[Elecraft] K3S vs K3 - upgradability

[Joe Subich, W4TV]

On 2015-05-14 3:41 PM, Ross Primrose wrote:
>
> I got the impression that new KBPF3As will have the necessary parts of
> the mod, but as I recall when the mods were described a few weeks back
> that there were changes that would also need to be made to the RF board
> & KRX3.  Hopefully in the next few days there will be some clarification
> on exactly what a K3 (no S) owner with no KBPF3s and the old synth(s)
> needs to actually buy/mod to get on the bands below 500kHz...

To get on 630 meters no changes are likely to be needed.  The existing
KBPF3 is good down to 250 KHz or so and the internal noise is below the
"sky noise" there.  To get reasonable receive performance at 137 KHz,
both the filter and bypass mods (RF board/KRX3) will probably be needed.

I'm hoping that the bypass mods are a substantial portion of the "lower
RF and digital noise" in the new K3S RF board.  It would be a shame if
one needed to replace the K3 with a K3S because of a significant change
there.

73,

   ... Joe, W4TV