Saturday, June 24, 2017

First 4m QSO - getting a transverter kit working

Almost a year ago I bought a 4m transverter kit from DF2FQ (XV4-40). I have basic understanding of electronics, acquired in part through the hobby but building a project like this was new to me. With my mechanical engineering background I am more confident in building robust stuff like antennas, masts, supports, baluns, etc. Soldering loads of tiny components on a board seemed challenging. 

However the level of documentation provided by DF2FQ and some motivating words by PG8M - who was already using the transverter - pushed me to the point that I ordered the kit. When I received the package I must admit it looked daunting. 

Lots of parts..
..and rather tiny

I started building the kit sometime in August last year. I tried to work as meticulous as I could (a challenge when you are as impatient as I am). When I had completed the kit and ran the first tests, I found that I received 70 Mhz signals with the radio tuned to 29Mhz. Hurray!

However, when I tried to transmit, the transverter appeared to be dead as a dodo. No LED, no signal. A very disappointing result. I did some tests (as far my knowledge goes) and could not find the cause of the failure. So the kit went back in the box it was shipped in. Time for other projects.

The Es season is rather good this year and I have enjoyed the effects on 6m but 4m was open a lot of times as well. I really had to get back to the abandoned transverter project. PG8M had already kindly offered to help me months ago and today I took him up on his offer. We went through the error checking process step by step, finding and fixing four major issues. It turned out I had made two soldering errors and two of the smd resistors were faulty. Whatever happened to these resistors I really don't know.

PG8M trying to locate the next error

The good news is that we ended up with a transverter that delivered up to 35W on 4m with 5W drive on 10m. 

There was no one around to do an on air test so back home I hooked up the transverter and put my tri-band yagi on a pole @2m high in the garden. PG8M was QRV 30km away with his 4 ele beam pointing in my direction. That is when I made my first 4m QSO.

DK7ZB tri-band beam in action twice this week

It is a bit late in the Es season but I am sure I will get back to this band in the future. The next thing I need is an antenna I can set up quickly at home in case of any high MUF situations. For 6m I use an end fed wire that I can attach to a pole that I push through the attic window. For 4m I am going to try a slim jim vertical. More on that later.


  1. Ziet er goed uit Lars. SMD is ook niet mijn hobby, veel te klein. Ben blij dat het voor je opgelost is. Kwam PG8M nog tegen volgens mij op de Jutberg radiomarkt. 73, Bas

    1. Tnx. Nu wel de smaak te pakken. Knutselhoek maar eens opgeruimd zodat ik een volgend project aan kan pakken. Marcel is idd te vinden op radiomarkten. 73, Lars

  2. Hoi Lars. Nou mijn complimenten dat je begonnen bent met de bouw. Smd is niet moeilijk alleen zijn de tekstopdrukken zo klein dat je ze niet door elkaar moet gooien en een vergrootglas erbij nodig heb.Gelukkig was Marcel de reddende engel en Bas, jij hebt inderdaad ook Marcel daar ontmoet. Ik heb julie nog aan elkaar voorgesteld. 73 Hans,PE1BVQ

    1. Tnx Hans. Het solderen van die smd's was prima gelukt - gebruik idd ook vergrootglas of telefoon (foto en dan inzoomen). Ze bleken dus alleen stuk te zijn. Hoe dat nou gekomen is weet ik niet.
      73, Lars.