Heh.. I actually use an 18" section of aluminum downspout, capped at the top. Just stuff the pre-amp, coax, and (in my case) splitter/joiner up inside it. A cable tie provides security against gravity having its way.

Cheers

From east mountain Hamilton, I aiming to run 3 antennas (30 foot tower, no obstructions): Toronto is closest (35 miles) and will use the 4221 fixed (non-rotored, non-amped), north Buffalo is next about 45 miles and again will aim a fixed second 4221, possibly amped. So far (20 foot mount), analog signals are fine except 17 (pbs). South Buffalo (60 miles) is difficult (4221 with no pre-amp) and I purchased a 4228 to hopefully get these channels, along with top of tower mount, with rotor and CM pre-amp.

QUESTION: How should I configure a pre-amp/filter, etc set up for the 3 antennas? Can I set the pre-amp just under the 4228 and how will this affect the other antennas/signals? But maybe I could use the pre-amp for the 4221 aimed at North Buffalo to get 17 better? I really don't need the pre-amp for Toronto/Hamilton. What type of splitter should I use?

Don't attempt to combine them at all on the tower. Instead, run separate RG6 coax down from each individual antenna, with or without masthead pre-amps.

Inside the building, insert the power-injectors for each preamp onto the corresponding coax leads, and then take the three coax feeds from there to an A-B-C coax switch ($18 from The Source), and a single coax from there to your TV set or PVR.

Even better would be to have a PVR with 3 tuner cards, and then just get rid of the A-B-C switch and run each antenna line into it's very own tuner card in the PVR. Such are the advantages of home-built PVRs (eg. MythTV, or SageTV).

Cheers

You'd probably end up getting worse picture than you do before
Your 10db amp probably adds 3.5db of noise along with the 10db overall amp, so you're only getting a small amount of extra gain, but are adding more noise to your system. ATSC systems work mostly on SNR (signal-to-noise ratios), as I discovered when I added a second tuner.
Splitting the signal made each line noisy/fuzzy when watching analogue, but for digital, my "signal meter" levels stayed identical. This is because the signal-to-noise ratio stayed the same - it's just the overall strength of the signal that changed.
For example - you have an FM radio. The sound is pretty good, but a little fuzzy/crackly in the background. By turning up the volume (amplitude), does that fuzzy/crackle sound go away? No.

I'm not sure noise on the second amp would be a problem. According to the HDTV primer the only noise figure that matters is the one for the first transistor in the chain. After that, whatever signal that exists is more than strong enough to overcome noise in the following stages. Heck, the amplified noise from the first amp probably overwhelms the noise added by the next (unless its attenuated by 100's of feet of cable).

I think the 42 dB (~16,000x) amplification would be more of a problem. That's almost certain to overload something. From what I've read in this thread, even 32 dB is kind of huge.

Hate to post twice in a row, but what do people think of the Antennas Direct CPA-19 pre-amp?

It seems to be designed for DTV:
- limited to VHF-Hi and UHF-Lo (up to channel 51 only)
- claims excellent noise figures (1.7 dB VHF, 2.0 db UHF)
- claims high overload resistance, and the modest gain figures would seem to support that (18.4 dB VHF, 17.3 dB UHF)

I'm looking for a pre-amp with high overload resistance and good noise figures. In my neighborhood, real channel 40 is almost 10,000 (40 dB) stronger than the next strongest channel - though the channel 40 antenna is 86° off axis from the other channels which may be my saving grace.

I guess those feature may count against it for those wishing to get VHF-Lo and UHF above 700 MHz, but wondering if anyone has any experience with it and what they think. I see it billed as being as designed for use with the ClearStream C1, C2 and C4 antennas, but that's jsut marketing, right? There's no reason it shouldn't work with a GH or any other antenna?

The numbers look good on that CPA-19, but I've never tried any of the Antennas Direct preamps. If you look at the Preamp Chart you'll see 2 other Antennas Direct preamps listed by holl_ands, so if he gives them the okay then that's fine with me. http://www.digitalhome.ca/forum/showthread.php?t=97938

Have you looked into the Research Communications preamp line mentioned in this thread? Spectacularly low noise levels!

I was looking into buying a pre amp and it seems that some folk (using a pre amp) occasionaly have a need to attenuate.
So , I thought that rather than go through that procedure ....what about using an adjustable pre-amp. After some checking around I can only find one (recognizable) manufacturer at a reasonable price....In fact,maybe too good of a price .Not unexpectedly,the one I looked at is not on Stampeders list.
The Antennacraft 10G212 for $19.95.
I then realized that the noise figure of<4.00db UHF was not so good.
Is there such a thing as an affordable,decent,adjustable pre-amp ?
thanks

Actually,I found this one this morning.
Any comments ?
Thanks
http://www.kitztech.com/?src=overture&OVRAW=tv%20antenna%20amplifier&OVKEY=tv%20antenna%20amplifier&OVMTC=standard&OVADID=3054864522&OVKWID=28022684522

Thank you for the reply.

I've been intrigued by the Research Communications preamp, but the cost and over seas shipping puts me off. I also think it'd be susceptible to overload in my neighborhood.

I did download the preamp chart early on. Finding the best combination of inputs, noise figures and overload resistance is as hard as choosing a new car. I wish they made a low-gain version of the 7777.

I'm wading through the AVS antenna topic (8,500 replies!) looking at holl_ands posts. This pre-amp stuff is confusing; by holl_ands logic most any low noise preamp should improve SNR almost always, yet so many people report bad results.

That kiztech amp is almost as intriguing as the Research Communications amp, especially at that price, provided you can trust their claimed stats. Too bad it has no power injector or protection from the elements. I think their claim that it can give mast-mounted performance from inside the house is disingenuous; the <1 dB noise figure isn't going to offset 6dB of cable loss.

That kiztech amp is almost as intriguing as the Research Communications amp, especially at that price, provided you can trust their claimed stats. Too bad it has no power injector or protection from the elements. I think their claim that it can give mast-mounted performance from inside the house is disingenuous; the <1 dB noise figure isn't going to offset 6dB of cable loss.
They're not even in the same game. If your goal is improved reception, then the the pre-amp has to go as close as possible to the antenna itself, before the transmission equipment can add noise to the signal.

The best pre-amp on the market, at 0.4dB NF, costs about $160 *delivered* in the USA. These things really work. I know, I've had one here for the past two years.

Cheers

But if you could mount the kiztech on the antenna mast, or if you had your antenna in your attic, that'd be a different story. Of course, who knows if their claims are true - I couldn't even find kiztech on reseller ratings.

Am I wrong to be concerned about overloading the Research Communications amp?

Callsing Real (Virt) NM(db) Pwr(dBm) Path Dist Az
KPXM-DT 40 (41.1) 64.1 -26.8 LOS 7.7 30°
KPXM 41 55.4 -23.5 LOS 7.7 30°
WCCO-DT 32 (4.1) 25.2 -65.7 1Edge 35.2 116°
KARE 35 (11.1) 24.7 -66.1 1Edge 35.2 116°
...
KSTC-DT 44 (45.1) 16.3 -74.5 1Edge 35.2 116°
KTCI-DT 16 (17.1) 11.8 -79.0 1Edge 35.9 116°


I get most everything I want from the 116° antenna farm, but 45.1 is intermittent and I can't even tune 17.1. I'm hoping a preamp would make 45.1 reliable, and maybe get 17.1 at least some of the time.

FWIW: I'm using a coat-hanger GH indoors right now, with 100' of RG6. An outdoor antenna isn't an option right now.

Am I wrong to be concerned about overloading the Research Communications amp?
Dunno. But they publish very detailed specifications on their web site to help you figure that out.

Here, none of our local or distant channels produce any signs of "overload" on the equipment. Despite a VERY high gain outdoor antenna array in front of the pre-amp.

Cheers

Hi Keef,

I have a Kitztech preamp.

Well, since I have nothing to compare it too, who knows if it is better/worse than any other pre-amp.

With it on, I get approx 5% better signal across the board. Might not be much, but it seems to do its job (for me at least)

Yes, I do have it next to my TV...but will mount it near the antenna in the summer (attic install)

The fact that it improves reception even when connected right next to the TV is a good sign (to some extent). I believe that means the amp's noise figure is better than TV's noise figure - though the TV's noise figure could be 8 or 10 dB, so we can't tell if the KitzTech is really less than 1 dB. Moving it closer to the antenna should make things even better, provided it doesn't overload the amp.

I finally waded through the AVS thread and found holl_ands' overload calculation spreadsheet. It's difficult to estimate some of the figures - like antenna gain with the station 86° off axis - but it looks like anything other than the Winegard HDP 269 would overload, and even the 269 might. To make matters worse, I have a strong FM radio signal in my neighborhood, and the 269 has no FM trap.

The fact that it improves reception even when connected right next to the TV is a good sign (to some extent).Truth be told any main brand preamp will do that. :) Make sure you have an attenuator handy (preferably in the 5 to 10dB range) whenever you are experimenting with preamps. When you're doing a lot of connecting and disconnecting it is also important to be sure that everything is grounded properly, and I always power-off all the gear when I'm playing with preamp connections.

Alright, so I read the whole OTA Faq and I have a few questions. (Mainly about the safety of my TV, I don't wanna damage it).

I bought a distribution amp thinking it was a pre-amp. It had a gain of 28dB and gave me more channels. Someone stated that it was overkill, and I was wondering if that is actually bad for my HDTV and could possibly damage it?

As well, I would like to get a pre-amp, now I am 18 miles away from the CN tower, where most of the broadcasts come from. Would that be too close to use a pre-amp?

And, I was looking at pre-amps, which pre-amp would most people recommend? Winegard AP 8275, CM 0068 or CM 0264?

It had a gain of 28dB and gave me more channels. Someone stated that it was overkillI stated that it was overkill because it is.

Amplification is only for situations in which your system is known to have lots of signal loss, but in your location that's not much of a concern so you definitely do not want a strong preamp like the ones you listed. I suggested that you should try a milder one, remember? :) A Winegard AP4700 is about right, and also pick up a 6dB attenuator too.

Amplification is only for situations in which your system is known to have lots of signal loss,
The point of a pre-amp is not actually the amplification it provides (beyond the first few dB).

But rather that it (1) generally always has a better Noise Figure (NF) than the equipment it is feeding, and (2) it boosts the signal as early as possible, before noise gets added through the feedlines, splitters, etc..

A good pre-amp almost always improves things. A noisy pre-amp or distribution-amp can definitely make things worse.

Cheers

There is always Post #14 in the FAQ for those who need clarification: