Archive for category Shortwave Listening

AA7AS 20m Propagation Report

Welcome to the AA7AS Propagation Report. Here, I give you the latest cold, hard scientific facts about what you can expect on the 20 meter ARO band.

Current Sunspot Cycle Analysis:

  • The current cycle has degraded below moped status. Further:
    • The chain has come off
    • Immediate status is stuck in a pothole
    • Handlebars are loose
    • The tires are flat
    • And… someone has stolen the seat
  • Protip: Clothes-pinning playing cards to the spokes is not a “linear” and will not count towards contest points.

That concludes today’s Sunspot Cycle Analysis.

Current f0f2

Current f0f2

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What is a Voicelid?

On the ham radio bands, a voicelid is an operator who is transmitting voice within, or partially within, a portion of the band traditionally reserved for data.

For instance, the USB carrier frequencies 14.230 MHz and 14.233 MHz have traditionally been reserved for slow scan television operations (also known as “SSTV”) for more than 50 years now:


20 Meter ARO Band

20 Meter ARO Band


So with regard to these frequencies, USB voice operation above 14.227 MHz (presuming 3 KHz voice bandwidth, which is generous) and below 14.236 MHz self-identifies the operator as a voicelid, as would (non-traditional, to say the least) LSB carrier point operation below 14.239 MHZ and above 14.230 MHz.

This is true both during non-contest and contest periods. Contests provide no legitimate excuse to intentionally interfere with others — that’s not radiosport. That’s simply rude, as well as outright forbidden.

This does not apply to USB voice transmissions on 14.230 or 14.233 that are actually SSTV related — those are part of normal SSTV operations.

So take a little time to learn about traditional non-voice allocations on all of the bands you operate within, and carefully respect the tiny bits of bandwidth they occupy. This is one of those important bits of operational knowledge that distinguishes the skilled radio operators from the unskilled ones.

#voicelid #sstv

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Kenwood and Yaesu, where are you?

ICOM’s R-8500, IC-7300, IC-7610 and IC-9700 are making huge impacts on AROs everywhere. This is no surprise to those of us familiar with SDR technology; older analog radio designs simply cannot offer the kinds of performance advantages a good SDR design can.

However, one thing these radios from ICOM have in common are some poor design choices; spectrum span choices are crippled compared to a center/demodulator tuning scheme; spectrums and waterfall displays that are insufficiently adjustable; noise blankers in the least useful portion of the signal path; insufficient “knobbiness”, so that the user interface of the radio is a great deal more clumsy than it actually needs to be.

The opportunity for Kenwood and Yaesu is clear: there’s an opening here to step in and knock ICOM off the hill they climbed up on.

Imagine a stand-alone SDR transceiver where:

  • You could conveniently place the spectrum/waterfall anywhere
  • You could adjust the amplitude/level of the waterfall and spectrum separately
  • The noise blanker reduced the noise on the display as well as in the audio
  • The display was capable of high resolution output to a monitor
  • Transmit pre-distortion provided very high quality TX
  • Important controls were given their own front panel placement
  • Full mouse/trackball integration was standard
  • Broadband IQ output was available for external use
  • Multiband EQ and compression / limiting for TX audio was provided

These are just some of the obvious places where ICOM’s radios, thus far, have fallen woefully short.

Yaesu? Kenwood? Where art thou?

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New SW station in West Australia up and testing

A new SW station is presently running test transmissions between 11:00 – 14:00 UTC. The transmitter is located near Perth, Western Australia, on 5,045 kHz, and is running 75 watts (300 PEP.) You can send listener reports to 77400fm@gmail.com.

At present, the station is ghosting the audio from sister station http://www.77400.fm/, so you can use that to confirm what you’re hearing.

It’ll likely be a tough catch here in the USA, but that’s the fun of it!

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An Interesting AM BCB DXer’s catch

KVCK, at 1450 AM, broadcasts a monophonic signal using the standard monophonic AM modulation scheme. The music feed to the station from its content provider, however, is stereo, and KVCK routes only one channel of that feed to its transmitter. So for any content that provides fully panned mix to the missing channel, no sound reaches the listener.

This problem has existed for decades, the station has been notified many times about it by email and in writing, yet it persists. The solution should be as simple as a stereo-to-mono cable or mixer, or, if the content is provided digitally, by a software setting or a call to the content provider.

That this has never been corrected comprises an interesting mystery with regard to KVCK, and makes it an unusual DX catch for BCB DXers.

Here’s a 20-second fragment of Marvin Gaye’s "Heard it Through the Grapevine"

First, here’s how it should sound. Pay attention to the ladies in the chorus from 13s to 20s:

Full mono, both tracks combined properly

Now, here it is from KCVK, on the afternoon of September 28th, 2016… listen again at 13s to 20s:

One track only (incorrect mixing at station or content provider.)

KVCK is like one of those double-struck pennies from the US mint. Very rare, and not a very good product — but interesting!

[EDIT:] Opportunity lost. They’ve finally fixed it, after many years. It’s a good thing. I guess. :)

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GAP 20m Monogap Vertical Dipole Review

I’ve been setting up a small trailer for use as a mobile, independently powered radio station for use at HF and VHF. To that end, it has its own deployable solar panels, internal power storage, and dedicated power conversion electronics. There are quite a few 12.6 VDC VHF and HF radios out there, and I own several, so the radios are less of a problem than a situation where I have to make some kind of fun decision between multiple good options.

VHF antennas are no problem. But the HF antenna… There’s the rub. If it’s to be truly portable, that means it cannot be large, and it will not be high in the air. Those are very significant drawbacks for most antenna systems; they directly impact both receive and transmit performance. So I went hunting. Eventually, I happened upon the Monogap 20 meter antenna, which is a vertical dipole; easily portable within the frame of reference of what can be safely transported in the bed of my pickup, light, easily mounted and unmounted, inexpensive, and — as it turns out — a surprisingly good performer.
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ICOM IC 7300 Transceiver Review

The

IC-7300

IC-7300

ICOM IC 7300 marks an important inflection point for the “big three” amateur radio manufacturers: The beginning of true software-defined RF processing from one end to the other.

As the first full SDR transceiver from “the big guys”, it is interesting to consider the price point, feature set, and performance both in light of the legacy analog designs, and as compared to what SDRs are known to be capable of.
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SdrDx 2.16a for OS X and Windows

Here we go:
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