Thanks for your answer,
My technical understanding and skill level are rather low - but let's see
if I at least understand what you are suggesting.
A simple internal RC shaping mod could be made for the Scout. Using
multiple caps and a rotary switch the audio could be operated wide open or
with the bass or treble rolled off or both the bass and treble rolled off.
This would be an improvement but I think I want the ability to peak/boost
the upper mid range as well. For that I would need "multiple RC and op amps
to make their effects stronger." I assume I would then need multiple rotary
switches.I would want a "multiple RC and op amp internal Scout modification
with 3 pre-set settings that would duplicate the audio shaping of the
Goldline, HC 5 and HC 4 elements. I assume this is not practical but I'll
ask anyway.
Could one of the Scout mod experts on this list tell me if there is room
inside a Scout to add internal "multiple RC and op amps" which wcould
duplicate the audio shaping of the Goldline,HC 5 and HC 4 elements with
corresponding knobs added to the Scout. Would this be practically possible?
73
Bob,KB1CIW
At 12:19 PM 8/18/02 -0500, you wrote:
>Capacitor shaping can work a great deal. That's all there is in the
>fanciest equalizer, just multiple RC and op amps to make their effects
>stronger. Simple RC using the circuit impedance for the R and adjusting
>the capacitor sizes can roll up bass and treble. The series capacitor
>having Xc equal to the load R sets the 3 dB corner on the LF roll off.
>I'd say you want Xc to equal the load R on the microphone circuit about
>500 Hz. I don't know what the microphone input resistance is so I can't
>suggest a value. Backing away from the microphone will also reduce low
>pitches. Adding a wind screen or two layers of wind screen will tend to
>roll off some highs. Different densities of wind screen or reduced
>exposure area of the microphone diaphragm will also affect the frequency
>response. Making the entry into the microphone a tube instead of grill
>will reduce lows (waveguide beyond cutoff attenuator), adding ribs to
>the inside of the tube will roll off highs.
>
>Then you have to add some gain to make up for the lost low tones.
>
>You can roll off the extra highs with a shunt capacitor, with the
>parallel of the source and load R's matching the Xc at the desired roll
>off frequency. I'd suggest 2400 Hz as a good high end roll off
>frequency, maybe 2100 Hz. I often run my passive speaker filter or my
>DSP to roll off at 2100 Hz. under poor conditions or the band pass
>tuning in the Corsair II works best rolling the highs off about there.
>
>The two roll offs combined can be set independently, yet are fairly
>gentle.
>
>73, Jerry, K0CQ
>--
>Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
>Reproduction by permission only.
>_______________________________________________
>TenTec mailing list
>TenTec@contesting.com
>http://lists.contesting.com/mailman/listinfo/tentec
>
|