Mastodawn

Filip SP9GMD Sep 9, 2025

🚀 DIY RF PCB kit nightmare! Designed an enclosure for a friend’s antenna tuner kit and fixed major flaws:

Weak PCB mounting — only 4 screws? Added 3D-printed supports.

Tiny coil pads — desoldered and reinforced.

Wobbly coils — stabilized with silicone potting.

Poor cable connectors — no connectors or strain relief.

Hand-drawn traces and awful via stitching — leaked silicone through gaps!

Bad RF grounding.

Ever seen worse? Share your stories!

Filip SP9GMD Sep 8, 2025

Another successful repair!

Marconi 2955 radio test set was developed in 80s. It can be still used nowadays for setting VHF/UHF radios.

This particular set didn't boot.

It turned out there were two reasons:
- shorted +12V line on PSU board
- broken 10MHz clock cable

After two hours of careful troubleshooting it works like a charm!

Filip SP9GMD Mar 6, 2025

🎄 Christmas Gift Hack: SILVERCREST SHZK 600 B3 Vacuum Cleaner 🧹

Got this vacuum as a gift, but the HEPA filter clogged quickly. Solution? Add a pre-filter! 🧼 Place a small piece of cleaning cloth or paper towel before the HEPA filter. Replace it when suction decreases. Easy fix! Have you hacked your vacuum cleaner? 🤔

#LifeHacks #VacuumCleaner #DIY #CleaningTips #SILVERCREST #Lidl

Filip SP9GMD Mar 4, 2025

🔧 Yesterday’s Lab Power Supply Adventure ⚡

I repaired a Topward TPS-4000 lab power supply from the 1980s. It has two 30V, 3A channels in a master-slave setup.
🛠 Issues:
🔸 Slave channel dead – a shorted Zener diode and bad LEDs/transistors.
🔸 Master channel unstable – turned out to be a cold solder joint on the main capacitor!
📖 The service manual was a lifesaver, and the build quality impressed me.
Ever had a repair like this?

#electronics #repair #hardware #engineering

Show thread

Filip SP9GMD Feb 1, 2025

⚡ The worst via stitching I’ve ever seen – Vias are too large and sparse; they seem randomly placed (likely by hand). Altium and KiCad have automated via stitching—why not use them? And remember my silicone potting fix? The first time I tried to pour it, it leaked through the huge vias… $18 worth of silicone compound wasted. Had to use a thicker variant the second time. 🤦‍♂️

Show thread

Filip SP9GMD Feb 1, 2025

⚡ Poor cable mounting – Surface-mounted cables with random pitch make repairs a nightmare. The designer could have added mounting holes or, better yet, used cheap JST connectors. Also, RF PL259 or N-type PCB connectors would have been a much better choice.
⚡ Poor grounding – The metalized areas around the screws are too small, meaning poor RF grounding. In high-frequency circuits, that’s a serious issue.

Show thread

Filip SP9GMD Feb 1, 2025

⚡ Unstable coil mounting – The coils should be either glued or mounted with plastic supports. Otherwise, they wiggle, leading to cracked solder joints. I designed 3D-printed enclosures filled with silicone potting compound to provide thermal transfer and stabilization.
⚡ No clearance guidelines, random trace widths – Looks like the polygons were drawn by hand. A proper RF PCB design workflow should ensure consistent trace widths and clearance rules.

Filip SP9GMD Feb 1, 2025

🚀 When a DIY RF PCB kit goes wrong…
A Friend’s Antenna Tuner Project
A friend of mine asked me to design an enclosure and finish assembling an antenna tuner kit sold by Dx World. Sounded like a simple task, right? Well… what could possibly go wrong? 🤔
Turns out, quite a lot. Read breakdown of the biggest design issues I encountered in the thread!
💡 Can you find more flaws? Share in the comments! 🔽

#RFDesign #PCB #Engineering #Electronics #Hardware #PCBDesign #RFAntenna #ElectronicsFail

Show thread

Filip SP9GMD Feb 1, 2025

⚡ Weak PCB mounting – Just 4 screw holes? Not enough! The board bends when held, which is a big no-go for a field-use device. This could have been easily avoided by considering mechanical durability during design. I had to 3D-print additional plastic supports to fix it.
⚡ Tiny soldering pads – The coil pads are way too small. Since most coils are wound on low-permeability iron powder cores, the connections got loose during shipment. My fix? Desolder, remove solder mask, and reinstall

Filip SP9GMD Jan 30, 2025

@SitaDulip I am programmer by trade, too :) You can start with cheap software defined radio like Chinese MSI2500 or RTL SDR. Just use random 20m of wire hanging from window as antenna and you can listen to ham contacts. If you get hooked - go for exam, buy some radio like Xiegu G90, Quansheng handheld and try to find what you like the most about ham radio. Ham fests? Field operation? Casual Sunday contants? Thinkering with equipment? You need to try on your own, because it's matter of preference :)