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

Reviews Summary for MFJ-434/434B
MFJ-434/434B Reviews: 39 Average rating: 4.1/5 MSRP: $179.95
Description: Contest voice Keyer (new improved)
Product is in production.
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MM0ERK Rating: 0/5 Aug 4, 2008 07:08 Send this review to a friend
night-mare  Time owned: 0 to 3 months
i bought the 434b thought i would be ok wish i kept my money will not work my 1000mp mk5 or my 1000mp no mater what i do cant get any transmit out so got fedup with the whole thing and the said item is now bined.if any body knowes of any other voice keyrs please let me know(not MFJ)
WA7MR Rating: 3/5 May 16, 2008 17:24 Send this review to a friend
OK once defects were fixed  Time owned: 0 to 3 months
Bought a new 434B to interface with my old TS-820S after my voice went hoarse during the 7QP contest. I bought some adapters to go from the 434B's 8 pin connector to the 820's 4 Pin. Should have worked, but didn't. No solder on two of the wires from the 8 pin front panel jack, and a poorly soldered SMD capacitor on the main board didn't help any.....
MFJ, in their infinite wisdom used SOLID wire for the speaker wires, so of course when the lid is lifted off the wires break off the speaker....
Reminds me a lot of a poorly built Heathkit.

The unit also did not come with a power cable or connector of any kind, so I had to make a Radio Shack run and fabricate a cable even to power the unit up.
The only problem left now is that the repeat control/switch does not seem to work, but I can live without that feature for now....

Hey, if we wern't hams we wouldn't be able to get any of these MFJ products working ;-).
W6RAM Rating: 2/5 May 10, 2008 07:39 Send this review to a friend
Jumper Problem  Time owned: 0 to 3 months
I just received two MFJ-434B voice keyers. The documentation says the internal jumpers are set for the Yaesu 817, 857, and 897. Neither unit worked with an 817. I had to drill out two of the sheet metal screws on one unit to get the lid off, and found that both units were jumpered for the Yaesu 847. After setting the jumpers to the right positions, the units worked. I sent e-mail to MFJ expressing my alarm and dismay at having to do this, but so far have not received a reply. I rated the units a "2" for this lack of quality control.
K0JDD Rating: 5/5 Mar 31, 2008 08:24 Send this review to a friend
Would Recommend  Time owned: 0 to 3 months
As far as doing what it is advertised to do, I have to give it 5 out of 5. I would recommend it to others looking for a versatile external voice keyer.

The 434B keyer works well with my Icom 746pro and BOTH my Heil Traveler Dual Boomset (using the Heil ICOM adapter cable), and my Icom SM-20 desk mic.
I have learned that the SM-20 gets its' DC power from pin 2 on the ICOM transceiver (an Icom only 'feature'), whereas the Heil gets its' DC power from Pin 1.
I had to change the default jumper on the 434B (see pg 6 of the manual) to get DC power for the Heil. Note that for this reason, the Heil only works with the keyer powered on.

MFJ does not recommend long term operation on the internal 9V battery, so I built a double fused power cable for the unit with Anderson power poles on one end and a 5mm/2.1mm DC Power connector on the other. (See pg 2 of the manual)

One behavior in my setup that I did not like, is that the keyer would not stop play out of a message when I used the foot pedal that I have attached to the ACC1 socket on the back of the Icom 746. I got to wishing that the 434B had a PTT accessory socket until I realized it does have one, "sort of."
There are two MIC connectors on the front of the 434, but you can only attach one Mic at a time. I am using the 8 pin round connector so that leaves the RJ-45 jack open. I cut the end off of an Ethernet cable and attached a 1/4" Phone Jack (Female) to the PTT and PTT GND leads. Plugging the foot pedal into that adapter and the adapter into the front panel RJ45 does the trick.

I spent $30 on the remote. I had to repair it to use it.
Problem 1. When the assembler stripped the PVC off the 8 conductor plus ground cable, he or she scalped the insulation off of several wires and severed 1/2 of the strands in the ground lead. The ground lead had been 'factory repaired' with a dab of solder but is was not up to specs. I re-did the entire cable.
Problem 2. One of the six push-buttons on the remote was 'sticky' so I cut it out and replaced it. I would recommend that first you try to build this remote yourself using the MFJ provided schematic (See pg 12/13 of the manual) and local parts -- providing of course that you can find the special 8 pin IDC connector (or something similar) to attach your new remote to the back of the 434B.
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.
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