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Reviews Categories | SWR & Wattmeters & Dummy Loads | MFJ-868 SWR/ WATTMETER Help


Reviews Summary for MFJ-868 SWR/ WATTMETER
MFJ-868 SWR/ WATTMETER Reviews: 28 Average rating: 3.5/5 MSRP: $139.95
Description: VERY LARGE SINGLE NEEDLE METER- VERY EASY TO READ AND VERY GOOD BACK LITE
Product is in production.
More info: http://MFJENTERPRISES
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You can write your own review of the MFJ-868 SWR/ WATTMETER.

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NR7N Rating: 5/5 Nov 29, 2014 17:28 Send this review to a friend
NR7N  Time owned: 0 to 3 months
I actually rate this meter at 4.5 but I will give it the nudge up.

First, this is actually a pretty good meter but the main problem is that it is not calibrated correctly. After calibration it is quite good. In fact, almost all diode detector based meters (95%+ of power/swr meters that hams use) are inaccurate to some degree. I include Daiwas, Diamonds Comets, etc. and even Bird wattmeters. The Bird is generally +/-5% and are more accurate then most because they have been calibrated against watt meters that actually measure the heat produced with the applied power. They are generally more rugged as well because of the environment they are desgined to work in. They are NOT a precision RF power measurement instrument so let's get that settled right now.

Almost any diode based meter can be calibrated within +/-10% if done with proper equipment. When I got my 868B I connected it up to a good dummy load and checked it for accuracy. The 20W range was pretty close but the 200W and 2000W ranges were off quite a bit (one high and one low). Again, this is not something special with MFJ as I just went through several new Daiwa meters that were actually worse.

Also check the directivity of the coupler for SWR measurements as my 868B read 1.5:1 into a known good high power load that was measured at 1.05:1. We'll get to that later.

My power measurement equipment consists of a HP 435B power meter and the corresponding thermcouple sensor (8481H) and a 500W Bird 30 dB attenuator (8325). A friend who has a metrology lab verified calibration of the 435B/8481H and gave me the exact attenuation of the Bird attenuator. In this way I have a calibrated measurement system.

The first thing to do with the 868B or any type of diode based power/SWR meter is to null the coupler when connected into a 50 ohm load. I ran 100W into the MFJ (set to read SWR) and adjusted the null capacitor on the coupler board for a minimum reading. The directivity on the MFJ coupler is quite good and it nulled right out. SWR can now be meaured accurately.

I then ran 20W (as referenced to the 435C/8481H/8325 with the MFJ in-line) into the 868B on the 20W range and adjusted the 20W pot for the correct reading. I did this at 200W on the 200W range and finally I ran 500W into the 868B on the 2KW scale (remember the Bird attenuator is rated for 500W). The MFJ is now calibrated and works great. it has good range to range tracking and seems relatively flat from 80 to 10M. I did not attempt to check at 160 or 6M as I don't currently operate those bands.

The construction looks adequate and the coupler assembly is well constructed and mechanically rigid. It is not a piece of junk.

Several other reviewers have complained about the meter light going out after a short period of time. A little diagnostic work found that the MFJ power supply was putting 13.8 VDC into a 12VDC bulb. The remedy was easy. I clipped the blue/white + VDC lead and inserted a 1W 39-ohm resistor. Make sure and put a piece of shrink tubing on each end before soldering. The voltage is now 10.7 VDC on the bulbs, they light the meter fine and should last forever.

The MFJ-868B is not worse then other meters on the market. It just needs to be calibrated correctly. Most of the competition's meters are just as initially inaccurate as well.
 
WQ5B Rating: 5/5 Oct 15, 2014 15:57 Send this review to a friend
all I expected  Time owned: more than 12 months
I have owned my Giant Meter for some time now and could not ask for more. It is better than a Swan Peak reading meter I owned 30 years ago but sold to fund something . This one is staying home when going to sidewalk sales . I did not know it had lights until I was playing with the ON/OFF switch and they lite up . One has now quit but I still see it . I will change them out when this one goes out but modify the circuit for a lower voltage & longer life. I would welcome any MFJ stuff some one may want to get rid of as it all sells well at flea markets .
 
K4SDW Rating: 3/5 Jun 3, 2014 18:02 Send this review to a friend
OK Meter  Time owned: more than 12 months
I have had this meter about a year now. It works good. I have had problems with the lights inside the meter. This is the 2nd time they have gone out. Not sure why. I replaced them the first time after about 2 months. 2 months later and they are out again so I will just use the meter without the lights. I did like to see that large meter lite up. I would probably spend a little more money if I had it to do over and get something more dependable. I guess you get what you pay for.
 
WD8FM Rating: 5/5 Mar 13, 2014 07:47 Send this review to a friend
Still Working Great  Time owned: more than 12 months
Just an update to my first review. My meter is still working great after more than 3 years of heavy usage. Still within +/- 2 watts and SWR readings almost no deviation when compared with 2 other watt/swr meters.
 
W8EDV Rating: 2/5 Mar 12, 2014 16:20 Send this review to a friend
Lights out in 6 weeks..  Time owned: 0 to 3 months
I like the size of the meter and it seems fairly accurate, however I can't recommend it because my light bulbs are out after only 6 weeks of light use. I only use the meter for a few hours at night and the bulbs went out in just 6 weeks. It's a big disappointment when you spend so much money on a meter that is just junk. I imagine shipping it back and having fixed will probably leave me without a meter for a month or so from some reviews I have read about MFJ repair services.. I like the look of the meter, and it does work, no problem there, they just need light bulbs that will run longer than 6 weeks...
 
WD8FM Rating: 5/5 Feb 18, 2013 19:13 Send this review to a friend
Works Great  Time owned: more than 12 months
I purchased mine NEW about 1-1/2 years ago and it has worked great for me the whole time. It Checked within +/- 2 watts with three different RF power meters and within .2 on the SWR meters. Close enough for me.
 
NV6W Rating: 2/5 Sep 30, 2012 11:24 Send this review to a friend
needs design review   Time owned: 6 to 12 months
I purchased this large analog meter several months back for purposes of HF linear amplifier tuning. Initial tests were satisfactory. However, I discovered that the device itself is not properly isolated. Station components placed near and/or on top of the meter result in incorrect readings. Also, both meter bulbs burned out after relatively light use. I found replacement bulbs, however, they're not easy to replace. The sockets are held in place by miniature plastic tie-downs, and the meter face needs to be taken apart to reach them.

I'm going to agree with John / ZS5J's previous review, which is quoted here, in part:

"...I re-calibrated the MFJ meter to read correctly on all 3 levels, and while I had the meter open, had a look at the quality of construction. Well, typical to MFJ, it is really cheaply and poorly constructed inside. MFJ is still way behind other manufacturers in terms of quality. And it can be seen that there is no testing of equipment prior to leaving the MFJ workshop, as can be seen by other posters reviews here..."

I'm planning to upgrade to a digital meter with proper isolation at some point.
 
WB6ZRP Rating: 5/5 Jul 30, 2011 10:52 Send this review to a friend
Great meter  Time owned: 3 to 6 months
I purchased the meter used, it's over a year old and still working fine. After a little calibration which is very easy, I found it to be very accurate. The two microsecond op-amp it uses makes it a very accurate PEP reading meter. It' very nice to have such a large meter, makes it just a glance to see my output with my amplifier. When I installed the 9 volt battery I took notice that the construction was good. Overall I always have had good luck with all MFJ equipment so far. I've had several tuners, meters etc.
 
W7MJM Rating: 5/5 Feb 8, 2011 10:36 Send this review to a friend
Big meter makes tuning amp much easier  Time owned: 0 to 3 months
This extra-large meter makes tuning my tube amplifier much easier. I can see changes in peak output in response to amp adjustments that I couldn't distinguish on my old Heathkit HM-2140. Accuracy seems to be within 10 percent of full scale for readings in the upper half of the scale. The meter seems easy to calibrate (one trimpot per power range); as soon as I can borrow a calibrated lab-quality instrument, I plan to tweak the MFJ to get it within 5% of the lab instrument. Very pleased with my purchase and would recommend this device to others looking for an easy-to-read, peak-reading analog swr/power meter.
 
NA5AR Rating: 5/5 Dec 26, 2010 14:00 Send this review to a friend
Works great for me.  Time owned: more than 12 months
I'm not sure why some folks are bad mouthing this meter. I have three of them and they all work great. Very easy on the eyes and easy to use. I've had a lot of meters over the past 40 some odd yrs of hamming and this one is as good as any. As with any equipment there are some that just don't work like they should but these works great for me.
 
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