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Old 29-Jul-2019, 8:59 PM   #1
xtal_01
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Antenna amp ... totally confused

I have read post after post and totally confused myself.

I am putting an antenna in the attic.

I want to put a "reasonably" priced amp on the mast.

I am hoping to stay in the $40 range.

Having had great luck with Winegard in my RV I was going to get a LNA-200 ... then I read the horrible reviews.

I can get the RCA TVPRAMP Z1

or the HAMZA 1515HD

or the CX-7778

... or ????

It is just for every one I pick, I start reading comments and none seems really happy with any of them.

I am in Vermont ... I get 18 channels ( well really 5 ... stations ) and maybe the is the best I will get.

There are some "fringe" stations from Montreal I would love to get but according to the map / chart / report ... it will be unlikely.

I am really in a hole with mountains all around.

Still if I can get a decent amp for $40, it is worth a try.

Any suggestions ????

Thanks .... Mike
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Old 29-Jul-2019, 11:18 PM   #2
OTAFAN
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Quote:
I am in Vermont ... I get 18 channels ( well really 5 ... stations ) and maybe the is the best I will get.

There are some "fringe" stations from Montreal I would love to get but according to the map / chart / report ... it will be unlikely.

I am really in a hole with mountains all around.



Hi Mike!

Please add your TV Fool report zip code and possibly also rabbitears.info could be very useful as well. Then the good Techs here can give your better advice.

I'm sure others will chime in with the help you're looking for.
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Old 29-Jul-2019, 11:41 PM   #3
xtal_01
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reception report

I can literally see the antennas on the mountain to the east of me. They are the only ones I get right own If I go just a bit more north with the RV, I can get the Canadian channels. I even picked them up once here a while back (experimented with an antenna ... an amp on it and another on the ground) but it was "flaky". As I said, I am in a deep hole (valley) with mountains all around. Don't think I will get more channels but for $40, wanted to give an amplifier a try.

Here is the report:

http://www.tvfool.com/?option=com_wr...9038b656564348
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Old 29-Jul-2019, 11:47 PM   #4
rabbit73
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Hello, Mike
Quote:
Originally Posted by xtal_01 View Post
I am putting an antenna in the attic.
That will make your signals weaker.

Quote:
I want to put a "reasonably" priced amp on the mast.

I am hoping to stay in the $40 range.

Having had great luck with Winegard in my RV I was going to get a LNA-200 ... then I read the horrible reviews.

I can get the RCA TVPRAMP Z1
The LNA-200 isn't that bad. The two RCA TVPRAMP1 preamps that I bought new in sealed boxes were defective; poor quality control.

Quote:
or the HAMZA 1515HD


That looks interesting, but I have no experience with it.

Quote:
or the CX-7778


That is the CX777 sold by electorica on eBay. They have changed the model number in the description to make it similar to the Channel Master CM-7778, which it isn't.

Specifications:

Power Source 100-240 V
Power Output: 12 V
Noise Figure ≤ 1.5 dB
Gain: 32 dB (says 30 dB in the image)
Bandwidth: 47-862 MHz

I doubt that the Noise Figure is as low as 1.5 dB. A Gain of 32 dB is too much; very easily overload as Channel Master found out to their dismay with their redesign of the CM-7777 with a single antenna input and a gain of 30 dB.

Quote:
I am in Vermont ... I get 18 channels ( well really 5 ... stations ) and maybe the is the best I will get.
Please post your TVFool report to give us a idea of you signals.

Quote:
There are some "fringe" stations from Montreal I would love to get but according to the map / chart / report ... it will be unlikely.

I am really in a hole with mountains all around.
Montreal doesn't sound likely.
Attached Images
File Type: jpg Hamza Focus Preamp2.jpg (112.7 KB, 427 views)
File Type: jpg CX777 Preamp3.jpg (152.2 KB, 418 views)
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Old 29-Jul-2019, 11:57 PM   #5
xtal_01
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Hey!

I put the report up (well a link to it ... I think this is the way to do it). Here is the link again:

http://www.tvfool.com/?option=com_wr...9038b656564348

So if the 777 (7778) is out, then maybe try the Hamza? I did like that it had a metal (shielded) housing.

I also see a half dozen "no name" amps on ebay ... is one better than another? Can any be trusted?

At one point with am RS amp (long story ... flipped over in a storm .. filled with water ... died) I was getting some stations to the West from Plattsburgh NY.

Seems like I need to fly a kite :-)

Thanks .... Mike
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Old 30-Jul-2019, 12:09 AM   #6
GroundUrMast
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I have an Antennas Direct 'Juice' and have also used the RCA TVPRAMP. Given the differences in construction, I am not put off by the price difference between the two. I can recommend both, favoring the Antennas Direct for it's performance, construction and US based customer support.

Having said that, I would caution against the common misconception that amplification gain is a substitute for antenna gain. All amplifiers will amplify what you feed them. If you feed them a weak signal mixed with noise, you will get more signal and more noise at the output plus any noise generated by the amplifier. There are a few examples of low quality tuners that can be helped with amplification but for the most part, an amplifier is only useful for overcoming cable and splitting losses. (Hence my signature.)

If there were signals on your report that were expected to be receivable but you were not getting them reliably, I would suggest moving the antenna out of the attic as the first step toward improved reception. If the signal(s) that were hard to receive were relatively weak, I would suggest an antenna with higher gain. Once you have reliable signals with the antenna, not more than 50' of coax and a single TV, then I would consider the merit of amplification.

What antenna are you using presently?
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Last edited by GroundUrMast; 30-Jul-2019 at 12:35 AM. Reason: Question...
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Old 30-Jul-2019, 12:42 AM   #7
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Hey Mike:

Here's your rabbitears.info report (takes about 20 seconds to load). You can actually go the searches there and put in your address to nail down reception at your specific location.

https://www.rabbitears.info/search.p...=dBm&height=25

Good advice above regarding amps. Looks like you have both High VHF (1) and UHF channels LOS and 1 & 2 Edge. Perhaps an RCA 751 or similar could work depending on any obstructions you might have, as your mentioned. You might want to think about a good antenna instead of the amps right now. Get up on your roof (safety first!) and find the spot which gives you the best reception.

Just my two cents worth.....

Last edited by OTAFAN; 30-Jul-2019 at 12:50 AM. Reason: additional
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Old 30-Jul-2019, 12:44 AM   #8
rabbit73
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Quote:
Originally Posted by xtal_01 View Post
Hey!

I put the report up (well a link to it ... I think this is the way to do it). Here is the link again:

http://www.tvfool.com/?option=com_wr...9038b656564348
Sorry, Mike; I finally did see the link to your report. I was composing my post at the same time.

I also favor the Antennas Direct Juice preamp, but it is more than $40.00. You could buy a less expensive amp and return it if you didn't like it.

However, I agree with GroundUrMast: get the right antenna in the right location first, then add the preamp.

What antenna are you using?
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Last edited by rabbit73; 30-Jul-2019 at 12:56 AM.
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Old 30-Jul-2019, 1:12 AM   #9
rabbit73
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The green signal line to Canada on the TVFool Interactive map doesn't even come on until I raise your antenna to 300 feet.







Attached Images
File Type: jpg xtal_01TVFmap2.jpg (147.9 KB, 381 views)
File Type: jpg xtal_01TVFcovCFTMcu.JPG (132.1 KB, 377 views)
File Type: jpg xtal_01TVFcovCFTM.JPG (161.3 KB, 375 views)
File Type: jpg xtal_01TVFp2CFTM.JPG (121.1 KB, 369 views)
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Last edited by rabbit73; 30-Jul-2019 at 2:09 AM.
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Old 30-Jul-2019, 1:49 AM   #10
xtal_01
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Like I said ... I need a kite!

Exactly ... like I said, I am in a hole here ... right down in the lowest part of a valley ... the river that runs in the base of the valley is my one property line.

I had a "fancy" home made tuned job till this week ... I don't remember what it was called ... gray-hoverman I think ... reflectors, directors, ... I made in one night just to test ... kept it up for three years, finally started to rot so I dumped it.

It got me 18 channels sitting on the porch (second story of our house).

I have a cheap Windegard FV-30BB just sitting under the TV inside the house upstairs .... I get 18 channels.

I have an RCA ANT751R ... just sitting on the lower floor of the house inside ... 18 channels.

And maybe 18 is all we will ever get. With the Gray-hoverman, I did get more with an amp ... sometimes ... don't know if the amp was flaky or the antenna (this was just a test model made of some thick aluminum wire and a wood frame ... but measured fairly accurately).

WOW ... I had never tried the "rabbit ears" ... super accurate ... I get the first 6 ... good and fair ... not the "poor" ones .. thought I think I did get one of the poor ones and one of the bad ones before my Radio Shack amp died.

Mike

PS..... there is no antennas mounted yet ... been building the house for 5 years ... almost done ... just got a new tv, thus time for a more permanent antenna ... I am always surprised that the RV antenna (20 year old amplified directional wineguard) seems to work as well as or better than anything else
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Old 30-Jul-2019, 2:22 AM   #11
rabbit73
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This is an image of your TVFool report:



This is a report from rabbitears.info which should have a more accurate list of channels:



To answer you initial question, if your antenna is mounted outside, a preamp and your TV tuner would be overloaded by your strongest signals. If your antenna is in your attic, the signals will be weaker, but it is difficult to predict how much weaker they will be because of differences in construction. Try it first without a preamp.
Attached Images
File Type: jpg xtal_01TVFreport.JPG (88.7 KB, 365 views)
File Type: jpg xtal_01TVFreportRE.JPG (168.7 KB, 363 views)
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Last edited by rabbit73; 30-Jul-2019 at 2:46 AM.
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Old 30-Jul-2019, 2:45 AM   #12
xtal_01
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OK, can someone explain the db rating to me. I know it is a measure of the strength of the signal. How can you have a negative strength?

Thanks .... Mike

PS ... get the first 6 ... the "good" ones
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Old 30-Jul-2019, 3:03 AM   #13
rabbit73
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Which dB rating on which report?

A negative dB number just means it is below a critical reference level at 0 dB. Zero dB doesn't mean no signal. Anything stronger than the 0 dB reference level is positive; anything weaker will be negative.

Quote:
PS ... get the first 6 ... the "good" ones
That's all you need for a complete set of the major networks. You're lucky; many others wish their OTA signals were that good.
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Last edited by rabbit73; 30-Jul-2019 at 3:05 AM.
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Old 30-Jul-2019, 3:24 AM   #14
xtal_01
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So is there a point where the -xxx db scale "ends"? Is it like + 100 to -100 or ?

And I may just call it ... still it would be nice to get say 57 ... and I have when I had the old RS amp on the gray.

I will check my budget to see how it fits into the "juice"

What would be the second choose ... RCA or 777 or Hamza or ????

Thanks so very much again !!!!!!!!!!

Mike
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Old 30-Jul-2019, 5:40 AM   #15
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Perhaps another way to explain "dB" would to use "sea level" as an analogy. Elevation that is higher than sea level is written as a positive number, elevation that is below sea level is written as a negative number. Sea level is the zero reference point for elevation. Even if you move between metric and imperial systems of measurement, the standard of sea level is a constant reference point worldwide.

You ask, "... is there a point where the -xxx db scale "ends"?"; (I presume you are referring to the predicted signal power available at your location per the TV Fool or Rabbitears reports) No, but if a signal is weaker than the random noise that is always present, no tuner will be able to lock on and demodulate the signal. Random noise levels are not constant, there is usually lower noise levels in the UHF band than the VHF band. Most appliances, power tools and home electronics emit some noise.

If you are looking at the gain specification of an amplifier, the "dB gain" value tells you how much stronger the output signal and noise will be as compared to the input.

It's possible to have too much gain. This is more likely to be a problem when there are one or more strong signals present. The CM7777 is known for it's high gain and it's tendency for overloading. It is designed for applications where there are no strong signals present. It's a good amplifier when it's used for what it was designed for (an area with only weak signals). When used improperly you can expect to get less reliable reception due to the distortion of the signals as they're over amplified. The signal levels on your report definitely are too strong for amplifiers like the CM7777.

Bottom line, An amplifier might get you a couple of additional PBS stations. I don't expect an amplifier to make any Canadian signals reliable at your location. You would need to mount an antenna on a mountain top to overcome the terrain between you and Montreal.
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Last edited by GroundUrMast; 30-Jul-2019 at 5:42 AM.
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Old 30-Jul-2019, 2:41 PM   #16
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Quote:
Originally Posted by xtal_01 View Post
There are some "fringe" stations from Montreal I would love to get but according to the map / chart / report ... it will be unlikely.
How badly do you want those "fringe" stations from Canada? They will most likely take extreme measures to receive at your location. Such as an powerful antenna on a 70-foot tower, high quality mast-mounted pre-amp, etc.


Quote:
Originally Posted by xtal_01 View Post
I am in Vermont ... I get 18 channels ( well really 5 ... stations ) and maybe the is the best I will get.

As others have said, most OTA-ers would kill for a location as good as yours. It is the best TVFool report I have seen in a long LONG time. You have line-of-sight to all the major networks (ABC, CBS, FOX, NBC, CW (sub-channel on WPTZ-NBC) and PBS. Count yourself as one of the lucky ones. A pre-amp will not help you receive any additional channels.

If I were you, I would put the RCA ANT751R on a gable end mount outside, pointed to Mount Mansfield and call it a huge victory. With that antenna, you could likely distribute to any-and-all TVs in the house. No need for a distribution amp or anything.

Heck, with signals as strong as yours, you might even get full-network reception at each TV with a paperclip on the end of a short coax lead.

Last edited by jrgagne99; 30-Jul-2019 at 2:44 PM.
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Old 30-Jul-2019, 2:44 PM   #17
xtal_01
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Awesome!

Thanks so much for the info!

Mike
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Old 30-Jul-2019, 2:51 PM   #18
xtal_01
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Just saw your post come in (we must have been posting at almost the same time).

Funny you mention that ... I took down the antenna, had the coax laying loose on the ground and still got 7 of the 18 channels.

With almost anything, I can get the full 18 channels.

Looking at all your advice, I will most likely just put a hold on my projects for now.

I am in the middle of building a new very tall workshop (the peak is 40 ft).

Maybe when it is done, I can try building a multi element beam and play around a bit.

Thanks again .... Mike
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Old 30-Jul-2019, 2:53 PM   #19
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PS ... should have said, I am just spoiled ... I take the RV to my mom's. She lives just 20 minutes from Niagara Falls in Canada .... tons of channels! I get all the Buffalo stations plus ones from Hamilton and Toronto.

Thanks again .... Mike
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Old 30-Jul-2019, 3:12 PM   #20
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Would your mom be willing to let you mount an antenna and place a media PC with tuner at her home? http://forum.tvfool.com/showthread.php?t=16637
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