Author Archive
SDR receivers and transceivers
March 27th, 2017 | 
Author: There is a real gap in my knowledge as I have never once tried an SDR based receiver or transceiver. SDR dongles are very low cost, so I really have no excuse.
On the Southgate site I read news of a new SDR 5W transceiver.
Pipit – 15m QRP CW transceiver
Many years ago I designed and built the Pipit, an 800mW CW transceiver with a direct conversion receiver. It really worked and for some time was my main rig. Used with a low dipole it worked some decent DX. The design was published in GQRP “SPRAT” many years ago.
Sadly, the rig was dismantled some years later. I regret this!
Amateur radio below 9kHz
Until a few years ago, the conventional wisdom was that you needed huge power and huge antennas to be copied “beyond the garden fence” at VLF and ULF. In recent years much has changed and time and again great distances have been covered by amateurs with quite low power and modest antennas.
The trick is great stability, very narrow bandwidths and long integration times, often of days. For several years just detecting a carrier was enough, but in recent times people have been sending simple messages using EbNaut software.
When at the old QTH I detected signals from several European countries using simple, homemade gear and free software.
Although not totally up to date at all times, I try to update news of amateur VLF and ULF experiments at https://sites.google.com/site/sub9khz/ .
Simple yagi for wi-fi router
This was first seen some weeks ago and I saw it earlier today in an email from Twitter. It shows you how to make a simple add-on yagi for your wi-fi router.
In my case I get sufficient range with the router “as is”. You might find it useful if you need to increase the range in a certain direction. It is a simple idea, which I like.
See https://hackaday.com/2017/01/24/a-simple-yagi-antenna-for-your-wi-fi-router/ .
OFCOM and 5G frequencies
OFCOM has published a paper outlining its proposed 5G frequencies.
See http://ofcom.cmail19.com/t/ViewEmail/i/7261046CD05FE3E5/59D1BD3EA2F08127C67FD2F38AC4859C
Our hobby in 30 years?
Although I cannot speak for other countries, here in the UK ours is a hobby mainly of older people and mainly men. When I was fitter, I gave several talks to local radio clubs in East Anglia and without exception, it was mainly OAPs who came along. OK, there were a few youngsters and women, but the vast majority were older men.
Amateurs and SWLs are a dying breed unless we can attract young people into the hobby. I am 67 and will be dead within 30 years, probably a lot sooner. An aging population will not buy so many rigs, will not support magazines etc. Numbers will fall, activity will fall, interest will drain away.
In 20-30 years we will be very much in uncharted territory. What will our hobby be like in years to come?
Heathkit Pipetenna
The resurrected Heathkit company has launched a dual band antenna. As much as I want them to succeed is this the best they can do?
They absolutely have to produce decent kits at decent prices or they will not survive. Their offerings so far do not exactly set the world alight. No, the offerings so far have not excited me. Years ago I started out with a Heathkit Electronics Workshop. Years later I had an HW8 which gave me loads of contacts with small wire antennas.
Please, think of your potential customer base, think about prices, and look at your competitors. I have no doubt a few loyal USA customers will support you, but far far more is needed in the competitive world of the 21st century.
