COMP strangeness

W1RE

I'm having some strange Comp issues. I see others are reporting there's a delay but I am not sure if this is that issue or a different issue. Basics: Running a 6700, SSDR V 1.0. Mic is Heil PR40, w/AMP tube MP pre-AMP. Input is front MIC using foot switch to control PTT. Voice setting has BIAS +20 dB OFF First I adjusted the audio mic gain with COMP off for max -1 dB. Then I slide the COMP slider all the way to the left and enable COMP. Now engage PTT and move the Comp slider ever so slightly to the right (maybe of the way to 1/10 to the right). The Compression meter show RED extending all the way to the right Max but *nothing* on the 1/4 of the of the meter (left most quadrant is unlit)? It almost looks like the meter is registering right to left, but I know that's not the way it's suppose to work. Could this be due to the erratic Comp others are reporting when PTT is too soon after adjusting compression settings, or is something else going on here? Thanks, - Bob, W1RE

Ken - NM9P

The compression meter registers from right to left. 0 dB compression is on the right and 25 dB compression is on the left. With my 6500 and PR22 I get about 5-10 dB compression with the compression control at 10.

W1RE

Thank you Ken. In all my previous (analog) radio experience the compression meters registers left to right with increasing compression. Add to that the legend on the Compression meter SEEMS to indicate - 25 dB to 0 dB. Finally all the other meter indicators also register left to right movement. Thus my confusion which I sincerely appreciate your helping clear up. - Bob

K4EAR

I suggested and love the opposite movement for the level and compression, along with the sticky bar for peaks, and think this should be expanded on in a future release with sticky bars for more graphing, aka the rf power, swr, with timing constants in mind.

Dale KB5VE

I agree the bar is neat. I would really like to have the db reading in digital for compression or the markings better. I like to be able to put back to previous setting.

Ken - NM9P

I would like to see the RF Power meter do peak & average like the mike level meters does. That is really neat. I have also suggested 5 dB tic marks on the compression meter. They wouldn't even need to label them, just put blue marks across the scale between the two lines that bracket the moving red meter. They could do the same with the mike level meter.

Michael - N5TGL

In my experience with pro audio gear (recording studios, etc) the meters that display the amount of compression always move from right to left with increasing compression. It's showing the reduction in signal being applied. IMHO, it's the correct way to do it.

Tim - W4TME

This is a great conversation that's separate from the main topic, so I created a new idea topic to continue the discussion. Please reference the new topic here: Peak Hold on other bar meters

W1RE

Thanks to everyone who responded. It turns out the SSDR software is working perfectly and it was my understanding how it is supposed to work that was to blame. Coming from a background of only analog HF radios (Kenwood, Yaesu) all of which had compression metering with left to right deflection combined with my confusion of the Compression meter scale being 0 to -25 dB threw me off. Thinking about it some more, compression reduces the 'volume' of the dynamic range, so it makes sense then that increased compression is a larger negative number, but originally that wasn't obvious to me. I had scanned the SSDR Software Manual only for the first time yesterday and unfortunately the section I read didn't provide me a full understanding of how all this is supposed to work. It would be great if an illustration of compression registering right to left was shown and making that point clear. The metering area is illustrated, but there is no compression indicated, so it's not as clear as it could be. After reading the entire manual beginning to end, combined with the replies from those in this community it makes perfect sense now. Please feel free to change this post from Problem to Question. Tnx + 73, - Bob

Andrew O'Brien

Ah, right to left for the compression meter. I would never have noticed that. The fact that the meter shows red is nothing to be concerned about then ?

KD0RC

Hi Andy, Correct, the compression indicator bar is red, and that does not signify anything.

On the other hand, if the peak indicator goes red, your mic gain (or DAX level for digital modes) is too high. The little peak indicator should go to -5 to -10 dB on peaks and never go into the red. The Flex radios have a very clean RF output provided the audio peaks are kept below 0 dB.