Pre-Amp - When and how much ?

[Scotsman]

Hi everybody, I hope it got this in the right place.
I tried searching around for this info, but I'm not too good with Computers or Technical stuff.

My question is pretty much like you see up on the Subject line.
I've seen where somebody has said you need an Amp when your Cables are like over 100 ft.
I've seen where somebody said you don't use one if you're closer than a certain distance from the stations.
I've even seen where some guy had a formula, where you needed the station output and did some math to get the size of Amp you needed.

Which one of them is the one you go by, and just how do you figure out how big an Amp is right ?

Appreciate any advice.

[winegard]

Good afternoon Scotsman -

Please refer to this post in the knowledge base...

http://www.winegard.com/kbase/kb_tip_results.php?tip_num=480

[Scotsman]

Hello Winegard, and thanks for the quick reply and link.

It was helpful, I already knew about how to figure my system loss, but your recommendations there has brought up some questions related to the use of a Pre-Amplifier.

I subsequently looked up two other FAQ’s.
HDP269 http://winegard.com/kbase/upload/WC-809%20_HDP-269.pdf
AP Series http://winegard.com/kbase/upload/chart29.pdf

Just using the numbers you gave on that FAQ, it seems like the HDP269, is a little short of compensating for a 13.0dB loss about 1% or so.
And of the second group the four AP models (25-40 mi) you said would work, seems like it's ok if you got an Amp that went over the 13.0dB you needed, about 30%.
And, if I needed to compensate for the 13.0dB at over 35 miles, you recommend I get a 29dB Amp, which would increase the overage to about 120%.

I don’t understand this,
1: Seems like the HDP269 is the only one that even comes close.
2: Why increase the Gain to such high levels ?
3: I need a simple gain 13.0dB gain to compensate, what does distance have to do with it, when I’m trying to deal with a issue related directly with my house !?

[winegard]

Good morning Scotsman -

The gain of a preamplifier is designed to overcome the cable losses and splitter losses of your antenna system. If you have 13.0dB of loss then the HDP-269 at 12 dB of gain is 1.0dB short which most likely you will never see on the TV set. The next option would be to the AP-8700 preamplifier that have an average gain of 17-18dB. This would give you an extra 4-5dB of signal which should not create a problem. However if you use the AP-8275 preamplifier which has 28-29 dB of gain the extra 16dB of gain could be too much for your TV sets to handle. Go for the AP-8700.

[Scotsman]

Winegard Adm,
Again, thank you for your prompt reply.

I just want to get something straight up front here.
I've been using Winegard products for over a half century, and NOBODY surpasses the quality, dependability and value of your products. I just happen to be one of those guys, who's a stickler for "saying what you mean" and "meaning what you say"!

I believe in the two previous posts, we actually came up with the same numbers. I, did it in percent, you, did it in decibels, but for all general purposes, same thing.

I guess I'm a little dense though, because when I read your FAQ (the one you first referred me to) there was no leaveway about which Amp I would choose. You gave some absolute distances, and never mention that I had a choice.

Yet, in your next post, you inferred "if you use the AP-8275 preamplifier", that it would be too much. I agree !
If I had a choice, why didn't you say that in the FAQ. Are you sure that distance is the best way to choose an Amp, when Signal Strength is such a major factor ?

[winegard]

You are doing it correctly. Please remember that the information I linked you was in response to another user or dealers question. While we provided specifics on how to calculate the correct amplifier we also gave him generalities to use in multiple situations.

Those suggest amplifiers (per distance) then need to be adjusted because of the specific users situation, run length, number of splits, etc.

I hope this clear it up.

[Scotsman]

Winegard Adm,

I have absolutely no idea what you're talking about !
I don't know who the other user or dealer are, and have never received any information from you concerning this issue.

However I'd love to have any "specifics on how to calculate for the correct amplifier" and "generalities to use in multiple situations".

Please send/post anything you have concerning that, it would be greatly appreciated !

Thank you,
Scotsman

[winegard]

Scotsman -

I am referring to the first link I posted to you. That answer was posted in response to another user or dealers question. Because your question was similar I linked it to you as well. However, it contains more informatoin (the distance generalities) that you do not need.

Again, you are doing it correctly and go for the AP-8700.