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Reviews Categories | Voice Keyers | MFJ-434/434B Help

Reviews Summary for MFJ-434/434B
MFJ-434/434B Reviews: 35 Average rating: 4.2/5 MSRP: $179.95
Description: Contest voice Keyer (new improved)
Product is in production.
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IW2CZG Rating: 5/5 Feb 27, 2008 14:09 Send this review to a friend
I'm satisfied  Time owned: more than 12 months
I'm using this voice keyer since 3 years and it perform flawlessy.

Just one recommandation:
the back panel is made of bare alluminium, so pay a lot of attention when connecting the DC plug because you can generate a short to the ground passing through the mike loop. This can drive the radio to a serious fault.
My suggestion are:
- always use a fuse to supply the keyer
- put some adhesive tape around the DC socket
- connect the ground wire to the RTX

Bet 73s de IW2CZG - Luca
W7TE Rating: 3/5 Jan 13, 2008 20:29 Send this review to a friend
QC Is a must. After a fashion, it works great.  Time owned: more than 12 months
When I first purchased, the brand new unit was missing the modular mic jack (RJ-45) "output for radio's microphone input" on the back. Was not installed at all. Called factory, they were a little taken aback but sent new unit out. Poor QC.

Received 2nd unit, looked as if everything was there but could not get it to talk back to me using the speaker. Something made me plug in earphones and wa-la. 2nd unit had a broken speaker wire on the speaker cone. Managed to fix it myself, just took a dab of solder. Was tired of waiting to get going, and didn't want to send it back. Poor QC.

Then when trying to interface with my Icom 746Pro, the jumper discription in the instructions is not correct on Jumper 5 (Direct) I had to jump pins 1, 2, 6, 7, and 8 which is not what the instuctions says. The radio would not transmit with the Icom decktop mic until I studied and traced the wiring and figured out why. Wasn't bad but took time. Poor QC on instuction manual.

Now just had a problem as the mic PTT would not work. Took an hour or better of testing and tracing and found a broken wire (cold solder) on the mic input to the board. Again a dab of solder and it is up and running. Poor QC.

As long as I can keep it working, it works great! Really like it, but QC makes me inclined to not purchase a lot of MFJ products. I do have a auto tuner (MFJ-929) that is just great and no problems at all. Excellent quality.
W4MY Rating: 5/5 Apr 9, 2007 01:32 Send this review to a friend
It worked!  Time owned: 0 to 3 months
I'm always fearful about buying an MFJ-(Anything) but the reviews were pretty good and I needed a voice keyer. Wav files from a PC are a little too far into the future for me.

Anyway, I just bought it, configured it for my FT-1000MP, built a cable, set the levels, and wala! it works good. Sounds good too. (a side note: The 'MP was not listed by name in the manual with all the other setup listings of "popular" radios. Like the 'MP is an "odd-ball"??? Had to use the "generic" instructions, but not difficult to understand.)

You have to give credit where credit is due. Maybe all that clean living is starting to pay off for me!
W3ADC Rating: 5/5 Nov 15, 2006 19:19 Send this review to a friend
Good Audio  Time owned: 0 to 3 months
I could tell a difference in the transmit audio from the 434/434B the B model sounded pretty good had to adjust the screw on the back of unit. Also as listed below mine came set for Yaesu 8 pin not modular as it says in the manual not sure how they messed that up but it seems to be better than the first one I had several years ago.

N9TGR Rating: 5/5 Oct 31, 2006 19:44 Send this review to a friend
Good Product  Time owned: more than 12 months
Ive been using the 434 for over three years and never had a failure or mishap,used it in lots of contests and field days and it works first time every time.No RF issues running legal limit with the voice keyer sitting on top of the amplifier,very easy to configure even with mine running thru a rigblaster and soundcard.Good product for the money.
W2MSK Rating: 4/5 Oct 14, 2006 08:11 Send this review to a friend
Good Job MFJ!  Time owned: 3 to 6 months
MFJ has a very spotty track record, some products are poor, most are marginally ok and then some are good. The 434B is a big improvement over the former model. They have incorporated all the necessary major enhancements and the outcome is a good product for its purpose. I use the 434B for VHF contesting in a large portable contest station with kilowatt amps and it performs as expected with no RF problems that I can detect. It outputs a strong voice level and keys the rigs correctly along with some nice features. Good product at a reasonable price.
K4CMD Rating: 4/5 Jul 13, 2006 07:18 Send this review to a friend
BEWARE OF JUMPER SETTINGS! Otherwise nice product  Time owned: 0 to 3 months
Well, good ol' MFJ loses a potential "5" from a reviewer because of a stupid mistake. I bought one of these things a month ago to use with my FT-897 on Field Day. I set it up according to the instructions, and I was happy I would not have to go inside the box to change its nine jumpers -- it comes pre-set from the factory for the FT-857 and FT-897.

Oh yeah?

I couldn't get the thing to transmit the messages I'd recorded at all. Nor could I get the keyer to record anything using the MD-100 mike I'd plugged into the front of it. Then it dawned on me that MFJ does not have the reputation of being the sharpest knife in the drawer, and I opened the box.


MFJ had pre-set the keyer for the FT-847, NOT the 857/897 -- a big difference, as it turns out that I had to change EVERY jumper to set it up for my rig and MFJ's claimed "default" setting.

Nice job, MFJ. I'm glad your erroneous information didn't result in a damaged rig!

Otherwise, now that I have set the keyer as it should have left the factory, it works rather well. Audio reports are good, and it is easy to use. The only complaint I have from an operational standpoint is that the volume from the internal speaker -- which is the only way to hear what you're transmitting unless you have a TX monitor in your radio -- is pretty low, even with the unit's volume control turned all the way up.

Let me say one other thing about MFJ and quality. In the instructions, they advise strongly to make sure you keep the 9V battery tab's contacts covered with the supplied slip-on plastic cover if you're not using a 9V battery. If you don't, those tabs -- which are at the end of a long pigtail -- could inadvertently land on something inside and cause a short. Well, when I received the keyer, I heard something rattling around inside (which I have learned is not surprising with MFJ products).

As with other brand-new MFJ products I've owned, I opened the cabinet to "fix" MFJ's mess-up. Fortunately I did not find a loose or damaged component, but the cover for the 9V battery tab! Turns out MFJ supplied a cover that is way too big for the tab, and it just slips right off, leaving the 9V pigtail free to dance around inside the cabinet, contacting everything on the 1-board keyer. AND it leaves the cover rattling around inside too.

As usual, I had to jerry-rig a fix to MFJ's less-than-elegant craftsmanship, using electrical tape to cover the tabs and to tape the pigtail to the side of the cabinet.

So ... this product gets a 4. As with most MFJ products I've purchased, it does a good job once you've gone inside and fixed MFJ's mistakes and oversights. But this time I was lucky too ... those misplaced jumpers could've put 5V where it shouldn't have gone. Other purchasers may not be as lucky, so do yourself a favor and VERIFY THE JUMPERS before you plug in your mike!
AF4KK Rating: 5/5 Apr 22, 2006 06:07 Send this review to a friend
Works very, very well!  Time owned: 3 to 6 months
Thank you, MFJ for finally putting a modular mic plug on the 434! Now I can easilly interface it with my Icom IC-7000. Although the 7000 has 4 voice memories, the MFJ-434 allows me to now have "eight" and it does it job very well! Good job, MFJ!
W3UTD Rating: 5/5 Apr 3, 2006 11:03 Send this review to a friend
Excellent  Time owned: 6 to 12 months
Easy to setup and easy to use. No-one can seem to tell the difference between my voice and the voice keyer.

Seems to be built well (unusual for MFJ) and works everytime I use it.
DL4EAX Rating: 5/5 Nov 11, 2005 03:00 Send this review to a friend
A great help for contesting and pile ups  Time owned: 3 to 6 months
I hooked up the MFJ-434 to my FT-847 and MD-100A8X (modified with an electret microphone).
Needed to adjust the output level (as described in the manual).
Works fine for me in contests and pile ups.
There is barely no differnce between my audio direct from the microphone and the audio from the MFJ-434.
The five memories give enough flexibility to store different texts for different situations.
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