Antenna setup advice please…

[xntrik]

Just got my BCD996P2, and wanting to install it as my primary listener in the kitchen, though I also have a BCT15X I’m looking at moving to the basement for the mrs to listen in during inclement weather and such. Will primarily be scanning local analog law/fire/ems, as well as MOSWINN, and occasionally opening up FRS/GMRS stuff for giggles. We have a 40ft tv tower next to the house, and I’m looking at putting my base antenna about 8ft below my twin TV antennas. I acquired this little gem, referred to as “the investigator” during one of my last used equipment purchases. And was able to track down the maker, “PEANUTPASTER” on eBay, but he hasn’t responded to my questions. Looks like it’s a “jpole” antenna of the home brew type, with this as part of his description “The Investigator is a dual band design antenna. With this design you get the full range of your scanners frequencies from 30 - 1200 MHZ with the Investigator being especially hot in the 400 - 1200 mhz range.” The “investigator” has a BNC connector on the end of about 6ft of coax, I’m looking to extend this down my tower with RG6, into my basement to a splitter to eventually feed the basement BCT15X, and kitchen 996P2. What I’m asking I guess is how much signal loss will I be looking at with a bnc coupler for my extension, and any suggestions on a simple splitter? I’d like to stay with the RG6 as my cable, since I have about 400ft of it. Total length of extension to the splitter would be about 60ft, then splitter out to scanners about 20ft.
Thanks for all the suggestions.

 

[mmckenna]

I'd strongly recommend avoiding those miracle antennas that get sold on e-Bay. It's usually a length of PVC pipe with a couple of different (non-tuned) lengths of THHN building wire inside.

In other words, you can easily do better.

But, RG-6, not an issue for what you are doing.
A decent BNC coupler will add a fraction of a Decibel of loss, maybe 0.1dB or so, not enough for you to notice.
60 feet of RG-6 won't likely be a problem, IF it's good stuff. While the RG-6 standard is usually good cable, each manufacturer will have some variance. Some of it is good, some of it isn't so good.

There are 'coax calculators' on line that you can try out, but they are usually only for very specific brands of cable.

Coax Calculator

 

[Ubbe]

If it's a j-pole type then it's very narrow banded, about half the bandwidth of a "normal" 1/4 or 5/8 wave vertical. Do you have a picture of it? Maybe it's another of those "super" scanner antennas on ebay that only has some electrical wires of different lengths.

If you split the signal it will be reduced to half strength. You RG6 at 900MHz and nearly 100ft will attenuate at least 6dB, the signal are reduced to half again and then another half again.

/Ubbe

 

[xntrik]

I’m not generally a fan of it either, HOWEVER, it was in essence free, I’ll most likely put something different up later on, but this gets me going for now. One other question… I know my tv antennas had to be spaced a certain distance feom
Each other, but is there some requirement or general rule of them for distance of a scanner antennas stand off from the tower?
Thanks again everyone for their help!

 

[xntrik]

Possible suggestions on an amplifier then what about an amplifier splitter? I just so happen to have a spare channel master CM-3414 laying in the basement….

 

[Ubbe]

I just so happen to have a spare channel master CM-3414 laying in the basement….

It has a 8dB gain and a noise figure of less than 2dB, that's good. Put that up at the antenna, or as close as possible to use that 8dB gain to compensate for coax loss and the splitting you will do. If you use it at the receiver it will only compensate for the 3dB loss for the split and not the coax loss. At the antenna it will have enough gain to compensate for an additional 5dB coax loss.

Antennas should be separated as far as possible if they are not stacked together. One wavelength of the frequency are the best but shorter distance can be used but will change direction pattern if there are enough metal that interfere.

/Ubbe