RCA TVPRAMP 1R Amplifier Question

[navagator]

Hi, Folks

I just have a quick question regarding the RCA TRPRAMP weatherproofing.

I have my new Winegard 8200U assembled and mounted to a temporary mast approximately 9 or 10 foot off of the ground. I have the RCA amp mounted a foot or so under the antenna with all of the coaxial ends sealed with coax seal except for the VHF input on the amplifier which would be unused. My question is, should this unused connection be sealed off, or would it be ok open? I have enough coax seal left to cover it if needed.

I have a couple of guys coming tomorrow to put it up on the pole, can't wait to get it up there.

Thanks in advance.

[rabbit73]

Put a 75 ohm termination cap on it.

[ADTech]

A plastic cap is adequate to keep moisture out of the connector. It doesn't matter for the rest of the amp as the enclosure isn't moisture tight anyway. A terminating cap, if you have one handy, will also work. The unused input doesn't need termination, though.

[navagator]

Thanks for your replies.

I just went ahead and covered the unused port with some coax seal.

The new antenna is up, signal quality is about the same, maybe a little stronger than the old antenna. But, I'm experiencing numerous signal dropouts. I'm not sure but I think it might be because the installers didn't get the new antenna up quite as high as the old antenna was, probably a few feet short. I have an older push-up type telescoping pole which is fairly heavy and difficult to work with.

Could the signal dropouts be a multipath issue due to the lower antenna height?

And, would I benefit from purchasing one of the newer HD tuner boxes, maybe a Homeworx, iview, or iKonvert? I currently have an older LG-4200 tuner. I like the way it works for the most part but I know it has an older chipset that probably doesn't handle multipath as well as the newer ones.

Thanks

[rabbit73]

I see you have some previous threads. The most recent one was:

Advice on whether to purchase a new antenna or not
http://forum.tvfool.com/showthread.php?t=13893

Is this tvfool report still good?
http://www.tvfool.com/?option=com_wr...46aed217075afd

or is this more like it
http://www.tvfool.com/?option=com_wr...82302011475802

[rabbit73]

I'm not sure but I think it might be because the installers didn't get the new antenna up quite as high as the old antenna was, probably a few feet short. I have an older push-up type telescoping pole which is fairly heavy and difficult to work with.

What you are talking about is called layering; it is possible, but testing is required to confirm it.
http://www.hdtvprimer.com/antennas/siting.html
http://blog.solidsignal.com/content....ANTENNA-part-2
http://www.tvantenna.com/support/tutorials/probing.html

Could the signal dropouts be a multipath issue due to the lower antenna height?

Multipath could be an issue at any height. Are there any trees or buildings in the signal path?

Is it 4th or is it 5th?
LG 4200A and the 5th Generation Chip
http://www.avsforum.com/forum/25-hdt...tion-chip.html

it works for the most part but I know it has an older chipset that probably doesn't handle multipath as well as the newer ones.

That is correct; the later generations of tuners handle multipath better. A newer tuner might, if the problem is multipath.

What TV are you using? Does it have a digital tuner?

Your strongest TV signal, K18GU-D with a Noise Margin of 55.8 dB and Pwr of -35.0 dBm, probably isn't strong enough to cause preamp overload after adding the antenna gain, but you might end up with too much signal for the tuner.



Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html

You have a very strong FM signal KTWA 0.6 mi away with a signal Pwr of +4.0 dBm that is a serious threat to TV reception. The FM filter in the RCA preamp is probably not sufficient to handle it; you should try adding another FM filter between the antenna and the preamp input. See attachment 1.
http://www.mcmelectronics.com/produc...-FM-88-/33-341
https://www.antennasdirect.com/store...on_filter.html
http://comingsoon.radioshack.com/rad...l#.VXR-zzjbJLM

If there isn't enough gain for the weak signals without a preamp, and using a preamp is too much gain for the strong signals, you can optimize the gain by inserting some attenuation between the antenna and the preamp input for the optimum gain needed for your signals. This called maximizing the SFDR, Spurious Free Dynamic Range.

[rabbit73]

Sometimes the aim of the antenna for maximum signal strength is not the best aim for maximum signal quality, as defined by SNR and errors. I first learned about this with an Apex DT502 converter box, that has dual signal bars, one for signal strength and one for signal quality (the inverse of errors).



I first aimed the antenna for maximum signal strength. Then, when I rotated the antenna slightly to the right, the signal strength was a little less, but there was a big increase in signal quality.

My Sony KDL22L5000 also gives a reading of SNR and errors of OTA 8VSB and cable clear QAM digital signals in the Diagnostics Screen. Here is a bad signal with picture freeze:



Good signal:



My Hauppauge 850 and 950 USB tuners can give a reading of SNR and errors, but the software isn't user-friendly for me.
http://www.hauppauge.com/site/suppor...l_monitor.html



My point is, if you can find a way to measure signal quality, you can optimize the aim of your antenna.

[navagator]

Originally Posted by rabbit73

Is this tvfool report still good?
http://www.tvfool.com/?option=com_wr...46aed217075afd

or is this more like it
http://www.tvfool.com/?option=com_wr...82302011475802

The later is the correct one.

Originally Posted by rabbit73

Multipath could be an issue at any height. Are there any trees or buildings in the signal path?

Yes, we do have some trees in the signal path for WHO, which is the channel we watch most of the time. I have attached a picture of the antenna/trees.

Originally Posted by rabbit73

Is it 4th or is it 5th?
LG 4200A and the 5th Generation Chip
http://www.avsforum.com/forum/25-hdt...tion-chip.html

Quote:
it works for the most part but I know it has an older chipset that probably doesn't handle multipath as well as the newer ones.
That is correct; the later generations of tuners handle multipath better. A newer tuner might, if the problem is multipath.

What TV are you using? Does it have a digital tuner?

I think the LG 4200A has the 4th generation chip??? When I purchased it our current tv didn't have a built in digital tuner. Later we purchased a Hitachi 57F710E tv set which did have a built in digital tuner but I continued to use the LG 4200A tuner, it seemed to change channels faster and I liked the EPG.

[rabbit73]

Yes, we do have some trees in the signal path for WHO, which is the channel we watch most of the time. I have attached a picture of the antenna/trees.

Thanks for the photo.

Uh-Oh.

Trees cause problems for TV signals.
http://www.hdtvprimer.com/antennas/siting.html

Example of Vegetation Affecting Signal Strengths-Part 1
http://www.avsforum.com/forum/25-hdt...-part-1-a.html
His trees in attachment.

The WHO signal (which is already weak by the time it gets to you) can be damaged by trees, multipath, primary overload from strong TV signals, primary overload from FM signals, a 2Edge path, and electrical interference noise on VHF.

but I continued to use the LG 4200A tuner, it seemed to change channels faster and I liked the EPG.

OK, I get that, but how does the Hitachi do with WHO?

[Billiam]

Navigator.

Are you getting a good picture on WOI Ch. 5 with the 8200 antenna?

You may need a pre amp with more gain and probably a lower noise floor for this situation. While the RCA pre amp is excellent and great for not overloading from strong signals, it lacks the punch for deep fringe situations such as yours.

I had a home about 40 mile east of KC a few years ago and I used the Winegard 7084 as well as the Antennacraft HBU 55 there. Both of those were able to give me some 2 edge signals below a positive NM. One was nearly minus 16 NM on UHF and thanks to the HBU 55 and a good pre amp I could always watch it. I was using the now defunct Winegard 8275 pre amp.

May want to look at something like the Kitztech units for this situation. I too had one Green signal on Ch. 19 while the rest in my TV Fool report were in Yellow or Red. I did not experience any overload issues using the 8275 pre amp even with the moderately strong Ch. 19. I think you can avoid an overload of the amp since it is only one channel and it is only moderately strong i.e. about the same as my Ch. 19 signal strength at that time.

Also, adding RG 11 in place of RG 6 may help if you have a cable run approaching 100 feet. Will give a half db or more of signal for you on many channels.

[navagator]

Originally Posted by rabbit73

OK, I get that, but how does the Hitachi do with WHO?

If I remember correctly it performed about the same as the 4200. I'll try and hook it back up and see how it does.

I talked to the installers and they're going to come back and raise it up higher, hopefully that will take care of the problem.

[navagator]

Originally Posted by Billiam

Navigator.

Are you getting a good picture on WOI Ch. 5 with the 8200 antenna?

No, the signal level for WOI is very low, not enough for the tuner to lock onto.

However, I did receive WOI with the first converter box I had, at least part of the time anyway. I believe it was a Zenith DTT-901. As I remember that converter box worked pretty well but unfortunately it was SD only.

[Billiam]

Originally Posted by navagator

No, the signal level for WOI is very low, not enough for the tuner to lock onto.

However, I did receive WOI with the first converter box I had, at least part of the time anyway. I believe it was a Zenith DTT-901. As I remember that converter box worked pretty well but unfortunately it was SD only.

Tuner quality varies greatly in some TV's and also the converter boxes. Some TV's I've had such as a Sanyo stunk while others like a Sony and Samsung were excellent at least where picking up weak signals is concerned.

If after raising the antenna you see any other channels such as WOI but don't get a clean lock on it all the time, you may be able to fix the problem with the pre amp I recommended. Kitztech makes pre amps for very weak signal areas.

[navagator]

Hello, All

The installers came out yesterday and raised the new antenna about 3 to 3 1/2 foot. This brought it to what appears to be about 1 to 1 1/2 foot higher than where the old antenna sat.

There was deffinate improvement.

I found channel 13 WHO to have a very slight increase in signal level and there was only a few very brief signal dropouts that morning. The rest of the day and night it was solid. I used to experience some signal drops in the morning hours with the old antenna.

With the extra height I also now receive channel 5 WOI and Channel 8 KCCI . WOI's signal strength was somewhat low and I expierenced moderate signal drops in the morning hours as well, however in the evening/night I was able to receive it fairly well with very few signal drops. Channel 8 KCCI I could not receive at all in the morning hours but in the evening/night I had a strong signal with no signal drops. The signal was actually slightly stronger than that of WHO channel 13. However, this morning I did receive KCCI but with many signal drops.

The extra height deffinately helped.

Also, most of the trees that are visible in the photo I posted earlier will be gone in a few weeks. The new owner of the next door property is basically leveling everything and building a new garage. So, all that should left in way of trees should be one limb from one of my trees. And while it will be very close to blocking the line of sight for my antenna to Des Moines I don't think it will. So, hopefully this will help also.

Thanks for everyone's help.