Some years ago I acquired some superb…and originally very expensive…SEI Crystal Filters on 1.4MHz. I knew I had a USB and LSB pair, but didn’t know which was which and had no idea about the correct termination impedance. What I needed was SEI Crystal Filter Data…which no one had. There have been lots of questions […]
Getting the RPi Wobbulator working on a ...
This post is about getting your RPi Wobbulator working on the new Raspberry Pi 2 computer. It assumes you are already using one on the older Raspberry Pi’s. The Raspberry Pi Wobbulator Kit is available from Cut Price Cables and I can heartily recommend it..although there are quite a few SMD components to install. If […]
The Horophone Story
This is the story of an old and unique Edwardian radio, the Horophone…type ‘A’ in this case…and how it came to be discovered and shared with the rest of the radio fraternity. A bit of history first… In the earliest years of the 20th century, a certain Mr. Norman Hall, set up the North Eastern Instrument […]
Kenwood TS790E CTCSS
If you are the proud owner of a Kenwood TS790E, you may be rather miffed that it won’t work with modern repeaters requiring CTCSS tones; the TS790E was made in the days of 1750Hz toneburst for repeater access in the UK. Both Kenwood and their dealers will probably tell you there’s nothing that can be […]
The PW Epsom by G4AR
As you may have gathered by now, I’m quite keen on homebrew equipment…I don’t mind whether it’s valve or solid state; I do however avoid SMD projects if I can. One of my main interests is valve (or ‘tube’ if you live across the pond) receivers. There are quite a few to choose from including […]
Maplin Direct Conversion Receiver
There was a time when radio hams and electronic hobbyists seemed to have more time to build things. Maplin used to publish an excellent magazine in those days…for just 85p…that featured projects you could build, along with hints and tips for experimenters. In September 1988, Maplin introduced a really excellent Direct Conversion Receiver which many people […]
Reinventing the PS-304
The Daiwa PS-304 has been with us now for at least 25 years…and most are still as reliable as ever. A great design stands the test of time and guess what…Martin Lynch and Sons are now selling the MyDel PS-304 Mark II. Specifications: Input Voltage: 230V 50Hz +/-2Hz Output Voltage: DC 1.5V – 15V continuous […]
Toyocom TQF-456C Crystal Filter
You probably found this page as a result of a Google search for the Toyocom TQF-456C crystal filter. I seem to collect filters like this…in case they are useful in the future 😉 It seems that an eBay seller known as ‘hifissb’, who breaks down radios and sells their modules, has a large stock of […]
Microphone Connections
Finding the connection details for your favourite microphone or rig can sometimes be a bit of a challenge. I recently came across G4WPW’s website which seems to contain the connection details for every rig I’ve heard of…and many that I haven’t. You can find it here.
16×2 LCD Display Bezel
I don’t know about you, but when I build a project, I like it to look right as well as work right. Most holes you drill can be done neatly…and / or covered by a washer or knob…but there’s a problem with 16×2 LCD display bezels; there are thousands of displays to choose from but […]