# in line signal amplifier



## gregftlaud (Jun 16, 2004)

i'm thinking of buying an in line signal amplifier so i can get a better signal than 60 on one of my local ota digital channels.

here is the amplifier

http://www.radioshack.com/product/i...13&cp=&kw=in+line+amplifier&parentPage=search

u think this might boost my signal by at least 5 points and also is there is chance it could blow out my ota signal input on my hd tivo

greg


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## bpratt (Nov 20, 2004)

I have had problems with Radio Shack amps. The best amp I have found is made by Electroline. I purchased an EDA2400 and an EDA2800. The EDA2400 is used for my UHF antenna and it boosts the off air signal on my HR10-250 from 85 to 95.

Here is a link to one on EBAY. You can probably pick one up for $15 to $25.
http://cgi.ebay.com/ELECTROLINE-4-P...873414804QQcategoryZ39803QQrdZ1QQcmdZViewItem


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## gregftlaud (Jun 16, 2004)

can that one also be used for a uhf/vhf antenna?

greg


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## TyroneShoes (Sep 6, 2004)

That one seems to have minimal gain. The old RS amps were really terrific...25 dB of very clean 2-stage amplification/variable gain/FM trap all for under $30, covering 5 MHz to 890 MHz. Unfortunately, they stopped carrying them last year. The ones they have now are kind of suspect. I would go Tru-Spec or Blonder-Tongue.

Greg, I'll go out on a limb and assume that you are a ways from the Miami transmit site. If so, I would assume that you probably won't have problems (in adding that amp). Search this forum for "amplifier" or "attenuator" or "variable" and you will find a good procedure for maximizing the signal reading using an amp and variable attenuator that works for whatever scenario you might have, close, far, hot antenna, set-top antenna. A simplified application of that technique would be to simply put it in line while monitoring the signal quality reading for your worst channel. If it goes up, leave it in, if it goes down, take it out. Also check your hottest channel for degradation.

If you have a hot antenna like a 4228 you might have enough signal already, assuming you are within 25 miles or so. I found that with a simple dipole at 12 miles I needed to add about 9 dB of gain to get the maximum reading (both less or more attenuation gave a lower reading). That is equivalent to the gain you might see on a 4228.


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## gregftlaud (Jun 16, 2004)

i'm only 10 miles from all the transmitters and i get all of them at aroun 90 except 7-1 wsvn which also happens to be on a vhf frequency.


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## bpratt (Nov 20, 2004)

> can that one also be used for a uhf/vhf antenna?


Yes it can. I use the EDA2800 which has 8 outputs for my uhf/vhf antenna. One of the reasons I like the Electroline is it does not amplify the signal too much. The HR10-250 has problems with too strong a signal.


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## gregftlaud (Jun 16, 2004)

ok i got the powered in line amplifier 10dB from radio shack and it gave me an additional 7 or so points higher on the local fox that i wanted. so it worked i suppose....for now

funny thing is ..it says in the instruction manual that u have to plug in the amplifier part right into the antenna...and that there can be no splitters or whatever in between the antenna and the in line amplifier. well...there are two diplexors in between the antenna and the in line amplifier and powered input into the tivo but it still seems to work ok

greg


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## btwyx (Jan 16, 2003)

That looks like the one I got from RS. It does have a significant effect on signal level, if low signal is your problem. (There are other problems it won't help with.) I got better amplification from a low noise pre-amp like a Channel Master 7777. The noise figure of the amp is more important than the gain.


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## TyroneShoes (Sep 6, 2004)

btwyx said:


> ... I got better amplification from a low noise pre-amp like a Channel Master 7777. The noise figure of the amp is more important than the gain.


That _can_ be important, but is not necessarily always the most important thing.

You will most definitely get more gain, as they are rated for much more gain. The 7777 and 7775 are the best preamps out there, because of high gain AND low noise figure.

But low noise figure is only important if the signal is very weak to begin with (and of course many times it is, or you wouldn't be thinking preamp in the first place). The amount of noise in a system is a product of the noise figure and the amount of noise at the input to the amp, and in a situation where the received level is moderate (relative noise is therefore low) or there will be a distribution split, gain is what you are looking for while NF becomes insignificant. IOW, if you only need a few dB of gain to get you into the sweet spot, the received level is then not so low as to make noise figure significant, and a medium-gain, high NF cheapie is just the ticket.


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