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SSB wideband carriers up and down 75M

Nov 1st 2019, 14:34

N4AOX

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
This noise is ruining enjoyment of 75M phone reception. It blanks out SSB qso's about 20db/S9. The carriers are spaced 25 KHz to 15 KHz. So far have tried computers off, lights off, Wireless off, remote wireless temp reading displays off, remote wireless security cameras off remote wireless printers off. Unhooking antenna makes the carriers go away, but also signal goes away. Rig is FT 891 with $20 Switcher Supply from Amazon. I am going to try a 12VDC battery next.
Nov 1st 2019, 15:19

W1VT

Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Yes, run a receiver off a battery. Then try flipping the main breaker as there are so many devices in a home these days. That $20 switcher is likely to be a problem. Proper filtering of power supplies adds to the cost/price.

Zak W1VT
ARRL Senior Lab Engineer
Nov 14th 2019, 00:03

N4AOX

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
You were correct. It was the switcher. Noise evaporated when replaced by battery. So, need a QST article on how to turn noisy switchers into linear massive iron and copper and pass transister pwr supply performance. Should be able to do it with enough chokes, caps, and shielding.

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