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Reviews For: QRPGUys 12W Dummy Load/Power Meter

Category: SWR & Wattmeters & Dummy Loads

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Review Summary For : QRPGUys 12W Dummy Load/Power Meter
Reviews: 3MSRP: $10
Description:
The QRPGuys Dummy Load/Power Meter is a 50 ?, 12W rated terminated load that is useful tool when setting up or diagnosing most low power transmitters. Useful range is from DC to 150MHz. up to 12 watts. With the use of an inexpensive 11 Megohm multimeter, and a little math, you can measure the power output into the 50 ohm load. The rated voltage of the detector diode is 70v, so measurements should be limited to 12 watts. There is also a terminal for direct RF from the transmitter for monitoring the envelope with an oscilloscope. It has an integral BNC male connector, so the use of an M/M adapter is not needed. It is 1” wide x 2” long, light weight, throw it in the go bag, and no cables needed. The required tools for assembly are a soldering iron with a small tip, rosin core solder, small side cutters, and can be built in less than a half hour. On a difficulty scale of 1 to 5, 5 being the most difficult, this is rated at 1.
Product is in production
More Info: https://qrpguys.com/12w-dummy-load-power-meter
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0035
NC0Q Rating: 2024-03-04
Accurate, Convenient, Easy to Build Time Owned: 0 to 3 months.
The instructions are very easy to follow. Give them a read-through before starting, and any "gotchas" will be revealed ahead of time. For instance, the dummy-load resistors, R1-R4, need to be elevated off the board for best cooling.

The kit took me about 2 hours to complete, mostly because the XYL arrived to sit down and divide my attention at exactly the moment I began winding the binocular-core transformer.

**TIP: Don't solder the transformer T1 onto the board before cutting/stripping/installing the "single turn" primary wires. I had a HECK of a time getting the primaries installed. I wished I'd cut/stripped/poked those wires through the core beforehand, it would have been MUCH easier to get all 8 connections made to the PCB in one go, rather than fiddling with those last 4 with the core already lashed to the board by the secondary wires.

The meter has no adjustments. This only became apparent to me after I initially put it into service and noted a reading that was roughly half what I expected. The final statement in the instructions addresses this conundrum. It was a simple task to drape a test lead across the unit's onboard dummy load into my oscilloscope. I adjusted the drive of my uBitx to register 20V p2p on the 'scope, and noted exactly 1W reading on the QRPguys wattmeter. This test was repeated across all bands 160-10 with the same results. 45V p2p registers 5W on all bands. Incredible! I have not yet tested the results below 1W but I would expect them to be quite reliable.

The SWR function is similarly trustworthy. I did not rig up any calibration standards, but I did compare readings of my 10/15/20/40m trap dipole at the various extremes with my VNA; the QRPguys meter corroborated the results very closely.

If you are looking for a good QRP/p meter for your field box, shack, or bench, this one will exceed your needs. Build it as described and trust it. I couldn't be more pleased!
K6SDW Rating: 2022-03-14
Small and effective Time Owned: more than 12 months.
I bought and built the dummyload a while back and it's so small and convenient for QRp power levels I use it over the large MFJ dummyload I own.
Super easy to build and measuring the relative output without a meter easy as well. And when done, I throw it the drawer.

I really like QRPGUYs kits, the manuals are very well done!

GL/73
WU7X Rating: 2022-03-14
Fun & Easy project Time Owned: 0 to 3 months.
If you are looking for a QRP dummy load, look no further. This is a fun project that takes minimal time to build. It works as advertised. The downloadable 2 page assembly manual is well done and will walk you through the process quickly and easily.

I have essential tremors which make my hands shake. The more I concentrate, the more they shake. I was still able to put this simple kit together in under an hour. If I can build this so can you.