On 11/23/2014 9:19 AM, Patrick Greenlee wrote:
I once had a tube type lab grade audio power amp with a switch on
both channels to roll off freqs below 8 Hz for uses such as music so
power would not be wasted in reproducing infra-sonic signals from
such as footsteps vibrating a phono cartridge.
Not sure what benefit audio down in the infra-sonic domain has for
hams but if someone is doing something down there then please speak
up as I'm sure lots of us would be interested.
[...]
For audio _inputs_ that might be used to transmit highly-processed
waveforms, I can see great advantages to DC coupling. Orban
recommends flat frequency response down to a least 0.16 Hz (not a
typo!) for AM broadcast transmitter audio stages in which the actual
audio frequencies are no lower than 30 Hz. Without such extended
response, processed audio waveforms (which are sometimes flat-topped
like square waves) would be unacceptably distorted. Perhaps some
other modes have similarly stringent requirements.
But I don't see why a headphone output needs to be DC-coupled. A
capacitor-coupled output that gives flat response down to 30 Hz
should be fine even for audiophiles listening to ESSB operators or
organ concerts on broadcast stations.
73,
Kevin, WB4AIO.
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
To opt out of the Reflector:
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
