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Reviews Categories | SWR & Wattmeters & Dummy Loads | MFJ-812B Help

Reviews Summary for MFJ-812B
MFJ-812B Reviews: 27 Average rating: 1.9/5 MSRP: $34.95
Description: 2-Meter & 220 MHz SWR/Wattmeter
Product is in production.
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W6TH Rating: 5/5 Dec 14, 2006 14:31 Send this review to a friend
Works great  Time owned: 0 to 3 months
I purchased this on eBAY the fourth buyer and it works as it should. No problems.

I insert a low amount of power to the forward power, not more than 5 watts and switch to reflected power.
Tuned two "J" poles using the 450 ohm line and covered the low and high end of two meters with accuracy. Diodes are non-linear so by applying high power will give a false reading, so do tuning with as low as possible power for the full forward setting.

I compared this with several other vswr meters like LaFayette, Radio Shack, Heathkit and they all were same readings.

Should you have troubles with such a simple test equipment, one should ask the advice of operation from a professional, but remember "do not overpower" the diodes.

73, W6TH A non vanity call.
KC9GUZ Rating: 3/5 Feb 12, 2006 09:27 Send this review to a friend
not the most accurate thing for SWR  Time owned: more than 12 months
Hooked up against my old MFJ 249 analyser (that is suprisingly very accurate!!) the 812 showed a significant difference in SWR readings.
I wish MFJ would get on the ball and do soemthing with their new stuff instead of producing JUNK that most people will end up returning or thowing in the garbage pail..
KG6POG Rating: 0/5 Jul 15, 2005 13:24 Send this review to a friend
Waste of money  Time owned: more than 12 months
I bought this on a recommendation and it is useless. It doesn't read anything correctly. I actually tossed a Diamond CP-22-E 2 meter antenna becuase it was reading the SWR at over 3.0.1. I almost took down my cushcraft 2 meter beam, but I had a freind check the beam out and it was working fine.

I wouldn't recommend this meter to an enemy.
KG4PTZ Rating: 0/5 Jul 3, 2005 15:27 Send this review to a friend
You get what you pay for.  Time owned: more than 12 months
This is my first, and probably last, MFJ meter. At first, I had no problems as it helped me tune my 2M 5/8 wave. Then I noticed that it would always read a higher reflected power than transmitted power on my dual-bander. I tested a j-pole and the meter showed a decent SWR across my operating frequencies. However, in the past few weeks while testing a 2M 1/2 wave antenna, I noticed that it would not give accurate readings anywhere in the 2M band. After testing it with antennas which I believe to have reasonable (less than 2:1) SWR's, I noticed that it showed less than 1W output when I was transmitting 5W. When I switched to reflected power, the needle was pegged. This is the second worst meter I've ever seen, only to that Workman I ordered (and discarded) a few years ago. I think I'm going to get a Diamond to replace this piece of junk.
W8OKN Rating: 5/5 Feb 12, 2005 20:19 Send this review to a friend
Works  Time owned: 6 to 12 months
This meter works fine... no complaints. I compared it to other meters and found similar results. Good meter.
KK4BH Rating: 5/5 Feb 11, 2005 06:50 Send this review to a friend
Works like it should.  Time owned: more than 12 months
I purchased a MFJ-812 new many years ago and have had nothing but excellant results with it. I used it to tune a homebrew 2mtr j-pole, a Cushcraft Ringo Ranger 2, a Hustler 5/8 wave magmount 2mtr mobile, and to check the SWR of my most recent antenna, a Diamond X50A. I've been licensed 40+ years and have used many SWR meters. This one performs like one should, showing low and high value readings across the band making it easy to tune the antenna. I only wish it would work on 440mhz.

KI4GPX Rating: 0/5 Feb 11, 2005 00:36 Send this review to a friend
Pure Junk!  Time owned: 0 to 3 months
I worked ALL day Saturday on trying to get my new J-pole antenna resonant on 2M. My mistake was using this piece of junk to test SWR. The other reviews here coupled with the fact that I've tested three different pieces of coax and three different styles of 2M antenna, tell me I should have bought another meter in the first place. BTW, ALL tests showed the same 3:1 SWR results -- no matter what I did (ie: choke balun; different coax; different coax jumpers; different antennas, yagi, j-pole & discone). I thought I was going crazy!
Wasted a day. Wasted another afternoon. Wasted $25.00. Pure junk! CharlieJ/W4TCJ
KE5GK Rating: 0/5 Aug 23, 2004 19:02 Send this review to a friend
Example of hype over performance  Time owned: 0 to 3 months
Ditto the previous review. This one is bad.
KB9VXQ Rating: 0/5 Aug 23, 2004 14:46 Send this review to a friend
Can't trust readings  Time owned: more than 12 months
Picked one up at a hamfest. Used but looked like new. The last guy probably sold it because he knew it was junk. I used it for awhile before knowing it was way off on readings. Tested it against a AEA Anaylist and a MFJ-259B and the swr readings were way off. Sometimes it would read higher and sometimes it would read lower. What do you do with junk like this?? Can't sell it knowing it may cause someone to blow their radio!! Still setting on the basement bench until I get mad enough to throw it in the trash (where it belongs) and loose all the money I paid for it.
KE5GK Rating: 0/5 Feb 26, 2004 01:01 Send this review to a friend
Cost Me A Repair Job  Time owned: 0 to 3 months
Blew a final in my 2M HT because of bogus readings from this MFJ "wannabe"!

What ever happened to truth in advertising?
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