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I recently tore down and remodeled my shack. When I put things back together, I repositioned just about everything, including eliminating a couple of unnecessary power supplies. During this process, I decided to power the MFJ-1026 Noise canceller to a small switching power supply. This noise canceller is used with both the main Alpha Delta DX-CC multiband dipole and a receive loop run around the yard to help phase out local noise sources on the lower bands.

I thought I blew up the MFJ-1026 by running legal limit too close to the receive loop because all I could hear was static, noise, high pitched whine, etc., so I took it out of line and put it on the shelf. Fast forward a couple of months and I purchased a W6LVP Magnetic Receive loop. During a temporary install of the mag loop, I noted the instructions said to only use the supplied 12v power supply and never use a switching power supply as it will inject noise into the RX signal. A light bulb when on and I put the MFJ-1026 back in line, powered by a simple 12v motorcycle battery. The RX was perfectly clean on the original RX loop and the noise canceller worked exactly as expected. So then I hooked it up into a linear power supply with the same result. The entire time it was "malfunctioning" was due to the switching power supply I had plugged it into.

Lesson learned: NEVER use a switching power supply to provide power to an amplified RX antenna!

<blockquote data-quote="Moleculo" data-source="post: 814771" data-attributes="member: 1">I recently tore down and remodeled my shack.&nbsp; When I put things back together, I repositioned just about everything, including eliminating a couple of unnecessary power supplies.&nbsp; During this process, I decided to power the MFJ-1026 Noise canceller to a small switching power supply.&nbsp; This noise canceller is used with both the main Alpha Delta DX-CC multiband dipole and a receive loop run around the yard to help phase out local noise sources on the lower bands.I thought I blew up the MFJ-1026 by running legal limit too close to the receive loop because all I could hear was static, noise, high pitched whine, etc., so I took it out of line and put it on the shelf.&nbsp; Fast forward a couple of months and I purchased a W6LVP Magnetic Receive loop.&nbsp; During a temporary install of the mag loop, I noted the instructions said to only use the supplied 12v power supply and never use a switching power supply as it will inject noise into the RX signal.&nbsp; A light bulb when on and I put the MFJ-1026 back in line, powered by a simple 12v motorcycle battery.&nbsp; The RX was perfectly clean on the original RX loop and the noise canceller worked exactly as expected.&nbsp; So then I hooked it up into a linear power supply with the same result.&nbsp; The entire time it was &quot;malfunctioning&quot; was due to the switching power supply I had plugged it into.&nbsp; Lesson learned:&nbsp; NEVER use a switching power supply to provide power to an amplified RX antenna!</blockquote>

[QUOTE="Moleculo, post: 814771, member: 1"] I recently tore down and remodeled my shack. When I put things back together, I repositioned just about everything, including eliminating a couple of unnecessary power supplies. During this process, I decided to power the MFJ-1026 Noise canceller to a small switching power supply. This noise canceller is used with both the main Alpha Delta DX-CC multiband dipole and a receive loop run around the yard to help phase out local noise sources on the lower bands. I thought I blew up the MFJ-1026 by running legal limit too close to the receive loop because all I could hear was static, noise, high pitched whine, etc., so I took it out of line and put it on the shelf. Fast forward a couple of months and I purchased a W6LVP Magnetic Receive loop. During a temporary install of the mag loop, I noted the instructions said to only use the supplied 12v power supply and never use a switching power supply as it will inject noise into the RX signal. A light bulb when on and I put the MFJ-1026 back in line, powered by a simple 12v motorcycle battery. The RX was perfectly clean on the original RX loop and the noise canceller worked exactly as expected. So then I hooked it up into a linear power supply with the same result. The entire time it was "malfunctioning" was due to the switching power supply I had plugged it into. Lesson learned: NEVER use a switching power supply to provide power to an amplified RX antenna! [/QUOTE]

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