[CQ-Contest] Poor transmit audio quality

[John WA2GO]

Is it my imagination, or has transmitted audio quality gotten significantly 
worse in recent years?

I would have thought that all the technological advances in radios would 
make transmitted audio quality better, but it seems to be getting worse. 
Could it be that "better quality" (albeit digital) receivers are less 
forgiving or somehow otherwise reproduce things more accurately, even if 
what they are reproducing includes harmonic distortion caused by significant 
overmodulation?

To say it in plain English:  I worked (or heard but didn't even bother 
working) a LOT of guys last weekend whose signals were PLENTY strong (and 
yes, a few weak ones too), but yet it was difficult or in some cases 
impossible to understand their callsigns - due to either severe overdrive, 
excessive compression, or both, even if the situation was not further 
exacerbated by an accent. I tried all kinds of filter settings, all filters 
off/wide open, no passband tuning, etc., and still no go. I said "sorry" to 
at least 3 or 4 callers that I simply could not comprehend, yet I could tell 
that I would be able to copy them perfectly if they turned their compression 
down. (I asked them to, but most apparently didn't understand. One turned it 
down enough for me to copy one more letter than I already had, but it wasn't 
worth blowing a great run when it wasn't a mult, so I let him go.)

To make matters even worse, some folks use their own personal phonetic 
alphabet instead of the standard one. That combined with massive distortion 
can make it extra-tough.

I wonder how many ops ever request honest audio reports during a contest. 
You can also do this before the contest, if you remember to keep the same 
exact settings. Some other great techniques are to have a friend record you 
(local on the low bands, far away on the high bands) and email you the .wav 
file , or to listen to yourself on a second rig (sans antenna or with 
appropriate RF Gain setting).

It's not safe to assume that if you are CQ'ing and getting answers, your 
audio is good. That just means it's good enough for people to understand 
you. (Or that they are able to read your call off a  packet spot - but don't 
even get me started on that one.  ;-)  It might actually be that if you made 
your audio even cleaner, you would get more answers and have an even better 
rate.

I have only addressed comprehension here so far. Another unfortunate 
consequence of overdrive and over-compression is splatter. To me, this is 
the ultimate offensive act in a phone contest. It's like driving down the 
highway straddling the dotted white line, taking up two lanes and not 
letting anybody else get by, and giving them all the finger if they get 
anywhere close by. When I hear a signal that is audible across 5 or 6 kHz 
(or more - gads!), I find myself wondering whether the op is doing it 
intentionally, or knowingly or just recklessly. I sit and listen for a few 
seconds, and if they aren't running fast and furious, I will almost always 
make it a point to work them (if I haven't already), and then politely say, 
"Hey, by the way, I'm not sure if you were aware of it or not, but I wanted 
to let you know that your signal is kind of wide - I think you might be 
hitting it a little hard - you are 20 over 9 on this frequency, but you are 
10 over down 2 kHz, and still above S/9 down 3 kHz"  or whatever the case 
may be. I have to say - every time I have done this, the op has appreciated 
it and has done something about it right away, which his neighbors on the 
band also appreciate profusely. (Sometimes I am one of them.)

I'd like to propose that for our next phone contest (and for each one after 
that as well, I mean why not?), we all remember to get an honest audio 
quality report, either from another operator over the air, or at least by 
listening to ourselves on a second rig. Gosh, I'm getting goosebumps 
already, fantasizing about all of the clean signals we'll all get to enjoy 
next phone contest!


For those of you who could use a bit more detail about how to achieve good 
audio quality (and I realize there may not be too many of you on this 
particular forum), you should start with reading the relevant section of 
your rig's manual again, then talk to other hams either locally or on the 
air (pick someone with good audio!), and ask them for a report and for some 
pointers. The general idea is to use the mic gain to keep the ALC within the 
allowable range (i.e., always below the threshold on the meter), and to use 
the minimum amount of compression needed to still produce full power - 
perhaps 5-10dB on peaks. Set the ALC first, with the compression off. Once 
that is set, turn the compression (or "processor") on and gradually bring it 
up while speaking in your normal operating voice. Watch your wattmeter as 
you speak. You will see the average power output increase slightly as you 
increase the compression. As soon as you get to a point where the average 
output stops increasing, stop turning up the compression. If your rig has a 
meter setting that shows how much compression you are getting, you will see 
it may hit 5-10dB on volume peaks. Don't forget to go back and check your 
ALC setting again now that you have added the compression. On some rigs, the 
two settings are very inter-related, so you may have to readjust one or both 
of them until you get it right. For example, as you increase the 
compression, you may need to turn down the mic gain to compensate, etc. This 
may vary, depending on how loudly you speak.  Once you have found the 
settings, write them down for future use so you don't have to do this 
exercise again. Also note that if you have a manually tuned-up rig, your 
mic-related settings could be slightly different from band to band;   
experiment some time to sure

I'll be looking forward to all that clean audio in SS phone!

73,

John
WA2GO