23 Feb. 2023 – SMD Soldering Practice

The evening began by Don, G4LOO showing SMD parts through a microscope which sent the  picture to a video projector and onto the screen.  The magnification must have been by hundreds of times.

As an introduction to SMD, members had seen the RSGB video showing the process of soldering such small parts. Seven members were brave enough to tackle the soldering during the evening. The hardest chore was identifying the actual SMD parts!  Some members had chosen to work on the SMD practice kit at home.

This practice session will continue next Thurs evening.

Members making a start
Don (left) checking the video
Close up Soldering

16 Feb 2023– Construction Winner’s Talk

Don, G4LOO began the evening with a quick run down of the RTTY contest of the week end. The score looks good and we await the final results.

The main programme started with Don’s explanation of his Weekend Project. The original details were published in PW June 2016. The item was an entry in the 2015 Hackaday one square inch competition.  Much later, Don acquired a commercially made board and started collecting the parts. The main delay in the building was the unavailability of a 74VHC4052 IC.  Upon completion the unit was plugged into an NTL dongle to up convert  HF frequencies to VHF

The One Inch PCB

The Kit Construction project explained next was Don’s Iceni 432MHz Transverter designed by Sam Jewell G4DDK.  Don added a 30W Power Amplifier and control circuitry to the complete the project.

The Kit Construction Project

The Major Project was a 70MHz 300w Linear Amplifier which Don started with a part assembled kit from Enigma Components Ltd. Combined with a 48v and 12v power supply with coax changeover relays and LCD display controlled by an Arduino control unit, the finished project can handle an SWR of more than 65:1. It has been tested into open and short circuit loads at the output without damage. With efficiency of about 70% at 350W with 48v the power gain is more than 22dB equal to 2W input for 300W out. The harmonic output is less than 70dBc at 140-150MHz.

The 70MHz 300w Linear Amplifier

It’s no wonder Don had been chosen as winner in all three categories in this year’s construction Contest!

 

 

2 Feb 2023 – Soldering SMD videos – Don, G4LOO

Credit:By Aisart – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4071999

The first video showed how professional production companies use state of the art equipment to solder surface mount devices to thousands of boards in minutes.

Next was an RSGB video introduction to surface mount device soldering for the radio amateur. It was apparent that good light and magnification were essential. The video showed step by step methods for different size devices and what to look for in good and bad solder joints.

It was pointed out that on another evening in the club’s programme, members would be given a chance to do their own SMD soldering practice using a small kit of parts provided by the club.

For those who would like to review the details of the methods used in SMD, view below: