Signal Amplifiers (Amps, Preamps, Distro Amps) - See Chart in Post #1

[DdDave]

Originally Posted by Schmerpy

Thanks. I tried one from The Source and it did absolutely nothing - no increase in signal quality whatsoever on any channel.

The problem is that you only have about 2.5-3dB of cable loss, so that's the most you can expect to gain back using a pre-amp. This is where the noise of the pre-amp becomes very important, you would need a fairly high quality one to even make this worth while. If you have 5dB of noise in the pre-amp, then you are actually going to be 2dB worse off than without it. Cheaper pre-amps can have noise in the 5-7dB range (or possibly higher), which may be why your Source pre-amp made things worse (combined with possible overload from the local stations)

Indeed, I would love to put it outdoors. But this is a townhome development and people are picky and are in close proximity.

The C2 is a fine looking antenna, and less obtrusive than a satellite dish.

[Schmerpy]

Thanks for everyone's advice. Based on a recommendation from saveandreplay, I ordered a CM7778 from them today. The guy there said that pre-amps are usually needed to make an attic installation function well.

We'll see. If I could actually receive all the stations I've seen come and go over the last four days, I would literally have 100% of the stations that are available locally (except maybe Rochester, which I have not seen), which tells me they're there...

I'll report back after I try the pre-amp.

[ota_canuck]

This sounds suspiciously like a typical sales pitch:

The guy there said that pre-amps are usually needed to make an attic installation function well.

A preamp doesn't make signals out of dead air, however as long as S&R have a good return policy, it's worth a try and you have nothing to lose.

[Schmerpy]

We shall see. It's hard to say. I'm skeptical too, but I have read many testimonials in a few places from people who claimed apreamp allowed them to stabilize all the stations that were intermittent.

Some even claim it worked when hooked up at the end of the cable run before the television. I suspect it probably depends to some extent on the tuner being used. When signals drop off to very weak levels, some tuners can't make sense out of them anymore, whereas they can when boosted. That's my feeling.

My television is from 2006 (Toshiba Regza 37HL66).

[manolid]

After purchasing a second TV, I've noticed that a few of my channels are not coming in as well as they were before. I'm pretty sure a distribution amp is what I need.

My question is this... Can I safely use a distribution amp with a pre amp? I'm pretty sure I know the answer to this question, but I need to be absolutely sure to eliminate any possibility of damaging my equipment.


Currently using a CM 4228 antenna with a CM 7778 pre amp. Thinking of getting a CM 3412 dist amp.

Any help or info is appreciated.

[loveota]

I run a CM7777 preamp into a CM 3412 feeding 2 tv`s . The distro does a fine job eliminating the signal loss of a splitter. You should have no worries.

[manolid]

Thank you

[wilspin]

Get one that has a variable gain contol and you can tweek it, more money but well worth it.

[ScaryBob]

A preamp + distribution amp will be more susceptible to overload. That could be an issue in a major urban area. A CM7778 preamp should be plenty unless there are major line losses or many TVs. Relocating or stacking the antenna, if possible, may be a better option.

[ota_canuck]

You are pretty close to Toronto's powerhouse of broadcast signals which may cause problems if over amplified.

Explain how your antenna and cabling is set up from the antenna through to the TVs.

Cable lengths and cable/splitter loses must be determined to be able to give advice.

- How long are the cable runs?

- antenna to the preamp's powersupply ?

- Power supply output to splitter

- How much cable run to each TVs

If your cabling is setup using long cable runs then maybe it will help. If cable length are short, then it may make things worse. Adding a distribution amp after the preamp powersupply won't damage your Tvs, but it may send too much signal or too much amplified noise to the tuners.

[Jase88]

The weather is changing, and we've had weird tropo over the last few days. So I wouldn't be too concerned.

I've got a CM7777 ahead of about 90' of RG6, a two split, then another 30' of cable to the sets, and I find my signal at both TVs is just fine. And I'm not as close to the CN tower as you are. No need for a dist amp here....

[majortom]

Agree with Jase88.
Ur 2nd TV is a co-incidence, weather's changin'.

I go from mast mounted pre-amp, to around 50-75 ft run, 4 way splitter as it enters the house, (grounding system there) using three of the 4 splitter outputs, terminating the 4th. About 25 ft drops to each tv. Plenty of signal available there to each TV.

What are the other details of your antenna system? Attic, or outside? rooftop or tower? how high, etc?

[tvlurker]

Originally Posted by wilspin

Get one that has a variable gain contol and you can tweek it, more money but well worth it.

Be careful using variable gain controls. In some instances, reducing the gain increases the Noise Figure, so you start to lose one of the major advantages of a preamp -- lower system noise figure than what you would get if you were relying on the TV's tuner as the first RF stage.

[wilspin]

You guys are right. In TO you must trap the locals if you want to boost the far away. When i was in Ajax pointing south, preamp overloaded some stations from TO. Really I have found you do not need preamps at all in TO.
Try removing splitter test each TV separately. go from there....

[manolid]

Originally Posted by ScaryBob

Relocating or stacking the antenna, if possible, may be a better option.

Scarybob, what do you mean by "stacking"

Thanks for the replies all