• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

Pre Amplifier Help

Status
Not open for further replies.

BMET_Matt

Member
Joined
Dec 19, 2002
Messages
8
Hello All,

I'm looking for a website or info on a Jim M-51, M-75, or M-100 Pre amplifier. I have seen posts on another website that says these are pretty good. Any info or recommendations? I saw a thread on RR but looks like it is for home use, but my radio is in my truck adn the Jim units work on external or battery power.
 

rbm

Member
Joined
Jan 25, 2005
Messages
1,394
Location
Upstate New York
The Jim M-75 can be used anywhere. It can be powered by an internal 9V battery or an external 12V source through a power jack on the side.. Over the years I've accumulated nine of them and I'm always looking for one more.

One good thing about them is that the gain is adjustable. You'll find that is a necessity for stable operation under varying RF conditions.

I've used them on handheld scanners outside with a small beam antenna for satellite reception. I've also used one in my vehicle at times. For vehicle use, you'll need to be able to adjust the gain while you're driving as you travel through high RF environments.

It has some built-in filtering.
Band A - 225mhz-1500mhz
Band B - 108mhz-185mhz
Band C - 25mhz-2150mhz

Gain is fully adjustable from -10 db to +20 db
Noise figure is around 2db

Here's what they look like:
 
Last edited:

BMET_Matt

Member
Joined
Dec 19, 2002
Messages
8
Any ideas on where can I purchase the Jim M-75? RBM, where did you purchase your units?
 

rbm

Member
Joined
Jan 25, 2005
Messages
1,394
Location
Upstate New York
I bought the first three new years ago. The rest I bought on ebay. That's the only place I see them now. They show up there a few times per year.
 

rbm

Member
Joined
Jan 25, 2005
Messages
1,394
Location
Upstate New York
Status
Not open for further replies.
Top