Re: 4S-Tuner SWR Red LED


Don, W9EBK
 

I'm at work so I don't have time to look at the schematic but from the description it sounds like the current limiting resistance on the Red L.E.D, or the cutoff current of that L.E.D, is too low.  L.E.D.s are usually 20mA, 40mA, or 60mA for maximum brightness,  but the cutoff varies depending on the L.E.D.  If someone wants to do a bit of experimenting, the fix might be as simple as swapping out the Red L.E.D for one of a higher maximum current rating so it cuts off at the signal level of a low SWR.  If there is a resistor in series with that L.E.D then a larger resistor might do the job.

If I get some time tonight I'll take a look at the schematic. 

Don, W9EBK 


On Wed, Mar 3, 2021, 9:29 AM Adam Allen <adamallen@...> wrote:
I have a similar issue.  I can get the green LED to full brightness, but at best (even at almost 1:1 SWR according to other gauges) the red only gets dimmer.  It doesn’t turn off or even “fully” dim. I’ve learned to live with it but if there’s a fix floating around I’m interested. 





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