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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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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.
W4ABX Rating: 4/5 May 10, 2005 08:58 Send this review to a friend
One short coming  Time owned: more than 12 months
The only problem I have run into with my keyer, is the repeat feature. The timer is not stable, as it will repeat at random intervals the higher I go with the setting (x10+) the more random it becomes. I would like to see it repeat at a reliable once every 10 minutes, with a check for busy status before sending.
"What do you want for nothing, a rubber biscuit?"
Yean, I know, buy a repeater controller with voice ID. OK, OK.
I would almost believe that an all knowing amateur could conjure up a fix for this! Or I could open my ARRL guide book, and find the answer my self.
PD2DB Rating: 5/5 Apr 4, 2004 16:09 Send this review to a friend
Can't live without it!  Time owned: more than 12 months
Have the 434 since one year. Because i use a special element in mine headset i need 8 volt. The 434 gives only adjustable voltage up to 5V. So i made a straight connection. Very simpel to use and no interference. Great audio. 5+
VE4MM Rating: 5/5 Jan 29, 2004 00:04 Send this review to a friend
No Problems  Time owned: 6 to 12 months
Used this for Nov Sweeps 2003.
Worked well and easy to use.
K3IXD Rating: 2/5 Apr 7, 2003 15:19 Send this review to a friend
MFJ-434  Time owned: more than 12 months
MFJ needs to institute a quality control program on their assemble line. When received, my first MFJ 434 voice keyer had the eight, remote keying, male pins bent and touching each other. The radio store replaced it. The second MFJ 434 failed several times before it was correctly repaired. Initially not all the memories worked, then in another contest the LEDs failed. And in a later contest, it completely failed. Once the "434" was finally fixed, it is a nice keyer; but anyone purchasing one should do it year before it is really needed. Exercise it before the warranty expires. I have used it with my ICOM IC-746 at home, with my Yaseu FT736r at W3SO in VHF contests, and with a Kenwood TS-850 at W8ZA in HF contests. At both W3SO and W8ZA, many MJF voice keyers are used and the initial failure rate is high!
T93M Rating: 5/5 Mar 23, 2003 15:19 Send this review to a friend
Works fine  Time owned: more than 12 months
I have used the unit in two contests , CQWW '01 nad CQWPX '02 (T93M/HI9) when I won first place in the world.
Both times unit performed great. I modified the back side adding 8 Pin conector for remote triggering via LPT port on my laptop. I use CT contesting software which easily can be set to triger memories from MFJ unit.
I guess I was lucky with QC of my unit.
EA4TV Rating: 5/5 Mar 19, 2003 05:40 Send this review to a friend
Quite goog product  Time owned: 6 to 12 months
My unit has not suffered any problem since i bought it. I miss some features and i also think it's quite expensive (as others mfj products). If you open it you can see that the product doesn't seem to be a high quality product. It works and it does what the manual says.
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