Pre amp and distribution amp?

[bigblock468]

I just installed a Terrestrial Digital 91XG and a Radio shack 30db pre amp for my OTA set-up. I'm splitting the signal to three TV's. Actually 2, and my Dish 622. Can i add a Channel Master CM 3044 22dB Four Output Indoor Distribution Amplifier and eliminate the splitters? Will this increase the signal strength to the tuners? How would I wire this? Any help would be much appreciated.

Thanks, Chris

 

[bhelms]

IMHO, only add the minimum amount of amplification needed to give you a reliable signal. Higher amplification almost always raises the noise figure (unless you have very low noise amplifiers) and that increased noise is a major detriment to a good signal. The RS preamp you are using is marginal. If it works for you, then stick with it. If you have a reliable signal when it is fed directly to one tuner (no splits, etc.) but that signal is not strong enough when it is split to multiple tuners, then you may be a good candidate for a distribution amp. But don't be surprised if that doesn't work either due to the increased noise. You might do better with a lower gain preamp, but one that has a very low noise figure of 2dB or less. Check out the Channel Master 7777 (23dB gain VHF, 26dB UHF, 2.0dB noise). The 91XG is one of the best UHF antennas out there. Did you try it without the RS preamp?

Channel Master - Off-Air Antennas for HDTV, UHF & VHF

 

[bigblock468]

I tried with my old AntennaCraft MXU47 and couldn't get a signal. I'm about 65 miles from the tower and down in a hole with lots of pines in between. During the course of the day I can go from no signal to 90 strength on the 622 meter. Sometimes barely a 55 and pixelating and 10 minutes later 75 and stable. I'm only trying for UHF as that's where all my local digitals are.

 

[Cokeswigga]

from what I found, your new antenna is a higher gain antenna, I would try it without the pre-amp and see what you get.

Then if you need one, a low noise low gain pre-amp, and try that... then if you still need more.. move up to a high gain pre-amp.

If none of the options work, then start with process of elimination

Try running the antenna direct to the 622. See if you get good reception. (try with & without preamp)
then try running it with a 2-way splitter to 1 TV and your 622. See if you still have reception.(try with & without preamp)
THen try splitting it 3-ways... see if you have have reception. (try with & without preamp)

I found that I had better signal quality with no preamp.

 

[bigblock468]

QUOTE: Try running the antenna direct to the 622. See if you get good reception. (try with & without preamp)
then try running it with a 2-way splitter to 1 TV and your 622. See if you still have reception.(try with & without preamp)
THen try splitting it 3-ways... see if you have have reception. (try with & without preamp) END QUOTE

Can I test this without bypassing the booster part that is on the antenna mast? Will the signal pass thru or does it have to be powered? It's alot of trouble taking the antenna mast on and off as it's connected to the rotator on a 10 foot section of mast


Thanks, Chris

 

[bhelms]

I don't see any way you can leave an unpowered preamp in line and have much of any signal make it through. I have a simiilar situation, so like you I want to minimize the number of times I have to take the darn thing down again. But in this case I think it's inevitable. Altho' the preamp works best closest to the antenna, the good news is that at least temporarily you could run an unbroken lead down from the antenna to where you can work on it, then do your experimentation there. When you find something that works then you can redo it properly.

The reception you described sounds to me as much like a multipath problem vs. outright signal strength. The meters in the receivers can't make any distinction as they're generally not looking at actual RF ss but instead the the bit error rate. With multipath interference you seem to get all or nothing, and that can vary with the relative strengths of the interferring signals that will change with tree movement (wind), etc. You might try repointing the antenna first before you do anything else. If you can still receive an analog UHF signal (you'll need a different tuner, maybe the one in your TV?) from the same location and similar channel number, that could tell you a lot. Ghosting is the multipath indicator...

 

[Cokeswigga]

As far a tuning an analog signal.. .the 622 only has a digital tuner
So you will have to check this with your TV


The 622 seems to have a good tuner, but you should try your TV directly as well to see who it deals with possible multi-path issues.

My 622 was 100% better at tuning than my 811 with a less than perfect signal.

 

[bigblock468]

My TV is a 32" Konka LCD and the digital tuner isn't as good as the 622's. I can still have a pic on my Panny with the 622 and using the Konka tuner at the same time an have no pic on it with a weak signal message on the screen. Although that's the case the tuners are close to the same as if the Konka goes blank the 622 is only 2 or 3 numbers on the strength meter from pixelating (usually around 55 or 56 strength)

Chris

 

[Cokeswigga]

Sounds like the 622 tuner is the best on you have.. I would try to maximize this.

Did you try hooking it the OTA to only the 622?

Then use the coax output to distrubute to your house.
This is what I did.

I put a 510 and 622 in my living room. ( I hated hearing the 510 'spin up' every night while sleeping)

I then combined the coax output of the 510 and 622, and sent that single line to the garage, where there is a splitter to all the bedrooms (Channel 3 is the 510, and channels 125 & 127 are the 622)
the 622 and the 510 send a strong enough signal to provide a 2-way splitter over 200' of RG-6.

I then reprogrammed the 622 #2 remote so that the "SAT" button controls the 622 and the "AUX" button controls the 510. Now I can watch and control both the 622 and 510 in my bedroom.

If I want to watch OTA channels, I tune the TV to channel 125, and control the 622, and I can watch any OTA I want on any TV.

This does NOT provide independant use of the antenna.. but it gives you something.