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Reviews For: MFJ-842 Compact Cross-Needle SWR/Wattmeter 140-525 MHz

Category: SWR & Wattmeters & Dummy Loads

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Review Summary For : MFJ-842 Compact Cross-Needle SWR/Wattmeter 140-525 MHz
Reviews: 10MSRP: 59.95
Compact UHF/VHF SWR/Wattmeter. Has huge 3" Cross-needle meter. Read forward/reflected power and SWR simultaneously. Perfect for mobile or portable operation. Two selectable power ranges, built-in meter light (+12 VDC). SO-239 Connectors. 3 1/4 W x 3 1/4 H x 3 1/4 D inches.
MFJ-842 covers 140 - 525 MHz, 15 or 150 Watts.
Product is in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
KK6DXD Rating: 2013-11-15
UHF meter is no good Time Owned: 0 to 3 months.
I wanted to like this meter, it was compact and worked well on VHF... but ultimately I had to return it. It worked great on VHF with an HT, dummy load and a few various antennas. However, it would only read 1/2 the watts on UHF. I tested it with a 50 watt mobile and two different HT's. The results were the same.

If it worked for UHF I would have been satisfied.
KE3JH Rating: 2013-11-05
mfj says it all Time Owned: 6 to 12 months.
Dosent read half of the watts out on uhf.
WB4Y Rating: 2013-04-25
No good Time Owned: 0 to 3 months.
Did not work properly right out of the box. The needle on the reflected power side does not move indicating a perfect match. Same on UHF and VHF on lower and upper portions of each band. Hooked up a known mismatch and meter still showed a perfect match. Don't waste your money.
K4HYJ Rating: 2012-10-17
Works OK Time Owned: 3 to 6 months.
Bought it from HRO. It works fine on 2m and 440 with my HT. It mentions a conversion factor for 220, but I haven't used tried it yet.

I do not have another meter to compare it to. It reads 5w from my HT and 1:1 into a dummy load. My homebrew roll-up j-pole reads 1.2:1 at 146Mhz. My HT has never indicated high SWR so I believe it's correct.
KF7VXA Rating: 2012-08-19
Pass on this one Time Owned: 0 to 3 months.
The first meter I had showed the power 5 watts lower than 2 other meters I borrowed from friends.
The SWR always read 1 to 1. A 1 to 1 would be nice, but I knew better.
I called MFJ and was told to send it back to the person who took my call and put it attention to him for fast turn around or else it might sit on the shelf for 3 weeks, so I did as requested.
Three weeks + later, still no meter so I called and got the same person, he had not sent the new meter out yet, but finally did so.
The second meter had a SWR needle that worked sometimes, but most times it did not and it read 10 watts out from a 25 watt radio, other meters with nothing different showed over 20 watts.
I decided not to spend another $12.50 to return the 2nd for a 3rd as I have no faith in this meter. I bought a Diawa meter and it works perfect. I should have spent a little more money to start with.
I would recommend this meter to no one and was far less than pleased with the service I got from MFJ
KE4SWC Rating: 2011-08-25
Works fine! Time Owned: 0 to 3 months.
Went to HRO to buy a VHF/UHF SWR meter. They were out of any meters except this one. Josh at HRO said lots of folks have had good results with these, some had not. He said they work great out of the box or they don't. He said we could open it up and look at it. He offered to let me connect my HT to it and connect to an antenna they had on the roof with a known SWR to check. He said it should read 1.2:1.

I keyed it up and that's what it read. It also read just a tad below 5 watts on forward power which my HT was set to. We then placed a Bird wattmeter in place of the SWR meter and it indicated 5 watts. So I was convinced.

Upon hooking it up at home to a TM-742a mobile, I keyed it up on 50 watts into a dummy load and it read just below 50 watts and the reflected power needle barely moved. The dummy load is 1.15:1. I tested it on my homemade 2m j pole (the reason I bought the meter) and moved the feed point around on the j pole to the lowest reading: 1.2:1!!

I tested the j pole with a IC-746pro and it's SWR meter read the same. Good enough for me!
N2OZO Rating: 2011-01-02
Mitty Fine JUNK Time Owned: 0 to 3 months.
Just puchased this unit to use a quick reference meter. The low scale is accurate but the high scale is so far off its not funny. Tried to calibrate per MFJ documentation, but the unit is so far out it CAN NOT calibrated.
The unit is going back to HRO tomorrow.
Don't waste your money !!!!!!!!!!
Spend the extra and buy a diamond.
N3EAY Rating: 2008-11-02
Don't waste time or money on this one Time Owned: more than 12 months.
Forward meter failed after 3rd use. Guess I should test more often as the third time I used it was over a year and put it past their "No Matter What" Warranty. It went into the trash. It is the last item I will purchase that has MFJ on the case.
K1LLR Rating: 2008-07-03
trash Time Owned: 0 to 3 months.
dont,,false readings then one of the needles got stuck..mity fine
KI6FLL Rating: 2008-07-03
A compact meter that's great for checking mobile installations Time Owned: 0 to 3 months.
I bought this meter because I wanted a quick way to check power output and SWR on my mobile and HT VHF/UHF radios. I wanted something that was small/mobile and a step up in quality from the $20-30 meters that can commonly be found in the marketplace. After browsing various store fronts and eHam reviews, I decided on the MFJ-842.

This is a simple SWR/wattmeter with a frequency range of 140-525Mhz. The only external control on the meter is a Hi/Lo power switch on the front. Hi range is 150 watts max forward power and 50 watts max reflected power. Lo range is 15 watts forward and 5 watts reflected. The meter appears to have a quality movement, but there's no zero adjustment for the needles (although they read very near zero). You can connect it to a 12v power source to light up the face, but I've not used this feature yet.

The meter comes calibrated from the factory. If you have a reference power meter (I don't), you can re-calibrate it yourself using 4 trim pots inside the case. Adjustments are hi range fwd, hi range reflected, lo range fwd, and lo range reflected.

So far I've used this meter with 2 radios at 3 power settings using 2 antenna systems. Readings were pretty much what I expected; power output near what the radio manufactures claimed and SWR between 1.1 and 1.3. This unit is going to work just fine for my needs.

Only downside in my book is the lack of zero adjustments for the dual needles and, since it is primarily a meter for mobile use, I wish it came with a case.