Friday, August 24, 2012

QRPometer case....

Finished product

A few months ago I built and blogged about my  QRPometer build from the 4 state qrp club its a great kit. In the post there was only 2 con's that I could think of regarding the kit.
1.The TX and Antenna connections were RCA and not BNC, the kit now ships with the RCA to BNC      adapters.  
2. The meter did not come with a case and the rear of the meter had an exposed circuit board. I felt this left the meter vulnerable to damage.

My solution to problem number 2
first attempt....not good
We have in town a great electronics parts store it's been here for just a few years now but it's fantastic I don't have to travel for about 40 minutes to the next closest store. I ventured off to the store for a case, it was a plastic case I had in mind. The metal and or aluminum  cases I felt were just not as easy to work with for the needs I had. I brought the QRPometer with me to assure I got the right depth and width. I found a case that was deeper than I was wanting but it was all they I purchased one.....that later turned out to be a mistake!!
New opening and front plate on
With the chosen Hammond 1594E box at home using my machinist ruler I traced the cutout on the box that was needed to house the meter. The best tool to cut the case I felt was the Dremel hand held rotary tool that I I thought!! With my pencil lines all in place the Dremel was used to make the hole, I found I was so consumed with the cutting line that I did not notice the spinning chuck that held the cutting blade was destroying my plastic box. As Murphy's law would have it this problem was only noticed after all the cutting was done. The top cover was a mess and since I am a VERY fussy person this just would not due. So it was off to the electronics store for another box and to rethink the opening for the QRPometer. It was not until I got home the idea came to me to use my coping saw. There is more control with the coping saw and a neater cut would be the end result. I also came to the conclusion that a smaller opening would be smarter as well, less cutting and less chance for a mistake. With the revised hole cut with
Meter in the new case
the coping saw the QRPometer with some tweaking of the hole fit just right. As always another thought came to mind........the meters power comes from a 9 volt battery that is sandwiched between the QRPometer circuit boards. In the future this battery is going to have to be changed. I am not going to want to take 20 minutes of dis-assembly and assembly to change a battery!!!! As you all know batteries go dead at the most inopportune times. It was off AGAIN to the electronics store for a 9 volt battery holder. I found the perfect flush mount holder and to instal it meant  to just extend some battery leads off the QRPometer board and cut but another hole in the plastic box. This was a very fast addition to the QRPometer box and the coping saw again made short work of adding an opening to the side of the plastic box.
9 volt battery mod
Side view of 9v holder


  1. Hello Mike, nice result. The Dremel is a nice piece of equipment, but not for cutting straight lines. I experienced melting plastic with it a well. Although you can file it straight afterwards. Anyway, it's nice to have a good electronics shop nearby. There is no such thing here, most of my electronics I order at via internet. 73, Bas

    1. Good afternoon Bas, yes I too found the Dremel melted the plastic even when using the blade for cutting plastic. I have had the Dremel for a long time and just forgot about it. I now am going to use it for more projects that it will actually work for.

  2. That's a smart looking device Mike, really nice job. Did you already have the box or did you order it especially for the meter? It seems whenever I do a kit or circuit from scratch the project cases I have are either too big or too small, but that one looks just right.


    1. Good afternoon Casey, thanks for the complement and it's how I work....if I am going to make something I want it to NOT look homemade. As for the box I was able to find it at the local electronic store here in town. This case was just a little to deep for what I was looking for but it was all they had and seemed to do the trick.