[AMRadio] TS 570-D on AM

[Rob Atkinson]

On Sat, Jun 22, 2013 at 1:06 PM, Donald Chester <k4kyv at charter.net> wrote:
>>From: manualman at juno.com
>>Additionally, the maximum transmitted bandwidth on AM is 4.8 KHz. The 570
> also has an equalizer to tailor your transmitted audio on AM.
>
> No matter how you attempt to "tailor" your audio, it's still going to sound
> muffled if you can't exceed 4.8 kHz total bandwidth. No highs  above 2400 Hz
> = loss of
> sibilance = loss of consonant sounds/muddled articulation = poor
> intelligibility.

That is correct.  The awful sounding Traffic Information System
stations on the AM medium wave band, usually operating on 530 and 1610
kc are limited by FCC to 6 kc bandwidth meaning an audio upper limit
of 3 kc.  This rig stock would be even more restricted and poorer
sounding than that, but there is probably a way to modify it, if it
employs the typical modern ham rig AM bandwidth limiting method, which
is  a Murata ceramic filter on the 455 kc mixer.  Just yank the filter
and jumper the slot with a wire and do all your audio limiting
externally.

73

Rob
K5UJ