[Premium-Rx] FW: New radio selection

[Jim Garland]

The comments about brick wall filters and CW copy are well-taken, but I
believe some of the newer ham transceivers -- e.g., the Elecraft K3, Ten-Tec
Orion I and II, and the Yaesu FT2000, plus others I'm not familiar with,
have ways to smooth out the filter edges to minimize ringing. The Elecraft
K3, in particular, has excellent CW copy down to a bandwidth of 50 Hz, which
is truly remarkable.

On the subject of the AM fidelity of the K3: my K3 has the 6 kHz roofing
filter and the AM DSP bandwidth can be increased to 5 kHz, not 4 kHz as
previously noted. I believe, but am not sure, that the BW can be increased
further with the wider 13 kHz roofing filter. I play the audio output into
an external audio amp with bookshelf speakers and the fidelity is excellent,
comparable to or better than any of my other receivers. I wonder if the
gentleman who is selling his K3 because of low fidelity has a problem with
his radio?

Jim Garland W8ZR

> -----Original Message-----
> From: premium-rx-bounces at mailman.qth.net [mailto:premium-rx-
> bounces at mailman.qth.net] On Behalf Of Tim Shoppa
> Sent: Saturday, January 31, 2009 6:20 PM
> To: premium-rx at mailman.qth.net; michaelob666 at ntlworld.com
> Subject: Re: [Premium-Rx] New radio selection
> 
> > > Other users have done the same.  But, I query, what have been the
> > > comparable standards of comparison?  If it's other ham gear, then that
> is
> > > frankly not a big deal.  I have used some of industry's best and I
> reckon
> > > my ears and fingers know a good set or two.  Once you have used
> commercial
> > > and military radios made by the likes of Racal, Redifon, Plessey,
> Skanti,
> > > Marconi, Dansk Radio, Collins, Siemens and Rohde & Schwarz, all made
> for
> > > the high end of the professional market, the likes of Icom, Kenwood
> and
> > > Yaesu pale significantly, though in fairness the very latest offerings
> > > from Icom have been a great improvement.
> 
> I am overall happy using ham gear on the ham bands. Compared to
> the commercial/military rigs, the ham rigs have completely appropriate
> AGC systems for a wide variety of signal strengths popping up and
> going away in crowded bands. They also have tuning rates and
> bandwidths that are right for the ham CW and SSB modes. They suck
> pretty bad for AM - AGC hang times and bandwidths on any ham rig
> from the SSB era onward are hardly optimal for AM.
> 
> The commercial/military rigs shine for "channelized" operation,
> sitting on one frequency, one station for extended periods. They
> do not work so well tuning around a narrow band filled with
> widely varying signal strengths - AGC hang on every commercial
> or military rig, whether short or long action is just wrong for this
> sort of band scanning. And they also seem to miss the boat with tuning
> rates.
> 
> There is one trend that both ham and commercial/military rigs
> have been following for decades, that is unfortunate for CW reception:
> the trend has been very much towards brick wall IF filters, which have
> wonderful specs but in the ears they result in horrible ringing, making
> it very tiresome to do CW on bands with lots of QRN's for extended
> periods.
> IMHO both ham and commercial/military rigs are misusing DSP techniques
> to go even more in the direction of brick wall filtering with wonderful
> specs but horrible listenability. My solution to this trend is my
> own homebrew receiver with a homebrewed crystal filter designed for
> linear phase response.
> 
> Tim N3QE
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