Beyond personal preference there are extremes in setup and microphone use that can range from frustrating to outright illegal. I’ll describe a few of these that I witnessed recently and then describe what I consider to be good practice for effective communications.
The meek operator sets his mic gain low, doesn’t use any compression (processor) and speaks softly; he’s running 100 watts but is only really using 25 watts at best. I heard a fellow in the South Pacific who fit this class; his signal was clear but right at the noise level making him hard to copy. He would end a QSO and several stations would try to work him but when he came back to one several would try again because it was hard to tell who he came back to. He would then get a little ticked and speak up asking for everybody to stand by except for whatever station he wanted to work – during this time his signal was strong and clear, 5-9, armchair copy but then he would fade back into a whisper and back down to S-3 or less. His operation is certainly legal but very frustrating to the folks trying to work him and of course to him as well as he is causing the confusion that is causing him to have to tell people to stand by.
Next is the guy who is splattering 5+kcs in all directions, he sounds fine if you tune to his frequency and he always seems to be parked next to that rare DX or the net operation you’re trying to work. His operation is illegal but he will not listen to anybody because he is convinced he knows what he’s doing and his equipment and operation is not at fault. If you try to tell him that he is splattering he will tell you it’s your receiver and how it just can’t handle his powerful signal. He will sometimes ask the guy he’s working if his signal sounds ok and of course his signal sounds OK on frequency. What he should be asking is for his friend to tune up and down 3kcs and make sure he isn’t splattering but this rarely, if ever, happens. Often this guy is also running excessive power as the guy he’s working just told him he’s thirty over, which is most likely illegal since the FCC rules tell us to run the minimum amount of power needed for communication.
Another is the guy with tons of background noise. Maybe it’s the sound of fans running on high, other radios or maybe it’s just the general noise and echoes from the room he’s in. His signal is pretty good but the noise is as loud as his voice and although his operation is technically legal it makes for tiresome listening. Sometimes this guy is splattering as well which means all of that background noise is splattering too.
So then what do I consider to be correct practice?
Let’s start with the source, the voice itself. You should speak in a consistent, moderately loud voice as if you are speaking to somebody across the room and what you are saying is important.
Secondly, you should be using a communications microphone. I know there are at least two groups of people that disagree with this, the AM folks and those who wanted to be news anchors and are now trying to sound like one on SSB, but the purpose of Amateur Radio is communications not glamour. That being said I will give them a general pass since for the most part they hang out on the same frequencies and have pretty good signals, but definitely not all of them. One problem with using a studio microphone (and I own a recording studio so I have many of these) is that they are broadband and pick up all audio frequencies including those outside of the range permissible in amateur radio; they also don’t have noise cancelling characteristics that are built into many communications microphones so they pickup more background noise than a communications mic. Studio microphones were designed to be used in studios, so unless your station is setup in a nice quiet (no fans), echo free vocal booth don’t waste your money on the wrong type of mic.
Now that you have the right mic, speak into the mic. Don’t hold it a foot from your mouth or sit it on the desk and talk from across the room. The mic should be held to the side of your mouth, nearly touching your lips. The reason you hold it to the side is to prevent your breath from hitting it directly. There are two reasons it needs to be close, first is to prevent it from picking up background noise and the second is for consistency. If you hold it 2 inches away now and 8 inches away the next time there will be a 12dB difference in level, that’s 2 S-units.
Processing: First the legality, the use of any form of echo, reverb, delay, or time based audio processing is illegal on Amateur and CB radio. Also, EQ or the equalizer should be used with extreme caution; remember your SSB signal is limited to a small bandwidth of about 2.8kcs. Also, unless you are singing bass even a deep voice has no content below about 125Hz. So the realistic range for communications is approximately 250-3000Hz. For the most part EQ should be avoided, for example, I don’t have a deep speaking voice but trying to compensate with EQ will not change that but it can introduce odd artifacts that waste power and can even cause interference. Choosing the right microphone will give much better results than trying to compensate for the wrong one with EQ so I suggest that as the primary path if you don’t like what you sound like.
Now for the processing that should be used. First, or actually last in the chain, almost all SSB transmitters have ALC built in which is a good thing. Ten Tec advertises their ALC light as the easy way to know you are hitting the ALC at a good level, if your rig doesn’t have a light it probably has a meter, in which case you should refer to the manual on how to set your level, but even if it doesn’t have either a light or meter you can tell where you stand by using an external power meter – the one built into your tuner is fine and I will describe how to read it a little later.
Compression should always be used; I know there are those that think that processor button should only be used those rare times when you need a little boost but in reality the only times it shouldn’t be turned on is when you are not operating SSB voice mode (digital modes for example) or when you are using an external processor. If you have ever listened to commercial broadcasts of any kind (TV radio, news, DJ etc.) they all use speech compression and probably more than you realize. Now how much processing (compression) is a matter of personal preference. I tend to go fairly heavy because I don’t care if my voice sounds processed I want to be heard clearly but there are those who don’t like the way it sounds a go much lighter trying to find the point where they don’t sound processed but they still have a consistent signal. When standard processing is overdone it can make a signal harder to copy because it wipes out articulation and inflection and levels all sounds (including background noise and breathing) which is why off and on air testing is important. The next step up is the RF Clipper, which works by converting the signal to RF, clipping the peaks, filtering it for proper bandwidth and then converting it back to audio. This is my tool of choice and once setup properly makes a signal much easier to copy under marginal conditions.
Testing and Adjustment
If you don’t have a dummy load you should get one, it is really not right to cause noise and/or interference while setting up your station. It also helps to have a second receiver and portable shortwave radio with a BFO and wide filters and the ability to record the output can be very helpful. Having a computer with an audio spectrum analyzer is also handy, Digipan software can be used if you don’t have any other options. In my case I used the spectral display in Adobe Audition (recording software).
OK let’s get started with your rig hooked up to your power meter and dummy load, if you own an amplifier leave it turned off and you might even want to bypass it completely. Set your mic gain to about 12 O’clock and your power output at full, processor off for now and match the frequency on your rig and receiver. Transmit a few words and fine tune the receiver (headphones are helpful to avoid feedback) so your voice comes back at the same pitch as it normally is. Now say a few words while watching the power meter and note the peak reading and how it is moving. Setup your receiver to record or feed it into your computer with digipan running and transmit a few words noting the bandwidth of the signal that shows up on the water fall display on digipan or your software. There should be nothing below about 150 Hz and nothing above 3000Hz. If you are using a ssb/ham receiver that doesn’t have wide filters you will need to do another test by tuning 3kcs up and making sure your signal is not heard and then tuning down 3kcs and making sure it’s not heard there either.
Now turn on the processor and set the processing control at 12 O’clock and perform the same test again. This time the power meter should move around less but the peaks should be about the same, in other words the average power should be higher. The bandwidth of your signal should still be about the same. Now with the output of the receiver being recorded try transmitting with the processor set to 10 O’clock, 12 O’clock and 2 O’clock – it helps to say where it’s set then say the same thing at each setting, for example “this is with the processor set at ten O’clock this is November Yankee Four Juliet Bravo Testing Five Nine Five Nine at Ten O’clock.” Listen to the recording and decide if you think any of these settings sounds too processed. Then do some more tests to fine tune the setting, for example if you didn’t the 2 O’clock setting was too much repeat the test using 2, 3 and 4 O’clock. Or if 2 was too much repeat using 12, 1 and 2. If you are using an external processor the methodology is the same but you may have more adjustments to try.
Once you find the setting you like best it’s time to set the mic gain. In this step you make sure you’re getting the most out without splattering. Remember we are still using the dummy load, now watch the power meter and transmit while adjusting the mic gain. What you are looking for is the exact point where the peaks on the power meter stop getting higher as you turn up the gain. The first time you do this it will take a few tries and it’s generally better to set the gain slightly low (peaks at say 90 watts) rather than slightly high (peaks at 100 watts but splattering). Now run the receive test and check your bandwidth again, if there’s anything outside the 150-3000Hz range you are overdriving something and need to go back and reduce gain.
The final test is on the air, ideally recording your local receiver and having friends check above/below your signal for splattering (or using internet receivers), and making sure you are not getting RF into your audio. If it all tests are good you are ready to go but remember to recheck often. You may get the occasional comment that you’re over-processing which you should take seriously but think about who it’s coming from, if there signal is of the meek variety they might consider any audible processing as a bad thing, they also might have their RF gain turned all the way up which will add another layer of compression to your signal, etc. so take the comment seriously but solicit reports from others as well. Now, if you are told you are splattering take that report very seriously and retest with the dummy load, reduce your mic gain, Etc.