(1) All audio is routed via 3 conductor shielded XLR cable.

(2) The audio output from the DEQ 2496 audio processor is routed directly to the microphone input jack on the TS-870 or the TS-590.   I adjust "gain offset" of the DEQ- 2496 as necessary (about -10) to help reduce line level audio output to something closer to microphone levels expected by the microphone input stage of the rig.   Alternatively, I have sometimes used e a W2IHY iBox to match line level to microphone level, audio isolate and impedance match.

(3) A "common point" rf ground system, although a good practice, is not essential to minimize the likelihood of rfi.

(4) A Daiwa SWR/Wattmeter is inserted between the linear amp and balanced line antenna tuner.

(5) Boom mounted Heil PR-35 dynamic microphone with the low end roll-off switch in the -3db position. You can read a review and comparison of this microphone and others by clicking microphone review.

(6) Current settings for the MIC 2200 mic preamp and the DEQ-2496 audio processor are discussed elsewhere on this page.

Audio components:

Boom mounted Heil PR-35 dynamic microphone. You can read a review and comparison of this microphone and others by clicking microphone review. "Michael", our Bengal Snow Leopard, thinks he is the station manager. :>)  

Kenwood TS-590 on top of the TS-870 with matching power supply above a rack mounted Behringer MIC2200Microphone Preamp and Behringer DEQ2496 Digital Audio Processor.

MIC2200 Microphone Preamp settings:

- Phantom power off (except when using a studio condenser mic)

- Phase Reverse button off

- Input gain +35db

- Cut on and set to 50Hz

- Parametric EQ on, frequency 160Hz, band width .96 and level of -12 db

- Output  +4db

DEQ2496 Digital Audio Processor settings:

⇒ GEQ (Graphic EQ) and Limiter- Bypassed

⇒ PEQ (Parametric EQ) - Five filters as follows:

Note: The Kenwood 870's TXEQ is kept in the "off" position and TX bandwidth is set at 3K for both transceivers. TX shift is 100.  The PR-35 microphone low end roll off switch is at position 3.

⇒ DYN (Dynamics processor) settings for the Downward Expander, acting as a noise gate. Gain is initially set to 0 db, ratio 1:1.8, attack 0.00ms and release 85.6ms. The threshold and ratio controls are adjusted until room noise diminishes to the desired point. The compressor capability of the DYN is not currently being utilized in favor of the DEQ as discussed below. Note: I have been able to avoid the necessity to use the DYN by keeping ambient shack noise to a minimum and close talking the microphone.

⇒ DEQ (Dynamics EQ) has three separate DEQ's available. Each one has 3 pages of parameters. DEQ 1 is configured for low frequency compression, DEQ 2 for midrange compression and DEQ 3 for high frequency compression as follows:

* adjust threshold as necessary to attain about -4 gain reduction.

** adjust threshold as necessary to attain about -5 gain reduction on voice peaks.
*** adjust threshold as necessary to attain clean "S" ing sound.

Note: The above settings work equally well with both the Kenwood TS-870 and the TS-2000. The DEQ2496 is being run with default settings in the "Utility" menu except for Channel mode" which is set to "stereo" and "Gain offset" which is set to +3.0 as makeup gain to partially compensate for some negative PEQ settings. DEQ2496 Input levels adjusted (output level of the preamp) to obtain peak meter reading -15db, RMS -21.5. The GEQ, DYN and Limiter are bypassed in both channels.

The above graph of received audio is courtesy of ZF1DG "Durl" recorded during a 20 meter QSO on 5/27/2010 .  Note the comparison between a transmit bandwidth of 3K as compared to 2.6K.  I typically maintain 2.6k which yields nearly identical perceived audio quality while occupying less bandwidth than 3k.