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Antennas Direct OTA Antennas & Gear

361K views 890 replies 153 participants last post by  JJMoney 
#1 · (Edited by Moderator)
If you're already receiving HD then this is not going to be a cost-effective experiment. However if you're still interested, a good quality antenna would be a Blake or a Televes. The Televes is a bit cheaper.I picked up two Televes for $300. They have a local HDTV Info and reception section with a lot of knowledge in it. Good search function as well. If you're looking for a 6000 OTA module, I'll probably be selling one in the next couple weeks. The bloody things sell for almost as much on ebay as they are new. I think they might be getting hard to find new. On ebay you can expect to pay about $130-140 US. Jonic is selling them for BEV for about $310 Cdn. Which DirectTV box do you have. I believe most of them have a built in OTA tuner. If it's the Hughes, it does, and it seems to be a decent tuner.
 
#525 ·
RE: Antennas Direct Antennas

Thanks. I recall when I contacted AD they recommended I buy from a Canadian distributor. AntennaCraft was like that too. Maybe it's a bit of hassle for them to do an order to Canada. But I do see now that they're showing the "one price, everything included," instead of surprising people with shipping charges, like some retailers. Though, I think $50 is a bit steep for shipping within the continental US, when most of their antennas fit nicely into smaller boxes.
 
#531 ·
I never have to do any attenuation with the HDP 269, or Kitz, in the same area. I tried the CPA-19 cause it says high overload resistance, had a better noise figure than all the other amps, and was KIND of reasonably priced. Oh well, lesson learned!

I have tried the CPA 19, in the West Island a few time more & the Montreal & US channels act crazy...

I will compare it next to the CM7777, if this one overloads, which I suspect it might, then we can say they are in the same category (in terms of overloading)

Have never had to filter out FM in suburbia, amp or no amp...
 
#534 ·
I will compare it next to the CM7777, if this one overloads, which I suspect it might, then we can say they are in the same category (in terms of overloading
Balm: May I ask why you need the CM7777? Have you thought about the CM7778?

In most setups, the CM7777 is overkill.

I'm a minimum of 40Kms from the strongest local transmitter in my area and find my CM7778 is more than adequate and I distribute to 4 tv's through a 4 way splitter.

Years ago, I used a Jerrold DSB107L "Desnower" preamp. Talk about overload! :rolleyes:
 
#532 ·
Another possibility is the Kitz has been shown to not have flat gain and amplifies lower channels more than higher ones. As a result, it may not overload on UHF as easily as it does on VHF. This may good in your circumstances (whatever they are since you are posting bits and pieces in multiple threads).
 
#533 ·
Thanks for your excellent comments


The post in the amplifiers thread is nothing to do with these posts, it is regarding a different location, & different issue. Sorry if I caused confusion.

My only point here, is that so far, my conclusion is that the PA-19 was horrible, for here in suburban Montreal.

here is this locations TVFool:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d2df9f80ebdcf11
 
#535 ·
Nope, dont NEED it, but im curious to compare it with the Kitz, & the PA-19, to learn more about the actual input tolerance of the PA-19 (besides I got the CM7777 at a good price)

Generally I do fine with Kitztech, or the Winegard amps. The rest is mostly for experimantation purposes ;)
In almost ALL situations I experienced, and compared to all the amps Ive tried (about a half dozen), the Kitztech is definately the best performer.
 
#545 ·
Looking at the spec sheet, I don't see the spec for OIP3. Are you looking at the IMD?
IP3 measurements are a figure of merit that indicate at what input level IMD manifests.

Either way, this is not the same as the "Maximum Input for two strong signals."
No it isn't. IP3 measurements are a much more modern measurement parameter that is used by the commercial amplifier world. Someday, perhaps, others will joint the 21st (or event the late 20th) century.
 
#546 ·
IP3 measurements are a figure of merit that indicate at what input level IMD manifests.
Yes, I understand that.

No it isn't. IP3 measurements are a much more modern measurement parameter that is used by the commercial amplifier world. Someday, perhaps, others will joint the 21st (or event the late 20th) century.
Okay, then maybe you can explain how to use the IP3 measurement to determine if the pre-amp will handle a known strong signal(or multiple signals) without overloading?
 
#547 ·
IP3 is power level at which the EXTRAPOLATED Input vs Output Power Curve
CROSSES the EXTRAPOLATED Input vs 3rd Order IMD Power Curve, see Fig 3:
http://www.arl.army.mil/arlreports/2007/ARL-TR-4235.pdf
So, as I've discussed here and on my webpage, we try to MATCH the Preamp
to the application, so as to MAXIMIZE Spurious Free Dynamic Range (SFDR).

Unfortunately in many REAL systems, the 3rd Order IMD Power Curve doesn't
follow a well defined straight line and might exhibit a hiccup half-way thru,
making it difficult to determine where the EXTRAPOLATION line should lie.
Some amps also exhibit a hiccup in the Linear Input/Output Curve, with two
vice only one gain compression point. So the IP3 "Spec" point can be a very
sloppy exercise by the test engineer, trying to draw two straight lines across
what may actually be to very wiggly curves....which probably vary quite a bit
due to typical part-to-part variations.

And, BTW, the various IP3, IM3 and other spec points can vary with frequency
and input signal levels: http://www.ti.com/lit/an/sboa077/sboa077.pdf
[There is usually a reason Preamp manufacturers are stingy with some specs.]

So I wouldn't want to use IP3 (a fictitious, non-realizable, power level well
above the max output power level) to guesstimate the actual levels of the
3rd Order IMD noise products (which are desired to be close to the very low
Thermal Noise floor).

The inherent non-linearity of the 3rd Order IMD Curve can be clearly seen
in Fig 3.14 and 3.18 for a modeled AlGaN/GaN HEMT device. Also
note that 3rd IMD curve is least linear when biased for the "sweet-spot":
http://www.uni-kassel.de/upress/online/frei/978-3-89958-654-1.volltext.frei.pdf

Modeled MOSFET device (Fig 3) shows a highly non-linear 3rd IMD curve:
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=1309692 [Requires IEEE access]
also measurements for a very low-noise Cascode MOSFET LNA (Pg 37):
http://rfic.eecs.berkeley.edu/~niknejad/ee242/pdf/ee242_lect13_mosamp.pdf
 
#549 ·
^^^ Getting off topic, but according to the pre-amp chart, the Max Input for Two Strong Signals for the old (dual input) CM-7777 and CM-7778 are as follows:

Code:
Pre-amp	 VHF	 UHF
CM-7777	-29.8	-35.8
CM-7778	-38.8	-36.8
The larger (less negative) the value the stronger signal it can handle. The CM-7778 is slightly worse for UHF and significantly worse for VHF.
 
#554 ·
#555 ·
Roger,

Thanks for your input. I emailed our web guy to move the C1 to the proper page.

The C4 and DB8 are where the boss said they are to be on our website. In the absence of any published industry specification that provides an objective definition of "multi-directional" and "uni-directional" along with the beamwidth transition point, etc, they'll stay where they are. If you can find such a specification or definition for these terms, please let us know.

Thanks for your input!
 
#556 ·
I am not aware of any such specification (and doubt if there is one). However, I wouldn't be surprised if the ClearStream 4 and DB-8 have narrower beam widths than some of your "Directional TV Antennas." It is more about not confusing the consumer and having them buy the wrong antenna than meeting a regulation.
 
#557 ·
Antennaweb lists the characteristics for the various CEA-certified Color Marks:
http://www.antennaweb.org/Info/AntennaInfo.aspx
But it is completely devoid of any SPEC NUMBERS...and it continues to baffle me
as to what is a LARGE MULTI-DIRECTIONAL Antenna. [e.g. CM-3010]
And why are ALL Antennacraft 2-Bay, 4-Bay, 8-Bay, MXU Yagi series and all HBU
series antennas ALL RED (except for the GREEN HBU-22) with absolutely no difference
between them???

To see the below CEA-2028-A standard, you'll have to find it at a well equipped
University Library, access via an on-line Standards service (many companies are
subscribers) or pay $60 ($45 to CEA Members):
http://www.ce.org/Standards/Standard-Listings/R5-Antennas-Committee.aspx
[No, I haven't taken the time or $$'s to obtain a copy.]

BTW: Although Antennacraft & Channel Master still use the CEA Color Mark system,
Winegard has changed to the www.dtv.gov signal levels (e.g. strong, moderate, weak)
as calculated by the DTV Reception Map link [much lower resolution than tvfool.com]:
http://transition.fcc.gov/mb/engineering/maps

And in addition to the recommended "range" (many times of very limited use), Antennas
Direct uses antennapoint.com to show you which A-D products have been bought by other
people in your vicinity....FWIW....but I live BEHIND the big hill and a small mountain!!!!
 
#558 ·
Roger,

Your point is understood. It's not about regulations, just definitions.

However, I wouldn't be surprised if the ClearStream 4 and DB-8 have narrower beam widths than some of your "UNI-Directional TV Antennas."
Indeed. The owner made the decision where to put them on the website. That's where they are.


Holland,

The CEA-2028-A document would be about the only thing I can think of that would have such a definition, if there is one. As Antennas Direct is not a participant in the CEA rating scheme, we've never purchased a copy of that particular standard.
 
#559 ·
^^^From what I have seen, CEA rating scheme isn't terribly usable as it is too overly simplified. Would rather see standardization of real specifications with real numbers rather than a vague colour scheme.
 
#560 ·
All the main graphs and plots please, from all the lab test sweeps etc, for each antenna model, available free online, for those customers who wish to see all the detailed technical performance specs.

Specify the conditions of test as well.

All manufacturers should have that info easily available for all their products.

... for those interested, or who might want to see it.
 
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