This a dual band VHF/UHF radio of mine that was refusing to power on.
A fairly quick fix, there is a transistor which controls power switching into the radio circuitry, Q31. But it is well buried on the underside of one of the main boards. (Main Unit B)
Segment of circuit responsible.
Proving faulty Transistor.
New Transistor in place.
And the news for today…I can finally see the electronics workbench after a mega tidy up. About the first time in a year.
What’s that? It’s a very stable and accurate source of a 10MHz reference signal for the “lab”. About 20 years old and originally came from USA for CDMA mobile phone base stations. The device has been broken for some years and I’ve finally got around to mending it. More to follow…….
The Whitebox radio project has reached the prototype stage. Video is Bruce Perens explaining the architecture.
Whitebox is an open source Software Defined Radio project. The aim being to get an amateur radio handheld in your pocket which looks and functions like a smart phone. Which can offer analogue and digital modes such as DMR and D-STAR in one unit…
Here’s some photos of a 1950’s era radio which I restored and got working. It’s a compact mains powered radio for Medium and Long Wave, dating from the 1950’s.
For information and guidance on this sort of project, take a look at Ray Heffer’s excellent Web Site & YouTube Channel.
Here is a recent eBay buy. This is a 1950’s era teleprinter. Called the Creed 75. These type of machines were used on the TELEX service, where businesses could dial each other and type written instructions or orders to the receiving machine. The 75 was never accepted into use on the GPO system, but was very popular for private links and they were even used as early computer terminals.
I plan to overhaul the machine and get it working to an internet news feed.
Unfortunately, the initial test, of plugging it into the mains, resulted in my house being plunged into darkness. So some insulation testing and fault finding is first on the agenda.