Fast AGC....

[74IN]

Why?

SSB sounds better to me on slow, keeps the audio up out of the hash.

Is it a CW thing?

 

[W5LZ]

74IN,
I agree, SSB does sound better to me with either a slow or medium speed AGC. But other modes sound better, are easier to understand when using fast AGC. The only 'other' mode that comes to mind right this minute is CW, then again, it's only my first cup of coffee. A variable AGC is a tool. If varying the speed helps you, or whoever, to hear the signal better, great. If not, then leave it on slow or medium. It 'compensates' for a strong signal desensitizing a receiver (helps with AM too), sort of a super quick variable RF gain control. I'll bet that you've run into situations where a fast AGC would have been of benefit. I can't think of a good way to describe that, other than a sort of 'pulsing' of the receiver, which doesn't really tell you anything useful, does it. Oh well.
- 'Doc

 

[SR385]

Variable is where you would see how handy it is, the fast/slow of the older radios I never found all that useful. The 'slow' really isn't all that slow and the fast is generally too fast.

The case I really make use of the variable AGC on my TS-2000 is static crashes. I can use the speed of the AGC against the crashes, to slow it down so it won't respond so quickly and the stronger signals aren't disrupted as badly.

The case where fast benefits for SSB use is running a net as with faster AGC response you can hear the weaker signals in between the stronger noises/signals.

And as already mentioned, for digital modes, it's useful to run it on fast.

 

[74IN]

Variable would be cool, but my 706 has only fast and slow, and the 430 has no choice.

The 430 seems to be slow, the needle eases back.

 

[airplane1]

I been experamenting with the AGC speeds and it is cool how it works. I did not know what it was for till reading these posts and asking in another post.

I have fast, med and slow. I think I like the med the best and it does seem to act like a super fast RF gain.

 

[SR385]

I been experamenting with the AGC speeds and it is cool how it works. I did not know what it was for till reading these posts and asking in another post.

I have fast, med and slow. I think I like the med the best and it does seem to act like a super fast RF gain.

That's basically what it is, an automated RF gain. By slowing it down you keep it from being affected by quick peaking signals...e.g. static crashes. By speeding it up, it responds better to faster signal transitions...e.g. digi modes.

 

[cyclops1970]

As you may have discovered already, it depends on the mode and the type of interference. Modes with sharp rise times usually work best with the AGC set slow so the reciever doesn't "pump"...especially when the AGC attack time is lazy. Trying to copy CW with the AGC set to Fast gets me mentally tired after about 15 minutes.

Aggressive AGC is usually required during such times as static crashes or during Field Day, when a transmitter 30 feet away is knocking the crap out of your front end.