PH2LB shack on the internet.

QRP-Labs QMX+

This page is work in progress and may be updated frequently (last update : 2024-04-23 14:41 UTC). 

Page content (needs update, derived from QMX page) : 

• Introduction
• The postal services 
• The manual
• Let start building   
• Control board 
• Mindfull toroid winding
• Again mindfull toroid winding
• To Buck or not to Buck
• Smoke test
• Boxing it up
• My tips

Introduction

I own a QMX now for over a year and although I'm terrible at CW, it's a nice little rig and a great kit to build. One thing I and a few other OM's where dreaming about was a QMX in a QCX+ style case so there was more room for experiments and mods. So once in a while this was mentioned in QRP-Labs.group.io group  and we kept dreaming of this  great addition to the QRP-Labs product catalog.

Then out of the blue, at the FDIM in Dayton, Hans Summers releases a new product: new QMX+ multi-band multi-mode transceiver. Turns out, he has been secretly working on it for the past year.  So when he added it to his webshop I didn't hesitated for a moment and ordered one.

Once again the waiting started. 

When the postal services screw up aka don't handle with care

After 2 weeks, my neighbor texted me that he has accepted a package for me (for some reason the package wasn't allowed to be dropped in my parcelbox) and I was as happy as a pig in the mud.

That evening I picked it up and the joy I had first turned to fear once I opened the bag the package was put in to. It seem that my shipping from QRP-Labs got some damage to the box. 

 

Opening the box and carefully unpacking the content which took some time (the QRP-Labs employees know how to wrap things up), it seem that there wasn't any damage. 

   

But unfortunately after closer inspection, I found that on the mainboard C501 and L501 where damaged. Although all the parts where nicely wrapped and packed, the force placed on the package must have shifted some parts, and put force on these to parts which are the highest parts on the mainboard. :-(   

  

C501 was torn off at the GND side taking his GND pad with him and L501 was damaged on the top top (missing 1/3 of it's top). I contacted Hans Summer through his Service Desk System and asked him if he could let me know the manufacture part number so I could order a replacement (I'm SMD capable so replacing a few SMD components is no problem). L501, seemed to be intact (resistance aprx 2 ohm), but I wasn't sure if the damaged top would negative effect the inductance. He ensured me that that damage happened to him also a few time, and it didn't have any negative effect. So that was one worry less. The C501 was a different story. He didn't have the parts in stock (his PCB's are manufactured in China and so all the parts are in the factory), but told tell me it was a standard 470uF 10V tantalum in Case D. I told him that I would hunt for the part my self at a few local suppliers, and Hans (great guy he is) offered to de-solder a cap from a stock PCB when I couldn't get any. 

But luckily my local supplier could order a bunch (minim order count 5), so after a week it got a call from my supplier that he got the parts. Take a hour me- eh shack-time, I removed the damaged ground pad and make a new one by scraping of the paint of the PCB and soldering a piece of silver wire on top of it. The cap was installed and although I can't test it, I have a good feeling about it.

 

With that fixed I could put it aside for the next shack time opportunity.  

The manual

As with every kit which Hans sells, the also was a very nice manual for the QMX multi-band multi-mode transceiver (scroll down to documentation).  Chapter 1 contain a Introduction  Chapter 2 contains a list building general guidelines, images of the PCB layouts (track and component placement),  technical specification and the full Parts list of all components in the kit and photo's of a finished QMX+ allowing to kit builder get a idea about what to expect. And after sub chapter 2.3 Inventory parts helping the starting kit builder to identify parts, the fun starts.

Let start building 

Just to be different I started with the front / control panel as mentioned in chapter 2.19 of the  manual. 

Control board and LCD display

I sorted all the parts, double check the PCB under my microscope and all the signal gave green, 

I started with the assembly under the (not so) watch full eye of Shack cat Moppie.

Some things that came to my mind / I have done different from the manual : 

• 2.20 - when soldering the female pin headers JP301, JP302 and JP304, don't try the squeeze your soldering iron between the pins. Just solder them from the side (outside / in).
  
  
  
  
• 2.21 - when installing CR2032 battery holder, I pre-tined the GND pad on the PCB a little, and pushed the  CR2032 battery holder in place while heating it again, soldered the + side and after that applied a little extra tin to the GND side pad. 
• 2.22 - when installing the microphone, you find out that it's hard (impossible) to place the microphone on the PCB. So I used a small piece of doublesided foam tape to fill up the space and make it easier to solder the microphone in place.
  
  
  
  
• 2.23 - when soldering the  push-button switches S302 and S303, solder a non ground ping first and check the alignment of the button (it should be flat on the PCB). Soldering the non ground pin first makes it easier to adjust when needed.
• 2.24 - when installing rotary encoders S301 and S304, do what Hans write : do NOT solder the push button pins (the pair near the mounting hole) from S301 (yet, we get back to those).
• 2.25 - step 1 - I'm a rebel, I leave the protective film on the LCD ;-)
• 2.25 - step 3 - don't forget to bend the LCD tab closes to pin 1 of the LCD
• 2.25 - step 4 .. 5 -  to encourage the screw through the holes of the LCD, turn them each a few turns after another, don't try to force them. (tools I used are mentioned below).
• 2.25 - step 11 - I didn't like this order. Next time I'm going to solder the header first to the LCD PCB and later to the PCB (but would stack them first using the screws and nuts to get the best alignment).

And done

 

Product placement ;-) 

Recently I needed to replace a few (micro) screwdrivers in my shack because after more then 30 years of usage, they just worn out. I could have replaced them individually,  but Amazon.nl had a good offer on the Wera 0513400001 Kraftform Micro Big Pack 1. I have used the tools before and they a great. So having some hobby budget left, I bought it for my self.

For the assembly of front panel I used: 

• WERA Kraftform Micro Electronics  2069 Nutdriver for electronic applications 051181260011x 5.5 x 60 mm
• WERA Kraftform Micro Electronics  2050 PH Screwdriver for Phillips screws for electronic applications 05118023001 PH 1 x 60 mm (it's not in the set but worth having it added to it).

Hint : when you are asked if you know a (holiday, season, christmas, birthday, etc) gift, do your self a favor and ask for this set from WERA. It's a great set to have in the shack when you are into repairs.
 

But it's 23:00 local time, so enough for this evening.

 

 

Mainboard construction : install a bunch of true hole parts

Section 2.5 of the manual describes the 32 through-hole ceramic capacitors to be installed. I sorted all the capacitors and wrote down the value on the paper tape.
Only 2 capacitors didn't have paper tape, so I installed them first.

For the installation, I decided to work group by group. IMHO it has the following advantages :

• You work in small iterations keeping a overview what you are doing.
• You keep track of the parts.
• You preheat the area a little making the soldering go easier (especially the GND pins). 

The image above shows C522 already installed. C522 was one of the capacitors which didn't have a paper tape on the legs.

Some things that came to my mind / I have done different from the manual : 

• I place the parts, bend the legs a little so they stay in place when I turn over the PCB. Then I always solder one pin of the part (or group of parts), then turn over the PCB again, check if the parts are correctly inserted (sometime they drop a little when you turn over the PCB) and adjust when needed.
• With this PCB (6 layer multi-layer PCB) it's good practice to solder the non-GND pin first, and after straiten the GND pin, trim the GND pin (not to short off course), then solder the GND leg. Remember it takes time to head everything. 
• When you cut of a pin, don't let it jump away (some cutters have a small spring to prevent that). Through it away in the bin or put it in a container. This will prevent sparks flying around when you are testing on the workbench.

 

All C's in place. 

And no parts left. So I must have done something good ;-)

Section 2.6 describes the installation of the 12 1N4007 diodes in which Hans writes : 

One lead of the diode needs to be bent over. It doesn’t matter which one, all that’s important is
that the cathode (white stripe) is correctly soldered to the pad at pointed to by the arrow. I chose to
bend the diode lead with the cathode.

I also chose to bend the diode lead with the cathode, that way, when looking at the schematic you can easily pick up the signal for and after each LPF (Don't know if the PIN diode construction is preventing this, but I will see that in the future). 

All diodes are in place and allowing me to pick off the signals in the LPF section easily.

Section 2.7 describes the installation of the 8 47uH inductors. Installation is straight forward and when bend nicely no problems are to be expected.

Section 2.8 describes the installation of the BS170 PA transistors. Not difficult but it's good to read the manual. 

At the bottom, the head of the M3 bolt comes quite close to IC503, so I checked it for shorts, but luckily it didn't. 

After this it was enough for today.

Next step, lots of transformer and toroid winding. 

To be continued

Mindfull toroid winding

Kind of . . .   

TODO ADD CONTENT   

 

Again mindfull toroid winding

 TODO ADD CONTENT  

  

To Buck or not to Buck

And Buck it is.... 

TODO ADD CONTENT  

 

 

 

Smoke test

TODO ADD CONTENT  

  

How much does it throw?

Using my OZ2CPU digitale RF mW-dBm-mV meter in combination with the -40dB RF Sampler I will measure the power output for the various bands.

TODO ADD CONTENT  (CHANGE PICTURE BECAUSE IT's FROM THE QMX)

 

TODO ADD CONTENT  

  The power outputs where (for 9V):

• 160m - x.xx W
• 80m - x.xx W
• 60m - x.xx W
• 40m - x.xx W
• 30m - x.xx W
• 20m - x.xx W
• 17m - x.xx W
• 15m - x.xx W
• 15m - x.xx W
• 12m - x.xx W
• 10m - x.xx W
• 6m - x.xx W

 

Boxing it up

The last step for this build was boxing it all up. And for that I followed Hans his manual section 2.27.

TODO ADD CONTENT  

 

First time FT8

A good way to check your rig is to run a few FT8 session with it. First RX and after that TX.

TODO ADD CONTENT  (PICTURES)

 

My tips

Some tips I would like to share: 

• Don't work on the QMX+ late at night.
• Read the manual (twice) before soldering.
• Take regular breaks with a beverage of your choice (alcohol based beverage, may seem to relax, but also might cloud your skills).  
• Become a member and read the posts on the QRP-Labs groups.io group. 
• And above all, take your time when building kits. Remember, it's not a race who finished it first, it's a hobby to enjoy. 

 But these tips are just the tip of the ice berg.

---