This is the place in this web page where common questions are answered. Below are a series of questions that have appeared over and over and a typical answer that is given. Some of the examples are provided by other hams and not by myself. I have included some that I get all the time form hams from all over the world with various degrees of expertise and years on the air. There is no such thing as a dumb question. I encourage anyone who has a technical tip or help, to please contact me and let me include them on this page. I really do not mind answering questions for others, but repeating them over and over, gets a little old. I will encourage all to first read this section of the page and make sure that someone else has not asked and had the same questions answered before. I acknowledge the help of Marty KA7GKN who provided many of the answers to these questions. Again if you have any question or an answer to a problem that you find would help other hams, please send them to me, and after I review them will post them here.
Q. Ok, I just listened to some amazing sounding stations and I was referred to this website. How do I get to sound like “what’s his name”?
A. This simple question has many layers of answers from over simplistic to extremely complicated. You must understand many of the fidelity stations you’re listening to have spent countless hours and dollars to achieve what you hear. The intent here is not to discourage you, rather keep your interest in perspective so you too in the future can sound like those you’ve heard. You have lots of work to do so if you’re ready let’s go!
Q. Ok I understand what you’re saying I have an average station, you know, a few dipoles, a vertical, a medium range rig like say, a Yaesu FT710, or another rig. I have the stock or a Heil mic. And of course the antenna tuner, no amp right now but someday. So what’s first?
A. Slow down, before you buy anything you must go through a learning cycle. This way you’ll understand what’s going on, realize your station limits, and determine your attainable audio goals. You have lots of required reading right now; some you might not understand at first. There is a completely different world of techy stuff and jargon you’re required to learn or at least be familiar with. Audio Jargon and Ham Jargon are not quite the same. Study this website, then go to other audio websites like NU9N, KC4PE, K6JRF to mention only three. Each one provides necessary information to help you avoid some of the frustration those before you, have encountered.
Q. Frustration? like what?
A. The list, can be endless but a few key areas are:
1. Equipment selection
2. Equipment installation [placement]
3. Proper cable routing and signal flow
4. Local interference like hum, rfi, ground loops, buzz, room noise.
5. Equipment settings [audio and radio]
Q. Ok, I get the idea, I’m ready, but I’m also over my head. Everyone I talk to tells me similar stuff yet it’s very different and confusing. Am I being flimflam'd?
A. Actually no! Just as you’ll get opinions and advice for a radio or antenna, you’ll find the same with audio. In the early years of this mode, there was a very steep learning curve, which also was expensive. Today, there are devices recognized that will provide you with the results you’re looking for. The good news is, the selection today is actually greater and even cheaper in cost than as recent as 2 years ago.
Some of the flim-flam you may be experiencing is due to those who have major dollars invested and they feel that unless you do exactly like them the process is a waste of time. I’m sure you have been through the same thing when asking about antennas. “ya need a 150’ tower and mono band antennas for each band” You settled for a dipole and for now you’re satisfied. The point here is to read the websites, listen to the various stations, take copious notes to see the pattern of equipment used with what radios. In fact, keep track of what the preferred radios for audio are. You will shortly see a pattern of equipment used.
Q. I don’t want the hassle of the “science experiment” of audio. I just want to sound good, better than I do now, you know what I mean?
A. I’ll try to help. You have one microphone, one radio, and all you want is to sound better, oh and quiet some room noise. I recommend you use the W2IHY 8 band EQ box with noise gate. It is a single box “plug and play”. The unit will interface with almost every radio and Ham microphone. You should not encounter any rfi problems unless your station is not set up correctly (which is a different topic in itself]. You will still require some on air assistance in adjusting the 8 band equalizer.
Q. I hear about “SPECTRA PLUS” what’s that all about?
A. This is computer programs essentially used as a spectrum analysis tool to graph your audio bandwidth and response. The graph can be very helpful in tailoring your audio adjustments to the anomalies in your voice and even in your Ham Shack. This is optional and there are many folks out there with the properly adjusted receivers and skill to help you. Most of the newer rigs have a display showing graphly what is on the bands and in some cases you can display your wave format. Many also allow for a remote monitor to attach to the rig via usb ports.
Q. I have lots of boxes a new mic, WOW! Can I have your settings, since you sound, as I want to?
A. My station set up is different, room noise is different, my voice is different, my microphone is different, and perhaps I even have a different radio than you... What works for me may not work for you. Each set up is unique period! This web site and others, have developed a “start-up” group of settings. Some of the websites discuss EQ settings, and other “box” settings that will get you into the ball park out of the box. Be aware, it may take you a while to find your “audio nirvana”. Patience is key here! As you listen to the “audio guys” you’ll notice some have never reached their unique sound and they constantly tweak the controls. This is just fine and is their approach to enjoying the hobby. Don’t fault them if they seem to avoid giving you specific settings. For every one not willing to help there are two eager to help. There are also many who do not have the skill or the capability to help so you can ask me.
Q. Hey what’s going on here? I listened to myself in the W2IHY box and I sounded great, then I listened in the radio monitor and I sounded Ok, then I had a signal report saying I sounded awful. What gives?
A. The secret answer here is “audio bandwidth”. When you listen to the W2IHY box, the monitor circuit is designed to “hear” the entire audio bandwidth of the equalizer. You hear full fidelity. When you listen to your audio via the radio monitor, most often the signal is tapped off from an “IF” circuit giving you a snapshot and not a true representation of your audio. Some folks have modified their monitor circuits to eliminate this occurrence. If you feed your W2IHY box or other audio directly into your microphone input, often the first stages of microphone amplifiers have frequency design limits, again some folks have changed the capacitor values in those circuits to expand the audio frequencies passed. Finally, your transmit audio is a product of your “IF” filters. The filters can vary from 250~2.4khz to 0-3.1khz or in some radios even wider or narrower. This is where your skill as a Ham operator comes into play. You need to understand your equipment and know its limits. If you have a radio with a bandwidth of say, 2.4khz you will not pass anything higher than 2.4khz even though you have a 3200hz setting at 16db on the W2IHY box! This is oversimplification but for now I’d rather not get into a technically complicated explanation.
Q. You have a nice fidelity SSB audio, but what I notice more is the fact you have such a quiet signal. How do you do that?
A. NOISE is defined as: any sound that is undesired. We audiophiles spend as much time dealing with “room noises as we do adjusting our audio boxes. Simply put, many of us have “tuned our ham shack rooms for minimal noise”. The actual room used for your Ham Radio Station is important. This room should be “anechoic “, which means void of echoes or reverberation. The best way to “tune the room” is to purchase a “SPL METER”
The meter will then help you determine the noise floor of the shack, specific equipment noise, and an average room noise your microphone is picking up. A typical recording studio will be quiet, 20-30 DbSPL. Learn how to use the SPL tester properly and measure the Ham shack, if it’s 50 DbSPL or less you have a reasonably quiet shack! Now how about the equipment? For example I have a small Mirage BD-38-G amp and the blower noise is 68 DbSPL. With my entire equipment running and a ceiling fan on high, I average a room noise of about 56-65 DbSPL. This measurement was taken at the location of my microphone. The microphone will process what it hears! I then adjust my “gating” to remove the room noise.
A key to a quiet room is equipment placement. Loud devices like power supplies, amplifiers, and even computers should be placed away from the microphone pick up range. If your Shack is noisy, avoid an omni directional mic”, rather use only “cardioid types” and you’ll notice less room noise transmitted. Another way to reduce background noise is to maintain the appropriate levels in your audio chain.
Average conversational audio is from 60-70 dBSPL so avoid shouting /yelling into the microphone.
Gating is a device/control that fully attenuates a signal, which falls below a predetermined threshold level. You use gating to remove the room noise. Proper adjustment is critical and often we overdo this setting. Also remember noise cancelling headphones may lesson the noise in your shack, but the noise will still come over the air to your listener. Many hams get that confused.
Q. RMS or PEAK values?
A. Most of the time your specs will reflect RMS levels. To review: 0 dBm is 1 milliwatt which equals 0.775 volts RMS across a 600 ohm circuit, and 0 dBV is 1 volt RMS. When we wish to evaluate the loudness of a signal as perceived by a human ear, the RMS value corresponds more closely with the sensitivity of our ears to audio energy. The exception is when we discuss the broadcast limiter. A momentary transient peak can cause over modulation and consequent signal splatter [spurious emissions], in this instance a peak detector/limiter is used [and not an RMS level] to address the signal.
Q. I’m confused, I hear everyone tossing around the term “Db this and Db that” What’s a Db?
A. Books are written about the “Db” so there is really no truly simple explanation, but I’ll try to make some sense of the use of “Db”in the fidelity SSB audio world The “Db” is a unit of audio measurement of sound pressure level [SPLI, signal level, and changes or differences in signal level. The decibel is a logarithmic [log] mathematical function that reduces large numeric values into smaller, more manageable numbers. STAY WITH ME! Decibel is calculated as being 10 times the log of the ratio of two powers and 20 times the log of the ratio of two voltages.
dBm= decibels referenced to 1 milliwatt
dBu -or- dBv= decibels referenced to 0.775 volt. [dBu is preferred]
dBV = decibels referenced to 1 volt
Keep in mind in the audio world we are looking at an impedance load of 600 ohms. So, 0.775v across 600 ohms equals 0 dBm. 1 volt across 1000 ohms equals 0 dBm some meters are calibrated in dBm so the meter indication is only accurate when across a 600 ohm load. Another unit of measurement is the dBu. This means 0 dBm= 0.775 volt across 600 ohms.
Relating dBV, dBu, and dBm to specifications:
In many products you see phono jack inputs and outputs rated in dBV [1 volt ref.] because that is the standard generally applied to such equipment. The XLR connector output level and some phone jack output levels [confusing huh?] are rated in dBm [1 milliwatt ref] or dBu [0.775 volt ref]
Typically, line level phono jack inputs and outputs are intended for use with high impedance equipment, which is basically sensitive to voltage rather than power. So, their nominal levels may be specified as “-10 dBV” This is the standard used in consumer grade audio equipment for many years! Typical line level XLR connector inputs and outputs are intended for use with low or high impedance equipment. Since older low impedance equipment was sensitive to power, XLR connector nominal levels were often specified as " +4dBm or + 8dBm". These levels are characteristic of sound reinforcement, recording, and broadcast equipment respectively.
Most newer Ham Radio’s utilize a 250 to 600 ohm microphone input impedance.
Finally, matching impedance is important for proper signal levels, controlling distortion, and equipment overload. A low impedance line output can be connected to a higher impedance input with minima! level change. But, if a high impedance output is connected to low impedance input that output may be somewhat overloaded and the frequency response may be adversely affected. In some cases, the equipment could also be damaged.
To truly understand the device specifications presented is in itself an amazing accomplishment. Most spec sheets are designed under specific parameters to advertise amazing results!!! Thus, sell more product [my opinion]. With that said, let me try approaching the Db from another angle.
* The Decibel is a technical term that describes the difference in amplitude between two signals.
*When a scale is specified, a DB can also refer to an absolute level.
* dBSPL is used to measure an absolute volume [sound pressure levels]
* The scale of your mixer's LED meter is marked in dBu [typically or selected to measure dBV ] which is a standard scale for measuring the amplitude of mic-level [or line-level] audio signals.
· Audio signal levels fall into three ranges:
1. speaker-level, 2. line-level, 3. mic-level
Mixers can work with line and mic levels. XLR connectors are usually designated mic-level and the TRS connectors are designated line-level. One of the mixer's functions is to bring the different signals into a roughly equal operating range. So, we have two signal levels, -10 dBV and +4 dBu that we have to work with:
If you take the output of a –l0 dBV piece of gear and patch it into something expecting a + 4 dBu level input, the sound may be too soft, even when turned all the way up. The reverse is also a problem, because the output of a +4 DBu device may cause distortion in the input of a device designed for –l0dBV level signal.
Some of our audio boxes can operate at either signal level by including a little switch near the input or output jacks marked “-10/+4”. Toggling the switch between these two positions calibrates that device’s inputs or outputs to conform to one or the other operating level standard. When possible, try to choose components that all use the same reference level-- all -10dB or all +4 dBu. Keep in mind -10 and +4 signals may be both referred or generically as “line level” signals even though the +4 level signals are of significantly higher amplitude.
Q I am looking at various cables in my junk box... .what shall I use for my audio gear?
A. NONE! You are using professional audio equipment in an RF enriched environment! This requires some planned cabling to avoid ground loops and rfi in the audio signal. I refer you to the “Short Primer On RF/RFI Grounding Techniques” report elsewhere in this website.
I strongly suggest you avoid using any of the bargain brand pre-made black audio cables in their plastic bags. Their if shielding is very poor and if you use any of them, you’ll get frustrated trying to hunt down where rfi is entering your audio. I know this from experience! If you must use cheaper brands for your source of wire let me recommend the following: 278-777 four conductor double shielded cable 30 feet per package, 42-2493 computer speaker cable 16 feet, 42-2492 computer speaker cable 8 foot. The computer cables above have dual shielding. I also recommend using a shielded AC power cord when possible. Be sure to verify you have the “shielded” cable since often the inventory is placed wrong! Also this power cord has the appropriate NEMA connector to fit AC powered ham and audio devices.
Aside from using double-shielded cables you really need to establish a cabling protocol for your shack. This means establishing a standard cable color code so later when you trouble shoot you will always know that red is tip or pin 2 of the XLR connector etc. You then should use when possible XLR connectors for audio, you’ll have better results in the long run.
Other cable options are “STARQUAD” This is a generic name and is offered by: Belden, Canare, Gepco, and Mogami. Bob Heil also offers an interesting audio cable called “Heil Wire” He will sell it on 20’ lengths.
Q. We can't easily get the type of audio transformer you show in the description of the Muft Box, here in this country. Will you get one for me and send it?
A. I am not in the business or position to get these transformers, but I can tell you where you can. Go to QRZ.com and search on W2IHY, yes the same one who makes the IHY audio equalizer. He can provide you with the transformers and just about any part you need to build the box or maybe a kit to do it all yourself.
Q. I have an Icom 746 and want to use it to produce great sounding audio like what I hear on 14.178. What secret filters or menus or both do I need to make this radio sound like the audio I hear.
A. The Icom 746 seems to be quite popular especially in Europe. As far as I know there are no filters or secret menus that will in themselves make you sound like the hams on 14.178. To modify this radio in any way internally is probably counterproductive. The radio can sound quite good in its present somewhat narrow band-pass. You can put any of the Pro audio boxes like an EQ in front of it and with a little work it will play quite well. But, if real high quality HI-FI audio is what you are after, you would be better off in my opinion getting a different radio with a wider band-pass like the Kenwood TS990.
Q. Why do I need a foam windscreen, and what does a foam windscreen do? My mic says it has a built in pop shield, what does this mean? How do I properly install a windscreen and does it ever need replacement?
A. Foam windscreens are actually not all the same! The foam is transparent to sound pressure waves, BUT acts like a labyrinth for high velocity wind or breath guests. WHAT????? When you speak into the microphone, you send pressure waves to the mic element. If pressure and/or velocity of the signal exceeds the design of the mic you'll get distortion, unwanted sounds, or even permanent damage to the microphone element.
The built in windscreen found in most microphones are designed to protect the diaphragm from high velocity air! You will still present popping, reverse breathing sounds [inhaling], noisy "S & T" sounds. The foam windscreen will attenuate this anomaly. You need to install a foam windscreen. To install the windscreen you should carefully slide it over the microphone, do not force it, you'll have a tight fit. I also suggest you do not butt the foam right up to the microphone screen. There should be at least 1/4" or 1/2" space between them. This is to provide additional protection and helps keep you a specific distance from the mic element.
You have seen studio shots of performers singing: and in front of them there is a round screen device [called a STOPPIT]. This is another type of windscreen and in addition this keeps the performer a specific distance from the mic element for maximum quality and reduction of the unwanted sounds.
Foam windscreen do deteriorate over time, and should be replaced oh, maybe every few years. Just as you should change your tooth brush after a cold the same holds true for the foam windscreen. the foam holds those nasty germs!
Q. Where can I purchase the mix-31 ferrite split bead and what will it cost?
A. You do have various sources for the mix-31 ferrite bead, DX Engineering, The Radio Works, and Mouser Electronics to name a few sources. The Mouser electronics part number for the 1/4" diameter bead is: 623- 0431164281 The cost per unit varies on quantity ordered, see page 639 of their catalog #622. for example the cost each is $2.18 and quantities of 10-50 is $1.81 and over 50 $1.50. I have found the prices at Mouser Electronics the best around. Other sources can charge from $2.50 to $3.18 each and no quantity price breaks. Refer to the specific vendor for other sizes of mix-31 split beads that they offer. Again Mouser electronics has the greater selection.
Q. I have been listening to various groups chatting about ... let’s call it fidelity SSB. I am not sure what all that means? I hear Hams talking about 0-3k, 80-3k, 100-3.1k, 100-4.k, and some way out to 6k. I also hear folks complaining, “you’re too wide!” “You’re splattering all over the band’s etc. I have a mid priced rig with no internal modifications and I have no clue what the hubbub is all about. Also, what is the proper bandwidth for the so called ‘ fidelity SSB”??? For that matter what is the proper bandwidth for DX audio”????
A. Now don’t get angry about my answer, I m trying to keep it in the viewpoint of a typical Amateur Radio station. Let me first answer your questions with another group of questions: What is the correct rf power output level we should use for rag chewing, DX, or contesting? What radio is the correct one for use when rag chewing, DX, and contesting? Finally, what antenna is the appropriate one to use for rag chewing, DX, and contesting? Do you notice a similarity to your original questions?
The FCC states in extremely broad terms [which is done on purpose] use the minimal whatever to accomplish your communication, also use good engineering practices. Then in the same breath experimentation and trying different things is encouraged throughout the Ham Community.
As you tune across the bands you II experience a myriad of operating techniques form those that WOW YOU to those that actually hurt your ears, are annoying, and fatiguing. You as the individual in charge and licensed to operate your station has to make some decisions as to what you want your station to present to those listening. Ah, another trite analogy. You drive through the neighborhood and look at the fronts of many homes, some are gorgeous, some look like early slum, and others look like a war zone or just plain. Just as our front yards represent our personality so does what we broadcast over Ham Radio. To make matters even more obscure is what is nice for one person is the opposite of another.
Now, I’ll address your questions:
1. DX audio in the purest definition is a very compressed stringent sound. It is void of almost all low frequencies and is designed to pierce through a pile up. The most typical example of a DX audio sound is with a HElL HC-4 mic element into a radio with the compressor [speech processor] full open. Of course, this is the extreme and there are variations to the concept.
2. Fidelity SSB audio in the most basic of descriptions is audio without excessive compression [speech processor, and a wider range of audio frequencies being transmitted. In other words, the lows, mids, and highs of conversational audio not typically heard in a DX type audio signal. Fidelity SSB audio is more pleasing to the ears, less fatiguing, and stuff you have heard and read before. Again, there is no set standard for Fidelity SSB audio. The range can go from 0-6khz and still be legal HUH? Yep, go listen to the AM Ham Stations they are 6khz wide with a carrier and are perfectly legal. Sideband came into the picture to eliminate the unwanted sideband and carrier to improve band use and operating. For some reason many folks are stuck in the position that SSB audio has to be without character and style and must all sound like a DX audio station. Thus the introduction of a sideband signal with personality. The audio is limited to the specifications of the radio being used. The newer high end rigs now even include transmit AND receive equalizers, so you can adjust the audio to your comfort zone, as with any good stereo radio.
The bandwidth used for fidelity audio is limited to the transmitter design and filters, either analog or DSP. The same holds true for the receiver, that’s how come you sometimes can’t hear what’s occurring when you hear someone say I’m boosting this 6db and your rig is essentially deaf. I’ll go out on a limb here and say the majority of Hams involved in this mode try to stay within a self-defined bandwidth of [approximately] 0-4k. Actually many of the rigs can hear 6k but only transmit up to 3.2k [+ 1-]. It’s truly difficult to give anything specific because of the many radios in use. The new TEN-TEC ORION, for example will transmit audio up to 3.9k! There are those that are indeed pushing the limits and go to 6k but they are the minority and not the norm! The is no rule in the FCC regulations that says you must not transmit in a bandwidth larger than 3K. That is just an old wives, or should I say old ham tail. Just do not interfere with an established QSO.
3. Splatter: This is another very technical topic and I have limited space here. I suggest you visit John’s NU9N website www.nu9n.com and read his section on “apologetics” Remember, most audio guys use top of the line equipment and have strong signals. Even a DX station with all knobs to the right will splatter! Another observation is when any rig has their noise blanker on there is a phenomenon that occurs and you hear more so called splatter. Simply, if you’re receiving within the transmitter’s bandpass your radio may demodulate the signal in addition to the one you want. The majority of radios used in fidelity SSB are not modified internally and meet the FCC’s acceptance! You will also experience “splatter” when tuned 1khz away from a strong DX station too.