I have a Mohu Sky antenna. It is installed outside, on a flat part of the roof with nothing around it. I do live in North Tustin, on the back side of a hill so Mt. Wilson isn't line of sight.
I get all the channels I want and for the most part all are fine except KABC (7) and KCal (9). At times they work great, but then they start going choppy (tiling) at times. The other day it seemed to be working great as it was overcast and when the sun came out it was having trouble again. I can't say that is always the case though.
I have moved the antenna all over the place, bought a compass and aimed it as best I could. Mt. Wilson is about 35 miles as the crow flies.
My antenna had an amplifier but it never seemed to make a difference,
although it isn't working at all now. I was going to buy this amp from Amazon, it is cheap but I get the signals so not sure how if or how well it will work. http://www.amazon.com/1byone-OUS00-0...SSXYG44S134DK1
Skip that amp, it's worse than the one that came with the SKY.
The SKY is pretty nearsighted on VHF, probably -15 to -20 dB on channels 7 & 9, based on a recent reception test I did.
What you really need is an antenna with positive gain combined with a decent preamp (low noise figure, modest gain). Your reception should improve dramatically when you get higher performance gear up on the roof.
My wife wants to get DirectV because of it, and I am definitely a cut the cable guy. Any help or ideas would be greatly appreciated.
I'll try to get you out of the hole that you have dug for yourself.
I agree with ADTech; you need a much better VHF-High (real channels 7-13) antenna because of your important channels 7, 11, 9 and 13 from 319 magnetic. You also have 8 CBS and 10 ABC from 143 degrees magnetic, but your new higher gain antenna will be facing the wrong direction for them. This will create a problem for CBS, unless you are able to receive KCBS on real channel 43 also from 319 degrees. I did another report using your estimated location, and small changes switch the two CBS stations around with slight changes in location because of the rough terrain.
The antenna to consider is the Winegard HD7697P. The 7694 doesn't have enough gain because of the terrain. The 7698 has the best gain, but it might be too big for your roof location.
If CBS becomes a problem, you could have a separate antenna and preamp for CBS from 143 and use an A/B switch to select antennas. Your TV tuner would need to be able to add a channel after scan so you don't have to rescan. Another alternative would be to have a separate tuner for the second antenna and feed the tuner output to an unused TV input.
The preamps to consider are the Antennas Direct Juice, Antennas Direct PA-18, Channel Master 7778, and the RCA TVPRAMP1R. The Juice doesn't have an FM trap, but I don't see a serious threat from strong local FM signals to your TV reception based on an FMFOOL report using your estimated location; see attachment. If my estimate is off, you can add an FM trap later. The other preamps have FM traps. The RCA is OK but has a history of quality control problems; you can buy 3 RCAs for the price of one of the other amps.
The coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC), the mast should also be grounded in a similar manner to drain any buildup of static charge, but the system will not survive a direct strike.
Please let us know the results of your tests on this same thread.
I bought what I did as I have a home also in Alpine, CA (East of San Diego) and it works pretty well so I thought OK now at home I am cutting all the cords.
I will research all available Antenna options or if anyone has anymore advise/recommendations I am open to anything. I don't mind paying the upfront price but it kills me to pay cable etc...
People pay for 200 channels of which that watch maybe 10, I can live without CNN and the rest but the regular channels are important to Mrs. Dave_Calif.
Thanks
Dave
I have just posted two picts one in the antenna and the other is from below the antenna showing its path. The second pict is 15 feet below the antenna. Also not (not easy to see) but there is power wires feeding the house below me.
Last edited by Dave_Calif; 2-Jul-2015 at 1:52 PM.
Reason: Added Picts
Sorry for the delayed response, I wanted to get up on the roof and take another pict to show you the actual direction. That big tree is the opposite direction behind where it is aimed.
I took another picture which is directly behind the antenna on the same horizontal height to try and give you a much better visual of what the antenna is pointing towards. I had to make them smaller to upload.
I could move the antenna to the chimney which is the second picture but it won't buy me much height than a couple feet. Plus then the wires are higher that the other current location since the wires are going downhill.
The TV is in the room right below the antenna with maybe 40 feet of cable and no splitters etc. I wanted to put it on the other end of the house which would be better, but that would increase the cable length by a lot and that concerned me.
I think the solution is a much better antenna so I am going to do some surfing and read up on the one you recommended. Maybe I should get a VHF one and use a switch depending on the channel?
Maybe I should get a VHF one and use a switch depending on the channel?
The 7697 covers VHF real channels 7-13 and UHF real channels 14-51 for 319 degrees magnetic.
You don't need a separate VHF antenna unless you want it aimed at 143 magnetic for real channels 8 CBS and 10 ABC.
Quote:
The TV is in the room right below the antenna with maybe 40 feet of cable and no splitters etc. I wanted to put it on the other end of the house which would be better, but that would increase the cable length by a lot and that concerned me.
When you mount the preamp near the antenna, it makes the signals stronger before the coax loss; you might be OK. You need to make some tests.
Get the 7698 and mount to the chimney. Where the Mohu is won't hold any of the Winegard antennas I don't think. When the Santa Ana winds blow we can get really bad winds, and I mean really bad. Put up maybe a 10 ft mast probably a 1 1/4 or bigger chain link fence railing. I figure get the best antenna and mount it solid.
Hold off on the preamp and see what just the antenna does. A question is would a preamp near the TV do much good? Since it has to be plugged in, that is really the first spot where it would be viable as where the cable enters from the roof, it is basically directly down to the TV.
Hold off on the preamp and see what just the antenna does.
OK, good. I think a preamp might help. If you pick the Juice, add an FM trap between the antenna and the input of the preamp.
Quote:
A question is would a preamp near the TV do much good?
A preamp near the antenna would give better results than a distribution amp near the TV. You are familiar with the Noise Figure (NF) of a preamp, the lower the better. There is also a total system Noise Figure based on all the components. When you put a preamp with a low noise figure near the antenna, it primarily determines the NF of the whole system. To satisfy your curiosity, try it both ways. An indoor distribution amp is primarily used to make the signals stronger for splitting to more than one TV. You don't usually need a preamp and a distribution amp.
COMPARE System Noise Figures
With and Without Preamps
Since it has to be plugged in, that is really the first spot where it would be viable as where the cable enters from the roof, it is basically directly down to the TV.
A preamp comes in two parts; the preamp itself near the antenna, and the power supply/power inserter inside near the TV. The coax between the preamp outside and the power supply inside carries the DC power up to the preamp and carries the signals down to the TV. No power outlet is needed outside.
When I was watching channel 7 tonight I plugged it into my laptop and my iphone 5 into it to charge it up. Channel 7 tiled. I was able to repeat it every time about 10 times. I can't charge my iphone direct as for whatever reason it doesn't charge of which I have had that problem with other Apple phones and aftermarket cables. I have another power charger for my phone and that doesn't seem to be an issue. I have tried various options and my phone and this LifeCharge seem to be a problem. My wife has an iphone 4S and that doesn't do what mine does. I can see the iphone being a similar frequency but the charger you would think doesn't transmit.
I am gone for the next few days but will will be testing some things this next weekend.
Sure seems really weird to me, but it is doing what I never would have imagined.
Well I have watched Channel 7 and had no problems until I plug in my iphone. Every now and again it will blip for a split second but it isn't even really noticeable. SO I am gong to continue to see how it goes in the next few weeks.
The power adaptor on the phone charger is a small transformer. Transformers are well known to be a source of RF noise like this. Try charging as far from the TV as you can get it. Or make a Faraday cage around the charger and/or phone.
It is not transformers that are RF noise generators, unless there had something gone badly wrong with them. Linear power supplies with their large transformers seldom cause problems. Cheap poorly filtered switch mode power supplies are notorious generators of radio frequency interference that is more likely to affect VHF channels then UHF channels. The problem is such power supplies are quite common now days, and can be found through out a house making it sometimes difficult to find the offending one.
Thanks for the replies. There is no question the cell phone/power adapter is a problem and I can handle that. Today it is raining and I am having some troubles on the same channels so going to up the antenna to the one suggested. I don't like the cable company so have to try and Mrs. Dave_Calif happy...
