eSSB

Creating high quality eSSB signals is now within reach of most amateurs.  With the arrival of SDR transceivers from Flex Radio Systems, Apache Labs, and Expert Electronics, getting a 4-8KHz bandwidth signal on the air is now easy.  Far from the days of modified Kenwood 950SDX radios we can now just dial in the exact bandwidth we desire without modifying internal components and filters.

 

There is more to creating really great sounding eSSB than just running more bandwidth.  You will need a decent microphone.  You don't need a $3k Neuman, but you should look for a quality microphone that has good sound.  If you have a Shure SM58 it will work, just maybe more EQ and processing will be used.  I use an inexpensive Behringer B-1 Condenser or MXL BCD-1 (~$150 1/2022), others use the broadcast industry standard Electrovoice RE20 or Shure SM7.  If you can get your hands on different mics to try out and see what works for your voice would be ideal.  Each voice is unique and each mic is going to give a different "color" to that voice.  Something else to consider is the type of microphone.  A dynamic will help reduce some of the background noise from equipment and the room, while a condenser will get more of the room acoustics, it will pick up more equipment noise.  The dynamic usually has a warmer sound while the condensers are known to be brighter and give a little more presence.  The condenser will require a power source like the 48v phantom power supplied by a mixer, the dynamic may be able to be fed directly to the radio.

 

Behringer B-1 condenser with pop screen.

 

MXL BCD-1 end address dynamic.

Now that you have a mic you need a way to get that sound into the radio.  Some radios have a built in EQ for transmit that is sufficient to get an OK sound with a dynamic mic, but to really get great sounding audio you are going to need much more.  Don't let that stop you from starting with a dynamic mic into the rig and trying things out, just understand you aren't going to sound like the local AM broadcaster.

Let me just stop and point something out.  Sound is very much like taste, not everyone likes the same stuff.  It is very subjective, so expect to get varying reports on sound quality.

When you want to get that nice broadcast or better quality sound it's time to get outboard gear.  You are going to need noise gating, equalization, and compression at minimum.  This can be achieved with discreet rack components or with one of the new digital mixers.  The Behringer DEQ2496 is a popular choice that has many of the needed processors built into one unit.  You may still want other processors along wit this.  I use a Behringer X Air XR12.  These are based off the very popular Behringer X32 live sound console.  They work very much like a SDR mixing console, the unit only has a power switch, headphone volume, and wifi selector switch.  You run it from a tablet, PC, or android phone.  I find all my needs met in this one unit.  Mic pre, gate, EQ, and compression, along with a huge selection of digital processors that are modeled from some of the sound industries most popular equipment.  You are able to use 4 phantom powered XLR inputs and 8 line inputs to get mics, computer audio, and radios into the mixer. Two AUX outs to get audio from the mixer to radios, speakers, or computer inputs for recording.  Speaking of recording, the XR12 has a built in recorder that stores .WAV files right to a USB stick.  Of course, the XR12 also has the standard stereo XLR L/R output to run to the speakers.  I run my computer sound, radios, and mics all to the mixer.  That way I have the option of listening to any source on the headphones or speakers, or I can send one mix to the phones and a different to the speakers.  You can listen to computer sound in the phones while running VOX on the radio!

 

Behringer XR12 Mixer

X Air Edit software for X Air digital mixer.

 

So now you have a microphone and outboard gear to get that sweet sound to the rig.  Now you need a way to listen to what you sound like, and to hear what the other stations really sound like.

This is where things get very subjective.  Great sounding speakers and great sounding headphones are the only way to get accurate sound reproduction.  One of the most important things is accurate reproduction of the sound.  You can't adjust anything without a reference.  The speakers and/or headphones must be that reference.  I use ~$130 Klipsch Promedia 2.1 computer speakers and ~$40 Superlux HD-668B headphones.  These are budget level and do a great job for the money.  If you just need nice accurate sound without spending several hundred dollars, this fits the bill nicely.  If you have the money, it really is a sky's the limit game.

 

HD668B

 

So, now you have all this great sounding equipment and are ready to put out some RF.  Not, just yet!  You are going to need ferrite.  Get good snap on ferrites for every cable.  I mean that, power cords, mic cable, coax cable, every cable that goes into or out of each piece of equipment including power cable are possible RF paths that must have ferrite to stop RF from getting into everything.  I have some cables with two turns on two cores to get the RF stopped.  A current choke at the antenna is a very good idea as well.  Learn how to wind a 1:1 current choke on a toroid core to make a common mode choke and you will save yourself many headaches.  You may also need to go to line isolation transformers.  Jensen makes the best, but you may want to sit down when you check prices.  I currently do not have any isolation transformers in my setup running about 500w on a 75 inverted-V that is right above the shack 35 feet with all the audio and RF cables running in a mess together.  Results will vary from station to station.

I hope this little teaser gets someone to step into the world of eSSB and high quality sound. Catch you on the air!