Sunday, March 22, 2009

Junior gets voice lessons thanks to Julius

I knew what I had to do to improve the TX audio and that was to dump the HC-4 mic element. Now do not get me wrong, the HC-4 does a very good job for what it was intended, but it just is not any good for the FLEX family of radios. If you want to pinch down your audio, the 10-band EQ will do it for you and you do not need a specialized mic element to accomplish it. I can make my PR-40 sound like a HC-4 with aggressive EQ cutting.

As I mentioned before, the headset has an Icom iC element that is a more "full range" mic element, but needs the 5 VDC for it to operate. I normally run my TX audio through a W2IHY EQ+ (and VERY good audio processor for ham radio from my friend, Julius Jones) to enhance the TX audio for my Icoms. The EQ+ provides the 5 VDC needed for the iC mic element and has several signal processing stages to work with too. So if I hook the FLEX-3000 to the EQ+ I can use the full range iC mic element in the ProSet Plus headset. It looks like I have a plan. Now it is time to execute.

So it was off to the junk box to find an old shielded 100BaseT Ethernet cable and a 5-pin DIN connector to make an EQ+ interface cable. The pin out for the cable just happens to be in the FlexRadio Systems’ Knowledge Center.

I found the necessary parts, including my reading glasses so I can see how to solder and I made an audio interface cable. If you are going to use an old 100BaseT Ethernet cable to make a cable that conencts to the FLEX-3000 mic connector, then this Knowledge Center article will be helpful in identifying the pins based on wire color.

Here is a picture of the FLEX-3000 connected to the W2IHY EQ+

As the youngsters say theses days OMG, did that make a MAJOR difference! The EQ+ is Junior's BFF now. I bypassed the 2-band EQ on the EQ+ in favor of the 10-band EQ in PowerSDR. I added just a smidgen of compression so I could use the downward expander to eliminate some of the ambient fan noise and last but not least, a dash of reverb for a slight mellowing. Ahhhhhh.

The iC mic element is much better suited for the FLEX family of radios since it has a 100 to 8000 Hz frequency response and no large “emphasis” at the 2 KHz point. The EQ+ can put out a lot of signal (gain) so I cut back the Mic input gain in the PowerSDR Mixer allowing the EQ+ to provide the AF gain at the earliest stage in the audio chain for the lowest THD (distortion).

Does it sound like a PR-40? No, of course not, but it also does not sound like $#*! like the HC-4 mic element did. Junior has found his full range voice and I could not be a prouder Papa.

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