DSP Settings

Adjusting Your Rig’s DSP Settings

Modern Amateur Radio transceivers offer a wide variety of features that may include DSP-based adjustments for your SSB audio. Follow this guide for simple instructions on how to get your rig set up so that you sound great on the air.

Before you can set up your rig, you need to think about what you are trying to accomplish. Do you work lots of DX and contests, or do you like to hang out on 75 meters and have long ragchews with local buddies? Do you have a wide range “studio” or “broadcast” microphone, or perhaps one of Heil Sound’s high-articulation microphones using the HC-4 or HC-5 elements? These are important factors to consider. . .

Wide-range microphones can sound great, but when applied on SSB as a general rule you may want (A) to add some high-frequency (treble) response to brighten up the pattern, and (B) to roll off some low-frequency energy (bass) particularly if you do DX and contest work.

The Heil Sound GM-4/GM-5 microphones, Pro Set 4/5 and similar boom sets, and other such mics using built-in enhancement of treble and roll-off of bass may not need any adjustment on the high-frequency side for local rag-chewing; however, depending on your voice and the degree of fidelity desired, you may want to add some bass response for local work.

Testing Your SSB Audio

The “Monitor” circuit provided on your rig is very unreliable as a way of evaluating your station’s audio characteristics. The bandwidth in which you’re listening probably is restricted, so you might make adjustments that over-compensate for this, leaving you with too much treble, too much bass, or both! Also, you don’t have the benefit of hearing all the net effects of AGC, etc., like other stations’ receivers, are employing. It’s much better to listen in a separate receiver because that is the only way you can get a “real-world” appraisal of your audio passband characteristics.

The first step is to disconnect the antenna on your monitor receiver. You may need to shove a very short piece of wire (an unfolded paper clip, for example) into the antenna jack, depending on the shielding of your transmitter’s dummy load. The objective is to listen to a signal at a level of about “S7” on the monitor receiver’s S-meter.

The next step is to turn off the Noise Blanker and any DSP Noise Reduction systems, as well as any DSP bandwidth or shaping features “such as Yaesu’s “Contour” control). The Noise Blanker will hopelessly distort your signal, by its nature, and the DSP features will perturb the received envelope, and you’ll never know what your signal truly sounds like.

Finally, if you have the ability to select the SSB bandwidth of the monitor receiver, set it as wide as possible. Use 2.4 kHz if that’s all you have, but 2.8 kHz, 3.1 kHz, or even 6 kHz will be better. Remember: you’re listening in a QRM-free environment, trying to hear all aspects of your signal. A narrow receiver bandwidth impairs your ability to get the full picture.

Now connect your headphones to the monitor receiver. Don’t even try to listen to yourself using a speaker—feedback does not help you optimize your signal.

DSP Setting Example: Icom 746/756 “Pro” Series, IC-7700/7800

Press SET > LEVEL, then scroll up to SSB TX Tone (Bass); rotate the main tuning dial to set the Bass to -2 for starters (-4 if using the PR-40 or similar mic with lots of bass response). Now press the down arrow to select SSB TX Tone (Treble), and rotate the main tuning dial to set it to +5.

Now set the transmit bandwidth (either with compression on or off) to Wide, and transmit while you listen to yourself in the monitor receiver. Depending on the mic you’re using, you may want to adjust either the Treble or Bass to get the kind of sound you’re looking for in the “Wide” bandwidth, which you’ll use for high-fidelity operating (rag-chews, etc.). Once you get the “Wide” bandwidth set, press and hold in the COMP key to try the “MID” bandwidth, then the “NAR” bandwidth. Odds are that, once you have “WIDE” set OK, the other two will be fine.

When you have the speech processor engaged (“COMP ON”), set the compression level for about 5 dB of compression on voice peaks.

DSP Setting Example: Icom IC-706 Series

Menu Q4 (or Q6, depending on the version of 706) gives you the ability to shift the filter passband, much like “IF Shift” on receive. For more bass roll-off, set this menu item to +150 to +200; to add bass (if using a mic with the HC-4 element, for example), set it to -150 to -200.

DSP Setting Example: Kenwood TS870

Set Menu #29 (Bandwidth) to 3000 Hz; set Menu #30 (Bandshift) to 100 to roll off some Bass response, and set Menu #31 (TX EQ) to H for DX work, or leave it at C for local rag-chewing.

DSP Setting Example: Kenwood TS2000 or TS 590

TS 2000Set Menu #21 (TX EQ) to H for DX work, or leave it at C for local rag-chewing; set Menu #22 (Bandwidth) to 3000 Hz.

TS 590 Menu 25 and 26 Bandwidth. Set to 3000

Menu 30 is the EQ.

DSP Setting Example: Kenwood TS570

Set Menu #13 (Bandwidth) to 2.4 kHz, and Menu #14 (TX EQ High Boost) to H for most applications.

DSP Setting Example: Yaesu FT-1000MP Series (including Mk-V/Field)

Start with Menu 4-4 (TR EDSP) set to off. Set Menu 5-9 (TFIL) to 6.0; set Menu 7-7 (SSB-t option) to 100-3100 Hz for fidelity, 300-3100 Hz for DX work. Leave Menu 8-9 to factory defaults for starters.

Listen to yourself in the monitor receiver while transmitting; you may now try Menu 4-4’s options. Option 3 frequently sounds the best, but each option does different things to different voices. With mics based on the HC-4 and HC-5, setting Menu 7-7 (SSB-t) to 100-3100 and Menu 4-4 Off will generally be all you need to do.

DSP Setting Example: Yaesu FT-100

Start with Menu #16 (Mic EQ) Off. Set Menu #64 and 65 (TX Carrier Shift) to +.05 to +.10.

DSP Setting Example: Yaesu FT-450

Set Menu #65 and 66 (TX Carrier Shift) to +200 for DX work; leave at default (0) or +100 for local work. Set the TX Equalizer to 2 for local rag-chews, 9 for DX work (1 is also good), and use the “4” setting when using mics with the HC-4 element.

On the GM-4 and GM-5, use only the “Narrow” element, as the “Wide” element has too much bass response for this rig.

DSP Setting Example: Yaesu FT-920

Set Menu 51 (Equalizer) to 1 or 2 for DX work, 3 (best) or 4 for local rag-chews. Or leave it off. Set Menu #59 and #62 (Carrier Shift) to +50, and Menu #60 and #63 (Carrier Shift with Processor On) to +150.

DSP Setting Example: Yaesu FT-950/2000 and FTdx9000 Series

These rigs use a three-band parametric equalizer system. In each of the audio “bands” (low, mid, and high-frequency areas), you can set the center frequency, amplitude, and bandwidth of equalization. Generally, the modulators of these rigs want you to roll off bass and enhance treble.

The menu numbers vary from radio to radio and are not even consistent within the vintage of the FTdx9000, so follow these guidelines according to function.

Set EQ1 Frequency to 200 Hz, EQ1 Level to -10, and EQ1 Bandwidth to 1. Set EQ2 Frequency to 900 Hz, EQ2 Level to -10, and EQ3 Bandwidth to 2. Set EQ3 Frequency to 2100 Hz, EQ2 Level to +10, and EQ3 Bandwidth to 2. Use the same settings for the “Processor On” menu items.

Set the SSB TX Bandwidth to 200-2800 Hz for high-fidelity rag-chews, or to 400-2600 Hz for DX work.

The speech processors of these rigs are very touchy. You may find it easier to get additional talk power, without distortion, by leaving the processor off and utilizing the 400-2600 Hz transmit bandwidth, perhaps with a little additional mic gain thrown in. Listen on your monitor receiver to be sure the audio quality is what you are trying to achieve.

Note that the mics and boom sets using the HC-5 elements (GM-5, Pro Set 5, etc.) are particularly well suited for these rigs, and particularly so in the case of the FT-950.

When using the PR 781 microphone with the FT-950, we recommend you set Menu #65 and #66 (Carrier Shift) to +200 Hz to remove some of the bass response.

All Things Yaesu

INITIAL SETTING OF YAESU Parametric EQ and HEIL PR Microphones

First, you need to set the transmit bandwidth. Try 200 – 2800 first. This will roll off some of the low-frequency response. You may be able to adjust to 100 as long as it doesn’t overload and sound too bassy.
Press the Menu and rotate the SELECT knob so it reads “TX BPF” (Transmit Band Pass Filter). Turn the Clarify/VFO knob to set this bandwidth of 2-28 (200-2800). ALWAYS remember to hold the MENU button for about 3 seconds to save any of these needed items.

Now we move onto the Parametric. A Parametric EQ is just as the term implies. You can adjust the parameters of the microphone audio. You do not need 8, 10 15, or a 31 band EQ when we are only dealing with a 3,000 Hz wide signal. A Parametric EQ usually has only 3 filters. If you have more than three frequencies which need ‘attention’ you have more problems than an equalizer is going to fix! Wrong microphone, not addressing (speaking into) the microphone correctly, too far away from the microphone, too much room echo and a host of other situations. With parametric EQ you can change the parameters of the EQ system. You can adjust the frequency, the bandwidth and tell those parameters to either notch (-) or boost (+).With normal two or three band equalizers, the frequencies are set and fixed by the design engineer of the radio. You only have control to either cut or boost the filter frequency they build into the transmitter.

The first thing to set is the frequency that you need to affect. There will be three important frequencies to attend to. Low end, Mid Range, and Highs. For most, roll off the low end by setting the first filter at 200 Hz. You then will tell the filter to roll that off or notch that 200 Hz. Do you want some big boomy low end? Boost it with that adjustment but it is best to reduce (notch) that low end a bit for cleaner and clearer audio.

The second adjustment is the Bandwidth which is set in the traditional audio nomenclature of octaves. In the amateur radio field, we aren’t dealing with music material but the adjustment affects voice the same way. If you set this first filter frequency to 200Hz. and have the parametric ‘Bandwidth’ control set to a wider setting (say 10), the filter will encompass the audio frequencies from about 100 Hz to 400 Hz. If you set the Bandwidth control of the Parametric to 1 or 2, the notch or boost you have set will only affect about 150 to 250 Hz. If affects just a small ‘slice’ of the audio if the bandwidth is set to a narrow number or setting. You would want to start by keeping that bandwidth to the halfway point.

The third control of the filter is either – or +. Notch or Boost. If you want to cut some low end, you notch -20 dB at 100 Hz. You want to boost that frequency, you adjust it to + 10dB. We have explained one filter. There are three and that is all you will need to make your transmitter sound terrific. You simply select the needed frequency, boost or notch that frequency and set the bandwidth as to how wide you need to affect. You can listen through headphones through the monitor but I have always found it better to listen through headphones through a second receiver while transmitting into a dummy load. You then know exactly how you sound to the outside world.

Let’s get started!

Press the (PROC) button momentarily so MIC EQ shows up on the display. This HAS to be shown as it turns the parametric EQ on.

There are three audio filters that you can change their PARAMETERS (thus ‘Parametric’ EQ). You set the frequency of the filter. You then set the Bandwidth of that filter and finally, you tell the filter if is notches (cuts, reduces) or boosts that filter frequency.

Using the Heil Sound wide frequency range microphones such as the PR 781, PR 30 or PR 40 you will want to roll off the low end as the preamp of the 950 does not handle a lot of bass response.

YOU have to make the final decision by listening to your own signal. No one else can make the adjustments. You are the station engineer.

Here are the menu assignments for the FT 950

These assignment Menu numbers are different for the other Yaesu rigs but the level settings are the same. Check with your Owners Manual for the menu numbers for your particular transmitter. These menu assignment numbers change – rig to rig.

Set filter one to 200 Hz. Menu 091 Frequency
CUT that filter -15 dB Menu 092 Notch or Boost
Bandwidth of 5 Menu 093 Bandwidth
Second Filter 900 Hz Menu 094 Frequency
CUT -6 dB Menu 095 Notch or Boost
Bandwidth Q 5 Menu 096 Bandwidth
Third filter 2400 Hz Menu 097 Frequency
BOOST + 8 dB Menu 098 Boost
Bandwidth 5 Menu 099 Bandwidth


NOW – DO NOT FORGET TO SAVE these by holding the menu button for 3 seconds. If you don’t do that, all of these settings go back to zero. Save your settings each time.

Now, I am not telling you that this is the end all. Since I can’t actually HEAR your transmitted signal, these are just starting points. We have notched some low end out by setting the transmit bandwidth in the beginning then with the EQ, we reduced some low end (menu 091) and this is always a major problem. Sometimes, you will have too much low-end audio from the microphone that actually overloads the mic preamp and ‘sounds’ like RF but it may not be. It is clipping the mic preamp.

The first low-frequency filter removes all of that low-end bass that destroys so many signals. They have lots of bass, no mids, no articulate highs so they end up sounding like mush. The mid frequency is very important. There is usually some craziness that happens around 400 Hz. That is usually notched a bit but there are voices that need some energy around 1000Hz attended to and you just have to make that decision by listening and select the midrange parameters. The all-important issue is the third filter where you achieve speech articulation. SO SO important and this + 8 dB boost at 2400 – 3000 HZ is the good starting point for that. The most important thing is to achieve a nice balance of lows, articulate mids, and crisp highs. So many times I hear stations with so much low end you can’t understand what they are saying because they have not achieved good mid-range speech articulation.


All of the new Yaesu series 9000, 5000,2000 3000, 1200 and the FT 950 have a balanced audio input on the audio board but Yaesu does not use it. They unbalance that 8 pin round mic connector input with their typical Pin 8, pin 7 connections. Sad.

The Heil cable CC-1 XLR-BAL (with an ORANGE, not traditional Yellow boot for early models) connects our balanced output microphone into the balanced input and will help reduce any RFI issues.

For best results please consult your manual.

DSP and Carrier Point Settings

Yaesu has, since the 1980s, provided means for adjusting the carrier insertion point (identical to “IF SHIFT” used on receive, only this is on your transmitted signal). This allows the operator to roll off lows, or roll-off highs, to change the articulation or bass response of your voice wave-form.
Beginning with the FT-1000MP, DSP settings were added to many rigs, allowing the transmit bandwidth to be varied, and additionally, it was possible to perturb the envelope to do things like peaking both high and low while putting a null in the center of the transmitted passband, etc.
It is impossible for us at Heil Sound to know what settings will sound “best” on your voice, in your station environment, with your microphone, for your interest (DX, Contest work, rag-chewing, or maximum fidelity) The recommendations below are just starting points; listen to yourself in a separate receiver (with its antenna disconnected) to determine what sounds best in your unique situation
FT-2000/3000/5000/FTdx9000 FT 950, FT 3000, FT 1200

All of the late model Yaesu starting with the FT 9000 all the way through the FT 1200 use the same Parametric EQ and mic preamp boards. The suggested level settings will be the same but the actual menu assignment labels are different.
EQ1: -6 dB at 200 Hz, Bandwidth of 2 (set to -10 dB if using PR 40 and you get Reports of too much bass).
EQ2: -6 dB at 900 Hz, Bandwidth of 2.
EQ3: +6 dB at 2400 Hz, Bandwidth of 2. Set to +10 dB for DX/Contest work.
SSB TX BW: Set to 400-2600 Hz for DX/Contest work, 300-2700 Hz for everyday operation, 100-2900 Hz for more fidelity. Note that power output meter will show “lower” power as bandwidth is increased; this is normal, reflecting lower power density per Hertz of passband.
FT-1000MP Series (including Mk-V and Field)
Menu 5-9: 6.0
Menu 7-7: Set “SSB-T” to 300-3100 Hz for DX/Contest, 100-3100 Hz for more fidelity.
Menu 4-4: Set to “OFF” while setting Menu 7-7 to your liking, then try each selection (“1” through “4”) while listening in a separate receiver to see if any of these improve your voice signal’s characteristics. Oftentimes “OFF” is best.
Menu 8-9: Generally, you don’t need to touch this one. However, the settings are identical, in principle, to those found in the discussion below for the FT- 920. Try them while listening on a separate receiver.
Speech Processor: Don’t be afraid to use it; the audio quality is excellent for most applications.

Menu 42: On (this engages the “Extended” Menu).
Menu 92: +5 to +10 to start, +15 for DX/Contest work.
Menu 93: -5 to -10 to start, -15 for DX/Contest work.
Note: The ideal setting may differ between USB and LSB, depending on other alignments in the rig. The LSB settings are “inverted” from USB, so a setting of -10 on LSB and +10 on USB should sound the same.

FT 857 D FT 817
Menu 46 DSP High Pass filter Default at 100. Set that to 200 to 300 on the low end

Menu 48 DSP Mic Equalizer
To set up the DSP Microphone Equalizer feature:

1 Press and hold in the [DSP] key for one second. This instantly activates Menu Mode No-048 [DSP MIC EQ].
2 Rotate the DIAL to select one of the following equalization choices: OFF: Microphone Equalization Off
3 LPF: High Cut (lower frequencies are emphasized)
4 HPF: Low Cut (higher frequencies are emphasized)
5 BOTH: High/Low Cut (mid-range frequencies are emphasized)
6 When you have made your selection, press and hold in the [FUNC] key for one second to save the new setting and exit to normal operation.
Menu 016 Carrier Balance -300 to +300 LSB Transmit
Menu 017 Carrier Balance -300 to +300 USB Transmit Adjusting These controls will give you a more low response or high response. As always listen to your test signal through headphones connected to a second receiver. You will hear the balance that will please you.
As always study the operation guide for further information.

Menu U-59 (TLSB): +100 for DX, +150 for Contest work, -100 for rag- chewing.
Menu U-60 (PROC LSB): +100 for DX, +150 for Contest work, -100 for rag- chewing.
Menu U-62 (T USB): +100 for DX, +150 for Contest work, -100 for rag- chewing.
Menu U-63 (PROC USB): +100 for DX, +150 for Contest work, -100 for rag- chewing.
Menu U-51: Set to OFF initially.
1: Mid- and high-frequency emphasis.
2: High-frequency emphasis (DX/Contest setting).
3: Low- and high-frequency emphasis, dip in middle.
4: Wide “broadcast” setting.

The FT-450’s Microphone Equalizer Menu item (“MIC EQ”) is very simple in its adjustment. Basically, there are three ranges (low, Mid, and High) for equalization; you can roll off any one of these, peak any one of these, or peak one and roll off another.
For DX and Contest work, use selection 9 (this rolls off lows and peaks highs). To roll off excessive bass in a microphone like the PR 40, use selection 1 (this rolls off lows while leaving mid-range and highs flat). To increase high-frequency articulation, without rolling off lows or mid-range, use selection 4.
See page 81 of the Operating Manual for details.

Menu 16 (MIC EQ): Set to OFF initially. Selection “2” emphasis high frequencies, while “3” cuts both low and high frequencies, emphasizing mid-range.
Menu 25 (MIC GAIN): 85
Menu 27 (Compression) 80
Menu 64 (T LSB CAR): Set to -100 Hz for rag-chewing, _150 Hz for DX/contest work.
Menu 65 (T USB CAR): Set to -100 Hz for rag-chewing, _150 Hz for DX/contest work.

Always consult your manual.

HEIL ICM electret Condenser on the Yaesu
All Yaesu transceivers are set up to use low gain, passive dynamic microphones into their high gain microphone preamplifiers. There are situations where you may want to use one of the Heil ICM microphones or headsets made for iCOM using the Heil iC element. These products require a bias voltage to power their internal F.E.T. Here is what needs to be added to the 8 pin connector to make that electret condenser work. Keep in mind the iC elements were designed specifically for the early iCOM rigs with low mic preamp gain. The iC elements have a lot of output to drive the early iCOM rigs. The Yaesu preamps are high gain so you will use a much low setting of mic gain with the Heil iC element. Thanks to GM0ONX for this drawing.

Heil iC to Yeasu adapter

All of the late model Yaesu starting with the FT 9000 through the 101 uses the same Parametric equalizer. The assignment numbers are different but the levels are the same.
The first and most important adjustment will be the transmit bandwidth. Set the TX BW to 400 -2600Hz for DX/Contest work. For everyday conversation,  100 – 2900 Hz.
Set filter one to 200 Hz. Menu 119 Frequency
Notch this filter -9 dB Menu 120 Notch or Boost
Bandwidth of 5 Menu 121 Bandwidth
Second Filter 900 Hz Menu 122 Frequency
Notch -3 dB Menu 123 Notch or Boost
Bandwidth  5 Menu 124 Bandwidth
Third filter 2200 Hz Menu 125 Frequency
BOOST + 6 dB Menu 126 Boost
Bandwidth 5 Menu 127 Bandwidth

All Things Kenwood

All Things Kenwood

Microphone Connection Basics

Kenwood rigs present relatively few problems in interfacing to Heil products. Kenwood HF transceivers have long been designed for dynamic microphone inputs, so the microphone amplifier stages have plenty of gain to accommodate the wide range of Heil dynamic microphones. These are our recommendations. For best results please consult your owners manual.

Pin Connections

8-pin Round (All Models)
Pin 1: Mic
Pin 2: PTT
Pin 7: Microphone Ground
Pin 8: PTT Ground

4-pin Round (TS-120/130/700/520/530/820/830, TR-2200/7200/7400/7500)
Pin 1: Microphone In
Pin 2: PTT
Pin 3: PTT Ground
Pin 4: Ground

8-pin Modular (TS-480, VHF/UHF Mobiles)
Pin 3: Ground
Pin 4: PTT
Pin 5: Microphone Ground
Pin 6: Microphone In

HT 3-pin 3.5 mm Plug (All VHF/UHF HT except TH-F6/7*)
Tip: +4V
Ring: Microphone In
Shaft: PTT
Note: Ground is sourced from the shaft of the 2.5 mm plug.
Heil Sound is investigating interfacing issues on these models at the present time.

DSP and Microphone Settings

Several Kenwood rigs have DSP and other settings that will allow the operator to adjust the response of the radio to your speech input from the microphone. These are easy to adjust in seconds.

It is impossible for us at Heil Sound to know what settings will sound “best” on your voice, in your station environment, with your microphone, for your interest (DX, Contest work, rag-chewing, or maximum fidelity) The recommendations below are just starting points; listen to yourself in a separate receiver (with its antenna disconnected) to determine what sounds best in your unique situation.

Menu 20 (DSP 1 HPF): 100
Menu 21 (DSP 1 LPF): 3100

Menu 13 (Bandwidth): 2.4 kHz
Menu 14 (TX EQ High Boost): H
Microphone Gain: 50 (Default Level)

Menu 29 (Bandwidth): 3000 Hz
Menu 30 (Bandshift): 0 or 100
Menu 31 (TX EQ): H or C
Menu 32 (RCV EQ): C or Off
Microphone Gain: 50 (Default Level)
Menu 22 (Mic AGC): 1 (but try 0 and 2)

Menu 22 (Bandwidth): 3000 Hz
Menu 21 (TX EQ): H or C
Menu 20 (RCV EQ): C or Off
Microphone Gain: 50 (Default Level)

Kenwood TS-590 Setup Recommendations

Kenwood’s exciting new TS-590S transceiver promises to be popular among active operators throughout the world. We are already getting a lot of questions about the best “settings” for the onboard DSP microphone equalizer.

The TS-590S does have a very sophisticated software-programmable equalizer system, but that’s not required in order to get on the air while sounding great.

Menu items 25 and 26 set the transmitter’s bandwidth. Leave them at factory defaults to get started; they’ll set you up for a low-end cutoff of 300 Hz, and a high-end cutoff of 2700Hz.

Now go to Menu #30, and select “C” (“Conventional”), which will give the audio frequencies above 600Hz a slight (3 dB) boost. That will be good for starters. You may also select “HB2” (High Boost 2) if you’re using a wide-range microphone, like the PR 781, on the TS-590. The High Boost 2 selection will suppress the lower frequencies, and give you more “sparkle” on the high side, for good communication-quality audio.

Ultimately, though, much of the fun of acquiring a new radio is the experimentation with its many features. Read the operating manual, especially on page 32, and then try out the many available bandwidths and equalization possibilities. Listen to yourself on a separate receiver, with its antenna disconnected and its noise blanker turned off, to know exactly how you’ll sound to others listening to you on the air.


Kenwood TS-990 Equalization Recommendations

Menu 00 : Adjustment Level -21
Menu .3 : Adjustment Level -16
Menu .6 : Adjustment Level -14
Menu .9 : Adjustment Level -7
Menu 1.2 : Adjustment Level -5
Menu 1.5 : Adjustment Level -1
Menu 1.8 : Adjustment Level +1
Menu 2.1 : Adjustment Level +4
Menu 2.4 : Adjustment Level +6
Menu 2.7 : Adjustment Level +6
Menu 3.0 : Adjustment Level +6
Menu 3.3 : Adjustment Level +6
Menu 3.6 : Adjustment Level +6
Menu 3.9 : Adjustment Level +2
Menu 4.2 : Adjustment Level +2
Menu 4.5 : Adjustment Level 0
Menu 4.8 : Adjustment Level 0
Menu 5.0 : Adjustment Level 0


All Things iCOM

Microphone Basics

DSP and Mic Gain Settings

When using a dynamic element on rigs like iCOMs, which were designed for electret microphone elements, one must not be afraid to do two things: (1) utilize the full range of Mic Gain available, and (2) turn on the Compression, using the Compression Level control as a secondary Mic Gain control if necessary.

It is impossible for us at Heil Sound to know what settings will sound “best” on your voice, in your station environment, with your microphone, for your interest (DX, Contest work, rag-chewing, or maximum fidelity) The recommendations below are just starting points; listen to yourself in a separate receiver through headphones to reduce speaker feedback (with its antenna disconnected) to determine what sounds best in your unique situation. Monitoring of your signal is particularly important when setting Menu item Q4, which has a huge effect on your transmitted tonal quality.

The iCOM 7300 has been updated to work with all Heil Sound iCM. For more on the iCOM 7300 settings, see below.

Icom HF rigs fall into three distinct categories, as far as microphone interfacing is concerned.

First, are the original “zero” models: 701, 720, 730, and 740. These had no microphone preamplifier, it was built into the microphone. Without the original microphone, you will have to use an outboard preamp such as a W2IHY or a small mixer/preamp.

Second, are the “low-gain” models (earlier designs like the IC-735/745/751/761/765/781, non-Pro 746/756, all 706 models, and the 7000, 7100, and 7200.

Third, are the “modern” designs: 746Pro, 756Pro series, iC-7600, 7700, and 7800.

To accommodate the low-gain Icom designs, Heil Sound developed a high-quality condenser element, called the “iC” (for iCOM) in our products designations, that provides the optimum frequency response, impedance, and (most importantly) sufficient gain to drive these earlier rigs. The “iC” element also works tremendously well with the “modern” types of Icom rigs, making it an ideal all-around microphone. This element is found in products including the iCM base station microphone, the Handi Mic iC, the Pro Set iC, Pro Set Plus iC, BM-10 iC, and the Classic iC but the HEIL ‘iC’ electret will not work on Kenwood or Yaesu which require only our dynamic elements found in our microphones and headsets.

Owners of “modern” Icom rigs wishing to utilize the specialized characteristics of Heil Sound dynamic elements (like the current HC-6 and HC-7, and discontinued HC-4 and HC-5) need only obtain the proper adapter cable (AD-1-I, AD-1-IM, CC-1-I, CC-1-IM or CC-1-XLR-I) to ensure proper interfacing. The AD-1-I and AD-1-IM include blocking capacitors that prevent the phantom power supplied by the radio from affecting the performance of the dynamic elements. If you try to use the AD-1-iC or AD-1-iCM adapter cable on a dynamic-element microphone, the lack of a blocking capacitor will cause the element to seize up, and no output will be heard. Microphones like the GM series, Heritage, Classic 4/5 Handi Mic 4/5, and the HM-10 Dual sound great on modern Icom rigs.

Using Dynamic Microphones on iCOMs

The PR 781 dynamic microphone, which sounds simply wonderful on modern iCOMs. It rolls off at about 150 Hz on the low side, and it has a few dB of boost at about 2100 Hz, but its response otherwise is very natural, and its large-diameter element provides sparkling highs and beautiful audio that responds very well to the audio adjustment capabilities of today’s Icom transceivers.

Pin connections on iCOM rigs are very straightforward and are shown below.

Pin Connections

8-pin Round (IC-730/735/745/751/761/765/720/725/726/728/781/901/910/3200/7700/7800 etc.)
Pin 1: Microphone In*
Pin 5: PTT
Pin 6: PTT Ground
Pin 7: Microphone Ground

*Pin 1 also carries voltage for the electret elements used in Icom mics. This voltage must be blocked for use of Heil Sound dynamic elements.

8-pin Modular (IC-703/706/2000/7000)
Pin 4: PTT
Pin 5: Microphone Ground
Pin 6: Microphone In*
Pin 7: Ground

*Pin 6 also carries voltage for the electret elements used in Icom mics. This voltage must be blocked for use of Heil Sound dynamic elements.

Click here to view pinout information for hundreds of rigs, mics, and connectors.

The iCOM 7610

The 7610 is a full-function transceiver with the addition of being able to be used as an SDR receiver.
The Heil iCM is the perfect and best match to this iCOM model.
Here are the settings for the Heil iCM or any Heil headsets with the ‘iC’ element:
Wide transmit bandwidth. (2.9 kHz) for casual contacts
Mid transmit bandwidth (2.4 kHz) for DX and CONTEST work
Mic gain at 30 to 40
Compression at 3
Bass EQ is set to -3 dB
Treble EQ is set to +3 dB
Here are the settings for the Heil Sound dynamic microphones:
Wide Transmit Bandwidth (2.9 kHz.)for casual contacts
Mid Transmit Bandwidth  (2.4 kHz.) for DX  AND CONTEST work
Mic gain at 80
Compression is set to 7
Bass EQ set to -3 dB
Treble EQ set to +3 dB
These are initial settings to get you started with a great sounding signal.  You may want to listen to your
signal through the Monitor as you tweak each setting to your liking.  Always speak into the microphone no more than 2 inches from your mouth.

DC De-coupling on Icom Rigs

If you do not have one of our microphones you need to do the above modification.

All ICOM transceivers utilize “phantom power” on their microphone inputs. Borrowing technology from the recording studios, DC power is applied via the mic line to energize the electret elements used in stock Icom microphones. At the same time, DC flows DOWN the mic cable while the mic audio is fed UP the same wire. Of course, the voice signal is AC, so DC flows one direction while AC flows the other direction – all on the same cable. This is pretty cool until you start having RFI problems, but we shall ignore that possibility for now.

The BIG problem with this is when you try using a REAL (dynamic) microphone. Connecting a dynamic into your mic input will provide a nice short of the +8V DC power straight to ground. SMOKE CITY!!!

To use any dynamic element on these phantom-powered inputs (which should NEVER be applied to the mic input of a radio transmitter, IMHO), the input must be de-coupled so the mic audio AC signal can pass through to the mic preamp, while simultaneously blocking the DC voltage from reaching that mic element. Simply install a 1 µF non-polarized tantalum capacitor in series with mic lead. You may get by with a .68 F or a .47 uF, but anything less (.01 µF, .005 µF, etc.) will not pass any speech audio worth listening to). The cap MUST be a non-polarized type. This will keep the DC factor into the mic preamp circuitry. But, you don’t need to worry about that so long as you purchase the correct adapter cable to go with your dynamic microphone. Please see our adapter selector to find the right cable for your rig.

Heil’s Amateur Radio specific microphones (non-3 pin XLR) have a 1 µF capacitor installed. All AD-1 boom set adapters have the decoupling capacitor installed in the 8 pin Foster connector. The coupling capacitor is NOT installed in our new high-impedance GM “VINTAGE” microphone, as this model should never be used with ICOM low impedance inputs.

The iCOM 7300

Enter the new iCOM 7300 hybrid SDR. Truly a game-changer in the amateur radio transceiver market. The 7300 is a terrific value. Great receiver, full coverage 160 through 6 meters. Excellent on SSB, works great on AM and FM and covers the digital modes.
For the iC 7300 we recommend the iCM or any of the headsets with the iC element.

For stunning hand mic performance the HMM-iC with the AD-1 i.

The PRO 7-iC has the appropriate cable included and will sound wonderful with a 7300.

Adjust the mic gain by watching the ALC meter. Never want to see over 50 or 60%.

Usual mic gain will be set between 65 to 80. Pay attention to the ALC.
Compression On at, 1 or 2. Never any more.

Equalization settings:
Normal conversation Bass -1 to +1 Treble +3
DX and contest use Bass -3 Treble +4
These are merely beginning settings. You will want to listen to your signal in a second receiver and make small minor adjustments to tailor the audio you desire.
The receiver also has a great equalization circuit so adjust the treble and bass to your listening preference.


Mic Gain: About 2 o’clock to 3 o’clock for dynamic elements, 10 o’clock for higher output “iC” condenser elements. But forget actual numbers. Always adjust mic gain by watching the ALC meter. Never see that even close to ‘the red’

Equalization: Normal ‘rag chew’ conversation Bass: -2dB Treble + 4dB

DX or pileup busting audio Bass – 5 dB Treble +5 dB

Compression: ON (if you desire) 10 o’clock – no more

TRANSMIT BANDWIDTH (TBW) This is confusing, but very important when trying to determine the type of transmit audio you desire. The same button turns the Compression On or Off also is used to adjust the Transmit Bandwidth Filter. Hold it for three seconds to change one. Quickly tap it for the other. WIDE TBW – Set to Wide for Fidelity, Mid for everyday operation, or NAR for very aggressive DX pile-up busting (significant roll-off of low frequencies will occur). Wide is 2.9 kHz. Mid is 2.4 kHz and Narrow is 2.1 kHz.

VOX Gain: About 65% or where needed

Anti-VOX: About 10% or where needed (keep in mind that the speaker level will affect this a lot)

VOX Delay: About 8%

IC-746 (non-Pro)

Menu Mi/F4 (TCN): 10 (Tone Control)

Mic Gain: About 3 o’clock

Compression: 10 o’clock


The iCOM 718 is a terrific value. Great receiver, full coverage .3 to 30 mHz, works great on AM, the digital modes, a terrific CW transceiver, DSP, etc. However, the Mic Pre Amp on the iC 718 has down in gain by -15 dB. It will NOT support dynamic microphones. The supplied hand microphone – as ALL hand mics, sounds hollow and mushy. Because of this low gain mic preamp Our GM, Goldline, HC 4 or HC 5 elements will not work. They will be very low in gain. The answer to making the iC 718 come alive is our iCM, handi mic iC or one of the headsets using only our high output ‘iC’. The iCM is the perfect match for the iC 718. Set the microphone gain to 70 and with the stock bandwidth of 2.4 kHz your SSB signal will be terrific.


Compression: Adjust for ALC mid-scale on voice peaks.

Mic Gain: 9

Carrier Point (Q4): Try +100 for DX/Contest work, -100 for rag-chewing.


Compression: Set for 10 dB on voice peaks on COMP meter.

Transmit filter: Set to WIDE for fidelity, MID for everyday operation, and NAR for DX pile-up busting.

Mic Gain: Set to 50% for “iC” elements, 80% for dynamic elements.

Hi-Fi on the IC-7000, 7100 series, 7200

For really beautiful audio, using a studio microphone like the Heil Sound PR 40 or PR 781, connect the microphone via an outboard equalizer like one of the fine products from W2IHY, and then apply the output from the equalizer to pins 2 and 11 of the rear-panel “Accessory” jack. Set the Transmit Bandwidth to Wide (100-2900 Hz), and you will be the talk of the band!

Heil Sound Traveler on the IC-7000, IC-706, and other Icom Rigs

The popular “Traveler” boom set works exceptionally well with the IC-7000 and IC-706. Just contact your dealer to get the HSTA-706 Adapter Cable, and the Traveler should work perfectly using the factory default settings on the rig.

For use on earlier Icom 8-pin (round) equipped rigs, use the HSTA-I8 adapter cable. For Icom mobile rigs, use the HSTA-706, and for Icom HTs use the HSTA-iHT.


All Things Elecraft

DSP Settings and Mic Connections: Elecraft K3 and KX 3

The Elecraft operation manuals are the best in the business and we highly recommend you read them thoroughly before making any adjustments or operating the transceivers.


The K3 utilizes the “Kenwood” protocol for connections to its front panel 8-pin mic jack, so use the CC-1-K for 4-pin XLR mics (GM Series, HM-10 Dual, and Handi Mic}, and use the CC-1-XLR-K for connection to 3-pin XLR mics (PR-781, etc.). Set the MAIN: MIC SEL menu selection to FP (Front Panel).

For headsets, use the AD-1-K for connection to the front panel mic jack. Set the MAIN: MIC SEL menu selection to FP (Front Panel). The K3 also has provision for direct connection of the mic cable from a Heil Sound headset, with no adapter required (!); in this case, set the MAIN: MIC SEL selection to RP (Rear Panel).

See pages 13, 17 and 20 of the K3 Operating Manual for more details.


What Kind of Mic?

We highly suggest our dynamic element microphones (HC-7, HC-5.1 , HC-6, Goldline GM series or PR-781 type). In this case, while setting up the MAIN: MIC SEL menu, tap [I] to toggle to “LOW” Mic Gain, and be absolutely certain that Mic Bias is off by tapping [2], as needed, to toggle to “OFF” for Mic Bias.

If you are using our high output “iC” element (Pro Set iC, Pro set Plus iC, Pro Set Elite iC, Handi Mic iC, or the iCM via the HSTA-K8 adapter cable), tap [1] to select “HIGH” Mic Gain, and tap [2] to set the Mic Bias to the “ON” option. Keep in mind this will have much more output and ‘may’ overdrive the mic preamp so keep ALC in range.
See pages 13 and 20 of the K3 Operating Manual.

Eight-Band Equalizer Settings

The K3 includes a versatile 8-band transmit equalizer, which is adjusted separately from the receiver equalizer. The K3 also has an “ESSB” mode, with a wider transmitted bandwidth for high fidelity operating. To achieve this, you will need to use our PR 20, PR 781, PR 30 or PR 40 microphones. Please read pages 35-36, and page 60, of the K3 Operating Manual, in particular, for more details of these subjects. Yes, you have to read the manual!

The table that follows details starting points for operation using two main categories of mics: the “articulated” elements (HC-6, HC -7 and HC-5.1 based mics), and the “wide range” elements, typified by the iCM, Handi Mic iC, PR 781 and the PR 20/30/40 genre. Remember to set the Mic Gain and Mic Bias properly, as described above.

The above settings are for “normal” operation. For ESSB operation, you may want to set the lower-frequency selections to positive settings, depending on which microphone you have and your audio sound objectives.

Again, these are necessary starting points for operation, and it should be noted that, when using the HC-6, HC-7, and HC-5.1 elements, the equalizer may be left at its default setting of “0” across the board, since equalization is already taking place in the mic element itself.

Mic Gain and VOX Setup

Follow the instructions on pages 28 and 29 of the K3 Operating Manual. There are many inter-dependent adjustments on the K3, and the setup instructions on those pages are excellent.

The best way to adjust ANY transmitter is to listen to yourself through a pair of headphones connected to a second receiver. Transmit into a dummy load and listen to yourself. It is the only way you will absolutely know how you sound to the outside world.

The Elecraft K3 and KX3 are remarkable transceivers. They have similar audio tailoring systems. Just as all EQ settings, we can only give you starting points for your transceiver. You must listen to yourself through it monitor system or through a nearby receiver and headphones. The first thing to set with any transmitter is the transmit bandwidth.

If you are setting for a normal ragchew conversation, you will want a bit wider frequency response of 2.7 kHz – 3.1 kHz . For DX work where you need to cut through pile-ups and noisy conditions, 2.1 to 2.4 kHz will be desired. Do not confuse this with receiver bandwidth response. Set the transmitter bandwidth and then adjust the equalization for the audio response you desire by listening to your signal.

Note that these are starting points only, and the best setup for your voice, your microphone, and your operating objectives may differ. Be sure to listen to yourself on a separate receiver (with its antenna disconnected and noise blanker turned off) as you make fine adjustments to optimize the settings for your operating situation.

Here are three EQ settings for the K3 and KX 3.