initial Ashly DPX-200 processor impressions

Hey Craig ! Maybe I'll hear you on that new box in the coming days, I've got time off and during the day we ought to try to get up a QSO on 75m where we can open things up. Yes, a 'scope is highly recommended, especially in these early stages of adjustment. You can run a long wire into the center pin of the scope input BNC and set the sensitivity and sweep rate to get a good image. Nothing sophisticated needed in terms of a pickup. Later you can make a pretty loop of some kind to dangle inside the cabinet of the 32V near the tank, and run some coax into the scope to dress it up.

I run a scope routinely when I'm on the air. In your case specifically, the "kick up" style of modulation metering isn't too reliable on the 32V series tabletop transmitter from Collins, I have found, but generally it errs on the low side than failing to reveal that you're hitting it too hard.

Looking at the Ashly spec sheet, I'm a little concerned that the unbalanced output impedance is only 100 ohms. The mic input on the 32V is high impedance, so you'll probably have to compensate for the mismatch with both level and EQ settings beyond what you might have expected.

With that in mind, the EQ curve across the bands of adjustment should look like a

smiley face. If you had sliders in the classic 32-band equalizer, the settings approximate the response curve. You've got knobs and shelves, more on that in a minute.

The transmitter, stock, puts a lot of energy into the midrange region. You will want to attenuate that and boost the bass and treble to smooth out the overall response. If that box has pre-sets, you might want to retain a "war time" setting that restores the emphasis on a pinched sound to pierce whatever congestion you're doing battle with.

With most EQ boxes I have gotten better noise figures by offsetting the curve and using more- and less- attenuation rather than a combination of attenuation and boosting. So on "Level," you might try a midway setting between 0 and -15, and not go above 0 until you know more how it affects things to make a given change.

As I look at the documentation, your shelving controls seem to provide up to four bands of equalization, with each band being adjustable as to the slice of frequencies it affects, and where the most emphasis is placed within that chunk. You don't need to use all four channels, with the in/out controls. This may help your initial setup by focusing on a piece at a time and sequentially getting the right amount of energy in that part of the audio spectrum you're messing with. My initial stab might be to use Ch. 1 for Bass, only 1 of the 20-20K channels to attenuate the midrange, and then Ch.4 to boost the highs as described.

If we get on as a 1-on-1 we can mess with it as much as you like. I'll roll tape and play it back, and we won't necessarily bore anyone else to tears. Mike's primer on compression techniques picks up the other half of the function your Ashley provides. There is some interaction, but I'd mess with the EQ first to balance out the audio you will be compressing.