Category Archives: General Article

Icom Remote Station setup

Too much QRM at your QTH?  No room for that monster 80m beam perhaps?  A remote station may be the answer!  All you need is a little place in the country (or a very good friend) where your (modern) transceiver and antenna array can live, some internet and problem solved!

Maybe you’re sick of lugging your rig on holidays with you?  5W from your 718 not enough?  Holiday antenna too much of a compromise?  Assuming you’re holidaying with internet, remote control is the answer!

Here’s how it’s done with the IC-7300 (step by step), courtesy of Bob McCreadie G0FGX at TX Films.  Skip to 17:24 if you’d just like to see it in action (and bypass the software install and setup):

The video addresses:

  • Setting up your computer and radio
  • Installing the RS-BA1 remote control software
  • Accessing the IC-7300 remotely
  • The RC-28 remote controller encoder (remote tuning knob)

To find out more about Icom’s remote control software, visit the RC-28 IP Remote Control System page (at Icom UK) where you will also find a list of compatible Icom HF radios.

For more information about the IC-7300 look here (at Icom Australia).

TYT MD-2017 Dual Band DMR Handheld – coming May 2017

As spotted by Steve VK2ZSW (thanks Steve!).

Remember all those dual band Chinese DMR radios that are coming to revolutionise the affordability of digital voice modes?  Here’s another one to add to the list, and it’s from the maker of the nearly ubiquitous MD-380 – TYT.  Interesting naming convention they’ve got going on here.

Article below from HamRadioReviews.eu, original post here – published Feb 15, 2017.

TYT just released the first ever image of the upcoming TYT MD-2017 dual band DMR handheld radio.

Back in November, a photo of a poster from PMR expo 2016 was published online, showing the MD-2017 model.  At the time it was still a rumor, as no other official information was released from TYT.  Just 10 minutes ago, the image you see above was published.  Still not at good resolution, but it provides some information.

First and foremost, it is no longer a rumour.  Second, the first 3 bullet points in the characteristics of this “leaflet”, indicate that it does support true TDMA.

It is rated as IP67 waterproof (which is always a plus) and has a GPS module.  Most likely, this will follow other models from TYT like the MD-380 or MD-390, which came in non-GPS and GPS versions.

Other than that, the model looks kind of chunky in size.  It has what looks like a proprietary antenna for waterproofing and a guard for the turning knob at the side.  There does not seem to be a channel-selection knob, which is kind of weird.  There are 4 buttons on the left side, with the PTT being in orange.  On the right side is the cover of the accessory port, which is screwed on for weatherproof-ness.

The keypad has two programmable keys (P1 and P2) which are shared with Menu and Back respectively.  Between them, there is a joystick-type rocker key with an extra button at the centre. Below these, the number keys with “0” at the left side.

The screen is colour and shows frequencies in large numbers.  This is also an indication that the radio is most likely designed with ham radio usage in mind, instead of the commercially targeted designs of previous radios from the company.

Here are the specs mentioned [my comments in square brackets]:

  • Dual time slot for point to point [they probably mean simplex]
  • Dual time slot for repeater
  • Use Time-Division Multiple-Access (TDMA) technology
  • Compatible with Mototrbo Tier I and II [we’ve seen that before]
  • Lone worker
  • Encryption function
  • Analog and digital combined [I hope this means something more, eg. watching analog and digital at the same time]
  • Single call, group call and all call
  • Remote kill/stun and activate
  • Firmware upgradeable

Expected release date is May 2017. No info on pricing yet.

New Pseudoscience – Earthing

Via the ABC‘s ‘The Weekly with Charlie Pickering’ S03E02, aired Wed 8th February 2017.

As Amateurs, we all know the importance of earthing things, right?  Did you know it’s good for your health too?  I’ll let this video explain….

Yes, that’s right – just earthing yourself through your nearest power outlet using an earthing product (starter kits only $199USD!) will help improve your health by letting you absorb the earth’s natural, electromagnetic energy while you work indoors or sleep!

Check out Grounded.com and Earthing.com for all the latest in Earthing goss.  Reconnect to the Earth, restore your inner balance & wellbeing!*

*speechless*

Here’s Kitty Flannigan breaking it down with all the respect it deserves:

*Not really.

Passive Intermodulation (PIM) Distortion

Bob VK2ZRE has forwarded the following info regarding a Passive Intermodulation (PIM) distortion – Bob adds:

This article may (should) be of interest to our members.  This is yet another mention and “explanation” of the “rusty bolt” effect.

In short, thanks to Keysight Technologies (emphasis mine) – Passive intermodulation (PIM) is a form of intermodulation distortion that occurs in passive components such as antennas, cables, connectors, or duplexers with two or more high-power input signals.  PIM in the transmission path degrades quality of the wireless communication system.

PIM is becoming a critical parameter recently due to installation of new technologies in wireless communication industries such as higher RF transmission power, multiband operation with a shared common antenna, or wider bandwidth signals with higher probability of PIM in the receiver band.

The article Bob has supplied is from Pasternack Enterprises who provide Low PIM cable assemblies, connectors, adapters, antennas and tappers designed to address applications where PIM can be an issue.  Note that this info is aimed at RF Engineers who work with LTE networks.

Pasternack writes:

What is PIM?

PIM, or Passive Intermodulation, is a type of signal distortion that has become increasingly important to detect and mitigate since LTE networks are particularly sensitive to it.

PIM is created when there are two or more carrier frequencies exposed to non-linear mixing.  The resulting signal will contain additional, unwanted frequencies or intermodulation products.  As the “Passive” portion of the name implies, this non-linear mixing does not involve active devices and is frequently caused by the metallic materials and workmanship of the interconnects and other passive components in the system.  Examples of causes of non-linear mixing:

  • Imperfect electrical connections: surfaces are never perfectly smooth so the areas of contact can have high current densities which can cause heating through a restricted conduction path causing a resistance change.  For this reason connectors should always be tightened to the correct torque.
  • Most metal surfaces have at least a thin layer of oxide which can cause tunnelling, or simply cause a reduced area of conduction. Some believe that this produces the Shottky effect.  This is why a rusty bolt or metal roof near a cell tower can produce a strong PIM distortion signal.
  • Ferromagnetic material: materials such as iron can generate large PIM distortion and should not be used in cellular systems.

As wireless networks become more complex with multiple technologies and system generations in use at a single site, the signals combine to generate this undesired distortion, which interferes with the LTE signals.  Antennas, diplexers, cables, and dirty or loose connectors can be sources of PIM, as well as damaged RF equipment or metal objects near or at a distance from the cell site.

PIM interference can have substantial impacts on the performance of LTE networks, which is why it is so important to wireless operators and their contractors to be able to test for, locate and mitigate PIM.  Acceptable PIM levels vary by system but as an example Test Company Anritsu said that drive tests have found an 18% drop in download speeds when PIM levels were increased from -125 dBm to -105 dBm, even though the latter number can be considered an acceptable PIM level.

Where is PIM tested?

Individual components are often tested for PIM both in the design and production processes in order to ensure that they are not significant PIM sources once they are installed – however, installation is still a critical piece of PIM mitigation because proper connections are critical.  In the case of distributed antenna systems, in some instances the system is tested for PIM as well as individual components.  PIM-certified equipment is becoming more common.  Antennas, for example, may be PIM-certified to a level of -150 dBc and those requirements are increasingly strict.

PIM is also assessed during the siting process for cellular sites, ideally before the cell site and antennas are placed as well as during the installation process.

Forgotten Audio Formats

Not Ham related, but here’s an excellent set of articles on Forgotten Audio Formats from (the always fantastic) arstechnica.com.  How many did you own?  How many did you have to repair?

Wire Recording

8 Track Tape

Elcaset

Digital Compact Cassette

The Highway Hi-fi

Talking Rubber (!)