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.
The Basics: Your Operating Preferences and Your Microphone
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 boomsets, 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 boomsets 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.