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touch control problems

Nov 15th 2011, 01:09

K4XU

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I bought a new Samsung 22" LCD LED backlit monitor for my logging computer. It has a touch control for on/off - no power switch.
On 80m it will turn off and on with my CW keying down to about 30W. The antenna is 75 feet away.
No amount of decoupling on the video and power supply lines will change or cure it. I tried shielding with foil. It was somewhat effective but it has the tendency to put the controller in permanent 'touch' mode and locks it up. It has a snap-together case - no obvious way to open it.
Most of the monitors I've seen are going without real switch.
Has anyone been able to beat this system?

Dick
Nov 15th 2011, 03:18

AA6E

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Dick,

You may just have an ultra-sensitive LCD, but more likely (I think) you've got too much RF in the shack. So you might work on reducing that by using chokes (ununs) to reduce common-mode antenna currents (on the outside of the coax shield). Chokes at the antenna and near your shack might help. Making your antenna more balanced (symmetrical with regard to ground and nearby structures) might help also.

You need to be sure that you're using the right ferrite material. The common Type 43 is not the best at low frequencies, for example. Type 31 is better. You might take a look at K9YC's paper on RFI, Ferrites, etc. (PDF).

73 Martin AA6E
Dec 21st 2012, 00:09

W9RTK

Joined: Mar 21st 2012, 09:27
Total Topics: 0
Total Posts: 0
Dick,
Did you ever resolve your issue with the Samsung Touch control? And if so, what was the fix. I too have exactly the same issue with my Samsung TV.

Thanks,
Rudi

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