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OTA Signal Strength

Started by daheels, Sunday Oct 26, 2008, 01:53:36 PM

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daheels

I am having problem with OTA signal strength.  I have dish network for a service provider and use a chimney mounted antenna for OTA.  I have a channel master 4221 and a spartan 3 amplifier.  I have a VIP 612 receiver and a VIP 622 receiver.  The problem I am having is my signal strength jumping all over the place.  In the span of ten seconds my signal strength will jump from 95 to 81 to 65 to lost signal back to 95.  This happens with all the local channels.  The problem is worse on the 612 but also happens on the 622.  I live in Brookfield near the intersection of North and Springdale.  Any ideas/suggestions?  Thanks in advance.

Phil

troyriley

With it being so windy yesterday, did you check all of your connections and make sure everything is fastened down really well? Maybe the wind was blowing something around up there.

techboy

Trees....especially on wet and windy days.   It's not the signal strength, it's the multipath.  Best solution is to mount the antenna higher.  Amplifiers tend to intermodulate.   Try a non amplified splitter.
Retired Broadcast TV / Radio Engineer WTMJ. ( 35 Yrs )

daheels

I have the antenna mounted as high as I can and the problem has been happening for awhile now not just on windy days.  Would not using the amplifier possibly help?

Jimboy

#4
1). Make sure the antenna is aimed properly. Bow ties facing the towers? The only reason I ask this is because I see so many antennas in this area aiming the wrong way based on their location. (unless you're trying to get other markets on purpose)  
 
2). Try removing the pre-amp. By that I mean actually remove the pre-amp from the line not just power it off. Most amps don't pass RF while they're off. Is the amp roof/mast mounted? Did you install it? If so be careful up there, or hire a professional.


After doing that post your results.

Talos4

Quote from: daheels;48885I have the antenna mounted as high as I can and the problem has been happening for awhile now not just on windy days.  Would not using the amplifier possibly help?

My experience with amplifiers/pre amplifiers and OTA in the metro area is that amplifers amplify everything. If there's interference in the signal that get's amplified along with the signal.

You're not that far out from the towers and you really shouldn't need a preamp to pull in the Milwaukee stations. If you're DXing that's a little different.

I have a relative in the Town of Pewaukee in a low spot that has a 4221 on the roof with no amp/preamp in the line and they get all the stations without an issue.

Take Jimboy's sugeestions and go from there.

daheels

Quote from: Jimboy;488921). Make sure the antenna is aimed properly. Bow ties facing the towers? The only reason I ask this is because I see so many antennas in this area aiming the wrong way based on their location. (unless you're trying to get other markets on purpose)  
 
2). Try removing the pre-amp. By that I mean actually remove the pre-amp from the line not just power it off. Most amps don't pass RF while they're off. Is the amp roof/mast mounted? Did you install it? If so be careful up there, or hire a professional.


After doing that post your results.

I'm pretty sure that I have the antenna facing the right direction.  I will trying removing the pre-amp tomorrow and see if that helps.  Thanks.

Buy_The_Tie

I was having a similar problem in New Berlin with 58.1 & 24.1.  In my attic I have a big 'ol Radio Shack VHF/FM/UHF antenna with a preamp, it was feeding a 4-way splitter which headed off to my TVs / HD Radio.

This weekend I installed a Radio Shack "UHF Only" antenna on the roof.  From there I go through a grounding block then right to my living room television (Sony 40" XBR).  The signal levels are *way*  more stable.  I have increased overall signal levels on 58.1 & 24.1, most other channels remained about the same with the exception of 10.1 (yes, I know this is VHF so this is expected).  The signal on 10.1 is still in the mid 80's and nice and stable.

I changed two things at once.  I switched from the large attic antenna to the small rooftop antenna, and at the same time got rid of the pre-amp.  Which was the magic bullet?

How best to supply 3 TVs and an HD radio?

troyriley

Quote from: Buy_The_Tie;48928I was having a similar problem in New Berlin with 58.1 & 24.1.  In my attic I have a big 'ol Radio Shack VHF/FM/UHF antenna with a preamp, it was feeding a 4-way splitter which headed off to my TVs / HD Radio.

This weekend I installed a Radio Shack "UHF Only" antenna on the roof.  From there I go through a grounding block then right to my living room television (Sony 40" XBR).  The signal levels are *way*  more stable.  I have increased overall signal levels on 58.1 & 24.1, most other channels remained about the same with the exception of 10.1 (yes, I know this is VHF so this is expected).  The signal on 10.1 is still in the mid 80's and nice and stable.

I changed two things at once.  I switched from the large attic antenna to the small rooftop antenna, and at the same time got rid of the pre-amp.  Which was the magic bullet?

How best to supply 3 TVs and an HD radio?

Going from a combination VHF/UHF antenna to just the UHF antenna was probably a big help. The strong VHF/FM signals you were receiving (which were also amplified) probably had an effect on the UHF signals, lowering the quality of those.

Talos4

Quote from: Buy_The_Tie;48928I changed two things at once.  I switched from the large attic antenna to the small rooftop antenna, and at the same time got rid of the pre-amp.  Which was the magic bullet?

How best to supply 3 TVs and an HD radio?


The magic bullet? probably both. Unobstructed antenna and losing the pre-amp.

Sometimes the simpler the set up the better it works.

As far as you 3 TV's and radio. You four way splitter is fine. There will be a bit of signal degradation to each but really it shouldn't be noticeable.

I'm feeding 2 TV's and 2 receivers from my rooftop OTA antenna without issue on the SW side of Milw.

TonyC

I had the same problem. but with my ViP722 OTA. Tried both a Radio Shack VU90XR and Channel Master 4221, different lengths of cable and a RS pre-amp. I agree with others, remove the pre-amp as you are probably no more that 15 miles from the towers. I'm sure you've checked Antennaweb.org and Tvfool.com already.

What I did was make the antenna lower - that is take it off the roof. 12.1 and 6.1 were my worst channels, while everything 18.1 and up was at 100 signal level. I had the antenna on a tripod about 7 feet above the roofline (22 feet total), now its on a metal clothespole about 8 feet up on the North side of the house. I still get drops but only when its windy, and that's probably nothing you can do about (trees reflecting). Think of a room with the same voice but different delays - the OTA receivers can't handle broken streams and that exactly what in analog was known as ghosting (phase delay).

10.1 is VHF and on the 4221 comes in around 70-73. Most of the time now all channels are steady - they drifted exactly how you described before and it drove me nuts (especially since its getting dark earlier when we all get home from work).

Don't forget to ground and lightning block your antenna. Static on the mast will introduce some pixel issues as well. Make sure your connectors are on well - I fought that issue also with the cheap RS crimp-ons.

TonyC

Cheesehead Dave

Quote from: Buy_The_Tie;48928Which was the magic bullet?

I probably have the same Radio Shack UHF antenna as you, and down here in Kenosha, it works just fine with no need for an amplifier, so that probably wasn't it for you.

Buy_The_Tie

Quote from: TonyC;48952
Don't forget to ground and lightning block your antenna. Static on the mast will introduce some pixel issues as well. Make sure your connectors are on well - I fought that issue also with the cheap RS crimp-ons.

TonyC

I have a separate wire connected to the mast of the antenna.  It follows the actual antenna lead down through an un-used chimney to a lightning arrestor block mounted in the basement.  From there it goes over to my electrical service box where it is connected to the main grounding wire that heads out to the grounding rods in the back yard.

I've found that the twist-on connectors for RG-59 & RG-6 work really well.  I refuse to buy another RS Crimp-on connector again.  They may work OK if I would actually buy the proper crimp tool, but I'm too cheap for that.