[Boatanchors] SSB Generation - Phasing VS Filter Opinion Sought

[Rob Atkinson]

On Fri, Jul 19, 2019 at 5:19 PM D C _Mac_ Macdonald <k2gkk at hotmail.com> wrote:
>
> The big problem with the phasing type SSB rigs is that the bandwidth no longer meet the current 3 kHz SSB standards.  That is why the HT-37s sounded "good"
> back then.

What is the 3 KHz standard and where can I find it?

tnx 73
Rob
K5UJ