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Old 4-Dec-2017, 2:25 PM   #81
blackstone
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The results from using a preamp are discouraging.
RCA TVPRAMP1R.

Tried various settings and connections and got -0- stations with any of them.
Here's what I tried:
FM Trap on
UHF separate (Yesterday this was set to combined with the same results)

Tried both UHF separate and the VHF post.
Have the DB8e connected to the power module which is connected to the CM 3414 amp.

Saw a YouTube video where a guy said he used just the outdoor box without power.
Tried that, too.

No results.
Was hoping this would help boost some of my weaker signals.

Is this a defective preamp?

Pretty sure I'm connected properly

Last edited by blackstone; 4-Dec-2017 at 2:33 PM.
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Old 4-Dec-2017, 5:49 PM   #82
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Since I'm trying to be greedy, I called Antennas Direct for their suggestions on optimizing my weaker signals.

They sell this preamp

I may try it and order a combiner from them if the one I have coming from Amazon doesn't work

It will only take a few minutes to find out later this afternoon when it gets here
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Old 4-Dec-2017, 6:29 PM   #83
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I may have gloated too soon.

I lost some stations completely and others went from normal to weak.
The only thing that changed was weather.
It got cloudier.

And, possibly, I attached the extra cable to two masts to get it up out of the way.
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Old 4-Dec-2017, 6:39 PM   #84
jrgagne99
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Quote:
Originally Posted by blackstone View Post
Is this a defective preamp? Pretty sure I'm connected properly
If the preamp killed your reception, then yes, something about it is likely defective.

Quote:
Originally Posted by blackstone View Post
I may have gloated too soon.
It is easy to get excited by periods of good reception. Several days of good reception are generally needed to confirm the quality of your installation. Improved reception due to tropospheric ducting last for hours or sometimes days. See http://www.dxinfocentre.com/tropo.html for DX forecasts, as well as rear-view looks.

Quote:
Originally Posted by blackstone View Post
And, possibly, I attached the extra cable to two masts to get it up out of the way.
This is not likely to have any ill effects.
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Old 4-Dec-2017, 6:40 PM   #85
blackstone
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Thanks for that input, jrgagne99.

The highs and lows of cutting the cord

My area is black on that map.
It says nil signal.

What does this mean?

Last edited by blackstone; 4-Dec-2017 at 6:44 PM.
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Old 4-Dec-2017, 6:41 PM   #86
rabbit73
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The problem with the RCA preamp could be that it is hooked up wrong, or it could be a bad preamp, or both. This is the hookup for the DB8e and the RCA preamp; it should work better than without the preamp.

DB8e > preamp > long coax > grounding block > power inserter > TV

If the signals are too weak for splitting:

DB8e > preamp > long coax > grounding block > power inserter > 3414 > TVs

To combine the CM for VHF only and the DB8e for UHF with no amplification for the CM:

Code:

        CM 
          \ VHF                               
           UVSJ > coax > grounding > power > splitter or 3414 > TVs
          / UHF            block    inserter
DB8e > RCA
       switch set to combined or separate, but preferably combined
       
The Radio Shack 15-2586 or the AD UVSJ will pass power to the RCA
To combine the CM for VHF only and the DB8e for UHF with amplification for the CM and the DB8e, using the RCA preamp as a combiner:

Code:

  CM 
    \  VHF                               
    RCA amp > coax > grounding > power > splitter or 3414 > TVs
    /  UHF            block    inserter
DB8e 
     RCA switch separate
If the combined/separate switch in the RCA preamp goes bad in the separate position, use the UVSJ as a combiner:

Code:

  CM 
    \ VHF                               
     UVSJ > RCA > coax > grounding > power > splitter or 3414 > TVs
    / UHF                  block    inserter
DB8e 
       RCA switch set to combined
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Last edited by rabbit73; 4-Dec-2017 at 6:44 PM.
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Old 4-Dec-2017, 6:53 PM   #87
jrgagne99
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Quote:
Originally Posted by blackstone View Post
My area is black on that map.
It says nil signal.

What does this mean?
It means conditions supposedly were not especially favorable for improved reception due to tropospheric ducting. That being said, as i understand things, weather fluctuations can change reception, outside of tropo ducting effects. In my case, I tend to get stronger signal when it is cloudy/overcast, vs. clear nights when the reception is typically not as strong (though still more than adequate for uninterrupted TV watching).

Last edited by jrgagne99; 4-Dec-2017 at 7:36 PM.
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Old 4-Dec-2017, 6:56 PM   #88
rabbit73
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There are some voltage tests you can make on the RCA preamp:





When the preamp is connected, the voltage will drop. It is necessary to use a T-adapter to have access to the center conductor to measure the voltage when the preamp is connected:





https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Attached Images
File Type: jpg RCAPreampVoltage1.jpg (159.6 KB, 267 views)
File Type: jpg RCAPreampVoltage2.jpg (154.7 KB, 263 views)
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Last edited by rabbit73; 4-Dec-2017 at 7:26 PM.
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Old 4-Dec-2017, 7:23 PM   #89
blackstone
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Thanks for that info, rabbit and jrgagne.

I've never used a grounding block.

Yesterday, I had the DB8e with the combined switch on.
Today, I had it set to separate.
In both cases, it completely killed the signal.

Here's how I tried it.
DB8e---.RCA--->LONG COAX--->POWER--->3414--->TV.

The DB8e is now 40' from the CM
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Old 4-Dec-2017, 7:41 PM   #90
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That should have worked if the DB8e was connected to the UHF input of the RCA.

Try it without the 3414.

Time to make some voltage measurements.
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Old 4-Dec-2017, 8:57 PM   #91
blackstone
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I'll be returning the RCA and trying a different one.
That was the only one in my town.

I don't have a lot of choices here.
I have Ace Hardware, Busy Beaver lumber, and Walmart.

Next town, which is a lot bigger and 30 miles away, doesn't have much more.
That includes Lowes, Home Depot, bigger Walmart, Target.
Too bad Radio Shack doesn't exist anymore.
I looked for some kind of electronics store but none around.
There is a Best Buy 45 miles away in another direction.

How could the signal degrade that much in such a short time?
Only 4-5 hours.
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Old 4-Dec-2017, 9:10 PM   #92
jrgagne99
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Quote:
Originally Posted by blackstone View Post
I'll be returning the RCA and trying a different one... I have Ace Hardware, Busy Beaver lumber, and Walmart.
I recommend getting one from Walmart or Walmart.com. My recollection is that they were generally of good quality with way fewer issues than the Amazon.com ones. Anecdotally, mine came from Walmart.com and works well.

Quote:
Originally Posted by blackstone View Post
How could the signal degrade that much in such a short time?
Only 4-5 hours.
I'm not at all surprised by this. It is not uncommon to see signal strength change by 5-6 dB (factor of 4) as weather patterns change. Especially for deep fringe situations. As a peronal example, last year on Superbowl Sunday, I was getting the FOX affiliate for 18 hours with 3 dB to spare, leading up to Sunday afternoon. Then at 2pm, signal strength began to decline and by 4pm it was gone completely... Murphy's Law.

Last edited by jrgagne99; 4-Dec-2017 at 9:12 PM.
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Old 4-Dec-2017, 9:36 PM   #93
blackstone
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I'll check out Walmart.com.
Usually, it takes a long time

I was looking at the PA18 UHF/VHF Antenna Pre-Amplifier Kit from Antennas Direct.
I can get a 10% discount which makes it $2 more than Wally.
WM has a pretty big selection which includes Channel Master and Winegard.

Which do you guys recommend?

Some have a 30 db gain, some 16, some variable.
It doesn't sound like a high gain always gives a better signal

Last edited by blackstone; 4-Dec-2017 at 9:46 PM.
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Old 5-Dec-2017, 12:42 AM   #94
blackstone
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Just got this delivered and hooked up.
Linear 2512 ChannelPlus DC & IR Passing 2-Way Splitter/Combiner
Got 13 channels VHF and 20 UHF.

(I almost always get 13 VHF stations).

It seems to work better than the previous splitter I was using.
Try another preamp and I expect to be as good as I can get.

I may try and raise the antenna a little to see if that helps.
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Old 5-Dec-2017, 1:10 PM   #95
jrgagne99
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Quote:
Originally Posted by blackstone View Post
I may try and raise the antenna a little to see if that helps.
Antennas are like real estate--- the three most important things are Location, Location, and Location. In my experience, moving the antenna around can often result in many dB increase in the SNR, vs. picking the right cable (sometimes even choosing RG-11), using low-loss preamp, (e.g. Kitztech KT-200), and other tricks can only result in a few dB at best.

As an example, I spent well over 40 hours mapping out all of the available rooftop area on my house for reception quality/quantity over a period of about 16 months. I found one particular location and mast height where I was able to get 80% of the channels I wanted, but was still missing one key channel. I was just about ready to call it "good enough" when I was able to borrow a big man-lift and fish around for reception up in some nearby trees using my antennas and a handheld portable TV. I was finally able to find a nice sweet-spot up in a big pine tree, where I get all 6 signals (19 channels) with 100% reliability. I used good-quality infrastructure (pre-amps, cables, etc.) to pipe the signal to my house, but the key to success for me was the location.


Quote:
Originally Posted by blackstone View Post
Some have a 30 db gain, some 16, some variable.
It doesn't sound like a high gain always gives a better signal
A 30 dB probably won't do any better than a 16 dB, unless your downstream losses really are that high. Here is a nice web-based utility to estimate your downstream losses, and by extension, the amount of amplification recommended at the mast. http://otadtv.com/cables/index.html

Remember, if there's no water in the well, a bigger bucket (more amplification) won't help. You need to dig deeper (get a bigger antenna) or dig the well in a different spot (move the antenna). Or something like that.
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Old 5-Dec-2017, 1:20 PM   #96
blackstone
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Good analogies, jrgagne99.
Checking the link.
Is my CM 3414 4 port amplifier considered a splitter?
And a question on connectors.

Do I count as a connector each connection to the antenna and combiner box as well as the connection inside to the splitter/combiner and the connection to the CM amp/splitter.
Or does this mean only if I connect 2 pieces of coax?

Thank you

PS: How do you check signal strength in various locations?
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Old 5-Dec-2017, 2:23 PM   #97
jrgagne99
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Quote:
Originally Posted by blackstone View Post
Is my CM 3414 4 port amplifier considered a splitter?
No. In this case, I think its positive gain should be counted to the positive side of your ledger. Rabbit may correct me on this.

Quote:
Originally Posted by blackstone View Post
And a question on connectors.

Do I count as a connector each connection to the antenna and combiner box as well as the connection inside to the splitter/combiner and the connection to the CM amp/splitter.
Or does this mean only if I connect 2 pieces of coax?
In this case, I think "connectors" means barrel connectors that join two pieces of coax.


Quote:
Originally Posted by blackstone View Post
PS: How do you check signal strength in various locations?
There are expensive (several hundred dollars) signal meters out there, but the poor-man's method is to use the signal quality indicator on your TV. Some use words like strong, good, and weak, others have numbers, some (like my Sony Bravia) give really useful information like the signal-to-noise ratio (SNR).

An intermediate approach is a little homemade widget using a Winegard camper/RV signal strength meter (Winegard RFL-332 SensarPro Black TV Signal Strength Meter), which requires 12V power (eight AA batteries) and a DC-blocker because it is designed for use with amplified Winegard RV antennas. Read R. Ross's review of the SensarPro on Amazon for instructions on the build. I built one and it works pretty well.

Last edited by jrgagne99; 5-Dec-2017 at 3:30 PM.
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Old 5-Dec-2017, 3:19 PM   #98
rabbit73
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Quote:
Originally Posted by blackstone View Post
Is my CM 3414 4 port amplifier considered a splitter?
The 3414 is a distribution amplifier. It consists of an amplifier and a splitter in one case.

The amplifier has a gain of 15 dB, but the splitter section has a loss of 7 dB per outlet, so the net gain for each outlet is 8 dB.
https://www.channelmaster.com/Antenn..._p/cm-3414.htm

Quote:
PS: How do you check signal strength in various locations?
The answer by jrgagne99 is correct. Use the TV that has the best signal strength meter; all you need is a relative indication.....more is better.

This is from my 19" Samsung TV:



I also like the Diagnostics Screen in my Sony TV. It gives relative signal strength and SNR. Screen shots from my Sony KDL22L5000:

Bad signal with picture freeze, SNR below 15 dB, and uncorrected errors:



Good Signal



Signal level meters are expensive.



I like to make antenna measurements, so I'm willing to spend the money. I bought the Sadelco 719E meter on the left when I retired from the government in 1988; it was $600. My wife gave me the Sadelco DisplayMax 800 meter on the right as a present; it was $1000.

Since that time, I have bought several meters on eBay, but I don't bid any more than I am willing to lose if a return isn't possible.

This one was $75 including shipping:

Attached Images
File Type: jpg Sadelco 719E2_1.jpg (226.0 KB, 83 views)
File Type: jpg SamsungLN19C350D_SSmeter.jpg (130.4 KB, 79 views)
__________________
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Last edited by rabbit73; 5-Dec-2017 at 5:53 PM.
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Old 5-Dec-2017, 3:38 PM   #99
blackstone
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Thanks for that info, Rabbit73.

Always good and I learn.
(Slowly)

Just ordered the PA18 UHF/VHF Antenna Pre-Amplifier Kit from Antennas Direct.
Should get here late Thursday so I'm status quo until then.

Reception is poor today; possibly due to rain.
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Old 5-Dec-2017, 5:59 PM   #100
rabbit73
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Quote:
Originally Posted by blackstone View Post
Reception is poor today; possibly due to rain.
Reception will always be variable with your weakest signals and with the channels that are off-aim for your antenna.

Your goal should be for reliable reception of your strongest channels in all kinds of weather.
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