Is there an advantage to variable gain distribution amp to pre amp?

handymantoo

SatelliteGuys Guru
Original poster
Oct 21, 2009
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northeast
I contacted both Wineguard and Channel Master technical service. They suggested I keep my existing attic mounted Channel Master directional antenna with rotor. Wineguard recommended a HDA 200 distribution amp so I could adjust gain to my liking. Channel Master recommended CM-0068DSB pre amp. Any thoughts? Also thanks to all who may have given me antenna suggestions in another thread. Looking at all possibilities. My TVfool info
TV Fool
 
To answer your question as best I can:
The Pre-amp will add less noise than a distibution amp to the recieved signal. Used at the antenna.
The Distribution amp will amplify the signal more, adding more noise, but will cost less.

My personal recommendation from your TVFool:

Don't use an amplifier where you are.
You are too close to need one.
I also live 8 miles from the local towers.

I use distribution amplifiers to add noise when I can't attenuate.
I have one attenuator and two distribution amps from when I started learning digital TV.

Attenuating usually works best

Using an amplifier helped analog TV show up much better.
Digital TV doesn't care nearly as much.
What kills Digital TV for most is what we called ghosts in the analog days and is referred to as multi-path in Digital TV.

You should receive all but the CW station easily.
The Fox and CBS station may need some attenuation(weakening) since they are VHF and will have more strong multi-path signals interfering.

If you're trying to DX, then good luck buddy! I wish you the best.
TV DXing is not my forte. My recommendation is for stable reliable reception for your stations to your north and west of you.
 
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handymantoo,

I'd agree with meinename on just about every single point he makes, specially you being TOO close for a Pre Amp !

I'm not sure I'm understanding what you're trying to do, is it to get that CW reception better? IF that's the case, it being a "2 Edge", the usual/only way to deal with that is MORE HEIGHT ! And, you're already at 20'.

Can you come back and post exactly what you needing/trying to do ?

Have a good Day ! :)
S.W.
 
I am trying to get local and stations in Boston. I have two 722 k(4 tuners) one tv and 2 fm receivers. The antenna I have when pointed 35 degree toward Boston works great for one 722k. When I split to add anything else I start to loose Boston Stations.
 
The only time I've pulled 2Edge channels reliably was VHF signals at 45 miles away.
No amp at that time either. :eek: :D

So I'd only bet on WWDP coming in reliably.
And by reliably I mean 1-5 hiccups (audio drop-outs or bad pixels) per 10 mins. :rolleyes:

Both of the amplifiers you were suggested add way too much noise for what you are trying to do.
The Winegard adds 4dB of noise
The Channelmaster pre-amp adds 3.7dB
For what you're trying to do you need something that adds less than 2dB of noise, closer to <1db but that starts getting +$100 expensive.

This is the closest distribution amp I can find on Channelmaster's site:
Channel Master CM 3418 | Antenna | Cable TV Amplifier
But it adds 2.7dB of noise which I think is still too much...

You listed 6 needed outputs. Forgetting the FM ports, I know I can get away with a high-quality 4-way for the 8-mile stations
Channel Master CM 3214 | Antenna | Cable TV Splitter

The cheap splitters branded under Phiilips and such that are sold around here in stores caused me more loss and trouble than they were worth.
I started collecting splitters from the local Comcast installers
Made a world of difference. the 4-way splitter linked above is one such splitter that I have.

Coax cable connectors also make a difference.
It is My personal opinion is that using non-compression connectors harms digital reception near as much as multi-path or other factors.
Almost all of the coax connectors (I'm talking about F-connectors here) besides Hex-crimp and compression that I've used in the last 4 years are rubbish.
Using slip connectors are only for strong FM and as a jump-cable between analog (RF Ch. 3/4) devices.

Cables with connectors like these need to have those connectors replaced with compression connectors:
[ame="http://www.amazon.com/100-RG6-Coax-Cable-Connectors/dp/B000HSEMBI/ref=sr_1_2/181-5072292-3910145?ie=UTF8&s=electronics&qid=1258686881&sr=1-2"]Amazon.com: 100' RG6 Coax Cable with F Connectors: Electronics@@AMEPARAM@@http://ecx.images-amazon.com/images/I/11qf5qycg1L.@@AMEPARAM@@11qf5qycg1L[/ame]

Back on topic:
Care to share some pictures of the wiring for suggestions for how to improve?
 
I am trying to get local and stations in Boston. I have two 722 k(4 tuners) one tv and 2 fm receivers. The antenna I have when pointed 35 degree toward Boston works great for one 722k. When I split to add anything else I start to loose Boston Stations.

OK. You are absolutely close enough to get stable reception at the 8 mile average distance you are at, that a pre-amp/amp shouldn't be needed. But when you are using an 8 way splitter (are you?) you have a -11dB loss per port. Added to that of course is the length of the cables themselves. Add to that an additional -.5dB loss per connection point (and don't forget about any baluns being used as there is a loss there also), and by golly you'll find that you do need an amp/pre-amp.

The biggest difference between a pre-amp and an amp is that a pre-amp has a seperate power supply. Distribution amps generally have a higher noise level than a distribution pre-amp does. Variable gain amps are nice because you can customize the amp output level for your situation very easily. Adding noise to a system for the sole purpose of attenuation as has been suggested is not something I would recommend. Actual attenuators are the ideal solution.

Now getting back to what you want/need, I recommend something that is very effective, low cost & low noise. You already have all the attenuation you can handle, so what you need now is to recover some of it so you don't have any dropouts. The only way that will happen is with a low noise pre-amp.

The trouble with the suggested CM 3418 is that each port is amplified. That is where you will get into trouble. What you want is the best low noise single output pre-amp, such as this:

[ame="http://www.amazon.com/Motorola-Booster-484095-001-00-Bi-Directional-Amplifier/dp/B000066E6Y/ref=sr_1_1?ie=UTF8&s=electronics&qid=1258691206&sr=1-1"]Amazon.com: Motorola Signal Booster 484095-001-00 Bi-Directional RF Amplifier:?@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41HG8Q6hI6L.@@AMEPARAM@@41HG8Q6hI6L[/ame]

You can get it on eBay or other electronics web sites, so look for the best price. And it doesn't have to be Motorola (though I do like them the best) as the EXACT same specs are used by other makers. Myself, I have one made by NexxTech (the one in my signature). Same thing, different name. I believe Channel Master also sells their own brand. Just as a FYI, I got mine for $7 shipped from:

Consumer Depot, Major Online Electronics, Computer Wholesaler Liquidator

They may or may not have more deals like mine. Mine was listed as a demo/display unit.

Anyway, connect the antenna lead to the pre-amp input, the amplified output to the input of the 8 way splitter. You should terminate the unused ports on the 8 way with 75ohm terminators and you should be all set.

The comments made about having quality 'F' connectors are spot on. You want the best you can get. A compression tool and fittings can be had for a reasonable price also on the net. I cheap compression tool is fine for the average homeowner since it isn't being used in a professional, day in day out, manner.

So if you do what I said, you will have your losses back and might gain +1dB if your lucky. If you're real lucky you might get an added channel or 2 that wasn't possible to get before the pre-amp was added. Let us know what you decide to do and how it works out.
 
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What is so great about compression connectors? I thought their main purpose was speed and ease of use. I have a compression tool that I bought at home depot; it is more the consumer variety, not pro grade, but it works for me. Prior to that I had a hex crimper.
 
The Wineguard HDA 200 has a seperate power supply. I prefer Wineguard or Channel Master. Look at the specs for the HDA 200 and see if it will work. Also I have a Hex crimper. Can it be used? The F connectors are really tight.
 
What is so great about compression connectors? I thought their main purpose was speed and ease of use. I have a compression tool that I bought at home depot; it is more the consumer variety, not pro grade, but it works for me. Prior to that I had a hex crimper.
Reasons I'll give for compression over hex but but probable not nearly a full list or completely accurate:

  • Full contact with shield braid and foil
    • Hex has 6 points of contact at best to the shield braid and foil, compression goes all the way round
    • Better conductivity having more contact
    • Less signal loss than Hex having the extra contact.
  • better weatherproofing usually
  • Much less likely to be pulled off/out
As for Ease of install:
Compression simply requires a good strip, flip back the foil, slip a connector on, compress, and finally pull to see if the connector slips at all.

Hex, as I understand, requires make sure the braid is pinched under the 6 flat parts of the connector. And after all that fuss, the connector can still be pulled off... :(
To those who may read who can make a good crimp, good for you! :up
There are those of use who aren't that good with a hex crimp or have only used compression. :eek: :D
The Wineguard HDA 200 has a seperate power supply. I prefer Wineguard or Channel Master. Look at the specs for the HDA 200 and see if it will work. Also I have a Hex crimper. Can it be used? The F connectors are really tight.
Can it be used? Sure.
But how well do you know how to use it?
Did you use it once/a few times or have you used it many times and are familiar in making a good crimp?

As for the amp I think you are wasting money on the HDA-200
I have two similarly rated amplifiers (24dB ampli., 4dB noise) and neither helped at all trying to get the similarly rated 2edge stations.
In fact they hurt my locals.

But that's my experience, You may have a totally different experience.
 
What is so great about compression connectors? I thought their main purpose was speed and ease of use. I have a compression tool that I bought at home depot; it is more the consumer variety, not pro grade, but it works for me. Prior to that I had a hex crimper.
There really is no difference in speed of installation. Actually, the compression connectors can be more difficult to install, depending on the flaws inherent to the cable they are being installed on, and hex crimp fittings also can have issues depending on the cable as well. The largest advantage is that a compression connector:
better weatherproofing
Much less likely to be pulled off/out
as has been said.

However there is nothing wrong with hex crimp fittings as long as they are properly installed. A compression fitting is the 'better mouse trap' of the 'F' connector world. The biggest problem with hex is that (and no offense intended to anyone here) people don't know how to correctly install them. Compression fittings are, for the most part, idiot proof. Now don't get me wrong, a compression fitting can still be installed incorrectly, but the likelyhood is many times less than hex.

The biggest problem is bad hex crimpers. If the crimp isn't correct, the fitting can be pulled right off. A correctly crimped hex fitting won't pull off without difficulty. A bad crimp and you can pull the cable right out with little effort. If given a choice, compression is the way to go. But if all you have is hex crimp, and the crimpers aren't cheap/worn/bent then that will be just fine. They worked fine for years before compression came along. No reason they won't work now.;)

The Wineguard HDA 200 has a seperate power supply. I prefer Wineguard or Channel Master. Look at the specs for the HDA 200 and see if it will work. Also I have a Hex crimper. Can it be used? The F connectors are really tight.
Just because the HDA 200 has a seperate power supply doesn't mean it is right for your application. Matter of fact I would believe that this particular model is overkill, and will hurt more than help. You don't want the FM trap since you have 2 FM receivers connected to the system. From your previous posts you aren't getting any interference from any FM stations so you don't need it. You also don't need the extra noise or the excessive gain.

Trust me when I say that the Motorola is a fine product and will provide years of professional quality service. The Wineguard and/or Channel Master units are also fine units. But if you insist on one or the other, then I would recommend this one:

Channel Master CM 3410 Ultra Mini Distribution Amplifier (CM3410) - Channel Master - CM3410 - 020572034104 - CM3410 CM 3410 indoor amplifier distribution amplifier channel master CM 3042 CM-3042 CM3042 CM 3042 CM-3042 QXMM

Same thing as the Motorola. All these units are made in the same factory, just labeled differently is all. But the CM 3410 has the right amount of gain, low noise and will accomplish what you are looking to do.

Don't hesitate to ask anything else.
 
Just my two cents,

First off, the proper way to receive UHF is by putting your antenna outdoors.

Who ever and for what ever reason - decided to put their antenna in their attic is just kidding themselves when they think that they can do it and not pay a price.

The price of using a indoors antenna is that even with a stick built home with 2x4 studding and 1/2 inch drywall and 5/8th plywood on the outside and plastic siding, you are going to loose no less then 6 db of signal.

The proper way to receive a signal is to put the antenna as high up in the air as possible, as far away as possible from a noise source - electric wires, electric switches, electric motor brush noise, ignition noise etc.

Did any of you ever hear of height gain? The normal difference in gain between a fringe signal at 25 ft vs 35 feet is about 6 Db. So by mounting your antenna high up above the roof and outside, you just got 6 Db of gain.

Amplifiers - no matter what you call them, amplifiers, pre amplifiers etc is just that, a amplifier. It cannot in a digital world replace lost data. All it can do is take a good signal and boost it to over come loss, such as long runs of wire and splitter loss. I have had heated discussions as to the loss of barrel connectors and F terminals. The reason for loss in a barrel connector is due to the fact that you are removing the shield from around the wire when you splice it onto a F connector. The loss of the shield is what causes the loss - as much as the loss in the terminal due to the fact that it is not a direction connection.

To understand how the RG 6 works, you first have to understand something called a Faraday Cage. Faraday cage - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Question_book-new.svg" class="image"><img alt="Question book-new.svg" src="http://upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png"@@AMEPARAM@@en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png

Basically what it explains is that with a good wire, you will have less loss and less noise left into the wire then with a poor conductor. So it is very important to use as good of wire as possible. The Walmart junk they sell in stores just doesn't cut it.

If a person does not have any problems with reception, they are not on the internet asking for advice. PERIOD!

Wood and plastic by themselves do not block reception. But the moisture in the wood will block reception. A piece of aluminum flashing 6 inches wide can block a signal. Asphalt shingles on the roof will not block your signal, but the moisture under or on top of the shingles will. Some building materials such as stone or concrete makes a building opaque to reception, as does aluminum foil on the building insulation both on the walls or on top of the ceiling below the attic where you are trying to get reception.

It is best to take the best signal you can get, amplifiy it with a amplifier that can make enough gain to overcome the long runs of wire and the splitter loss and still produce the best signal with the lowest amount of loss from noise.

Once you hit the signal noise floor, the signal is lost forever and that is it. No amount of amplification will over come it.

The problem with places like Washington and Oregon is that when you have a transmitter on one side of the mountain and a house on the other side or deep down into a valley where the signal passes over their heads and does not hit the ground,, the UHF signal refuses to travel through the mountain or down into the valley, and you are left with a high signal but with no place for it to go.

UHF is line of sight, you can compare UHF to a flashlight analogy.

If you shine a light up into the sky, the light does not come back down and shine on the ground unless it has something that can reflect it back to you.

If you shine a light to the north, you will not have any light to the south and vice verse. If you shine a light at the side of a hill, it will not travel through the hill and it will not travel up over one side and down over the next. If you shine it up over a mountain, it will not shine down into the valley below.

VHF is like sound. If you shout, a person inside of a building can hear you. Sound will travel up over one hill and down over the next. Sound will go around corners while light will not.

People have all kinds of experience with VHF - because television stations have used VHF for over 60 years. It's when you try to take VHF technology and apply it to UHF that you get yourself into trouble.

Here is a very good point. There is a station in Altoona PA - WTAJ (1000 Kw), on the other side of the mountain 10 miles away is a transmitter for WJAC (5000 Kw). The people in Johnstown cannot watch WTAJ on UHF due to the fact that the mountain is taller then the transmitter antenna. At the same time the people in Altoona cannot watch WJAC from their main transmitter on UHF - even though there is only 10 miles of separation between the two.

The stations are forced to put up translators to cover the lost area or loose that portion of the audience. The cable companies and Sat TV providers all loves this situation - due to the fact that when reception is lost, they are all more then happy to come out and for $50 a month restore your service. But the television broadcasters are reluctant to put up translators to serve a couple more viewers in a down economy.

The second example is WWCP - Fox TV 8 out of Johnstown and WATM out of Altoona. Neither station could afford translators - both station is owned by the same person, even though one station lists Palm Communications as it's owner and the other I think is Primemedia. To conserve money, they petitioned the FCC and got approval to use each others transmitters to broadcast their signal into the adjacent market. WWCP uses its high def channel to broadcast their signal and uses it's sub channel to broadcast WATM's signal. WATM uses it's channel - 23 ( Actual channel 24) to broadcast in High Def and uses it's sub channel to broadcast WWCP's signal into the Altoona market. Without this permission, both stations ran the risk of the lights being turned off and transmitters being shut off.

The next step is the connector it's self.

Anything that is easy to push on is also easy to fall off. If I had a $1 for every connector that I threw away in the last year, I wouldn't need to look for a job next week. I gave away my compression terminal tool and I would not have another one for the simple reason that when you push on the terminal - it is as tight as it will ever get. After a couple of heat cycles, the insulation on the outer jacket of the coax shrinks and the terminal falls off.

The same is true with a crimp on connector. Unless you follow good crimping practices and use some sort of weather proof, you are going to have nothing but problems. Electrical tape and anti seize is the best medicine for a crimp on terminal.

The other thing is using the right antenna for the job. You would not use a 1/2 ton pick up truck to haul 20 tons of coal. You would get a 20 ton truck and haul it all in one load. The same is true when it comes to a antenna. There is a certain size of antenna that must be used to receive a signal properly. Unless you use a antenna that is large enough to receive that signal, plus a extra little something for when the weather try's to block your signal, or when tropo floods in your signal in the summer and then falls off in the winter and you are left with no signal at all.

You do not use a small antenna and then amplify it to get the best reception, you use the proper sized antenna and even a antenna rotor - when you have signals from more then one direction to properly aim the antenna for best results.

Even in my situation, channel 6 - WJAC which is a 5000 KW station has sparkles in the picture when I have the antenna pointed a little off center of the signal, and I am only 40 miles from the transmitter. With a Winegard 8200U antenna and a Channel Master CM 7777 pre amp!

Just like with the flashlight, if you point it north, you will not have light to the south. Yes you can receive some signals off the side and back of a antenna, but that is not the proper way to receive a signal.

When ever a signal - market is all UHF, I usually recommend a XG 91 or a Channel Master 4228 HD antenna.

When you have a mixed bag of signals, I usually recommend a 769_P Winegard or a Channel Master or a HBU 22 Antennacraft antenna.

You can throw good money away after bad on trying to get reception in a fringe area or you can use the best - cheapest antenna and do it all at once.

That's my opinion and I am sticking to it.:angel:
 
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Just trying to answer a complicated question with a simple answer.

I am sure that there are people out there that could make plutonium out of common household items and a microwave set to 1800 degrees for 6 hours.

But I am not that well versed in that subject.

However I do understand reception and can explain it with real world terms and examples that anyone can understand.
 
Just trying to answer a complicated question with a simple answer.
And you are wrong, AGAIN, on both points. The question was not "complicated" and your "answer" is not "simple".

I am sure that there are people out there that could make plutonium out of common household items and a microwave set to 1800 degrees for 6 hours.
As per your norm, completely irrelevant.

But I am not that well versed in that subject.
Nor the subject being discussed here in this thread.

However I do understand reception and can explain it with real world terms and examples that anyone can understand.
There is just so many incorrect "examples" and "explainations" in your previous 'book', that I just don't have the time to go thru and correct you, AGAIN. :rolleyes:

Really, JB, you need to stop your unfounded 'know more than anyone else' attitude and stop the nonsensical posting. And don't call me out to point out your 'mistakes', because you know I can and will. And if I have to do it again, I will bill you for my time doing so.
 
JB antennaman please only post 3-4 sentences. I had to force myself to read your garbage and found very little was true. It is at a point, where you post a reply I will generally skip reading because of your wordyness and lack of accuracy. That is a problem for those looking for help. Please consider them and shorten your diatribes.
 
and why does JB need to point out about the stations in his area? That takes up 1/2 of the OT part and nobody cares about his podunk stations

Even in my situation, channel 6 - WJAC which is a 5000 KW station has sparkles in the picture when I have the antenna pointed a little off center of the signal

thats funny. Last I checked there were no sparklies in digital. Analog yes (and seeing both OTA & free to air I've seen plenty of both) but if the antenna is "off centre" that gives you a lower signal.....sure as hell no sparklies

so once again.....WRONG!!
 
Remember guys, there is an ignore list as well...
After reading JB's posts enough, JB got on mine about as fast as another former member well known to the FTA section.
 
And I always like a good laugh and to make fun of him and his 'knowledge'. ;)

Besides, if he is left to continue posting unchecked, there's no telling the damage he could cause with all that 'knowledge' to lurkers and members alike that don't realize he is spouting nothing but false crap. That in turn gives this site a bad rep.
 
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as staff I dont have that option ;)
I understand that. Poor, poor, Iceburg having to wade through all sorts of nonsense. ;):p:D

And I always like a good laugh and to make fun of him and his 'knowledge'. ;)

Besides, if he is left to continue posting unchecked, there's no telling the damage he could cause with all that 'knowledge' to lurkers and members alike that don't realize he is spouting nothing but false crap. That in turn gives this site a bad rep.
Glad you're having fun with it.
I wish I could get paid just to respond to all of the nonsense I see...
I'd have 15 hour workday's again!

Sometimes annoys me that I can't call someone out on some nonsense as I've 0 experience in what some of the other people are talking about.
Other times (on other boards) I completely avoid threads that are filled with such utter nonsense (4th hand experiences, overly-distilled facts misconstrued to falsehood) that it would take a JB-size post customized to each and every thread.
So I try to keep my efforts focused here, and keep the facts straight.
The one thing that gets me motivated is someone willing to learn to help themselves.

I guess I would've missed a real gem talking about sparklies on a digital signal if Iceburg hadn't quoted it. ;)
Note: added this story after the story below
The local religious low-power repeater (not the TBN one) recently switched to digital.
When I checked their digital signal I was horrified to what I saw.
A black and white static mess of Daystar, with occasional color. My guess was they where using a analog satellite receiver to pick up the Satellite feed with the dish in sore need of a realignment.
Now mind you, my TV/Converter is getting a perfect Copy of what they are transmitting. With digital TV, Nothing I can do with my TV and OTA antenna can fix what they are broadcasting.
==================
Reminds me of when "This TV" was added at the local station, right about the time the THIS satellite feed was having real issues. In my local AVS OTA thread, people were calling the local station "unprofessional" and a "joke" when the fault wasn't even on the local's end. I could only tell them what I saw on the satellite feed from another station. The satellite feed and the local station were dropping out at the exact same time in the program with the same bad picture. :rolleyes:
==================

So handymantoo, what did you choose to do about the Boston stations?
 

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