Question: Suggestions to improve a suddenly missing reception

[No Static At All]

I'll look into the CM7777...it's about $50 on ebay...are there any cheaper, but similar options available?

This is what I would choose. It is much less likely to overload than the 7777.

 

[Tim58hsv]

But I'm pointing my antenna directly at the towers, does that make a difference? It kind of sucks...that was a brand new amp and I don't think I have the receipt or the packaging...I got it at Best Buy, but I will call them and see if they'll take it back because it's defective?

If they won't take it back then buy another one of the Best Buy amps and try it. If it works put the bad one in the package and take it back for a refund. If the new one doesn't work either you'll know the problem isn't with the amp.

 

[dkreichen1968]

The AntennaCraft 10G201 is rated for mixed signal strengths and is what I use to distribute the signals through my house. Again its currently $50, but I think I paid $30 for mine. Of course that was before OTA DTV started to get popular.

Antennacraft 10G201 High-Gain HDTV-FM Signal Amplifier : Antenna Amplifiers | RadioShack.com

You need to be careful about overloading the tuner on your TV or other receiver. That becomes tricky since most TVs and converter boxes don't have a true signal strength meter on them. The HDhomerun has one, and the RCA DTA800 has one. Most of the others have signal quality meters, not strength meters.

A folded dipole is any folded piece of wire like this. DIY TV Antennas - Folded Dipole The key is getting the length right. I think it's 83" for channel 6, but I need to do some calculations and get back to you. A HLSJ looks like this. Pico Macom HLSJ VHF Band High-Low Antenna Separator-Combiner (HLSJ) - Pico Macom - HLSJ - If the high side will pass UHF then you just hook the ANT751 to the high side, and the dipole to the low side.

 

[brian.betteridge]

83'' from end to end? or 83'' of total folded length? Because an 83 inch wide antenna on my patio wouldn't fit...I only have about 5 feet of space to deal with, tops.

I'll check the antennacraft preamp. I have to run some errands tomorrow that take me right by radioshack.

 

[dkreichen1968]

83" end to end, but being as close to the towers as you are a shorter one should work.

Now you know one of the reasons we hate low VHF, big antennas. The other reason is it is subject to a lot more RF noise.

I just recalculated the dipole length at 70 inches 147/82.3MHz/.0254 meters per inch

 

[brian.betteridge]

Ok, some updates. First of all though, thank you all for your help, it is much appreciated.

1. I returned the Rocketfish Amplifier. No problems.
2. I bought a RadioShack variable gain amplifier, single signal. I dialed it in to about 5db gain, and let 'er rip. GREAT! 32 channels. I figure if the signal starts coming in weak I can up it to compensate for things like weather...Still no ABC (vhf), which leads me to...
3. I am going to attempt to make myself a VHF antenna. RS sells a combiner that is made for UHF and VHF, though I'm not sure if that's a gimmick or if I have to get one specifically for that purpose.

I may have some questions regarding the VHF antenna, which I will post in a separate thread.

Many thanks.

 

[Fringe Reception]

Brian,

The Radio Shack UVSJ signal combiner is not a gimmick. Unlike a standard splitter/combiner it is specifically designed to combine unlike antennas, one being for UHF and the other for VHF. Regarding building your own antenna for VHF, take a look in my photo albums here and you may get some ideas about how to build your own. Good luck!

Jim

 

[dkreichen1968]

The only thing to be aware of is that the UVSJ will filter ALL of the VHF out of the ANT751, so your VHF antenna will need to pick up the high VHF signals you get now.

 

[dkreichen1968]

Yes, UHF will pass through the HI side of a HLSJ with no attenuation.

Great thing to know.

 

[brian.betteridge]

as far as I know (based on tvfool) all the stations I'm currently receiving are uhf. I'm not receiving a single vhf station.

 

[dkreichen1968]

as far as I know (based on tvfool) all the stations I'm currently receiving are uhf. I'm not receiving a single vhf station.

Your not pulling in 12 (12.1) or 9 (60.1)?

 

[brian.betteridge]

you are right, I stand corrected...I am getting 12 (WHYY)...however the 60.1, 60.2 and 60.3 are all black.

 

[dkreichen1968]

however the 60.1, 60.2 and 60.3 are all black.

Are you getting a signal strength reading on them? They may just be broadcasting the carrier wave with the channel map.

I checked out their web site and decided they are one of the few Christian TV stations that have decent programming (John MacArthur, R.C. Sproul, Kay Arthur, Way of The Master, Calvary Chapel, etc.), and no Crefo Dollar or Benny Hinn.

 

[brian.betteridge]

Ok here's a thought on my reception. It's been recommended to build a wider vhf antenna to splice into my current antenna signal.

Would it be possible for me to put extensions on the vhf dipoles currently on my antenna? That would be a lot easier for me, and I could tailor it to my available space...

thoughts?

 

[Fringe Reception]

Brian,

VHF-UHF 'combo' antennas are designed from ground-up and personally I wouldn't want to spend the rest of my life running the math (and probably a whole bunch more math I have no clue about) that a supercomputer can do to design such an antenna.

Years before the Internet and this website was online Martin E. Meserve - K7MEM - VHF/UHF Yagi Antenna Design I spent days with piles of notebook paper and a hand-held calculator to design single frequency (channel) Yagi antennas. I know of no online calculators that can design a combination antenna, although there is a free program that can 'dissect' the design of any antenna and determine its' mathmatical functionality. http://home.ict.nl/~arivoors/

The right antenna or the right tool gets the job done. If you want to alter an existing functional antennas you are literally on your own, experimenting. There's nothing wrong with experimenting (look in my albums here) but in this case I wouldn't hold your breath.

Jim

 

[Tim58hsv]

you are right, I stand corrected...I am getting 12 (WHYY)...however the 60.1, 60.2 and 60.3 are all black.

Have you tried aiming the antenna in channel 9's direction? It should come in. On the other hand channel 6 could be a problem if the amplifier has an FM trap since that will kill a lot of the channel 6 signal. If possible, turn the FM trap off and give that a try.

 

[brian.betteridge]

how do i turn an FM trap off? I don't even know what that is.

 

[dkreichen1968]

Your amp may not have one. If it does it should be specified on the amp, or in the manual. A FM trap filters out the FM band, which is in between low VHF and high VHF, so that it doesn't interfere with the TV signal. The FM band borders on channel 6, which is why Tim was wondering about it.

 

[brian.betteridge]

Ok I will look into it...

but bigger issue...Here we go again!

Just this afternoon I went to turn on the TV and flip around, and I'm only receiving signal on about 10 channels. They're the same handful of channels I was receiving before and all the usual suspects are gone. It's relatively clear outside, not windy, nothing much going on weather-wise, except for some snow/rain moving in tomorrow. Did I burn out another amplifier? I don't understand what's going on here.

 

[dkreichen1968]

Did I burn out another amplifier?

Maybe! You may need to put an attenuator in front of the amp to keep the signal from your hot signals (which ever ones those are) from overpowering the amp. I know that Radio Shack had 6 dB ones. They may have smaller ones too. I don't know if that will knock down your channel count.

By the way, what are the 10 channels you get? What are the ones you lose when this happens?