Reception difficulty with local PBS & Ind stations

[DennisC]

Here is my TV Fool report for my location: http://www.tvfool.com/?option=com_wr...8e03935022572e
Currently have the Antennacraft U8000 8-bay UHF antenna and the Winegard YA 1713 Prostar 1000 10 EI, HI band VHF antenna (on top of pole) with a Antennas Direct Clearstream Juice UHF/VHF Preamplifier all mounted on same pole attached to chimney on top of 2 story home (30’ +). I have just installed this pre amp above as the Clearstream CPA 19 stopped working. One local PBS station WKPC PBS KET (channel 15 or 17 from Louisville, KY) will work some of the time but not at all dependable. During a channel search the TV locates the WKPC station with 3 of it’s 6 sub channels only. WCLJ Ind 42 and WKMJ PBS 68 are local Louisville stations that I am unable to pick up during a TV channel scan. My antennas are four years old and work extremely well with the following WAVE, WTTV, WHAS, WBNA, WTIUO, WLKY, WBKI, WDRB, WMYO and channels 42 with 5 sub channels and 63 with 6 sub channels. Open to suggestions to correct these issues and will appreciate any assistance?

[rabbit73]

Hi, Dennis:

Please redo your tvfool report at your antenna height using exact coordinates of the antenna. Your present report is at 10 ft. I tried doing a report at 30 ft using an estimated location near Walmart Supercenter and Goat Milk Stuff in Scottsburg, and the report looked a lot better.

I see a lot of trees in your area. Are there trees or other buildings in the signal paths?

Is the Juice getting the same channels as the CPA19, or is there a difference?

Which way are the antennas aimed?

Are you combining the two antennas with a UVSJ or a splitter in reverse?

Is your U8000 still modified to make it bi-directional by removing or rotating the reflector rods, as mentioned in your previous thread? If you disable the reflector, you are making the antenna bi-directional, but you have lost some of the gain that you had in its original forward direction.

[rabbit73]

One local PBS station WKPC PBS KET (channel 15 or 17 from Louisville, KY) will work some of the time but not at all dependable. During a channel search the TV locates the WKPC station with 3 of it’s 6 sub channels only.

I only see a main and two sub channels, but PBS is known to change the lineup.
http://www.rabbitears.info/market.ph...&callsign=wkpc

WCLJ Ind 42 and WKMJ PBS 68 are local Louisville stations that I am unable to pick up during a TV channel scan.

You are on the fringe of coverage for WCLJ:



And there is a peak in the signal path:



The results are similar for WKMJ.

[DennisC]

Thanks for responding rabbit73. I can answer some of your questions now but have to get to an appointment and will follow up later. Here is my new report after I measured and got 25’ to bottom edge of lower antenna. http://www.tvfool.com/?option=com_wr...8e03367320af70 Actually I am about 1/8 mile north of the Walmart and 1/8 mile West of Goat Milk Stuff in Scottsburg. I am in a subdivision with only a few trees, I have a tree close to the antenna on the East side but not blocking the aim I don’t think, no thick tree growth South of the antenna for at least 1/8 to ¼ mile. I will need to get on top of the house to check but I am sure I connected the 2 antennas with a combiner not a splitter. My knowledge of this topic is not at all technical so I am unsure exactly what a UVSJ is. Is there a simple way for me to determine if the U8000 is modified to make it bi-directional as I had the antennas installed by a local electrician about 4 years ago and I simply do not know. Can I attach a photo and if so would this be helpful? The CPA19 did bring in the PBS stations but for some reason WAVE channel 3 was always a problem. Now with Juice pre amp WAVE 3 is great and PBS is very poor or no signal. There are no other buildings close by other than private homes. The wind over time may have rotated the antennas if that is possible? I don’t know the exact direction the antennas are aimed until I get on the roof to check although they are generally South and a few degrees to the West I think. Hopefully this can help some.

[ADTech]

The only expected performance difference between a Juice and a CPA19 has to do with the filtering. The CPA19 had a bandstop filter from approx 250-400 MHz, the Juice dropped that one in favor of a 4G/LTE low pass filter. Other than that, there's not much difference in amps.

Trying to receive a weak UHF station off the back of an 8-bay antenna is unlikely to result in reliable or dependable reception.

Feel free to post photos, they'll help identify components and configurations.

[rabbit73]

Thanks for the new report; it looks better. The terrain in your area is very uneven, so small changes in location and height make significant differences in your report.

I will need to get on top of the house to check but I am sure I connected the 2 antennas with a combiner not a splitter. My knowledge of this topic is not at all technical so I am unsure exactly what a UVSJ is

I'm just double checking. A splitter that is used to feed two TVs from one line can be used in reverse to combine two antennas. That doesn't always work because when the same signals from each antenna reach the combining point they can interfere with each other. A UVSJ is designed to combine a VHF antenna with a UHF antenna with low loss and keep the signals separated. UVSJ is short for UHF-VHF-Separator-Joiner, and it looks a lot like a splitter.

http://www.radioshack.com/vhf-uhf-go...r/1502586.html

http://www.solidsignal.com/pview.asp?p=uvsj

Is there a simple way for me to determine if the U8000 is modified to make it bi-directional as I had the antennas installed by a local electrician about 4 years ago and I simply do not know.

In your previous thread there was a discussion about removing the reflector to make the antenna bi-directional to receive signals from the north and the south. I don't know whether you did that or not. You also considered aiming the unmodified antenna north for the weaker signals while receiving the stronger from Louisville from the back. The third alternative was to just aim south for Louisville, IIRC.
Moving U8000 reflector bars vertically
http://forum.tvfool.com/showthread.php?t=2203

and this was your thread before that:
How do I improve reception
http://forum.tvfool.com/showthread.php?t=2182
.


The reason why I'm asking is because the best reception results are when the unmodified antenna is aimed directly at the transmitter.

Open to suggestions to correct these issues and will appreciate any assistance?

I'm not too sure we can correct your issues. You seem to be doing as well as can be expected considering your tvfool report has many weak signals that have terrain interference and trees probably growing into the signal paths. We just want to make sure that what you are doing is making the best use of the equipment you have. It is possible that if you replaced the U8000 with an Antennas Direct DB8E with both panels aimed in the same direction directly at the transmitter and mounted it a little higher there would be some improvement. Whether it would be worth the trouble and expense, I can't predict.

I think that when WBKI comes in "extremely well" your expectations are raised to unrealistic heights, because it is a Tropo signal that might be terrific at this time of year, but isn't likely to be consistent.

And look at what the WKPC signal has to get above on its way to you:

[DennisC]

Rabbit73 you have provided a lot of information. I will follow-up tomorrow after I have time to double check some of these issues. Thank you

[rabbit73]

I don’t know the exact direction the antennas are aimed until I get on the roof to check although they are generally South and a few degrees to the West I think.

If you don't have a pocket compass to aim your antenna to the magnetic azimuth, you can use the green signal lines from the interactive map to pick a landmark for aim. You can move the cursor to the antenna location:
http://www.tvfool.com/index.php?opti...pper&Itemid=90

[DennisC]

Rabbit73
Sorry for the delay in responding. Ok, the Winegard YA 1713 Prostar 1000 10 EI, HI band VHF antenna (on top of pole) is currently aimed at about 157 degrees. The Antennacraft U8000 8-bay UHF antenna is difficult to measure the aiming direction although it is about 170 degrees. After being mounted for four years they may have moved some and may need to be re-aimed. The two antennas are combined with a UVSJ device. Yes the U8000 was modified to make it bi-directional by removing the reflector rods. The main difference in reception now compared to the past is that I am not getting the local PBS on a dependable basis and would like to fix that if possible.

[rabbit73]

The main difference in reception now compared to the past is that I am not getting the local PBS on a dependable basis and would like to fix that if possible.

OK, Dennis. I did another analysis with the idea of improving your reception of WKPC PBS.

1. If you look at the terrain profile in post #6 for WKPC you will see the red signal line just grazes the surface for the last 4 or 5 miles at the right end before it reaches you. It seems likely that trees have grown taller along that path. One of the ways to compensate for that would be to raise your antenna higher. Maybe you can put the UHF antenna on the top. If that is impossible, there are other things to try.

2. The antenna aim is critical for a high gain antenna because it has a narrow beamwidth. It must be aimed at 185 degrees in reference to true north by the green signals lines, or 190 degrees magnetic by a pocket compass, not a smart phone compass.

3. When you removed the reflector rods from the U8000 to make it bi-directional for Indy and Louisville, you lost some antenna gain. If you are willing to give up Indy, you can replace the U8000 with an Antennas Direct DB8E with both panels aimed at Louisville. This will give you more gain for Louisville by adding back a reflector, and because the DB8E is designed to have more gain at the low end of the UHF band where channel 17 for PBS is located. The gain for bowtie antennas is usually lower at the low end of the UHF band. If Indy is still important, you could have a separate antenna just for it.

4. When I aim an antenna, I first aim for max signal strength. I then adjust the aim while monitoring signal quality, as measured by SNR (Signal to Noise Ratio) and Errors. They don't always happen at the same azimuth. My Sony TV has a Diagnostics Screen that gives signal strength, SNR and Errors. Other ways to measure signal quality are with a converter box that has dual signal bars for signal quality and signal strength like the Apex DT502, a SiliconDust HDHR, or a Hauppauge USB tuner with signal monitor.

I can't guarantee that these ideas will give you the improvement you want, but they have the best chance of doing it.

[DennisC]

rabbit73 I do appreciate all of your effort to provide assistance for my situation. I will try several of your suggestions in hopes of improving our reception. Thank you again

[DennisC]

How close together can the 2 antennas be located on the same pole? I'm simply not sure if locating them only a few inches apart causes any complications. If it does not cause a problem I can move the Antennacraft U8000 8-bay UHF antenna up at least 24".

[rabbit73]

A few inches might cause a problem.

Try it and see.

For the best chance at PBS, the UHF antenna should be on top and it should have a reflector.