Signal Strength Differences

[h2oski]

I have one channel that I have problems recieving with my current antenna setup. The channel I am having problems with is 27.1 on freq 26. Can anyone explain to me why a channel that is broadcast from the same location as the rest of my channels has a weeker signal strength? The signal strength readings from my 622 for the channels are listed below. Here is the antennaweb channel listing for your reference. My current setup is a Radio Shack Antenna Model: VU-190 XR with the Radio Shack preamp Model: 15-2507

Channel......Freq.....Signal Strength
3.1 ............50 ......92-96
15.1 ..........19 ......91-94
21.1 ..........20 ......96-97
27.1 ..........26 ......70-80 (Very Unstable)
47.1 ..........11 .......90-94

Thanks

h2oski

 

[teamerickson]

Have you tried without preamp? You have a big antenna and are not to far from the towers. Maybe you're overloading channel 3. Or, maybe channel 3 puts out less power than the others.

You can use this to get tower info. Just fill in the blanks. http://www.2150.com/broadcast/

 

[Rick0725]

What is the length of coax from antenna to tv or distribution point.

are you splitting signal.

please give more details.

The rs preamp is rather noisy and would like to see you replace that.

but first need a better understanding of your setup to determine which preamp would be best there.

also need an idea of signal strength without an amp.

remove the preamp and run direct to the tuner and post the signal strengths so I can compare.

 

[h2oski]

What is the length of coax from antenna to tv or distribution point. There is probably at least 75 ft from antenna to the tv.

are you splitting signal. The cable from the antenna comes into the basement where it then goes into the preamp control box. After leaving the preamp control box it goes into a combiner that combines the dish signal with the antenna signal. Then behind the TV it is split so it can go in to the back of my 622 reciever.


please give more details.

The rs preamp is rather noisy and would like to see you replace that.

but first need a better understanding of your setup to determine which preamp would be best there.

also need an idea of signal strength without an amp.See the chart below

remove the preamp and run direct to the tuner and post the signal strengths so I can compare.

Without the preamp my signal strength is in the 60s for all the channels if they come in at all. The preamp set at the minimum level gives me great signal strength across all the channels except the one in question.

Channel......Freq... Signal Strength at Max Setting ...... Signal Strength at Min Setting
3.1 ............50 ......92-96.....................................................100
15.1 ..........19 ......91-94.....................................................91-97
21.1 ..........20 ......96-97.....................................................95-100
27.1 ..........26 ......70-80 (Very Unstable).............................75-98 (Very Unstable)
47.1 ..........11 .......90-94....................................................97-100


I think the big problem is that I lost a lot of leaves over the past couple of days and my antenna reception has improved significantly. My house is surrounded by trees that are taller than the house. However it still isn't good enough to use without the preamp on any of the stations. I would be willing to bet that channel 27.1 is over amplified.

 

[Rick0725]

without preamp.

direct from antenna to tv? you just did not just unplug the preamp right???

 

[h2oski]

I left the preamp on the antenna that is on the roof inline, but I did remove the preamp control box.

 

[Rick0725]

I left the preamp on the antenna that is on the roof inline, but I did remove the preamp control box.

no preamp and no powersupply.

has to be direct from antenna to tuner to test.

 

[Tower Guy]

I have one channel that I have problems recieving with my current antenna setup. The channel I am having problems with is 27.1 on freq 26. Can anyone explain to me why a channel that is broadcast from the same location as the rest of my channels has a weeker signal strength?

Thanks

h2oski

WKOW analog on channel 27 is probably overloading your preamp and causing intermod into channel 26. You must disconnect the preamp from your antenna and remove the power inserter. If you feel that you need a preamp, the Winegard HDP-269 is designed to resist overload.

 

[h2oski]

Well I removed all of the components of the preamp from my system. All of the channels are great except channel 27.1 on freq 26. Below is a list of the signal strengths without the preamp.

Channel......Freq.....Signal Strength
3.1 ............50 ......98-100
15.1 ..........19 ......98-100
21.1 ..........20 ......98-100
27.1 ..........26 ......75-95 (Very Unstable)
47.1 ..........11 .......96-99

Now it looks like I have too much antenna for my location. Is there anyway to take care of this problem without buying a new antenna? If a new antenna is the solution what do you recommend?

I think my antenna requirements are going to change depending on the time of the year. I have lost a significant amount of foliage over the past few days and that is when I started to notice the problems the most.

Thanks

h2oski

 

[Jim5506]

Do you see any ghosting on analog ch 27?

Sometimes multi-path is frequency dependent and could be singling out one channel to mess up. Try pointing the antenna slightly left and right and see if that helps.

 

[Rick0725]

Now it looks like I have too much antenna for my location. Is there anyway to take care of this problem without buying a new antenna? If a new antenna is the solution what do you recommend?

too much antenna...nope.

overload is rare when sending an un amplified signal to a tuner.

75' coax 5 db loss
2- diplexers about 7 db loss.

signal level is tamed by the time it gets to the destination.

hard to determine cause of problem from here.

try jim's advise...peak antenna on the analog version of 27.1...looking at a picture.

if there is ghosting, peak antenna till ghosting is minimized.

also would like to have you change channels and observe if you are getting any co channel or adjacent channel interference. if so let us know which channel.

to determine if overload is an issue, when you aim away from the 27.1 dt tower, does the signal level go up? if it does than overload may be an issue. but doubt it unless some other channel is affecting it

I have a winegard hd8200p longer and a little more robust then your antenna with shorter coax runs, 19 miles from towers, all stations yellow to lt green at the web, and amplified with a no overload.

Do not feel general signal overload is an issue there.




any fm towers nearby?