rg6 length and loss

[psdavidson]

for scan Only, will RG6 quad shield have too much loss at 100' to 150'?

 

[n5ims]

for scan Only, will RG6 quad shield have too much loss at 100' to 150'?

Loss for a specific type of coax is directly related to two factors, length and frequency. You specified length but not frequency so we can only give you half of an answer. Yes it will have loss. At some frequencies it won't be all that much, but at others it will be quite a bit.

Also the "too much" part is relative to two different things as well. One is how much signal strength do you have and the other is how much do you need. Scanners are designed for a certain amount of signal strength to work correctly (actually a range of strengths) where you get a good signal without noise. Less than the lower value of that range and you'll get noise. More than the top value of that range and you'll overload the circuit and have problems. If you have very weak signal levels and top notch coax you may still have "too much" loss. If you have very strong signal levels and really lossy coax you may be reducing the signal levels to the point where you no longer overload your circuits so you could actually have "enough" loss.

To help you answer your question, start with a coax loss calculator (like Coax Calculator) and plug in your lengths, frequencies, and the various types of coax to see what you come up with for the values. Lower loss is generally better unless you live in an area with very strong signals.

There's always a tradeoff between loss and cost (with some other things like ease of installation, etc. thrown in). You can get cheap coax that works horribly and expensive coax that works great. You can also find some that is lower cost but works better in your situation than something more expensive.

There is also the factor of what that specific type of coax was designed for initially. Some was designed to work well at lower frequencies while others were designed for higher frequencies. They may look quite similar but work very differently.

RG-6 was designed as a TV reception coax and works quite well there. It's easy to install and not all that large. One advantage to scanner folks is that most scanner frequencies are between the TV channels so RG-6 generally works pretty well for scanner use. The impedance is different, but for receive-only applications this shouldn't matter that much. For the size and cost, RG-6 will probably give you the best "bang for the buck" in many situations. It will be smaller, easier to install, and cheaper than most other choices (thinking of LMR-400 here), but will give you a bit more loss. Will it be "too much" loss? Don't know your specific situation so I can't answer that with any certainty.

 

[psdavidson]

Thanks for the awesome reply. So far mostly around the 155 area.

 

[DisasterGuy]

A good RG-6 quad shield at 100-150' will serve you well in VHF.