Reception challenged

BobR

DTVUSA Jr. Member
#1
Our reception has degraded lately and I'm hoping from some insights for improvement. Lots of pixelization and image lockup. I'm not very familiar with terminology, but hopefully I can get enough information across.
Jim-in-Seattle, if you see this, you may be able to lend better insight as you were here picking up the CM-7000 I sold you back in May.

- Antenna was purchased several years ago from Radio Shack for about $100. I can't find a model number, but it looks similar to the Antennacraft Colorstar C490 except the long arms are angled rather than perpendicular to the frame, and it has a bow tie where the wire connects.
- It's mounted on a rotating mast about 3' above the roof ridge and about 19' above ground level.
- Recently upgraded from flat wire 300ohm to coax (25 foot run pretty much straight down).
- Our signal analysis: TV Fool
- Tuner is an Elgato Hybrid plugged into a Mac Mini

I'm thinking the mast height is probably the next issue to address. Currently the mast is 4', thinking of going to 10'. Would that need guy wires? Are there collars available for attaching guy wires to a rotating mast?

Thanks!
 

dkreichen1968

Moderator
Staff member
#2
Did you use a new high quality balun (300 ohm to 75 ohm transformer) when you replaced the cable? That may be a problem. What channels are you having problems with, and what channels are you trying to receive? If your signal strength predictions are accurate (i.e. no tall buildings near by or thick trees... Actually trees could explain some of your problem.) I see no reason to go more than 3 or 4 feet above roof line. I'd actually advise you to replace your current antenna with a Channel Master 3010 You should be able to get all the green stations without a rotor.
 
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MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#3
If your current antenna is like the Antennacraft Colorstar C490 it's a bit of overkill. You have nothing but Canadian channels on VHF Low Band, and they're going all digital soon. I'd go for something smaller, and concentrate more on the UHF and VHF-hi (since you need VHF-hi for 8, 9 and 11). Going smaller would let you raise the antenna a bit without having to Guy-Wire the mast, helping you clear trees - which may be your biggest problem here.

Tell us what obstructions are around your home.
 

BobR

DTVUSA Jr. Member
#4
I got a new balun from Radio Shack. Seemed to be decent quality. Included a boot for weather protection.
I'm certainly open to a smaller antenna rather than guy wires. Would the CM 3010 give potentially better reception, or comparable?
Our primary watching is on channels 38, 39, 48, 9, 13, all nearly due west of us.
There are certainly trees to the west of us, then the terrain drops to a lake; there's another ridge and lake between us and Seattle where the towers, but we're higher than the middle ridge.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#5
:welcome: Bob!

Which channel or channels have become unstable? If several changed at the same time, my guess is rainwater has entered your coax or balun.

Please remind me: are you using any pre-amps or distribution amplifiers and can (or could) you receive KVOS-12 (35) Bellingham or any Canadian channels?

Raising your antenna a few feet might help, especially for Canadian channel reception. I may be mistaken, but (I think I heard) CHEK-6 has moved to UHF, so 10 may be the only VHF holdout. One source says it has not gone to UHF - yet.

Even when 'only' using ten feet of mast, I suggest using guy wires when using large antennas, especially at higher elevations. Your local Radio Shack may have masts, guy wire and mast rings. The QA Store has some mounting accessories and not all is on the showroom floor - its in the stock room, so you have to ask. Fry's may as well, although it seems to me they are no longer restocking much in the OTA area of the store. In a pinch, I probably have a used mast-ring for you.

By the way, 50 mph gusts are predicted for the Seattle area tonight.

Best regards and thanks again for the CM-7000!

Jim
 
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BobR

DTVUSA Jr. Member
#6
We're not using any amplifiers and I'm just trying to get the Seattle channels.
Pretty much all channels went bad.
So, my first step was to swap out the flat wire for quad shield coaxial. I also got the new balun mentioned above so I could connect it. That didn't help and I can't imagine they have water since they've only been out there a few days and i think I protected the connection well.
Today we raised it higher on a 10' mast, and it seems to have made things worse, but it may just be the weather which is blustery.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#7
:applause:Bob,

Where I live I was told by Engineers I would never be able to receive decent OTA reception (analog). That dates back long before the US went to digital. In those days, it was true but not now. I am an Imagineer and I don't like to lose.

Since you lost a bunch of channels at the same time and no one else in our region has, something is wrong on your (receiving) end. This week I have read reports of interesting Tropo coming from Canada and signals not usually received from the Seattle stations being solid in Bremerton at sea level. I captured 24, The Shopping Channel for the fiirst time a couple days ago: not dependable, but detected and locked for the first time. Also, a new (to me) subchannel KWPX 33.5 for 20 seconds.

So the question is: what else changed in your antenna system or what changed in your neighborhood? Okay, trees are shedding, but if I recall, most of the trees around you are Evergreen. Is there a mobile crane with a tall boom parked between you and Seattle? Has your reception of channels from Tiger Mountain changed? Again, do you get KVOS or Canadian stations? My question is about what has NOT changed.

Jim
 
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BobR

DTVUSA Jr. Member
#8
Jim, good questions.

Lately we've only been watching 4, 5, 7, 9, so I hadn't noticed Tiger Mt. status. Checked it a little bit ago and I'm not getting anything for 33. So, I guess that indicates it's a system problem on my end since Tiger Mt. is clearly visible from our place and in a completely different direction.

I'm not aware of anything that changed prior to the problems showing up. Which was basically why I started with replacing wiring assuming rodent or other damage.

As I think back on the events, we were getting no channels at all period. I checked the connections between the 300ohm wire and the antenna, disconnected and reconnected everything between the antenna and computer. I was able to get channels again, but there was more pixalization and locking up.

So, since the time things went bad, I have:
1. replaced the 300ohm with coax and new transformer (all new wire between antenna and tuner)
2. raised antenna about 6 feet
3. replaced the tuner (today after raising the antenna the computer wouldn't find the tuner; it was diagnosed as dead by Elgato support and I was able to exchange it at the Apple Store)
4. reinstalled the EyeTV software and blew away preferences (when I ran the auto channel search it only found 4, 7 and 22 and their subchannels)

I'm at a loss for what could have caused the degradation.
What to do next? Replace with a better/more suitable antenna? Get a preamp? Play with the height of the antenna?

Thanks again for everyone's ideas and assistance,
Bob
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#9
Bob,

How recently did these changes happen? Did it coincide with freezing temperatures in your area? It froze here both Saturday and Sunday nights. If water entered your coax and froze, that can kill it.

Jim
 

dkreichen1968

Moderator
Staff member
#10
Have you noticed any damage to the antenna? Especially broken or bent wires that connect the elements. Is anything shorted out (cross wiring touching each other, the mast, or the frame of the antenna)? That type of antenna is very straight forward and robust, but it sounds like there is a problem with it that happened when you started having reception problems.
 

dkreichen1968

Moderator
Staff member
#11
Bob,

How recently did these changes happen? Did it coincide with freezing temperatures in your area? It froze here both Saturday and Sunday nights. If water entered your coax and froze, that can kill it.

Jim
We're not using any amplifiers and I'm just trying to get the Seattle channels.
Pretty much all channels went bad.
So, my first step was to swap out the flat wire for quad shield coaxial. I also got the new balun mentioned above so I could connect it. That didn't help and I can't imagine they have water since they've only been out there a few days and i think I protected the connection well.
Today we raised it higher on a 10' mast, and it seems to have made things worse, but it may just be the weather which is blustery.
I'd say based on this that something happened to the antenna that he hasn't noticed yet.
 

dkreichen1968

Moderator
Staff member
#12
Most of your stations are in the green zone on TVfool with signal strengths approaching 70 db(NM). In theory you shouldn't even need a roof top antenna. Something must be wrong with the antenna, the cabling (which I doubt since you just replaced it and the problem started before hand), or your tuner. As a point of reference my weakest station TVfool predicts at -12 db(NM) and my antenna looks like this. Picture 009.jpg

I recommended the CM-3010 because it is bidirectional meaning it should pull in the stations from Seatle and Tiger Mountain without a rotor. That comes in handy if your planning on recording.
 
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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#13
...I recommended the CM-3010 because it is bidirectional meaning it should pull in the stations from Seatle and Tiger Mountain without a rotor. That comes in handy if your planning on recording.
It also has the advantage of maintaining the TVGOS signal to keep your schedule up to date. :becky:

Jim
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#14
I'd say based on this that something happened to the antenna that he hasn't noticed yet.
Dan,

I went back and reread the entire post and I agree with you: it appears his antenna is faulty or it could indicate his new balun is defective or it had water entry, then it froze and failed.
------------

Bob,

Have you tried other TV sets to see if their tuners behave the same way?

Jim
 
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BobR

DTVUSA Jr. Member
#15
We only have the one TV tuner hooked up to the Mac. No other TV's. And the tuner was replaced yesterday when the other one died.

The problems started a couple weeks ago, and the only component left that hasn't been replaced is the antenna. I haven't noticed any damage, but there must be something amis.

Sounds like the CM 3010 is the way to go. I'll pick one up and try it out after the holiday weekend.

Thanks gentlemen, I'll let you know how it goes.
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#16
We only have the one TV tuner hooked up to the Mac. No other TV's. And the tuner was replaced yesterday when the other one died.

The problems started a couple weeks ago, and the only component left that hasn't been replaced is the antenna. I haven't noticed any damage, but there must be something amis.

Sounds like the CM 3010 is the way to go. I'll pick one up and try it out after the holiday weekend.

Thanks gentlemen, I'll let you know how it goes.
I've had a couple situations where someone using a PC had a hard time getting reception, but when hooked to a TV, reception was perfect. I would seriously consider locating a small TV (or a converter box) you could borrow to verify that it's not a computer problem.
 

BobR

DTVUSA Jr. Member
#17
MrPogi, I think I need to track down a TV to try.

My new CM 3010 arrived today, but it's actually performing slightly worse than the old antenna. I did buy a CM 3038 amplifier with the 3010, but it was shipped separately and hasn't arrived.
Here is the latest:
Last week I tweaked the connections on the old antenna, and it helped. I had good reception on 4, 7, 9, 22, 33 and others, but no reception on 5, 13 and others. The absence of reception on 5 is mysterious and unfortunately is the channel i'm primarily trying to get. Those with good reception show signal quality of 75-80%, and strength of 50%
SignalStrength.jpg
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#18
Bob,

I had an inquiry about a week ago about KING-5 (48) from a friend in Lynnwood who had lost their signal: he had to re-aim his antenna to receive them. About the same time there was a posting elsewhere from a chap in Bremerton who suddenly started receiving them. I checked my own reception and their signal 'level' has not changed for me. I look at their tower at least twice per week, hoping they will install a new antenna on top of the tower to replace the side-mounted stick and so far, no changes have been made that I can see.

This is a real stretch, but the three different viewers reception changes might be do to the Christmas lights on the tower. In years past, the light strings stayed on the tower all year, but last year they were lowered to replace light bulbs and Evening Magazine did a story about it. I don't know if they are now raising and lowering the strings annually but if so, it might explain reception changes.

Nerve needed to string lights on 400-foot tower | KING5.com Seattle

Jim
 

BobR

DTVUSA Jr. Member
#19
The CM 3038 amplifier arrived and I finally got a chance to install it. I followed the directions installing the card in the CM 3010, and connecting the powered module. As soon as I plug the module into power a channel that normally has good signal loses signal. When the module is powered I have no signal for any channel. I did triple check that the tuner and antenna were plugged into the right ends of the module.

Since signal is 70+ on the channels we can get, might the amplification be causing it to overload?

I still need to track down a TV to try...

Thanks again,
Bob
 
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