[Elecraft] Re: KX1 PSK31? [how about FSK?]

[wayne burdick]

Hi Eric,

Great idea, but the KX1's final amplifier operates class C. To make the 
KX1 transmit on SSB would require class AB PA bias and the addition of 
a balanced modulator. This is not readily accomplished with either 
internal mods or an external adapter.

However, it may be possible to operate the KX1 in any low-data-rate, 
dual-tone FSK mode. This is compatible with a class-C final amp, and 
should require only a firmware change. The KX1's key jack would serve 
as the data input/output port for connection to a computer. 
Unfortunately FSK (e.g. traditional RTTY) is not quite as popular as 
PSK31 for QRP use, even though good reliability is possible with some 
variants.

Would this be of interest?

73,
Wayne



On Oct 2, 2004, at 12:32 PM, Eric Ward wrote:

> When I was tuning around today on my KX1, I heard the usual strong 
> warble around 14.070 and I got the brilliant idea to: plug a patch 
> cord from the KX1 headphone output to my soundcard input, launch PSK31 
> Deluxe, crack open the AF gain, and boom, 5 QSOs popped up right away.
>  
> I know the thinking on omitting an SSB option from the KX1 is because 
> voice doesn't typically work reliably below about 10W, and an SSB 
> board wouldn't fit in the KX1 case.  But like CW, PSK31 can work like 
> a champ even at 100s of mW.
>  
> So how about an Elecraft-designed-and-produced *outboard* SSB adapter 
> for the KX1, designed specifically for PSK31?  On biz trips, I usually 
> have my KX1 and laptop--it would be great to take along one more 
> little black box and be able to work PSK31, while making use of the 
> KX1's KXAT1 capability to match a hotel room random wire on multiple 
> bands.  (The Small Wonder Labs PSK series looks exceedingly cool, 
> but is rock-bound to a single band and requires an external tuner for 
> non-resonant antennas.)
>  
> Good idea?  Dumb idea?
>  
> 73,
> Eric
>  N0HHS KX1 #670
>

---

http://www.elecraft.com