[Elecraft] Icom IC-7300

[Phil Wheeler]

Thanks for the explanation, Wayne. Funny thing is 
that I never think of the K3 as *functionally* an 
SDR radio, I guess because I don't have access to 
the I/Q signal -- unless it accessible in some 
sneaky way I don't know about.  OTOH in principle 
it seems one could take the I/Q output of the KX3 
and build their own "back end", playing all sorts 
of games -- not that I plan such an adventure. 
However, last Summer I did build one of the Tiny 
Python Panadapters in the April 2014 QST which was 
a fun project made possible by the KX3's I/Q port, 
though I soon replaced it by the much more capable 
PX3.

Aside from its "cosmetic" features, which don't 
particularly appeal to me, the Icom-7300 looks 
like a radio not well suited for operation in 
crowded bands, DX pile-up situations, a 
strong-signal environment or Field Day. It will be 
interesting to see what the QST and Sherwood tests 
reveal.

There are some SDR dongles which will provide a 
"look at multiple MHz of bandwidth" at very low 
cost :-) Such a capability can be useful in 
monitoring a band you're not currently operating.

73, Phil W7OX

On 9/3/15 3:47 PM, Wayne Burdick wrote:
> Hi Phil,
>
> Just to clarify: Both the KX3 and K3/K3S are SDRs. A major difference between these rigs and something like the IC-7300 or Flex 6xxx series is that our A-to-D converters (ADCs) are protected from wideband interference by a narrowband I.F. The K3/K3S uses crystal filters, while the KX3 uses precision, narrowband low-pass filters.
>
> In direct-sampling SDRs, the ADC is right at the front end of the radio, protected only by wideband LC filters. The result is typically 15-20 dB lower blocking dynamic range. More subtle is the effect of multiple signals, which can combine in phase to hit the limit of the ADC, resulting in unwanted images.
>
> It's a tradeoff; a direct-sampling SDR can allow you to look at multiple MHz of bandwidth on its spectrum display, if that's of interest.
>
> Wayne
> N6KR
>
>
> On Sep 3, 2015, at 2:57 PM, Phil Wheeler <w7ox at socal.rr.com> wrote:
>
>> Joe,
>>
>> Thanks for addressing what to me is the core issue with any rig -- performance. A "bells and whistles" user interface -- and that can be a matter of personal preference -- may sell a lot of rigs, but to me performance is key in selecting a base station transceiver. I can compromise performance for special applications like portable ops, QRP, etc. but I want my main station radio to be near the top of the list in the Sherwoodian sense.
>>
>> After looking at the information here http://www.icomamerica.com/en/products/amateur/hf/7300/default.aspx an in the pdf file linked here: http://www.icomamerica.com/en/downloads/DownloadDetails.aspx?Document=746
>> and from the general appearance of the Icom-7300 (ports, controls, etc.) I don't expect it to be near the top when Rob Sherwood tests it. Of course, it hinges on a number of factors -- including those you brought up below -- and I could be surprised. Even so, while I'm not spring-loaded against SDR rigs (the KX3 is basically an SDR radio, after all, and I enjoy mine), I can do without a touch-screen interface.  But I've been at this for 62 years now, so maybe I'm just "old fashioned" :-)
>>
>> 73, Phil W7OX
>>
>> On 9/3/15 1:39 PM, Joe Subich, W4TV wrote:
>>>> I think this is Icom's way of dipping their toe in the water and not
>>>> upsetting their fan base by introducing an SDR in convention looking
>>>> hardware. I am confident that they will be releasing a whole line of
>>>> stand alone SDR rigs...
>>> The question will be what quality ADC Icom uses in the front end of the
>>> 7300 and how clean (phase noise) they can make the synthesizer (clock).
>>>
>>> If they have enough ADC bits to provide dynamic range, their claimed
>>> synthesizer phase noise comparison should put the 7300 at about the
>>> same level as the Ten-Tec Eagle in the Sherwood "chart" (e.g., 92-95
>>> dB IMDDR3, -134 dBc @ 10 KHz phase noise, 125-130 dB 100 KHz blocking
>>> [ADC limited]).
>>>
>>> If Icom "cheaps out" and uses an ADC with limited resolution (number of
>>> bits) like some of its commercial products, the 7300 is likely to fall
>>> way down the list - into the neighborhood of the IC-7000 or FT-2000.
>>>
>>> 73,
>>>
>>>   ... Joe, W4TV
>>>
>>>
>>> On 9/3/2015 3:19 PM, Wm Robert Leschyna wrote:
>>>> Personally I feel that a touch screen is a must in a "stand alone" (no pc
>>>> needed) SDR, as it allows the future development and or creation and use of
>>>> soft keys for functions that we may not even think of today. As for the
>>>> IC7300, most of the time  you will likely be using the most commonly used
>>>> functions which appear to be tied the physical knobs and buttons, and not
>>>> have to touch the screen that much.
>>>>
>>>> SDR is the way of the future, heck it is the way now, and I think this is
>>>> Icom's way of dipping their toe in the water and not upsetting their fan
>>>> base by introducing an SDR in convention looking hardware. I am confident
>>>> that they will be releasing a whole line of stand alone SDR rigs...
>>>>
>>>> I have owned a K2 a couple K3s and KX3, I love Elecraft and love supporting
>>>> a made in North American brand, but frankly am confused as to why Elecraft
>>>> isn't leading the pack on stand-alone SDR?
>>>>
>>>> 73
>>>> Bob