The Ponk Room Blog

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2021-08-22 Raspberry Pi
2021-08-18 Vintage or Obsolete ?
2021-07-22 IFrames
2021-07-21 Placing images and captions
2021-07-19 HTML Text Editors
2021-07-14 Le Jardin
2021-07-08 Synology releases Version 7 of DSM
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2012-11-28 Mostar Bridge
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About The Blog

The list above shows tha last 15 entries. I'll probably change the selection method to a date based system once there are a few more entries. Click an entry title to see it.

This is the blog which used to be on another of my websites, now defunct (www.cobblers.org.uk). The last post was 8 years ago I moved it here without any problems. The editing functions have been brought up to date, so I can now add new entries and upload pictures. The display code (text) has been updated too e.g. the broken links are either removed or fixed.

25th June 2021

Vintage or Obsolete ?   

Posted On: 2021-08-18 12:10:35

Tech becomes dated very quickly these days

Yaesu FRG 8800 comimunications receiverI bought this Yaesu Musen FRG8800 receiver back in the early 80s. It was, at the time, a top of the range, full featured communications receiver. And  I was, at the time, a  very keen amateur radio enhusiast, so we were a good fit ! I used it for about 12 years or so, then my interest in computers took over from the amateur radio. The Yaesu went into the cupboard, along with a lot of other radio-related stuff. Somewhere around 2006 it became "vintage" according to one of Google's definitions. Anyway, during the COVID lockdown I had this yen to do some short wave listening and see if I could still read morse code, so I found the Yaesu ( which had got right to the back of the junk cupboard by now ) and plugged it in, but it was dead, no longer working. I had no hope of fixing it without a circuit diagram and a 'scope and signal generator at the least, so it has moved, in an instant  from "vintage" to "junk". It is also obsolete because the methods it uses to process radio signals have been replaced by other techniques, Now there are no IF transormers, no tuning coils, no superhet conversions, no tuning range switching,  to name but a few techniques which are no longer used. If you are interested in really old radio communications equiment, take a look at Alan's Radio Museum.

So when I went looking for a replacement for the Yaesu, at first I could not find anything comparable. That, of course, is because now there is nothing comparable. Then I stumbled upon a  web site explaining SDR ( Software Defined Radio ) and I realised I had missed the revolution ! This little Airspy HF+ Discovery SDRblack box is the Airsspy HF+ Discovery which tunes from 500kHz to 31Mhz and 60Mhz to 260Mhz all in the space of 45 x 60 x 10 mm. The RF bits are in the black box and a USB cable ( not shown ) connects to a PC ( Win 10 ) which supplies poewer to the SDR and where an SDR program displays the digital output from the box on a sceen which emulates a receiver, with controls, switches, indicators and so on.  You can get the idea from this website. Their SDRs, so the blurb says, wil  also run on Linux amd Macs, and the PC can run a variety of other software packages,, most of which are free. Pictures on this company's web site imply you can plug the USB output into eg a raspberry PI  which can connect via your router to the house WiFi, so you can see the output and tune the receiver from anywhere where you can connect to your home network. I intend to investigate this.

A lot of investigation and experimenting called for here. I am wary of a lot of the stuff on YouTube, Some of it makes sense, most of it is just plain wrong and some of it pointless - e.g. a 2 minute video of some wally opening a parcel which contains an SDR. If you need a UTube video to show you how to open parcels, you are going to struggle joining your SDR bits together. I think you will learn more by looking at the application notes of people like Analogue Devices who are one of the companies making the chipsets for SDR. This is an interesting and easy to read note about the  history of radio development..

Anyway I have just bought (17th Aug 2021 ) an Airspy HF+ Discovery and a Raspberry Pi V4 so I can start doing some experiments. No mention of aerials (antennae) yet, but I'll talk more about them in some future episode of this blog after I get the hardware working.. More later !