Tuesday, April 10, 2012

QRPometer ready for action

QRPometer complete
Well the QRPometer has made it from a pile of parts to a very useful tool for the shack and portable op's. It's no wonder this kit sold out in record time and now the 4 state QRP group will have to round up more parts and move out some more kits as the demand is out there. I began this project the same way I have with all my projects.... by doing a parts inventory. That went by without a hitch all the parts and pieces were present and accounted for. It was then off to the "puttin" the parts where they belong. The instructions are very easy to

Solder blob mod done
follow and very well laid out. If you are not sure about things and need a picture you will find it on the 4 State QRP groups website. During the resistor install there is a note to hold off on two resistors until after the calibration stage. I did get an email from the 4 State group letting me know that there is also a third resistor that should not be installed as well. Now that is great support each person that ordered a kit receive an email with updated info! There is a very small mod that has
Ribbon cable soldered to LCD
 to be done to the LED meter a solder blob has to be removed from a pair of pads. A new blob has to short a pair of center pads it went very smooth and allowed me to use my Hakko 808 to remove the solder blob. With all the parts installed it was now time for calibration and I wish all kits could be this easy to calibrate!!! All that is needed is a voltmeter (my Fluke meter) for the first step and then an RF input between .5W to 5 watts (my trusty K3) for this second step.

The kit pro's
1. Very easy to build and calibrate
2. No toroid or SMD for those kit builders who shy away from them.
3. Instructions are well written and very easy to understand.
4. Meter has a built in dummy load when measuring power.
5. When meter is turned off it can still be left in series with antenna and transmitter the meter is in bypass.
6. Professional silk screen front panel.
7. Parts layout on the the circuit board are...may I say "Elecraft quality"!

Calibration complete
1. The TX and ANT connectors are RCA and not BNC. I had to buy RCA to BNC adapters.
2. There is no cover for the back of the circuit board.

So lets put 2 and 2 together.......7 pro's to 2 con's = home run!!


PE4BAS, Bas said...

Hello Mike, great pictures and kit. Strange the choice for RCA connectors? I would prefer "normal" PL connectors. I don't know how small the kit is but could it be "mod" to use PL chassis? 73, Bas

VE9KK said...

Hi Bas, there was a pic on the net for a BNC mod but I went to a local electronics dealer for PC mounted BNC's and they just did not seem to match up to the PC board so to much of a mod's would have to be done to the BNC PC board connector to make it a worth while effort. I settled for the RCA to BNC connector. As for PL connectors I never really looked into that....but they do need more space than the BNC type mode and not sure if there was that that much room on the PC board to do it.

John AE5X said...

Hi Mike - do you have another QRP wattmeter to compare it with?

VE9KK said...

Good evening John, I do have the LP 100A which goes down to QRP levels I could use that meter to compare too.

Paul Stam PAØK said...

Hi Mike, well done, a very handy meter for qrp activities. I agree with Bas for PL connections. But I understand that they don't match with the PC board. 73 Paul

VE9KK said...

Good morning Paul, I had seen someone who put this meter together and was abl to use BNC type connectors. I did find some at the local electronics store but they would not match the PC board layout. It's no big deal I was able to get some adapters.