End fed wires – new hams love ’em

Hams impoverished for space to erect a ‘full size’ antenna for HF pursue a range of options and end fed wires figure highly.

New hams who heard the maxim that ‘any antenna is better than no antenna at all’ will try to use bed frames, window frames, balcony railings, anything metallic to get on air. This cry for mediocrity is to prevail over a quest for understanding, ham radio as it has evolved.

The ‘net abounds with conflicting advice:

  • (Yates 2010) recommends a T50-2 powdered iron core;
  •  (VK2AVR 2014) states do not use a powdered iron toroid.. they won’t work.

They cannot both be correct. Continue reading End fed wires – new hams love ’em

TNC-X – channel access behaviour

I have been investigating ‘lost APRS packets’, a result of many root causes.

One is a perception that when I drive in the local area, I often do not hear my own digi ‘echo’ yet I find that it did receive a packet and submit it to APRS-IS. This problem is much more apparent using a TNC-X that with any other KISS TNC in its place. Continue reading TNC-X – channel access behaviour

Does anyone assess to their digi / iGate performance?

During recent evaluation of a range of APRS servers and TNCs, I have inspected APRS-IS records and my own server logs to identify possible anomalies caused by the equipment under test.

In that time I have found defective records caused by digi / iGates: VK2JMA-5, Vk2YGV-5, VKWUWP-2, VK2UWP-1, VK2MPJ-1,VK2ZEN-5, VK2AMW-1, VK2RHR-1, VK2LKH-1, VK2MB-1, VK2BEN-1. Continue reading Does anyone assess to their digi / iGate performance?

The mobile APRS W2 digi left town this morning

APRS is characterised by a lack of standards or guidance, but mostly by a lack of compliance with those standards and a lack of understanding and common sense.

VK2UWP is travelling around the countryside and from the look of it, setting up a WIDE2 digipeater in the local caravan parks without regard to its dysfunction. Continue reading The mobile APRS W2 digi left town this morning

TNC-X – DCD behaviour

I have been investigating ‘lost APRS packets’, a result of many root causes.

One is a perception that when I drive in the local area, I often do not hear my own digi ‘echo’ yet I find that it did receive a packet and submit it to APRS-IS. This problem is much more apparent using a TNC-X that with any other KISS TNC in its place.

A possible explanation is that it did echo but I did not hear it due to collision with another digi.

So that led me to explore whether TNC-X fails to quickly detect the other digi already transmitting. Continue reading TNC-X – DCD behaviour