[Elecraft] Questions and K3 options? Please!

David Yarnes w7aqk at cox.net
Wed Jul 2 09:36:23 EDT 2008


Bill and All,

I would primarily just echo Julian's comments.  He did a 
pretty good job of answering your query.  A few additional 
thoughts though.

First of all, regarding the Pro III.  I really think the K3 
is superior, but so many folks out there rave about their 
Pro III's that, if you actually tinker with one, you may 
fall in love with it.  The bandscope on the Pro III is a 
really big feature, and very useful.  It's a very competent 
radio, and I think you could get one for a fair amount less 
than you would probably spend on a K3.  So, you could get 
back into "business" for less money that way, and have a 1st 
class rig to boot.  Eventually the benefits of the K3 would 
become more obvious, but perhaps not right away to someone 
just getting back into the water.  By the way, I just got 
notified that my panadaptor kit from Telepost (the LP-PAN) 
has shipped.  This will give me a reasonably comparable 
accessory to the Pro III's bandscope, but it is outboard, 
and does require using a computer.  But don't get me wrong, 
the K3 would be my first choice, particularly if you don't 
mind spending a few more bucks in the process.  You would 
really end up with a radio that far surpasses anything in 
the Pro III class, and even those costing much, much more.

Regarding the K3, Julian is dead on about the filters.  You 
would probably do fine with the 500 hz one.  I have the 400 
hz in mine, and it's 8 pole instead of 5, so sharper skirts, 
etc.  And it's only a few more dollars.  The DSP in the K3 
is so good, you may not need anything lower than that.  If 
you really get into contesting, or digital stuff, the 
narrower filters will become more attractive.

The ATU in the K3 is superb, especially for an internal 
tuner.  It's range is considerably better than 3:1, and 
where you might find that useful is on a band like 40 
meters.  Depending on what frequency you cut your antenna 
for, wide band excursions on the lower bands can be a 
problem.  I usually cut mine for the CW portion, but when I 
go to the higher end of the band, some internal tuners tend 
to choke trying to match up there.  Not so with the K3.  My 
favorite personal experience story with the K3 is that I can 
tune my R8 vertical, which supposedly only goes down to 40 
meters, on both 80 and 160 meters using the K3's ATU.  Now, 
that doesn't mean those antennas perform very well 
there--they don't!  But it's not for lack of an acceptable 
SWR being presented to the TX.  But on 40 meters for 
example, your antenna cut to favor one end of the band or 
the other will still perform very nicely at the opposite 
end.  The same would probably be true with an 80 meter 
antenna.  Above 40 meters, most internal ATU's will do O.K. 
And be advised that you really have to be realistic about 
doing things like running an R8 on 160 meters.  I can do it, 
but I don't--at least not routinely.  I really only get 
about 2:1 there, and that tells me "watch out!"  If you 
can't get something close to 1:1 using the ATU, you probably 
need to be cut the power back a little or a lot, depending 
on just what your actual SWR reading is.  But anything under 
say, 1.5:1 or so, is probably fairly safe.  Others can tell 
you better about this perhaps.  On 80 meters I get 1:1 all 
over the band, so I don't worry much about it.  But the 
antenna is still pretty inefficient, so folks still don't 
hear me very well with it.

You can live without the 2nd RX, and perhaps very nicely. 
But as Julian says, if you become a contester or DX chaser, 
you would probably really appreciate the benefits a 2nd RX 
provides.  The thing about the K3's 2nd RX is that it 
actually is pretty inexpensive--under $600.  Consider, on 
the other hand, The Icom 7800 vs. the Icom 7700.  The 7700 
is pretty close to being a 7800, but with just one RX.  Even 
the Icom rep admitted that at Dayton.  But the 7800 is 
thousands more than the 7700.  Same thing with a Ten-Tec 
Omni VII and a Ten-Ten Orion II.  The cost difference is 
less, but still much more than adding a 2nd RX to the K3. 
There are other subtle differences between the rigs 
mentioned above, but by far the biggest difference is the 
2nd RX.  By the way, the Pro III doesn't have a 2nd RX, and 
has no provisions for adding one.  So, if you ever felt the 
need for that feature, you'd be shopping for a new radio. 
At least with the K3 you have the option to expand.  And in 
the K3 the 2nd RX is an exact duplicate of the main RX.  In 
many rigs having the 2nd RX feature, there is a somewhat 
lesser RX in position 2.

Dave W7AQK





----- Original Message ----- 
From: "G4ILO" <julian.g4ilo at gmail.com>
To: <elecraft at mailman.qth.net>
Sent: Wednesday, July 02, 2008 1:17 AM
Subject: Re: [Elecraft] Questions and K3 options? Please!


>
> Filters. I think you'll get quite a few different opinions 
> on this. Bear in
> mind the K3 has DSP filtering which is pretty good. A lot 
> will depend on the
> filter bandwidths you personally like to use. I like to 
> tune around with the
> bandwidth set to 1KHz. But you don't need brick-wall 
> skirts for such a
> tuning-around bandwidth, so I think the DSP filtering is 
> fine for that.
> There is no need for a 1KHz roofing filter. Some may 
> disagree. I think a
> 500Hz 5-pole (or 400Hz 8-pole if you're willing to spend 
> the extra) is
> probably all you need at this stage. If you think you need 
> the extra help to
> winkle out weak ones next to strong signals you can always 
> add a narrower
> filter later.
>
> Updates. Yes, the K3 is highly software dependent. UPdates 
> provide things
> like improved NR. Just browse the firmware release notes 
> to find the changes
> we've had so far.
>
> Second receiver. I haven't gone for that. BUt if you are 
> really into
> competitive DXing you may find it useful to listen on the 
> DX frequency and
> the calling frequency at the same time. If you're into 
> contests you may find
> it useful to be able to monitor two frequencies at once.
>
> ATU. The Elecraft tuners are streets ahead of the tuners 
> that come in the
> Japanese rigs. By which I mean they can tune over a wider 
> range (typically
> up to 10:1 compared to up to 3:1.) On the other hand , if 
> you have a 10:1 or
> greater SWR at the rig then you'll be losing a lot of 
> power in the co-ax
> unless it is very short. So the wide range is probably 
> more use when using
> the radio in the field than at the home QTH.
>
> HTH.
>
> -----
> Julian, G4ILO  K3 s/n: 222 K2 s/n: 392
> G4ILO's Shack: www.g4ilo.com
> KComm for K2/K3: www.g4ilo.com/kcomm.html
> -- 
> View this message in context: 
> http://www.nabble.com/Questions-and-K3-options--Please%21-tp18230713p18232454.html
> Sent from the Elecraft mailing list archive at Nabble.com.
>
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