[RTTY] New Radio

[Ian White]

When we all say "spectrum scope", what are we actually talking about? Is
it only the spectrum analyzer display, the waterfall display; or both?

Thinking about hardware radios as opposed to SDRs, I find the
front-panel spectrum analyzer displays almost worthless. The built-in
screen is also too small to include a worthwhile waterfall display. 

When operating, I focus almost entirely on the waterfall because that
displays a time-history of everything that has been happening for the
past several minutes across the entire displayed bandwidth. That is a
huge information resource which can be transformed into more QSOs and
more contest points. The waterfall shows at a glance if there are any
free channels and how long they have been free (so even before sending
"QRL?" I can usually know the answer). Meanwhile the color shading shows
how well I'm holding my run frequency, and also which signals are
spreading and hogging the band. The spectrum analyzer display cannot do
any of this. 

To extract the maximum possible information from the waterfall, I
normally maximize the available time-span and keep the waterfall
front-and-center on a wide-screen monitor. For most modes, only the two
small log input windows need to share space at the bottom of the screen.
RTTY is the only exception because the multiple decoder windows have to
take priority on the center screen, so the waterfall has to be pushed
away to a smaller monitor at one side.

I currently have two K3s with different types of spectrum/waterfall
displays. One is the P3, although I find that it absolutely requires the
SVGA adapter. The P3's own screen is bright and clear, but simply too
small to display the detail that's in there. There is also an issue with
the P3SVGA's limited color palette which tends to suppress weaker
signals. The big advantage of the P3 is its very tight integration with
the K3, which allows full advantage to be taken of the dual receivers.
On the other hand I don't count it a particular advantage that no
external computer is required, because a computer is usually running
anyway.

Leaving the specific topic of RTTY, but continuing on-topic for SDRs in
general...

The other K3 is used with external VHF/UHF transverters, and here the
spectrum/waterfall display uses a separate SDR, attached to the K3 at
the IF frequency of 28MHz. On VHF/UHF it is important to display
everything that lives and breathes across the entire "contest band",
which in Europe extends over at least 250kHz. Important multipliers tend
to lurk at both the top and bottom ends of that range so 200kHz is not
enough. Several good SDRs, including the SDR-IQ and the P3, had to be
ruled out for that reason. In the end I found that the SDRplay RSP-1
delivered the best combination of dynamic range, available spectrum
width (far more than I need) and value for money. 

Again after some experimentation, I settled on the HDSDR software, which
gives a very readable and sensitive display on the large screen and
provides most of the facilities of a second receiver.  I particularly
value the facility to tune the K3's second VFO using any combination of
the VFO knob, point-and-click with the mouse, rolling the mouse wheel
for fine tuning, clicking on the bandmap in N1MM+ or typing frequencies
directly into the callsign window. That frequency agility for wide-range
S&P is notably lacking in the P3, and again the difference comes out in
contest scores. 

The next generation will be software that can tag the waterfall display
with callsign information... but without having to buy an IC-7300. 
 
73 from Ian GM3SEK


>-----Original Message-----
>From: RTTY [mailto:rtty-bounces at contesting.com] On Behalf Of Bob Burns
>W9BU
>Sent: 29 September 2017 14:41
>To: rtty at contesting.com
>Subject: Re: [RTTY] New Radio
>
>On 9/28/2017 2:39 PM, Don AA5AU wrote:
>> ...but Icom could have made things a lot easier by just adding the
>> external RX antenna port to the radio to begin with.
>
>How many other currently-produced $1500 HF radios have a second
>antenna
>port or RX antenna port? Yes, the Kenwood TS-590SG does, but it doesn't
>have a spectrum display.
>
>Icom apparently built the IC-7300 to a price point. Given the other
>features included in the radio, there may not have been room within
>their price constraints to provide a second or RX antenna port...or a
>video output for an external monitor.
>
>Rob Sherwood NC0B gave a talk at the Dayton Contest University about
>"disruptive technologies" in which he discussed how SDRs have changed
>the HF radio landscape. His presentation talks about the IC-7300 and he
>estimates that Icom sold approximately 10,000 IC-7300s in the first
year
>of availability. Rob also discusses how he has used an IC-7300 in
contests.
>
>You can view Rob's presentation at: https://youtu.be/owaaT6u4XkY
>
>As for viewing the spectrum scope on an external monitor, there are two
>options:
>
>1. Use Icom's RS-BA1 software (approximately $100). It's a Windows
>program that provides full rig control of several Icom radios including
>the IC-7300. RS-BA1 can display the spectrum scope on a computer
monitor.
>
>2. Use N1MM+. The authors have tapped into the CI-V commands for the
>spectrum scope so they can, from what I understand, display the
spectrum
>scope as an extension of the N1MM+ band scope complete with worked
>stations and highlighted spots indicated on the spectrum scope. See
>https://youtu.be/nasSxs_ueK4
>
>Bob...
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