The Official AVS Antenna and Related Hardware Topic! - Page 295

Can anyone tell me if any of today's rotators can completely sync with a tv's tuner? -- put another way, when selecting a tv's channel pre-set, can a controller be made see that channel input and spin the rotator to match the channel, or is it still two separate operations: tv - controller?

FWIW, the CM7000 converter box, & the CM9521 rotor use the same remote codes. If you have the 9521 programmed with the appropriate channel #, it will rotate the antenna everytime you punch the channel # into the converters remote. It won't work with the channel up/down buttons correctly though. You have to punch in the actual channel # for it to work.

I guess not quite, but similiar.

Nice antenna, thanks for sharing the pic!

W-G's 6-element VHF Yagi has been discontinued.
[Total of 5-elements plus a VSWR matching "stub" next to driven element.]

Antennacraft Y5-7-13 5-element VHF Yagi is equivalent:
http://www.solidsignal.com/prod_disp...p?prod=Y5-7-13
[Since it uses a folded dipole, it does not need the matching stub found on W-G's.]

===========================
Alternatively, you can use the longer, 10-element W-G YA-1713:
http://www.solidsignal.com/prod_display.asp?PROD=YA1713
http://www.summitsource.com/winegard...le-p-4589.html

Or the AntennaCraft (9?) 10-element Y10-7-13 VHF Yagi:
http://www.solidsignal.com/prod_disp...om=Large#xview
http://www.starkelectronic.com/acantena.htm

Thanks hollands, you are the best.

As there is already an ATSC tuner in this Pioneer tv, I suppose programming a Harmony universal rc might accomplish most of the same objectives as you suggest -- I donno as we don't have one yet. Otherwise, it seems that surfing channels will have to be more deliberate and require separate inputs by the user (?)

If they aren't the right kind for your cable, yes. You don't want to crush coax.

I also took detailed pics and measurements of it, in case I wanted to model it later.

I'm slightly curious about that. The rotor accepts two digit channel numbers, or three digit "Degree" headings I though.

How would it know the difference between 32.1 and 321-Degrees?

I ask assuming you own both to answer this...

I own both, but never nmade a connection with a pre-programmed channel position on the rotor and a channel change with the CM7000.
I would assume using the decimal point would confuse the rotor since it isn't looking for that.
I don't remember if you can enter a decimal point in for the 7000.

This only works with 1 or 2 digit inputs. If you put in 3 digits; the rotor will go to that compass position. The 9521 has to be pre-programmed for this to work.

BTW; since I replaced the ultra-thin rotor wire CM wire with higher quality RS wire; the antenna is staying sychronized much better. It eventually completely quit working because of the CM wire.

I was aware the 9521 has to be pre-programmed for that to work, it was the three digit thing that had me.

But then the CM-7000 will go to the xx.1 channel by default if you input just two digits and wait for it to time-out. All xx.? channels are same direction for any given channel anyway.

So it seems all that one would need to change was the 9521 accepting channel up/down commands so xx.2, xx.3, Etc. could be accessed without the rotor wandering around. Right?


Edit:
Or did they see this comming and only the numeric keys from the CM-7000 work on the rotor, and not the CH Up/Dn ones perhaps?

Has anyone tried to rebradcast the DTV signal from a CECB so that TVs in their home can receive DTV on ch 3 or 4? For example I have an antenna in my attic feeding my downstairs TV, but upstairs their is no cable feed to the bathroom or bedrooms. Since I don't watch TV upstairs much, I think I would be satisfied if I could rebroadcast the signal from one of my TV converter boxes so that any upstairs TV could receive DTV programming on ch 3 or 4. Would I need a linear amp to be able to get the CECB RF output signal strong enough to rebroadcast? I realize that all upstairs TVs would have to watch the same program that the rebroadcasted CECB is tuned to, but this may not be a big issue.

How long the cable lasts when buried in soil depends on how good the cable insulation is and probably how acid the soil is. You can buy direct burial cable from Belden and other big suppliers that will last for decades when buried. It has to say direct burial. Pulling cable through conduits usually does not guarantee a long life unless it is direct burial cable because usually the conduits fill up with water so the cable is immersed in water most of the year. As I recall the insulation was some type of polyethylene and it was very stiff and hard to strip.

HDTVPrimer updated the 4228 page. Apparently, a new version is coming:

http://www.hdtvprimer.com/ANTENNAS/cm4228.html

wire through garden hose, been done...works fine.

Use a vacum to pull kite string through, then pull the wire back.

I use that crappy irrigation tubing at $20 per 100' myself...buries easy with a spade blade and a properly fashioned stick. High-tech isn't always the best answer. Does the (Proverbial) shed need better???


Anyway, I ran a piece of old RG-213 (Like RG-8U, NOT 75-ohm for sure) up through the center of a house once. left a three foot section bare center conducter on each level with a slightly spaced ground tracer from start to stop of that break keeping the shield active the rest of the way.

Works amazingly well. Won't work with smaller coax, you need a junk piece of that big-ole CB-Band wire or equivelant. The emission doesn't even make it to a portable TV in the driveway so I don't belive it's an issue about disurbing ones neighbor. Rabbit ears were what did the receiving work of course on the house TV's on each level... CH-3 box was in the celler, so three levels were fed. But then again, there was no local Ch-3.

RonandLeanne,
one normal 75-Ohm TV cable to a central location feeding a 75-to-300-Ohm adapter balun would feed a pair of rabbit ears just fine if that fits your bill. Assuming that 2/3 or 3/4 (box dependant) gives you a choice of an unused channel in your area. Your basicly back-feeding the balun from the 75 to the 300 changing it from a single ended signal to a differential one for the rabit ears. Just connect the balun and rabbit ears flat leads accordingly.

Forgive me if the stone age techniques here have banjo's playing in yer head (lol)...

If you want good rotor wire, try a ham radio store like the wireman or Texas towers.

Most of these places take mostly phone orders mind you. Their online ordering systems suck.

I just hooked my CM-7000 back up.(Unfortunately, the Zenith works better here) The CM-9521 remote control operates both units; but the CM-7000 remote only controls the convertor box.(Can anybody explain that?????)) The up & down keys on the 9521 change the channels also. Hope this helps.

Glen

New version of chinese junk.

Antennas Direct (Terrestrial Digital) ClearStream2 mini review and comparison with DB2 on Indoor Antenna Round Up thread.

You would need quite a bit of gain to get this to work....

Which would ALSO retransmit the Converter Box's internally generated RF Noise
throughout your neighborhood. Which could degrade reception on other than CH3/4.

PS: If it's more than a few milliwatts, you could also be in violation of Federal Law.

PPS: Cable companies regularly patrol neighborhoods looking for leakage from
their cables...and could inadvertently find YOU.

Most boxes transmit enough to make it twenty, thirty feet tops with rabit ears through a balun to a TV with rabit ears also. I got nothing but snow on a good portable battery TV in the driveway as example, and perfectly watchable picture on the units about fifteen feet from that center feed. So that is safe.

The channel 2/3 or 3/4 outputs of equipment are very low power. On some you can get away with one splitter (3.5-Db loss) before it degrades, on some you won't notice unless you put a three-way or larger splitter. But much over about a 5-Db loss and your already loosing it.

But you do bring up a good point, you wouldn't want to amplify them and rebroadcast that.


Digital Rules,
That is very helpful, I am considering that rotor control head because of my CM-7000's here. I'll call them and see what I can find out.

Info and Questions on my situation:
TVFool reports that all the stations I am interested in are in exactly the same location, 20 miles away, and signal strengths at my location range from -48 to -70 dB. All UHF, line of sight (I am on a hill and the transmitter is on a mountain)

I have two TV's: One upstairs and one in a half-basement. A MANT510 work barely adequately on some stations in the in the basement, and was actually fairly decent when located upstairs, but with occasional digital artifacts and drop-outs. If I ran the MANT510 signal into the pre-wired cable-TV lines from upstairs to downstairs, the downstairs TV would get better, but still not perfect. The ridiclous amount of amplified gain of the MANT510 would only help when upped to maybe 10 dB max.

So I figure I needed just a little stronger antenna signal, with minimal gain and low noise.

So I bought a radio Shack 15-2160 and mounted it in my attic (thin layer asphalt shingles)

http://www.radioshack.com/product/in...entPage=family

The Performance of this antenna was a slight improvement over the MANT510 on the upstairs TV, but was worthless when it had been split off to go downstairs also (through the cabnle TV line. All other branches of the cable tv line were disconnected)

So, I got a CM 7777 and mounted it close to the antenna. This actually degraded the picture upstairs, evidenced by more noise and digital drop-outs, and didn't help the downstairs much.

Question: What signal level is considered "too high" ? I know that -100 dB is considered the lowest level for reasonable reception, but I don't know where "too much" is. Imagine my signal strength is -49 dB, I get another +12 dBd from the antenna, and +26 dB from the preamp, with a -4 dB loss at the splitter, giving me about -15 dB at the upstairs TV.

Thinking I might be overloading the upstairs TV, I moved the CM7777 to a position AFTER the splitter, so the Antenna signal is unamplified through the splitter, and only the leg going to the downstairs gets the amplification.

THIS SEEMS TO BE WORKING WELL. I imagine there might be only 40-75 feet of coax between upstairs and downstairs. So I speculate that I was overloading the upstairs TV, and the +26 dB of the amp is not overloading the downstairs because of the losses of 40-75 feet of coax.

Is this making sense ? I am surprised that the reception is so sensitive to signal level such that +26 dB overloads the upstairs but is necessary for the downstairs. It makes me think there s only a range of acceptable signals that is about the same as the loss in the coax which mught be only 8 to 12 dB (a rough estimate).

Is this true ?

Thanks for any insights.

Amber O'Doul,

You are right at the limit of what the "input" of the CM7777 can accept without overloading(around -50 to -60db). Moving the pre-amp furthur down the line lowered the input signal enough to alleviate the overload condition.

The CM 7777 is designed for fringe/deep fringe areas. I like the Winegard HDP-269 in higher signal strength areas; but unfortunately; it lacks an FM trap.

What stinks about my situation is that I have ONE station that's at about -39 dBm which makes all but an HDP-269 unusable as the one close and strong signal overloads anything else. But everything else is around -102 to -108 and could benefit from the added gain of a 7777 (especially if I decided to try rotating the antenna and looking to other markets). Fortunately these weaker signals are stable and relatively strong even with an HDP-269.

Ziggy,

How much difference did the HDP-269 make with your set-up? Did you gain any stations; or just increase the reliability of what you were already getting?

If you've got line of sight to nearby transmitters, chances are the CM7777 is overloading.

With that kind of signal strength, you should be able to split off the U75R to both TVs with no amplification and get all the channels. Since putting the CM7777 on the downstairs leg seems to help, I'm thinking maybe the run of coax you are using to get from the attic to downstairs is bad.

Another possibility is that having the antenna in your attic is causing issues, not just attenuation but multipath due to internal reflections. You can try moving the antenna around inside the attic, but outside would be better.

That has crossed my mind also. But it is difficult to rerun cables through a finished house. Standard cable-tv cable is similar to RG-59 or RG-6 isn't it ? I could find no markings on the cable.

That is my backup plan.
As I mentioned, things seem to be working well right now, but If I have any more drop outs or issues associated with rain or snow on the roof, I will just mount something on top of the roof. Once I have committed to running cables from outside, then I can just run a cable down to the basement from the oustide also.

Thanks.

I only added the preamp because I plan to split the signal three ways soon, and some of the signals were weakened enough by the splitter without a preamp that they seemed like they'd drop out frequently.

With no splitter inline and only feeding to one tuner, I really don't need any preamp.