HAMNET Report 6th December 2020

Folks, yet another Tropical Cyclone is on its way towards India and Sri Lanka. GDACS is reporting on Cyclone Burevi -20, not with extremely strong winds yet, but threatening the vulnerable East coast of India, and Sri Lanka just below it. The provinces of India along its Eastern coastline are still drying out from last week’s storm, which was directed in a more Northerly direction, and apparently spared Sri Lanka.

Here’s an insert from the website HACKADAY, written by Jenny List, but quoting Robert Bolton KJ7NZL, who has scathing things to say about amateur radio’s preoccupation with disaster communications. She writes:

”As many a radio amateur will tell you, ham radio is a hobby with as many facets as there are radio amateurs. It should be an exciting and dynamic place to be, but as those who venture forth into it sometimes sadly find out, it can be anything but. Communities whose interests lie in using $1,000 stations to chase DX (long-distance contacts) are often tightly knit, there is an advancing age profile, and a curious fascination of many amateurs with disaster communications. It’s something Robert V. Bolton, KJ7NZL has sounded off about in an open letter to the amateur radio community entitled “Ham Radio Needs To Embrace The Hacker Community Now More Than Ever“.

“In it he laments the fact that the influx, in particular of those for whom disaster preparedness is the reason for getting a licence, is to blame for amateur radio losing its spark, and he proposes that the hobby should respond by broadening its appeal in the direction of the hacker community. The emphasis should move from emergency communications, he says, and instead topics such as software defined radio and digital modes should be brought to the fore. Finally he talks about setting up hacker specific amateur radio discussion channels, to provide a space in which the talk is tailored to their community.

“Given their experience of the amateur radio community hackers are bound to agree with him. The hobby offers unrivalled opportunity for analogue, mixed-signal, digital, and software tinkering in the finest tradition of the path set by the early radio amateurs around a hundred years ago, yet it sometimes seems to have lost its way for people like hackers.”

A thought-provoking article for people like us, because we have a desire to be of assistance during emergencies, transmitting valuable information, instead of just tinkering, chewing the rag, or chasing DX. Clearly, the EmComm individual is different from the rank and file radio amateur in some ways, and the electronics hacker wishes to be amongst the experimenters in amateur radio, and not allied to the operator who views the message as more important than the equipment used to convey the message.

Well, the 53 year old Arecibo Radio Telescope certainly took it upon itself to self-destruct this week, as the suspended platform with all the receiver front-ends above the dish built into the ground, broke free from its remaining cables and crashed in to the dish. The twitter feeds have been full ever since of important scientists who had been using the dish and its receivers and transmitters for research, reminiscing about the observatory and its feats. There were several suggestions that an attempt should be made to build another radio telescope of such magnitude in the Western Hemisphere to replace it. I didn’t realize that the Chinese FAST facility can only operate for 12 hours a day, severely limiting the amount of research time available to the world. It also is unable to do radar, because the instrument platform suspended over its dish is too small for the radar apparatus needed, and it also has receivers up to 3 GHz only, unlike Arecibo, which had equipment functioning up to 10 GHz.

So my remarks about FAST in China being an acceptable substitute for Arecibo are not strictly true. It would seem that the gap left by Arecibo’s demise is greater than we imagined.

May I remind you that the strongest signal ever broadcast from Earth out towards the stars came from Arecibo? In 1974, the broadcast formed part of the ceremonies held to mark a major upgrade to the Arecibo Radio Telescope. The transmission consisted of a simple, pictorial message, aimed at our putative cosmic companions in the globular star cluster M13. This cluster is roughly 21,000 light-years from us, near the edge of the Milky Way galaxy, and contains approximately a third of a million stars.

The broadcast was particularly powerful because it used Arecibo’s megawatt transmitter attached to its 305 meter antenna. The latter concentrates the transmitter energy by beaming it into a very small patch of sky. The emission was equivalent to a 20 trillion watt omnidirectional broadcast, and would be detectable by a SETI experiment just about anywhere in the galaxy, assuming a receiving antenna similar in size to Arecibo’s.

The tweeted messages record the sadness with which the scientific community, who were already mourning the decision to decommission the radio telescope anyway, views its self-destruction. Let’s hope that future funding can be found to build a new one.

Pieter ZL1PDT, ex ZS1PDT, has sent me a link to a 15 minute YouTube video, extracted from the American TV channel called Ham Nation, in which Valerie Hotzveld, NV9L, visited Arecibo, and actually climbed down into the instrument platform at Arecibo to view the feed horns and receiver front ends, suspended above the dish. This can be found at https://youtu.be/IqGnnpwEwug. Please see this written report on the SARL website front page under HAMNET, to find the URL, if you didn’t catch it.

TX Factor is back with another episode, this one episode 27. There is a visit to the home of the editor of Practical Wireless Don Field G3XTT, who moved home a year ago. The TX Factor crew visited him and his station to find out how well he has settled in. Then there’s a discussion about setting up an OpenSpot Gateway for mobile digital use, and finally the General Manager of the RSGB, Steve Thomas M1ACB talks about the amazing media response to this year’s amateur radio revival during lockdown.

This is all available at www.txfactor.co.uk

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.