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29-Sep-2011, 4:32 PM
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#1
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Senior Member
Join Date: Sep 2011
Posts: 135
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Best (low-noise?) pre-amp?
Next on my list of "to-buys," is pre-amp...
Which is the best. I know that's a "loaded" question...
I've heard CPA-19, CM 7777, Motorola, and some Winegards are the best...
Looking through reviews on Amazon.com, they seem to be top-notch...
Anyone with their own good or bad experiences, recommendations?
Is the CPA-19 good (or optimized) only with their Antennas Direct antennas?
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29-Sep-2011, 4:58 PM
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#2
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Antennas Direct Tech Supp
Join Date: Jan 2010
Posts: 2,942
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Our CPA19 may be used with any TV antenna with 75 ohm connectors.
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29-Sep-2011, 5:03 PM
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#3
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Moderator
Join Date: Oct 2010
Location: Greater Seattle Area
Posts: 4,773
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The CPA-19 has two qualities that recommend it for your situation.
Low noise - It generates less noise internally than any other brand of consumer grade preamp.
High input capability - Many preamps are designed for use in weak signal areas. If you use the weak signal preamp in an area with strong signals, you risk overloading the amplifier which will distort some or all signals to the point that they can't be decoded error free.
The CM-7777 is a good amp, for weak signal areas.
The Winegard HDP-269 competes for the same applications as the CPA-19 but it produces slightly more noise internally.
http://www.kitztech.com/ offers very impressive noise performance, but they do not indicate high input capability. You could contact them if you're interested.
__________________
If the well is dry and you don't see rain on the horizon, you'll need to dig the hole deeper. (If the antenna can't get the job done, an amp won't fix it.)
(Please direct account activation inquiries to 'admin')
Last edited by GroundUrMast; 29-Sep-2011 at 5:19 PM.
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29-Sep-2011, 6:05 PM
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#4
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Antennas Direct Tech Supp
Join Date: Jan 2010
Posts: 2,942
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Quote:
Low noise - It generates less noise internally than any other brand of consumer grade preamp.
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Actually, the PA18 is quieter by a few fractions of a dB. It's the combination of the still low NF plus overload resistance (IP3 between 25 to 30 dB) that I like about the CPA19.
I haven't personally tested an HDP-269, so I can't offer any assessment of it's performance. It does enjoy a good reputation, something that doesn't come easily.
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30-Sep-2011, 2:51 AM
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#5
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Senior Member
Join Date: Sep 2011
Posts: 135
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Quote:
Originally Posted by ADTech
Actually, the PA18 is quieter by a few fractions of a dB. It's the combination of the still low NF plus overload resistance (IP3 between 25 to 30 dB) that I like about the CPA19.
I haven't personally tested an HDP-269, so I can't offer any assessment of it's performance. It does enjoy a good reputation, something that doesn't come easily.
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Check out this site:
http://www.solidsignal.com/p/?p=3561
It shows CM 7777 has NF of 2.0 UHF, same as CPA-19.
And it shows PA-18 has a HIGHER NF. hmm...
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30-Sep-2011, 5:27 AM
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#6
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Moderator
Join Date: Oct 2010
Location: Greater Seattle Area
Posts: 4,773
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The folks at AD made an improvement to the CPA-18 a while back. Many vendors have not updated their ad copy. http://forum.tvfool.com/showthread.php?t=905
The CM7777 is fine so far as NF is concerned. But the high input capability of the CPA-19 tips the scale in its favor.
__________________
If the well is dry and you don't see rain on the horizon, you'll need to dig the hole deeper. (If the antenna can't get the job done, an amp won't fix it.)
(Please direct account activation inquiries to 'admin')
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30-Sep-2011, 5:51 AM
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#7
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Senior Member
Join Date: Sep 2011
Posts: 135
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Quote:
Originally Posted by GroundUrMast
The CPA-19 has two qualities that recommend it for your situation.
Low noise - It generates less noise internally than any other brand of consumer grade preamp.
High input capability - Many preamps are designed for use in weak signal areas. If you use the weak signal preamp in an area with strong signals, you risk overloading the amplifier which will distort some or all signals to the point that they can't be decoded error free.
The CM-7777 is a good amp, for weak signal areas.
The Winegard HDP-269 competes for the same applications as the CPA-19 but it produces slightly more noise internally.
http://www.kitztech.com/ offers very impressive noise performance, but they do not indicate high input capability. You could contact them if you're interested.
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I still don't understand what high input capability means....
As for that Kitztech pre-amp with 0.4db NF, here are some reviews:
http://www.rabbitears.info/blog/inde...Kitztech-KT200
http://www.avsforum.com/avs-vb/showthread.php?t=1328965
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30-Sep-2011, 2:15 PM
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#8
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Senior Member
Join Date: Aug 2011
Location: USA Gulf South
Posts: 231
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Quote:
Originally Posted by be236
I still don't understand what high input capability means....
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GroundUrMast explained it clearly in the post that you copied. It means that the preamp will tolerate high-powered signals without saturating and will not ouput signals that are too powerful for your TV tuner to handle.
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30-Sep-2011, 4:00 PM
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#9
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Senior Member
Join Date: Sep 2011
Posts: 135
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Quote:
Originally Posted by MisterMe
GroundUrMast explained it clearly in the post that you copied. It means that the preamp will tolerate high-powered signals without saturating and will not ouput signals that are too powerful for your TV tuner to handle.
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Ah... okay.. but then what Spec line item should I look for? Just that it says "high input?"
Also, I will be aiming the antenna at the low/weak stations only. So hopefully the stronger Seattle stations don't get a strong signal since I'm not pointed at their direction, so maybe this "high input" should be less of a concern.
I'll have a 2nd antenna just to get the Seattle stations, which it does just fine.
Last edited by be236; 30-Sep-2011 at 6:13 PM.
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30-Sep-2011, 4:05 PM
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#10
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Senior Member
Join Date: Sep 2011
Posts: 135
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As for that KT pre-amp with 0.4db, I'm hesitant about it, since it's not weatherproof and you have to make your own enclosure, which I dont know how do to correctly.
My idea would be to just put a grocery plastic bag and rubberband tie it. heheh... ya, I know... bad idea.. heh.
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30-Sep-2011, 4:06 PM
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#11
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Senior Member
Join Date: Dec 2009
Location: Delmar, NY
Posts: 1,236
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Quote:
Originally Posted by be236
Next on my list of "to-buys," is pre-amp...
Which is the best. I know that's a "loaded" question...
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The best preamp is;
1. Doesn't overload in your location.
2. Has sufficient gain to overcome your distribution losses.
3. Has a noise figure low enough to pick up your weakest station.
4. Low cost and high reliability.
Suggestion of a preamp without a TVFool report is like asking what's the best fish to catch without knowing if you are in a stream, lake, river, or ocean?
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30-Sep-2011, 4:26 PM
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#12
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Senior Member
Join Date: Dec 2009
Location: Delmar, NY
Posts: 1,236
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Quote:
Originally Posted by be236
you have to make your own enclosure, which I dont know how do to correctly.
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http://www.polycase.com/wp-27f
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30-Sep-2011, 4:28 PM
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#13
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Senior Member
Join Date: Sep 2011
Posts: 135
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Quote:
Originally Posted by Tower Guy
The best preamp is;
1. Doesn't overload in your location.
2. Has sufficient gain to overcome your distribution losses.
3. Has a noise figure low enough to pick up your weakest station.
4. Low cost and high reliability.
Suggestion of a preamp without a TVFool report is like asking what's the best fish to catch without knowing if you are in a stream, lake, river, or ocean?
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Yup, already done all that, got Tvfool report, posted many questions in other forums, etc...
Looking to get channels with NM of -7 to -15 dB... There are two channels like -10dB and -7dB, that if I can get , I will call a success.. got my antennas narrowed down to 91XG/CM3023 ... and know my line loss is maybe 6dB, from 100ft (total) RG6 cable run and maybe 2-3 combiners....
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30-Sep-2011, 4:39 PM
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#14
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Senior Member
Join Date: Dec 2009
Location: Delmar, NY
Posts: 1,236
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Quote:
Originally Posted by be236
Looking to get channels with NM of -7 to -15 dB.......
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It's the strength of the strongest stations that matters more than the NM of the weakest station.
I can't find your TVfool report posted elsewhere.
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30-Sep-2011, 6:01 PM
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#15
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Senior Member
Join Date: Sep 2011
Posts: 135
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Quote:
Originally Posted by Tower Guy
It's the strength of the strongest stations that matters more than the NM of the weakest station.
I can't find your TVfool report posted elsewhere.
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Hmmm.. I dont understand that. I would think that it's the NM dB value at your particular location regardless of the broadcaster power Kwatts that matter.
I mean I would rather have a high NM value from a weak TV station, rather than a strong TV station giving me a weak (low) NM value, no?
Anyways, here's my Tvfool report (set it for Pending Digital).. I want to get the Cxxx stations (Vancouver stations) in the weak NM ranges:
http://www.tvfool.com/?option=com_wr...60b5ef0bf930b4
Also for a baseline comparison, I can get channel 27 KBTC at 2dB NM with my old Radio Shack VU-190 VHF/UHF combo antenna, with about 75 feet RG6 cable total, with maybe 2-3 combiners just fine, no pre-amp on my DTV converter box (Dish Pal or Artec model brand).
Last edited by be236; 30-Sep-2011 at 6:11 PM.
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30-Sep-2011, 6:55 PM
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#16
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Senior Member
Join Date: Dec 2009
Location: Delmar, NY
Posts: 1,236
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Quote:
Originally Posted by be236
I mean I would rather have a high NM value from a weak TV station, rather than a strong TV station giving me a weak (low) NM value, no?
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The strong TV station limits the ability to insert a preamp without added distortion. That makes it harder to pick up a weak signal.
The ideal situation is all TV stations to have identical NM values.
Background information about distortion is here.
http://www.microwaves101.com/encyclo...101.cfm#causes
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