely) make no sense. Does this make sense? Its hard to clarify black magic!

Jim
 

howardc64

DTVUSA Jr. Member
#12
Thanks for everyone's reply. I'll definitely get some RG-6 soon. After spending a whole day watching various channels, I can see some channel's (5 & 16) signal quality fluctuate throughout the day. Sometime it drops low enough that I get a lot of hiccups. It seems RG-6 won't solve whatever that is causing this variation. So I likely have to get something with wider lobe or a rotator as Jim In Seattle suggests.

One note I'd like to share with everyone is I live in an area with abundant tall evergreens rising 4-5 stories tall. There are a whole bunch directly in the direction of most of the channels I want. It seems my reception is affected by winds. Perhaps all of these trees swaying is the cause of my weaker stations hiccups?

I think I'll start with a wider lobe antenna + RG-6 and see where that takes me. I'll post back with results after :)

Update: I found a Seattle OTA forum on avsforum.com. Members there living near me seems to be having atmospheric degradations with channel 5 (16 is same station). I'll explore a bit there further to see what people have found.
 
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MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#13
One note I'd like to share with everyone is I live in an area with abundant tall evergreens rising 4-5 stories tall. There are a whole bunch directly in the direction of most of the channels I want. It seems my reception is affected by winds. Perhaps all of these trees swaying is the cause of my weaker stations hiccups?
I'd be willing to bet that's your biggest problem. Evergreens are pretty difficult to shoot through, and the fact that your reception varies with the wind just makes it more likely that this is your problem. Can you move the antenna to a better location, or trim some branches to get you a straight "line-of-sight" shot at the problem transmitters? I would try that before changing antennas or cable.
 
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howardc64

DTVUSA Jr. Member
#14
Trimming trees is not an option because they are on various other people's property. I also living in a country club and they like to preserve the tall tree community look.

When I rotate the antenna +-15 degrees, I can see various stations reception improve (from say 60%-80%+ according to my Panasonic TV's signal quality meter). However, channel 5.1 don't improve very much and other people in my area on avsforum.com also comments on this station. I'll follow up on that.

Besides hooking up a rotational unit, is there a way to put up say 2 antennas with each pointed in different direction and merge their signals for the HDTV tuner? I guess this will inherently create multi-path (which is bad?) as well?
 

dave73

DTVUSA Member
#15
Besides hooking up a rotational unit, is there a way to put up say 2 antennas with each pointed in different direction and merge their signals for the HDTV tuner? I guess this will inherently create multi-path (which is bad?) as well?
This varies for people. It is possible to join 2 different antennas, but you will have some signal loss when do so. With you being so close to most of the stations, it might not be much. With most stations in the 266° - 271° range, & the other set in the 154° range, if you join 2 antennas, you need a UHF only antenna pointed in the 154° range (RF 33, 42 46, & 51), & a VHF/UHF combo antenna for the stations in the 266° - 271° range. As for using your Channelmaster CM4228 antenna for VHF is not a smart thing to do. I don't care what anyone says, but that antenna (like the Antennas Direct DB8 and others like it) aren't really made for VHF. I have heard of some people who use one of these antennas, and complain that they can't get certain stations, because they're on the VHF. Channelmaster may make the claim that the 4228 works for VHF, but the guarantee doesn't work for everyone. Some Antennas Direct antennas have filters on them that keep the antennas from picking up VHF (I believe the ones with circular elements). I say that for your VHF's (if you're willing to get a separate VHF antenna, then get the Antenncraft Y5-7-13 antenna for the VHF, & let the 4228 work as a UHF only antenna. The other option would be to get a completely different combo antenna like the Winegard HD7694p or Antennacraft HBU33. If you're gonna insist on using your 4228 for VHF, then get another 4228. I however still recommend either a traditional VHF/UHF combo antenna, or get separate VHF & UHF antennas. I bought the Winegard HD-1080 antenna back in 2009 mainly for 1 TV station in my area that broadcasts in a different direction. When I decided to try it out on Chicago stations, it picked up RF 7, but not RF 12, but got all UHF stations. After that, I have never recommended using any 2, 4, or 8 bay antenna for VHF, because the results vary for person to person.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#17
It is possible to join 2 different antennas, but you will have some signal loss when do so.

It can work if you are willing to accept 50% signal loss from both antennas, plus the loss from the extra coax and splitter. It also can result in profound multhpath issues.

When two 'same-band' antennas are connected together with a splitter, the received signals are 'mixed' BUT they are also divided between the receiver and the other antenna: half of the signal from each antenna goes to the TV and half of the signal from each antenna goes to the other antenna. This includes attempting to combine a VHF-UHF combo antenna to any other antenna using a common splitter.

Since the signals improve with a small change in antenna direction, rather than trying to combine two antennas I advise using a rotor or an antenna that is less directional such as a 4-bay. If VHF-13 was the only troubled channel, I'd seriously consider combining a high-band VHF Yagi such as the mentioned AntennaCraft Y5-7-13 and your Channel Master 4228 with a UVSJ, with both antennas on fixed mountings.

Howard, it seems Mr Pogi and I had a meeting of the minds on this one: I have a spare KSQ 4-bay you could try. It is sized almost the same as your 4228 but it is designed for the current UHF band which ends at channel 51. Most bay antennas (including those on YouTube videos) are designed for the old channel range up to 69. If it improves your UHF channels but not 13, you could still add a VHF Yagi to it with a UVSJ.

Jim
 
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howardc64

DTVUSA Jr. Member
#19
Hey gang, the channel I'm having reception quality with is 5.1. My understanding is all digital broadcast is in UHF correct? Clearly, my CM4228 is not a VHF antenna.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#20
Howard,

KING-5.1 is real channel 48, at the top of the current UHF band. Although they have an approved Construction Permit, KING-5 has not yet replaced their old low-band VHF antenna from the top of their QA Hill tower and they are using a side-mounted temporary transmitting antenna at a comparatively low height. Ironically, it is a channel I receive well, but from an entirely wrong direction ... as near as I can tell, I receive it via a 'bounce' off of a downtown skyscraper. More black magic.

Here's a frequency list: http://frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi?TITLE=47&PART=73&SECTION=603&YEAR=2002&TYPE=TEXT

Channels 2-6 are considered obsolete for digital television, but still available for Broadcasters if they want to beat their heads against the wall for fun. Between channels 6 and 7 is FM radio and other services. Channels 7-13 are active high-band VHF and locally we can receive channels 8, 9, 11 and 13.

Jim
 

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