Jim M75 Pre-Amplifier With Pro-197

[LH2428]

Where would you place a pre amp on a 100 foot 50x2 BNC cable …. Closer to the scanner base or as close to the antenna as I can get?
Thanks for your help

 

[tvengr]

A preamp should be placed right at the antenna. The object is to increase signal strength to make up for loss in the cable. The higher level also results in less noise pickup on the cable. If a preamp is placed at the scanner, you will be amplifying a weaker signal which will increase the noise level. Be careful with the amount of gain in the preamp. The front end of the PRO-197 is easily overloaded. You need to use a good quality preamp covering the frequencies you wish to receive. Inexpensive preamps are notorious for creating intermod problems which can ruin your reception. The old Radio Shack inline coaxial preamps added all kinds of garbage to the signal. I have looked at the output on a spectrum analyzer. You can reduce cable loss by using LMR-400 cable.

 

[LH2428]

Thank you for the reply. I just ordered the Jim M75 Pre-Amplifier

I will make sure to install at the antenna end not receiver end

 

[tvengr]

Thank you for the reply. I just ordered the Jim M75 Pre-Amplifier

That preamp appears that it is for indoor use only. There are other ones designed for outdoor use. Some are powered by an indoor power supply which feeds dc up the cable so that you do not need to run an additional cable.

 

[LH2428]

My antenna is in the attic 👍🏻

 

[tvengr]

A 100' cable run seems awful long for an attic antenna. I have a 2-story house with an attic antenna and use a 25' LMR-400 cable. for scanners on the 1st floor. At that length, cable loss is negligible.

 

[LH2428]

A lot of wire going around baseboards to get to the garage. More like 75 foot

 

[buddrousa]

Home Owners Association
You need an antenna that looks like a FLAG POLE