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Reviews For: MFJ-815D HF/6M SWR/Wattmeter 2KW

Category: SWR & Wattmeters & Dummy Loads

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Review Summary For : MFJ-815D HF/6M SWR/Wattmeter 2KW
Reviews: 7MSRP: 89.95
This is the latest model of the MFJ True Peak-Reading
SWR/Wattmeter covering 1.8-60MHz
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
N8RT Rating: 2023-06-27
Very accurate and displays true PEP RF POWER Time Owned: 3 to 6 months.
The MFJ 815D CROSS METER HF WATMETER RF 1.8 TO 60mhz. OUTPUT ACCURACY WAS VERY GOOD COMPARED TO MY BIRD 43. THE 815D HAS 2 RF POWER RANGES OF 300 AND 3KW ,AND SWR up to 8 to 1. Has led meter backlight . And a 9vdc can be installed for portable use.
N4DEK Rating: 2023-02-04
Great Meter Time Owned: more than 12 months.
I too have compared this meter to several different high end wattmeters and it has always been right there with them. I think its one of the best kept secrets in ham radio for a cheap wattmeter that performs excellent.
K6SDW Rating: 2022-02-09
I'm satisfied Time Owned: more than 12 months.
I'm happy with MFJ watt meter....nice to have the choice between peak and average readings.

Meter appears to be accurate enough for ham radio use.

LNXAUTHOR Rating: 2021-12-25
Good after a quick fix Time Owned: 3 to 6 months.
purchased a returned 'warehouse' unit from a large online seller at a 35% discount...

received meter and promptly hooked it up to a 12V supply and to a variety of rigs and antennas - measurements seemed spot on

the manual touts this meter as being able to run off an internal 9V battery... after opening up the case and putting in a fresh cell, i found out why the meter had been returned - it didn't work! (note: the meter backlight will not illuminate off 9V)

traced the culprit to a cold solder joint on the plus (+) lead from the battery to a PCB ... after a quick touch with an iron the meter functioned as expected

it was also nice to see the meter work well at QRP levels, with accurate rendering on the LO setting and Forward power needle

i did not test Peak metering

for me the meter is good... QC should have caught the cold joint
WE5GNF Rating: 2020-12-24
A Great value and a great operating meter. Time Owned: 0 to 3 months.
I checked this meter on my station with a LP-100A digital meter that a friend had at my QTH. My meter read almost the same output power within a watt or two that the digital meter showed. I was very impressed with the accurate readings the MFJ-815D displayed. The true peak reading feature works well as all of the features on the meter did. For the money that I spent for this meter I can honestly say I would do it all over again if I had to. I highly recommend this product. The meter was built with easy to function controls and the meter is easy to view. I will say that the scale of wattage is 300 watts, and 3,000 watts.
KM4NYI Rating: 2018-12-30
Great True-Peak Power Meter Time Owned: 0 to 3 months.
First, the MFJ 815D is a 3KW meter (not 2KW as the title says).

The MFJ 815D is really a very nice piece of equipment for the price. It has two ranges (300 watt and 3000 watt max), and reads true peak. Most meters in this price range claim to read average or peak power, but the peak power merely switches in a capacitor to hold up the meter reading. The MFJ 815D, however, includes an op-amp circuit where you get a true PEP reading. When reading peak power, it also switches in a capacitor that slows the downward fall of the meter needles, but it does go up to show the real peak. A quick comparison can be made by switching between average and peak while transmitting SSB; and you can see a pretty accurate peak power measurement.

Because of the PEP reading circuit, it requires a 12 volt source to function. The meter face is LED lit with a soft white color and is easy to read at a glance. The front panel switches are easy to use push-buttons, and the case is made from very sturdy black power coated metal.

My only complaint was the poor quality control MFJ is notorious for. When I unpacked mine, I noticed the 12 volt jack in the back was off-center and so were the front panel push-buttons. I disassembled it and added a couple of small washers underneath the circuit board mounts and brought everything back into line. While I had it apart, I examined the boards and the soldering, and everything looked very good. The manufacturing quality of the meter was great except for the board being mounted slightly off-center.

MFJ has several models they call a "True Peak Reading" meter, and a look at the diagrams show all of them are basically the same circuit, so you can buy the model 815D and save money over the fancier models (or even the Ameritron version). I bought this to replace a Daiwa that cost more than the MFJ, but the PEP function was worthless. Any SWR meter that claims to read PEP but doesn't require a power source will not give you a true peak power reading.

Overall, I would highly recommend the MFJ 815D to anyone looking for a nice cross-needle power meter that really reads peak power, without spending an arm and a leg. This is probably the best value in a cross needle meter you will find today.
K9RE Rating: 2018-09-20
Accurate and Useful! Time Owned: 0 to 3 months.
I purchased an SWR/Wattmeter (a different brand) and was very disappointed to find that it did not even come close to reading PEP correctly. It was a passive circuit that just switched in a capacitor in the so-called PEP mode. I asked the dealer to let me return it (they were not happy about that) and bought this one instead. This is a great unit! The PEP readings on SSB and AM accurately track what I see on my monitor scope. This allows you to see what is really going on with your signal. It can be powered by a 9V battery (internal) or an external 12V power supply. You can monitor your average or PEP output at all times, and it also shows you the SWR continuously on the cross-needle meter. When I opened the case to install a 9V battery, I was very impressed by the amount of circuitry inside, plus the quality of construction. I highly recommend this very useful instrument for your shack. Another plus; it works on 160-6M so it's perfect for use with your new all-band rig.