My Dad used to have an engineering workshop that included things like lathes, milling machines, drilling machines and the like. After he passed away we sold his workshop equipment at Mum’s request. I wish I’d kept his green Myford lathe, but I wasn’t ready for one at the time. I’ve needed various bits making over […]
Microwave Modules 15dB Attenuator
The Microwave Modules MMT1296 and other transverters, rely on a 15dB attenuator between the transverter and the driver radio for matching. When these transverters were designed, 10W output base and mobile transceivers were the norm. When you buy a second hand transverter, these attenuators are often missing. I had a similar experience and wondered what […]
Maplin Ranger 160m Receiver
Maplin produced another little receiver, in addition to the famous direct conversion project from 1988…it was called the Maplin Ranger. The 160m receiver covered from 1.8 to 2.2MHz and was designed for AM, SSB and CW. This time the receiver is a ‘proper’ superheterodyne design with an IF of 455KHz. I obtained one of these […]
Blekok Micro-40S SSB Transceiver
The Micro-40S is a single board SSB Transceiver by Indra Ekoputro YD1JJJ. I didn’t buy one of these thankfully, but a friend brought one for some TLC. These things are supplied rather badly, ready built and working. The one that came to me had a short circuit IRF510 output PA MOSFET. An easy fix but […]
STE (Milano) 2m VHF Tx and Rx Modules
I recently acquired a homebrew transceiver from the Angel of the North Radio Rally. It’s a 2m / 145MHz FM unit with crystal control, that outputs a heady 1W of RF. Crystals are installed for the local repeaters and simplex channels used in the 1980’s, when people actually used 2m before upgrading to a class […]
3B/240M Tube on HF
Has anyone out there ever used a 3B/240M (CV2214) valve / tube in an HF amplifier? I came across one of these, new and boxed, amongst my collection of treasured family heirlooms…it looks like a miniature 5B/254M but isn’t. The 3B/240M or CV2214 is a small grounded grid triode for use up to 200MHz. It […]
SEI Crystal Filter Data
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 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 […]