I dunno about the quality of the various amps, but a simple RF amp can just be 2-3 transistor circuit with a few other complimentary components added.
What I can recommend, would be that an RF amp be placed as close to the actual antenna element(s) as practical, and not at the end of a long feed line. This type of setup requires power-thru-coax delivery of the voltage needed by the amp, whether built-in, or near the antenna. This eliminates the need for additional wires to be added for powering the amp. Most mast-mount amps have this type of power adapter included.
However, there are some coax cable types that have two power leads attached to the coax cable in a siamese fashion (cross-section looks like a figure
8), so using a variety of amps could be practical if everything is enclosed in a weatherproof and UV resistant enclosure.
Close to the bitter edge of off topic, but not quite.
Yes.
No.
No.
You're welcome.
The explanation is easy enough. The pancake antenna is nothing but a big circuit board inside. The difference between the amplified version and the non-amplified version is one MMIC amplifier (probably a Mini-Circuit Labs MAR-6) two caps, one resistor, and maybe a choke. Total added costs, in large quantities, is about $0.50. Because the boards are identical, and the cost differences are minimal, the selling prices are the same.
There's a reason why two models are offered. The amplifier is useful in weak signal areas, but a disaster in very strong signal areas, where overload and intermod from nearby TV xmitters are a very real problem. Two versions gives the customer a choice.
The antenna amplifier is also useful for compensating for the losses of the coax cable between the antenna and the receiver. If the cable is fairly short (i.e. less than 15ft), then the antenna amplifier isn't going to do much good. However, if there is 50 or 100ft of RG-6a/u attached, the antenna amplifier is very necessary to preserve the receiver sensitivity.
External versus internal amplifiers is a religious issue. There are merits to both approaches. I can't offer an opinion without knowning how the antenna is to be used, the location relative to the desired TV stations, length of coax, and receiver model (so I can check the sensitivity specs). For what it's worth, I don't like such pancake omnidirectional antennas (with or without amplifier) as an omni antenna has very little gain. The name "Metro" might offer a clue that it has to be used in a metropolitan area, where strong signals are usually present.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
The MSRP of the MS-2000 is $110, while the MSRP of the MS-1000 is $70. SolidSignal is offering a much greater discount on the MS-2000 at the moment.
I don't know why the MS-2000 is so heavily discounted... the commonest reason for this is probably "We bought too many, we need to reduce our stock, so let's blow them out at just barely above our cost."
Not necessarily. The antenna units themselves are the same diameter, same height, and probably have very similar gain and directivity patterns (i.e. not much and not much). They may even be identical except for the labels printed on the outside.
Could be. However, you'd probably need to pay substantially more in order to get a really high-quality amplifier.
TV amplifiers are very much a mixed blessing. A mast-mounted amp can help overcome the signal loss in the cable going down to the house, and may enable you to use a passive splitter to divide the signal among multiple TVs or DVRs or VCRs. However, such amplifiers have serious limitations:
- They don't do anything to help overcome the effects of multipath reflections (i.e. the signal from the transmitter reaching your antenna via several different paths, due to reflections off of buildings and trees and planes and etc.). Multipath causes ghosting on analog TV channels, and can cause abrupt signal dropouts and "macroblocking" on digital TV channels. Since an amp can't distinguish between the different signal echoes on a given channel, it doesn't help matters.
- Amplifiers can be subject to strong-signal overload, which generates internal distortion and can make the signal quality at the TV worse than it would be without an amp. This can be an issue if you have any sort of strong VHF or UHF transmitter in your area... a nearby TV station tower, a ham radio operator, a police or fire station, etc.
- Amplifiers add their own noise to the signal.
A really high-quality TV amp will have bandpass and band-reject filters tuned to allow only TV-band signals into the amplifying electronics (filtering out unwanted signals before they saturate the amp), will have a good low-noise, high-dynamic-range amplifying transistor or chip, and will have only as much gain as you really need to pull in the stations you're trying to boost.
Most cheap amps have little or no filtering, and a single MMIC amplifier chip which may have too much noise, too little dynamic range, or too much gain for your signal environment.
In general, I think you'd get the best results if you were to buy a
*directional* antenna, put it up high on a mast, and use a remote-controlled rotator to aim it at the station you want to receive at any given point in time.
If aiming isn't possible, and you have to use an omnidirectional antenna such as these "flying saucer" types, I'd suggest mounting it up in the clear (well away from trees), as high as you can manage given your situation, *without* using an amplifier... and then see if you get acceptable signal quality at your TV. If not, lower it and add the amplifer (right below the antenna, not down at the TV!) and see if this helps matters. If even this doesn't help, you'll need a better antenna (one with directional gain) and a rotator.
I think you might as well buy the MS-2000... it's probably basically the same antenna internally as the MS-1000, and you'll get the cable and amplifier "for free" due to the current heavy discount on the price.
--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Thanks Bill and Jeff. I'll reply just here if it's okay.
Maybe. That would answer the question, which intrigued me intellectually.
Okay, that's still a possibility for later.
Actually, I just installed a RAdio Shack signal amp, that I found on their discount table marked down from 55 to 8 dollars I thought it might overload the signal, so I put a small tv in the attic just to check this on at least one local network station that it was tuned to. AFAICT it had no difference on that station, or when I got back to my bedroom, any of the others.
It also has a pot that is supposed to lessen the amplification, but that had no effect either. I told myself that my DVDR tuner overcomes overloaded signals, but the marginal stations are probably no stronger either, so I guess the thing is broken. Even though the green LED goes on. It didn't look like a return, but maybe it was. (Because there other sale stuff was more like 50% off.)
I suppose you guys would check this by connecting an oscilloscope to a tv co-ax, and compare that with the output after the same co-ax input goes through the amp. Should I do that? I have an old Heathkit or was there EicoKit oscilloscope that I bought usedn and have never managed to use much.
I was planning to do that as a next step, at least to tvs in two upstairs rooms.
Somewhere I got an adjustable signal attenuator that I could put in the antenna circuit.
Ugh.
There is a whole set of 5 stations in DC that have foreign country broadcasts, that I can get late at night but not at all or just for a second or two during the day. Plus another set of 4 stations I can get sometimes. I was hoping to get these all the time. Plus the NBC station in DC when Baltimore has some local sporting event on. Except for NBC, I didn't even know about them before I got the antenna for the attic (I can't more it to a pole or tower.)
I bought a fairly big directional antenna, put it as high as my situation allows, and when I had a smaller rotating antenna, I soon got tired of rotating it. In addtion to the current antenna, I was considering the 2000 that started this thread, which is omnidirectional and should improve reception for the local stations that the big antenna doesn't point to.
Sounds good to me. If worst comes to worst, I can put an attenuator in the co-ax to the tuner, or I can bypass the amp electrically.
FTR, I later noticed another flying saucer antenna that is directional and rotates and has a memory of which direction it should point for which station. Wow!!! But it's about 150 dollars. My browser is jambed up right now or I'd tell you the name and model.
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