SignaLink – cheap alternative for poor PTT / AUDIO via USB

This was a prototype, i’m not proud of it but it was cheap and working.


What’s inside ABBREE 47cm SMA-Female Dual Band VHF UHF 144/430Mhz Foldable CS Tactical Antenna For Walkie Talkie Baofeng

Teardown to see what’s inside:

Teardown of RT4 Radio Tone battery 4600mAh for Zello PTT smartphone

This is good real capacity battery.


What’s inside SignaLink USB Interface – Tigertronics

When i was making jumper connectors to set up SignaLink i decide to take couple pictures and show You what’s inside.

Radio Tone RT5 Android Zello PTT mobile radio – quick look at car network radio

Quick testing of RadioTone RT5 Zello PTT mobile radio (it’s dedicated to use in car but in mine application will be a base station).
First impression is good, very loud and clear audio , remind me very much DMR Motorola DM4600 especial round mic connector plug… and i like it 🙂
Keep in mind this is not a DMR radio, just android smartphone.

Vintage Psion Series 5 Palmtop Handheld Computer PDA with Epoc OS

Video and Pictures 🙂


20.05.2018 SSTV pictures recevied on 11m 27.700Mhz

I decide to check if there is activity 11m (27.700Mhz) – and Yes, in couple of minutes i received following pictures and decoded using android phone.


why visual inspection is important – fixing current limiting – Simple soft start for high power mains device before it fail

Here is simple example why it is important to do visual inspection on Your electronic applications.

In this case i was able to spot leaking capacitor before it failed and create more expensive failure.


Guess why it failed… maybe it’s because they use 35V and silk screen stated 50V?

Of course i will go for 50V… higher the better.

Another example why not trust in Chinese stuff 😉

Modification of original military issued handset H1089 to work with TRI PRC 152 replica radio

I got myself a TRI PRC 152 replica radio because I like size of it and overall look of this dial band radio.

My budget was low and I had to chose between ruler antenna or H250 handset adapted by TRI company to fit their radio.

I chose antenna,  but meantime i got myself a original military H1089 handset, nice green almost meet TRI prc 152 radio and would make a nice couple.


From electronic point of view there are couple problems:

  1. Impedance of microphone – it’s critical You can’t use without fixing it because You won’t be redable
  2. Pinout problem – don’t disable built in TRI PRC 152 replica radio internal speaker when plugging in original handset

Overall look:


Solve microphone problem, it’s possible to build transistor amplifier for original microphone but I don’t see point, You can get from e-bay tiny microphones for less then 1 USD and fit it inside and that’s way i chose.

Replace microphone for modern civilian (HAM)  – You can get it from almost any modern hand-microphone.



I puncture plastic film to get almost whisper readability (indoor as base station) – if You are going to use outdoor don’t do this because You loose watertight and can be hard to read in lout environment.



Fixing always on speaker mic inside radio by shorting A-E pin inside plug.

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If needed very lout sound – replace speaker inside handset for low impedance

Fixing Imation Disc Stakka storage CD/DVD automated carousel

Very simple fix of Fixing Imation Disc Stakka storage CD/DVD automated carousel.

It won’t eject disks. Cause was a damaged (loose) driving belt. There is not much force, so i replace it with a rubber band. Working perfect like new.