| KU4QD |
Rating:  |
2002-04-15 | |
| Decent within it's limits, but you're better off with an MX-28S |
Time Owned: 3 to 6 months. |
The Mizuho MX-10Z is an early, lower power version of their 10m SSB/CW handheld. The later model, the MX-28S (also known as the AEA DX-Handy) was a 2W, updated and improved version of this rig.
The MX-10Z puts out all of 300mW. Yes, when 10m is wide open you can make contacts with less than a third of a watt, even on SSB. That's the beauty of 10m. If you've seen the MX-28S and think it's spartan, well... it's rich in features compared to the MX-10Z. This rig had no S/RF meter, no RIT, no attenuator, and no charging circuit. Otherwise, performance and operation are similar to the later model.
The receiver is hot enough, and thanks to the lack of a synthesizer it's got a nice, low noise floor. The receive audio is pleasant, and can be appreciated better through a larger, external speaker. Transmitted audio quality is OK, and very good indeed if you have the speaker/mic.
The rig is best on SSB. On CW there is no QSK and no sidetone, and the CW-2S unit for the MX-xxS series rigs does not work with the MX-xxZ rigs, including the MX-10Z. The good news is that the PTT button latches, so sending, either with the little push button on top of the rig or (better yet) with an external key isn't quite as annoying as on the later rigs. Still, I miss the reassurance of hearing the code I'm sending. I definitely miss the sidetone.
I should also point out that other MX series accessories commonly found for the later rigs (such as the DX-Handy/MX-28S) don't work with an MX-10Z, and finding the right accessories is, well... difficult. They included the M-4 speaker/mic. and the PL-10 linear amplifier: 300mW in for a whole 5W out.
The radio runs on either a single 9V battery or six AAA batteries. Operating voltage is critical and really must remain over 8.4V, so rechargable batteries are really not an option with this rig. The good news is that the battery (or batteries) last a very long time. The rig only draws 40mA on receive, and a whole 180mA when transmitting.
The MX-10Z is the same size as all the other Mizuho HTs: 1½"(D) x 2 5/8"(W) x 5 5/8"(H), and weighs in at just over a pound, making it an ideal lightweight travel companion. The telescopic antenna offered works after a fashion, but really requires a counterpoise. I've never made a contact without a counterpoise, but I can hear fine that way. Really, at these power levels, a bigger, outside antenna is required for any hope of regularly making contacts.
The rig is VXO controlled with two crystal slots, each crystal providing 50kHz of bandwidth, so you are pretty much limited to 100kHz of a band that is 1.7MHz wide. This is no different than the MX-28S, but it is a fairly severe limitation. The standard crystal which was provided with the rig covers 28.50-28.55 in the General portion of the band, which actually isn't a bad choice for SSB QRP, since it's less crowded than 28.3-28.5 and has plenty of DX. Optional crystals are still available for any other 50kHz segments directly from Mizuho on a special order basis. Expect to spend about US$23 per crystal to add/change band segments. Don't even think about domestic crystals: I don't know what Mizuho does, but US made crystals almost never give the full 50kHz of bandwidth, and often give much, much less.
One other point: many, if not most, of the MX-10Z rigs out there were sold as kits. If they were put together well, they're fine. If not... Most of the MX-28S rigs, by comparison, were bought wired and tested.
There really isn't anything "wrong" with an MX-10Z, and within its limitations it performs quite well. There isn't much difference in resale price between the more common and newer MX-28S and the MX-10Z, so unless you are a die-hard Mizuho collector who has to have every last model or are particularly interested in milliwatting, this rig doesn't make a whole lot of sense. I got mine pretty cheaply, it is a relatively rare model, I do collect Mizuho, and I wanted to see what I could do with 300mW, so I don't regret the purchase. I just wanted to point out that this rig certainly isn't for everyone, and that there is a better Mizuho alternative for most people. |
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