RF gain issue

K6JV

I have always had the RF gain at zero which would have the S meter at 5 with just the noise. Now I have to increase the RF gain to maximum to hear anything. Have I lost something in the front end of the receiver? It is a 6400 via Smartlink to a remote site.

Lasse SM5GLC

Do your S-meter still show S5? Are the s/w still show you are using the same antenna port as earlier? What does the SWR show when you transmit? I ask as this may help us to spot the problem.

/Lasse SM5GLC

K6JV

The SWR was fine and no the S meter showed S1 when the RF gain was all the way done. Suddenly now the radio is almost normal except the RF gain has no effect on the S meter reading.

KD0RC

That is proper operation - the RF Gain should not affect the S-meter reading. There is a section in the SmartSDR manual on adjusting the RF Gain. I find that I occasionally need to adjust it depending on band conditions and time of day.

Lasse SM5GLC

Just to add one thing, by altering the BW you will see different reading on the S-meter. Going from 3kHz down to 300 Hz will show almost a 2 s-unit drop (i.e. 10 dB). This is for noise only.

John KB4DU

The S meter displays the signal strength (all signals the selected bandwidth) , unlike a traditional radio that measures the agc in the if stage to drive the S meter. On any radio if changing the rf gain affects the S meter, the s meter is inaccurate.

Mike-VA3MW

K6JV

A few questions.

RFGain or AGC-T

What are the settings for both.

What bands?

What procedure are you using to adjust your AGC-T?

73, Mike

K6JV

HI Mike, whatever the issue was with the Maestro it fixed itself!

I use the published procedure to adjust AGC-T.

The issue was happening on all bands. The issue was that the S meter fell to S1 and the sensitivity of the receiver was way down. Adjusting the RF gain made the S meter go up and down.

The radio suddenly popped back to normal sensitivity and the S meter back to it's usual S5.

Weird🤬