BEWARE OF POTENTIAL NOISE ROUTED THROUGH THE SOUNDCARD
(December 6th, 2015)
When I started being active with EME communications back in 2013, my RX performance was very poor initially. Inexperience and flawed setup were the main drivers of my misery. One of the component in my hardware which I found to be most damaging to my RX performance was the impact of my Soundcard on the noise level. I am currently using a Signalink USB soundcard.
It took me a while to uncover this issue which was severely degrading my RX. I found that connecting that soundcard to my IC746 PRO was increasing the noise level by about 3dB, which is a killer in the world of EME! I traced back the wire that was responsible for this issue.
The video to the right below shows what happens when the soundcard is connected "as is" to my ICOM 746 PRO. The noise increase is dramatic and very noticeable on the waterfall.
The solution? I have setup a relay between the soundcard and the ICOM 746 PRO which only enables the soundcard-to-radio wire connections while in TX mode. In RX mode, all the wires are disconnected so no noise pickup is possible. The audio going from the ICOM to the Signalink USB is routed using a separate cable, that one is not a concern.
The morale of the story? In the world of EME, DO NOT trust anything! I suggest to add/connect each individual piece of hardware one at the time, and verify the impact of their presence on the noise level. You will be surprise what you will find. Adding a bunch of stuff to your EME station without testing them individually is a recipe for disaster...
***WARNING: For Best Resolution, it is critical to select 720p HD resolution in the youtube "settings" at bottom right of the player. The 360p default setting won't yield good enough resolution to see the details. It will take several seconds before the High Resolution kicks in, so you will need to restart the video from the beginning when the High Resolution is active and select to view the video in "Full Screen Mode" for best experience...***