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Reviews Categories | Antenna Tuners/Matching Networks | MFJ-921 VHF Dual Band Tuner 144 - 220 MHz Help

Reviews Summary for MFJ-921 VHF Dual Band Tuner 144 - 220 MHz
MFJ-921 VHF Dual Band Tuner 144 - 220 MHz Reviews: 10 Average rating: 4.4/5 MSRP: $79.95
Description: The MFJ-921 Dual Band VHF Antenna Tuner covers 2 Meters and 220 MHz. Its built-in SWR/Wattmeter measures SWR in 2 power ranges -- 300 or 30 Watts. The meter is usable for both 144 MHz and 220 MHz bands. It will give you low SWR with practically any antenna.

The MFJ-921 is designed to match a wide range of impedances for both mobile/base operation. It will handle up to 200 Watts of output power. The antenna tuner has SO-239 input/output connectors, wing nut post ground. It has an eggshell white and black aluminum cabinet - - it fits just about anywhere!
Product is in production.
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You can write your own review of the MFJ-921 VHF Dual Band Tuner 144 - 220 MHz.

AA7LX Rating: 5/5 Oct 29, 2015 00:46 Send this review to a friend
Buy It ! Quality from MFJ !  Time owned: 0 to 3 months
Buy it ! Very few products that MFJ manufactures and sells is high quality. I mean exactly that, products that work for what they are designed for and are built with quality materials. There are only two items I've found from MFJ(so far) in years of being a Amateur Operator that, I believe fall in the standard(s) noted above. This is one of those products: worth buying for your Station ! I was able to get the 2-meter SWR down from 2:4 and higher,... finally down to 1:2 or 1:1 or better from a home brew Quad Antenna... and the 921 worked according to reading the directions ! ...And, the measurements were repeatable ! ...Double-checked 921 against Daiwa 2000W and 3000W SWR/Power Meters ! ...SWR read within or less than a 1.2 difference and, Power measured within 5-8 Watts between the 921 and the SWR/Power Meters ! ...No problem using 300w setting on the 921. Just put a mark where the new calibration for the 300 setting ! Didn't have problems understanding the 300w re-calibration, unlike other reviewers. Don't reset the front panel knobs ! Just follow the instructions... Being unable to find a 2-meter tuner elsewhere on the market--I was first cautious about MFJ anyway-- however, this tuner does what it's supposed to do ! No stray capacitor problem touching the front knobs--everything tight and solid. Looked inside--circuit board and solder joints good. Back-end connectors are tight and solid ! Tested with Volt-Ohm meter, all connections looked good too ! I'm impressed ! I hope it keeps working ! At this rate, I will purchase the MFJ 440Mhz Tuner !
Recommend this 144/220 Mhz Tuner... (Other item from MFJ that meets high standards are MFJ's Frequency Counters !).
WB1GXM Rating: 5/5 Jan 19, 2015 10:09 Send this review to a friend
Performs as expected  Time owned: 0 to 3 months
Just added a new one to my 2m ssb ops. Works slick. Cross checked readings with another piece of gear. Reading right on. looks great - works great. I got a good one.
KE4KE Rating: 4/5 Apr 21, 2012 10:22 Send this review to a friend
Works well  Time owned: more than 12 months
I also used one in an FM broadcast transmitter to match the exciter to the final amp. There is still one in a transmitter somewhere in Kentucky!
KI4GTJ Rating: 5/5 Feb 3, 2012 01:58 Send this review to a friend
Great  Time owned: 3 to 6 months
Works like it should on 2m and 220MHz
K8OCN Rating: 3/5 Jun 20, 2009 23:09 Send this review to a friend
Loss on rec and 220 band  Time owned: 3 to 6 months
It worked find on transmit but the insertion loss was to much for me. I do not have the equipment to give you numbers but I can tell you we have a group of guys that chat on 220 simplex in the evenings. One of the guys is far enough out so that I only get one bubble on my Alinco 235. No real noise and its almost full quieting.

After I inserted the tuner I had no problem getting the SWR flat, but I could no longer hear my friend.

I tried it on 2 meters and did not seem to have the same problem. It did not have any measurable insertion loss on 2 meters using my crude tests.
W4KVW Rating: 5/5 Jun 20, 2009 21:15 Send this review to a friend
GREAT  Time owned: more than 12 months
I have had a couple of these over the last 10 or so years & they worked as they are designed.ONLY used on 2 meters but they are simple to use & NO ISSUES!
G0RRL Rating: 5/5 Feb 9, 2009 05:26 Send this review to a friend
does the job  Time owned: 0 to 3 months
just bought the MFJ-921. ive tested it at 20wtts and its spot on. i cant run more than 50wtts so i cant comment on the 300 .. but if the reading is out on a higher range then id say the metering needs looking at.
i have a dual band aerial. my swr is reasonable on 433mhz but appalling on 144mhz. i made a short patch lead and tuned for lowest SWR and it went down to almost zero and gave the full 20wtts out.
thumbs up. i could have built one but this saves me searching for parts. the case has some nasty sharp edges but generally well made and compact.
W6JAK Rating: 5/5 Feb 8, 2009 15:34 Send this review to a friend
Two Years Later  Time owned: more than 12 months
After two years of operation, nothing new to report other than there have been no problems and the settings have proven to be repeatable over time.

To answer the previous (non)reviewer's question: if you loosen the knob and reposition for the 300W point, you will then throw off the calibration for the 30W point. You must put on a new label for the 300W point.

I'm giving it a 5 this time because of the reliable service and to be fair to MFJ for being rated a 3 from someone who hasn't owned or even used this tuner.

formerly KC6PJK
G0RRL Rating: 3/5 Feb 8, 2009 10:36 Send this review to a friend
swr mission  Time owned: 0 to 3 months
ive just read the last review .. as i also need to do something about my aerials swr on 2-meters. im planning on one of these tuners. i was looking at the photo and it struck me that -couldnt the knob be slackened off and moved to re-calibrate and then tightened up???- that would save having to use stickers. anyhow ill find out about it when i get my one.
ps. this is not a review at this time.
KC6PJK Rating: 4/5 Dec 17, 2006 20:48 Send this review to a friend
Does the job  Time owned: 0 to 3 months
I needed a tuner to use my M2 VHF Beam for reaching a distant MARS repeater. Other choices were to either buy/build a new beam for the MARS frequency or modify the one I have. Since I didn't want to climb on the ladder on top of the roof again to remove/re-install the beam, I opted to try this tuner.

Quality of construction is good and the built-in SWR meter makes for a handy, compact unit. The SWR meter is on the small side, but is readable. For the price of this unit, some compromises are expected. I am now able to work the repeater so the tuner paid for itself by reducing the SWR to 1:1 without risking my neck getting the beam down.

I would give it a five; however, my only complaint is that the 300 Watt setting is marked on the faceplate but the setting is not factory calibrated. Not being factory calibrated is not necessarily bad, since Hams should be able to calibrate an SWR meter. My gripe is that I had to create a pointer label out of tape for the calibrated point, so now there are two marks for 300 Watts. My recommendation to MFJ is to leave the faceplate unmarked for the 300 Watt setting and provide a label for the owner to apply once the meter is calibrated.

Other than that, this tuner works good and MFJ's product fills a need for the amateur radio community at a low cost.

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