Monthly Archives: April 2015

Editorial: Designing a Perfect Portable Radio (HT)

Let me start with the history of the handheld radios that I have owned, and then I’ll get into my ideas of combining existing and new features into “my” perfect HT.  WARNING: This is a long article.  Scroll down to Part 2 if you want to get past my history bit.

PART 1 – MY HT HISTORY

Yaesu FT-470 HT Image from hampedia.net

So I recently purchased a Yaesu VX-8DR HT package for just about $700 (this includes programming software and cable, spare high-capacity battery, quick charge cradle, speaker mic and GPS unit to enable the built in APRS).  My last four HTs have been from Yaesu (FT-470 dual bander bought in the early 90s, VX-5R tri bander bought in 2000, VX-7R quad bander bought in 2006, and the new VX-8DR), and I still have all of them lying around somewhere.  To me, Yaesu is where it’s at with HTs.  That FT-470 was expensive when I bought it (I was in high school and anything over $100 was expensive.  I’m thinking the ‘470 was close to $400, it may have been less.  If Baofeng or Wouxon was an option then, I’d have probably taken it.)  The ‘470 was also big.  Especially when you had the good battery and the 12V charging adapter on it (picture on right is with the small battery.  The big battery was about 1½ times the size of the small battery.  The 12V/charging adapter fit between the radio and the battery).  It was also heavy, and would make a formidable substitute for a blackjack if you held it by the rubber duck antenna.  It could monitor VHF and UHF at the same time. Read more

Projects: FM radio with “old style” LED Bargraph Frequency display

Thorsten Singer’s FM Radio with LED Bargraph Frequency Display. Nice looking project!

Another gem from Instructables here.  This time it’s an FM Receiver with a custom LED Bargraph frequency display, brought to you by Instructables user Thorsten Singer.  The bargraph is cool and all, although I would probably add digits to the display to make it more tunable.  However, it’s a very well thought out project and nicely constructed, and it is something that you could use every day, so it gets points here.  Even the hand drawn schematic is classy.

 (image source: banggood.com)

TEA 5767 FM Receiver Module (image source: banggood.com)

It’s based on a TEA5767 FM Radio Receiver module that Thorsten bought from BangGood.com, who currently lists the price of these modules at 5 pieces for $5.51 USD, which is on par with some of the current Ebay prices.  The controller is an Atmega 328P chip with an Arduino bootloader (the Instructable has links to the source code as well).  It appears to have four pushbutton presets, and a rotary encoder for manual tuning.

Other than adding a digital display (I’d even go with a four digit LED display in lieu of an LCD, just to add class and glow to the panel).  I’d probably also add a dual LM386 amplifier circuit for the output.  This thing is so cool I may actually build one!

There is a short YouTube video below that shows the operation of this receiver.

Published from DFW, Texas

 

 

Projects: Masking a PC Board for etching-using the “Press’n’Peel” Method

Peeling off the “Press’n’Peel” leaves the laser printer toner behind as an etch resist. (Image source: Instructables user clacktronics-uk)

So I was once again cruising Instructables and I found this excellent tutorial explaining the “Press’n’Peel” method.  It has literally been forever since I have etched a custom PC board — it’s just too easy to use strip boards for those small projects (I’m a big fan of protoboards like the Adafruit Perma-Proto boards that have the same layout as a breadboard–it makes it really easy to transfer your prototype to a permanent project).

Anyway, this tutorial is pretty cool.  You use a laser printer to print your solder mask to a blue sticky sheet of plastic.  You then iron the sheet onto your copper.  When you peel it off, the printer toner is fused to the PC board and you etch as normal.

Looks easy enough!  Might have to come up with a project to try this with.

 

— Published from DFW, Texas