Signal Amplifiers (Amps, Preamps, Distro Amps) - Page 8 - Canadian TV, Computing and Home Theatre Forums

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post #106 of 4311 (permalink) Old 2006-12-02, 11:08 PM Thread Starter
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Originally Posted by danjorgensen View Post
I just order a KITZ Amp from EBAY and It say it works great without climbing the towel. does a Kitz Amp from Kitz Tech on Ebay Realy Work?
That's an unknown brand of preamp to me, but here's their website:

I'd be very interested to see if it is a good performer. Anyone have knowledge of this unit? For $49.99 U.S. I might even get one for testing.
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post #107 of 4311 (permalink) Old 2006-12-16, 11:53 PM
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Antenna pre-amps?

Hi All,

I have a set up that works pretty well for receiving HD-OTA signals from Buffalo. I'm using a Channel Master antenna with a cheap no-name cable amp to boost the signal. So as you would guess, the signal is boosted (about 6dB), but I will still occasionally get a few errors.

Has anyone done or seen a comparison test of different amps (dB gain, noise figure, etc. etc)?

I think I need to upgrade my $5.99 amp.

Thanks in advance,

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post #108 of 4311 (permalink) Old 2006-12-30, 02:33 PM Thread Starter
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Kitztech & ResearchComms OTA Amps

I received this by PM from a DHCer named bwam:
I have been using a Kitztech amp for about a month now and it's giving me better results than the ChannelMaster 7777 that I had. The Kitztech gives me a better signal-to-noise ratio with my receiver (the OnAir GT) than the ChannelMaster did.

I have an attic mounted UHF antenna - the XG91 (mounting on the roof is out of the question in my situation). I used to have a 4228 coupled with a CM 7777 preamp. Would lose several stations from time to time.

The XG91 cleared up that problem - brought in those stations consistently. Still I could see some channel degradation and then ditched the 7777, experimented with the Kitztech. Found the Kitztech stabilized the signals cleanly.

Am located in Atlanta, Georgia. One caveat - the Kitztech is not made for outdoor mounting (given its power supply). I can use it because the antenna is in the attic. I was going to consider the ResearchComms preamp but found that the combination of XG91 plus Kitztech solved my problems. All my stations come in consistently through all the seasons. Thus didn't have to go the expensive route of ResearchComms...
My only comment is that anytime an antenna of any design is mounted in an attic there will be consequences that are almost always unpleasant. Glad to see that a satisfactory solution was found in this case!
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post #109 of 4311 (permalink) Old 2007-01-01, 10:42 AM
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Just a note about preamps.

Not to say the Kitztech amp is not as good as it claims but what you have to consider is that you need to consider when to add a preamp.

You should not add a preamp if the cable length is shorter than 60' and you did not intend to split the signal. If you do you will end up with overload on certain channels.

Normally you need a preamp if your cable from antenna to the tuner is more than 60' and then you do not need a high gain preamp. A preamp like the Winegard AP4700 at 19db is strong enough.

Using a channel master series 777x at 26db gain will surely create problems on certain channels.

Using a booster like the Kitztech will surely help if you have channel overload since its a variable gain of up to 20db.

I have found with experience that if your cable run is shorter than 50' and you need to split the signal you can use indoor amp/distribution amp to run the cable another 30-50'.

Even though they have a much higher noise rating 3.5db+ it does work better than having signal loss through the cable.

It all depends on your situation on what to use.

Good luck.

CM4228/9521/7775;F.RmJvc70FH96/8300HDPvr/Dish 612;B.Rm LC52LE810UN/8642HD;Study LG50PK550/Xbox360;
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post #110 of 4311 (permalink) Old 2007-01-08, 11:58 PM
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Question Preamp & Attenuator suggestions?

So, I tried two different brand of "amps" from Radio Shack. I installed them at the distribution point inside my house, about 70 or so feet from the antenna head, before it feeds thru my house up to my JVC HD-ILA tv/tuner.
Nothing. Didn't do anything..either better or worse. One had about 15db rated gain, the other 20db.

I'm going to the USA this week for a week, and am thinking of picking up a CM 7775 or 7777. I want to capture CBS and PBS...I can get all the other Buffalo major stations no problems, between 65 and 74% depending on the weather.
The local stations, though, are much stronger at 85-95%.

If I put the preamp, will that be enough to "blow" my tuner when I tune to the local stations?
Otherwise, can I install an attenuator downstream that only attenuate certain stations/frequencies? Tinlee has one that has gain that is user-adjustable, and also one that has "five selectable switches". Not sure if these switches are frequency bands, or dB switches.

Anybody have some good suggestions?
(Am running CM4228. See previous posts a couple of posts up for reception results.)

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post #111 of 4311 (permalink) Old 2007-01-09, 02:01 AM Thread Starter
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Mik, given that you say there are no problems with the Buffalo signals and that there don't seem to be persistent dropouts, flickering, or outages, are you sure you need to amplify? That CM4228 seems to be doing its job quite well.

With today's 5th Generation ATSC tuners its not so necessary to have really high signal numbers anymore, so you might want to rethink this.
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post #112 of 4311 (permalink) Old 2007-01-09, 09:38 AM
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Mik on my Jvc only 40+ will lock on to the signal and will not drop out.

At 63 signal strength on Cbs your tv should lock properly.

When you position your antenna using your rotor for Cbs is that view clear or going through your trees ?

Your Pbs is weird as you get good signal from Fox. The number you posted for CW23 is that position for the best signal strength as I get 94 on that channel.

Regarding the preamp it will not blow your tuner. When you get the 7775, run through your channels if you find that one or two channels break up/pixelates then you can add attenuators or a variable one till that channels locks and comes in properly.

This is the point that you stop reducing the signal level.

A note about preamp use: Did a install this past weekend 4221 very short cable run no more than 40' and customer wanted a 2nd split to another room so I suggested a indoor amp. Customer then did not want to drill another hole and bring that cable back out and prefered if it was all doen outside.

Normally you do not need to use a preamp if your cable run is short and only going to one tv.

From his location pre pointed his antenna for 160' on a compass and then hooked up my meter to fine tune the signal. Tuned to make sure Nbc and Fox was good and then tightened it up.

With the meter I ran a display to show all Buffalo and on another page the Toronto channels. Showed very strong reception.

Connected the preamp and then went inside to do connect up the power supply. Did a scan and guess what got basically ONE channel Cbc 5-1. Went home got my Sam 260 same thing all other channels 0 signal.

Connected the meter at the end of the power supply and it showed very strong signals. At this point determined the preamp was too much gain, so I went back on the roof removed it rescanned and there was all the channels.

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Last edited by Yaamon; 2007-01-09 at 09:51 AM.
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post #113 of 4311 (permalink) Old 2007-01-09, 09:42 AM
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I agree Stampeder...but it seems so weird that CBS and PBS (both broadcasting from Buffalo as well) are unable to be captured.
Plus the fact that I *did* get CBS for one day at 65%...then it went away.
One in a while it "pops" up at about 3%'s almost as if it's lurking just below the threshold of having enough data packets for my tuner to assemble into a picture...

I mean, if it was a line of sight issue, then wouldn't the other Buffalo stations die off also? I recall that it's broadcast kW isn't as high as the others, so that may be partially to blame..

I don't really want to buy a new Tuner...that's making things redundant and also more conspicous for the wife (if you know what I mean..).

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post #114 of 4311 (permalink) Old 2007-01-09, 09:48 AM
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Well, I am pointed through (more like over the tips) of trees for all my stations (local and Buffalo). I don't move the rotor's locked at about 155-160 (remember I don't have a proper 180 reference point since these guys didn't use a compass).

The number I posted for CW23 is the best signal strength...I don't get anywhere near 94 (but then again I am not running a preamp. I think you are, right?)..

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post #115 of 4311 (permalink) Old 2007-01-09, 10:45 AM
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Mik Nbc, Cbs, and Abc comes from south Buffalo area with Fox, CW, Pbs, MyTv comes in from the Niagara area.

So to try and get Pbs it would be slightly a different position from Nbc which is the most eastern station in Buffalo.

About line of site reception, if you have good elevation then you don't really have a problem. The towers that the station broadcast from has different height with taller being better.

The tuner in the jvc is good that I would not think about upgrading. Last year before summer was able to get WB49-1 on the Jvc tuner.

Mik so sad the installers did not even setup your rotor that it point at 180'. Guess they have not read the instruction manual once to know that it said align the rotor and antenna to 180' so you can use it like a compass.

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post #116 of 4311 (permalink) Old 2007-01-10, 03:50 PM
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Location: St-Eustache, UFH=CM-4221, VHF=10y13s, CM-7778
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Blonder Tongue Voyager

I bought a Blonder Tongue Voyager it has 2 (1 VHF, 1 UHF) 300 ohm inputs and a 300 ohm output. It is also writen on it 4 transistors. Look to me very old but kind of new. I bough it at Addison for $1.99.

My question
Since the power supply also has 300 ohm input/ouput does DC pass thrue a Balun?
Any of you have an idea of the performance?
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post #117 of 4311 (permalink) Old 2007-01-10, 03:59 PM Thread Starter
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Blonder Tongue gear is top notch professional grade. Your unit seems like an oldie you've got there but the price is amazing!

Here's how you would hook it up (the power injector goes indoors so you need to run 300 ohm twinlead outside):

Antenna's connectors <-> short length of 300 ohm twinlead cable <-> preamplifier <-> long length of 300 ohm twinlead cable going indoors <-> preamp's power injector <-> matching transformer (300 ohm balanced-to-75 ohm unbalanced) connected to output terminals <-> coaxial RG59 or RG6 cable to TV

If you're in a heavy interference area you could use shielded 300 ohm twinlead. If you don't want to run something this old or with 300 ohm twinlead you could use it as a paper weight.
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post #118 of 4311 (permalink) Old 2007-01-11, 11:17 PM
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The receiver has an Automatic Gain Control circuit, AGC, which will reduce strong signals...

Receiver overload
Signal amplifiers are supposed to be linear. That is, the output is a magnified but otherwise unaltered version of the input. But too much signal can make an amplifier non-linear, usually clipping off the tops and bottoms of the sine waves. When this happens, all channels are affected, not just the one that is too strong. In fact, the too strong signal is usually not a TV station. A close FM station or police station is more likely.

If you add a good amplifier to your antenna system and your results get worse instead of better then you have overload, and you need to reconsider more carefully what you are doing.

Overload never causes any equipment damage.

An attenuator is a resistor network that can be used to reduce the gain of an amplifier. 6 dB attenuators are available at Radio Shack. If an antenna system needs two amplifiers, where the output of one amp feeds into the other amp, too much gain (overload) can result and an attenuator is usually the simplest solution. If you don’t have two amplifiers, it is unlikely that you will ever need an attenuator.

If you are close to an FM station, there might be a narrow range between too much and too little amplifier gain. (Too little gain = dropouts, too much gain = overload.) You can make that range larger by using an amplifier with an FM trap or by using a more directional antenna. VHF preamplifiers usually include FM traps that can optionally be disabled. Freestanding FM traps are also available. FM traps can either cover the entire FM band or can be single frequency traps that you tune to the offending station. The former are less effective and tend to attenuate channel 6. If the FM station is close enough you might need more than one FM trap.
Is it true that there is no worries about equipment (tuner) damage if you send too high of a signal to it? ...and that the tuner will compensate? or is the worry that there is only so much that the tuner can compensate for, after which damage may occur? I have read conflicting opinions on this.

Last edited by Kevin S; 2007-01-11 at 11:23 PM.
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post #119 of 4311 (permalink) Old 2007-01-12, 08:13 AM
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Old Channel Master 0064C preamp specifications?


I just got my hands on a used CM 0064C preamp. It definitely is an older design than the current 0064 DSB (Spartan 3).

From the researches I've done, it appears that the 0064C is a Spartan 2 model, but I haven't been able to find its specifications on the net.

Does anyone know what the specs for this model are?

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post #120 of 4311 (permalink) Old 2007-01-12, 11:41 AM Thread Starter
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Kevin_S, I too have heard different opinions on tuner overload, and I used to be in the "no it doesn't happen" camp until I bought my LG LST-4200A tuner, which plainly says in its manual to always use an attenuator at first hookup in order to prevent possible overload damage. I've heard other new ATSC tuners are also sensitive in that respect.
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amplifier , dtv , ota , preamp , signal strength

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