Pro-2018

[Porkins]

Hope I'm posting this in the right section.

I have a Pro-2018 and I'm looking to add on a RS Model: 20-176 antenna outside my house. I have a shed in the back yard that I plan fix a pole with the antenna on it. What cable do I need? RG58? What connects do I need? I assume a BNC male for scanner side but what for the antenna? Also the cable needs to be 100 ft, from the scanner to 20ft pole on top of shed is 80ft.

Thanks,
-Joey

 

[gmclam]

Coax

Your post would probably get responses more on topic in the "Antennas ..." forum.

The bigger issue is not the specific scanner you are using, but What is the highest frequency you want to monitor? While 100 feet of coax might be "OK" for lower frequencies, there will be a huge loss at upper frequencies, such as the 800MHz band.

Even if I was using this antenna for VHF, I would not use RG-58 for a 100 foot run. I'd get the best coax I can find. Especially when monitoring UHF frequencies, many people here recommend LMR-400. I am using a similar type Air802, but you might even consider LMR-600 or this.

You'll also need the appropriate connectors, and possibly the tools to install them. I have one antenna that uses a PL-259 and another that uses an N connector. My scanners all use BNCs, but there are filters, splitters and other devices inline that are a mix of different connectors. It is impractical to run this heavy duty cable all the way to the scanner. I get the signal into the house, and then use a very low loss RG-6 for the final stretch to the scanners. Note that all RG-6 is not created equal. The stuff I bought has been swept to 2250MHz.

 

[Porkins]

Thanks Gmclam.

I must have missed the antenna section. Also thanks for the recommendations on coax. The air802 400 looks to be in my budget.

 

[gmclam]

Big difference

Here's a little more to the puzzle. There are tons of these types of sites on the web that will calculate how much signal loss you will have through various brands & types of coax.

Here's one. When I selected 8240 RG-58, 100 feet and 800MHz, it calculates the loss at 12.6dB. When I select LMR-400, with the same parameters, the loss is 3.6dB. A loss of 3dB is a loss of 50% of the signal. 6dB loss would be 1/4 of the original signal. 12dB would be 1/16 of the original signal.

 

[Porkins]

Thanks again. Your one of the most helpful members I have came across on here. Looks like I'm gonna re- think the length.Probably gonna mount the antenna up on the roof of the 2nd story. Would cut out a good amount.

 

[gmclam]

Thank you for your kind comments.

When it comes to antenna effectiveness, nothing beats elevation for getting signals that are farther away or perhaps otherwise obstructed by something. While many people can just "throw something up onto the roof and run coax from it", there are many times when a system has to be well thought out and designed. I've seen plenty of situations where the signal at the other end of a coax from an outdoor antenna is LESS than that of a rubber ducky right there at the radio.

Is this antenna for general purpose listening? Do you have a specific signal you are trying to get? What is the highest frequency of interest? If you're just trying to get aircraft band for example, you can get away with more than if you're trying to pick up a distant 800MHz trunked system.