[amsat-bb] Placement of Preamp

[W3AB/GEO]

Frank,

Congrats on your new ears.

The best location for a preamp is at the antenna. That way line loss will be minimized & noise will not get amplified.

Since you have wide band preamp that will hear everything, you'll want a bandpass filter in front of it. The filter should be tuned narrowly to the frequencies you want to work.

This will be difficult due to the single coax feed. But, if you can put the filter at the driven element you should be successful. That would between the diplexer and driven element.

Again, with that preamp you may experience desensing and/or intermod.

Sounds like great place to start. Have fun.


⁣___
Sent from my two way wrist watch
73 de W3AB/GEO​

On Mar 9, 2019, 12:36, at 12:36, WA2NDV <wa2ndv at gmail.com> wrote:
>Hello all,
>
>So on a lark I purchased a Chinese preamp that claims to cover almost
>DC to light LOL.  seen here
>
>On 440 uplinks I was swamping my 2 meter RX so I have a 4 pole 2 meter
>bandpass filter inline now.
>
>My question is where is the best place to place the preamp, output or
>input of the bandpass filter. Right now its on the input to the filter.
>
>Does anyone have some real world experience with this ?
>
>I have a single coax dual band antenna feeding a 2/440 duplexer. 2
>Meter radio is Yaesu FT-817 and 70cm radio is a FT-991A so this filter
>and amp are fed from the duplexer 2 meter port.
>
>I just heard XW-2C at 3 degrees—never heard that before so it is
>working.
>
>I appreciate your comments.
>
>73
>Frank
>WA2NDV
>
>
>
> 
>
>
>
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