[Elecraft] K4

[Richard Lamont]

On 19/05/18 03:18, Jim Brown wrote:
> On 5/18/2018 4:38 PM, Richard Lamont wrote:
>> On 19/05/18 00:15, k2ud at roadrunner.com wrote:
>>
>>> What features would your K4 have?
>> Compared to the K3S:
>>
>> RX maximum audio bandwidth increased from 4 kHz to 6 kHz.
>
> Why?  It's a ham transceiver.

To be able to decode multiple digital signals at once. Also to diagnose
intruder signals. And yes, occasionally, to listen to AM broadcasts,
without having to buy something else as well when I've just drained my
bank account to buy a K4! There's no inherent reason why this needs to
compromise the performance as a purely ham rig - it just makes it more
useful for one or two other things as well.

>> More macro buttons.
>
> Can't argue with that, but the radio would need to be bigger.  Have you
> studied the manual for the many ways to save presets of frequency, mode,
> etc. ?  Lots of things we want to assign to macros can be solved that way.

Yes thank you. Bigger isn't a problem for me. If it is for you, don't
buy a K4, stick to the K3(S)!

>> Higher resolution S-meter (more bargraph segments).
>
> Why is that important?

Because it's often useful to be able to see small changes in signal
level, which you can't do at 5-6 dB per segment. For example when
rotating an antenna.

>> 1/4" jacks instead of 3.5mm ones.
>
> Why?  Quality of jacks and plugs?  Simply buy good quality plugs
> (Neutrik and Switchcraft are the good brands) and make your own cables.
> And if you want those bigger jacks, the radio would have to be larger.

I always buy Neutrik if I can, but IMHO there is no such thing as a good
quality 3.5mm jack plug. They are just too small and flimsy.

>> Longer&fatter 13.8V power cable
>
> Buy a Power Pole connector pair, buy the size of cable you want, pull
> out your soldering iron and make any power cable you want.

Obviously, but if I'm buying a K4 it would nice to have a cable in the
box that is long enough to reach from the rig to the PSU.

>> 24-bit digital audio i/o, without going D-A-D.
>
> To what benefit?

To get the same dynamic range on the audio I/O that already exists on
the 15 kHz IF. I'd like to be able to examine received signals using an
audio spectrum analyser with the maximum available dynamic range.

>> Steeper filter slopes on SSB TX passband to widen audio while staying
>> within 3 kHz occupied bandwidth (cf IC7300).
>
> Buy and plug in a 8-pole 2.8 kHz roofing filter to replace the 2.7 kHz
> filter. If you can tell the difference between that and 3 kHz bandwidth
> you've got better ears than me. Further, any audio content below about
> 400 Hz is wasted in a communications circuit.

I already have the 2.8 kHz filter, and I'm more interested in the slope
at the top end than the bottom. Some other rigs seem to do better by
doing the slope in DSP and using the roofing filter for just that -
roofing. (The 6 kHz filter, if fitted, could be used here.) As for
content below 400 Hz, you're right for DXing, but if you're trying to
have a normal conversation it's much nicer if it goes somewhat lower.

73,
Richard G4DYA