[CQ-Contest] Elecraft, TenTec & contesting radios

[Bill Coleman]

On Mar 6, 2004, at 4:46 PM, Bob Schreibmaier wrote:

> I have used serial number 2552 and must agree with Bill.
> It has the right architecture to be an excellent receiver,
> but the filters are not good enough.  I have also found
> the opposite sideband rejection to not be quite up to
> many other radios.

While I'd agree that the filters could be better, since their rejection 
slopes are slightly shallow, I'd disagree about the receiver in 
general. The K2 has so little IMD crap in the passband that it is a joy 
to listen to. Even a very crowded band sounds quiet.

Remember that the K2 filters are setup in software. It is possible to 
mis-adjust the BFO settings and end up with poor rejection. It could be 
the problem you have with the opposite sideband is a mis-adjusted 
filter.

> However, the biggest problem I have with the radio is the size.
> The tuning knob is way too small, plus there are additional
> controls close by on its left, getting in the way when
> you're trying to tune.

The tuning knob is small, and the controls on the left are a bit close. 
Some hams have changed to an FT-100 knob, which allows one to tune 
using the dimple, which keeps the fingers away from the controls on the 
left side.

> I also don't like the fact that the sideband used on CW
> is different on some bands.  It's annoying when you're
> used to the pitch of signals going in one direction as
> you tune each band and then finding different behavior on
> the K2.  There is a "reverse" switch, but I don't think
> one should have to use it when changing bands.

The reverse works, and the mode is remembered on each band, so this 
shouldn't be a big deal. In reality, though, I haven't really noticed 
the reversed tuning.

> Overall, the receiver is very good in the presence of
> strong signals (until you get very close, as Bill noted).
> I very much like the single-conversion approach.  It
> would be nice if they had the ability to use at least
> one 8-pole filter and, preferably, the ability to
> cascade two 8-pole filters (like the old TS-180S).

Biggest problem is -- where would you put it? The K2 is really squeezed 
tight. The SSB board is already crammed full

> That, plus the judicious use of DSP could make for
> really nice basic receiver performance.

I find the DSP filters are really clean and can help.

> I haven't used a K2 on phone, but have been told that
> the VOX gain is inadequate (sometimes) and that it
> needs an anti-VOX control (that it doesn't have).

I've already made one mod that improved the VOX sensitivity. It's still 
slightly inadequate. I may build a pre-amp.

Never had trouble with the anti-VOX.

> I've also been told that the 100-watt version folds
> back power with SWR too quickly for some tastes.

There's new KPA100 firmware that fixes this.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901