Pre Amp Question

Status
Not open for further replies.

ve3opc

Member
Joined
May 26, 2008
Messages
148
Location
Picton Ontario
I recently purchased a MK2000 Moonraker 20 DB Pre Amp and am quite satisfied with its performance...I am wondering if I stacked a couple of them if it would dramatically improve performance even more?....Or could I possibly run into problems with over amplification of signals..?..
 

rbm

Member
Joined
Jan 25, 2005
Messages
1,394
Location
Upstate New York
I've used preamps for years.

I believe that you'd have huge problems if you do that.

However, there is such a thing as 'distributed amplification' where you 'could possibly' benefit from a second preamp.
An example of that is if you have one preamp at the antenna with a long feedline. You 'may' be able to benefit by adding a second preamp inside to overcome that loss.

BUT, not with so much gain. More like 10 dB or so, a very low noise figure and, high IP3.

I've done exactly that, in several instances, with good results.

Experimentation for your exact setup is the only way to know for sure.

Rich
 

JamesO

Member
Joined
Jan 22, 2003
Messages
1,813
Location
McLean, VA
With most Pre-Amp set ups you need to get it as close to the antenna as possible.

The lower the Noise Figure the better.

Often in Metro areas you will need to install a FM Broadcast Band trap between the antenna and Pre-Amp.

You do not want to cascade Amplifiers, unless you now what you are doing and have a spectrum analyzer to really see what is going on. I do run another very low noise Amp near the scanner to overcome a VERY long cable run and a 4 way splitter feeding multiple radios. It is like an amplified multi coupler but I have separate components.

I run this Pre-Amp with good results - http://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf

I run a FM Broadcast filter on the input to the Pre-Amp like this - FM Notch Filter 88-108MHz for SDR; Excellent Rejection 85dB; Bandstop; 9th order | eBay

Another low cost LNA with a good noise figure is this Pre-amp from the same person that offers the FM Broadcast Band trap - Ultra Linear Low Noise Amplifier PGA-103 10MHz - 2GHz LNA Gain 20dB; NF 0.5 dB | eBay
 
Status
Not open for further replies.
Top