After having my interest sparked in the 33cm band, I set out on a search for equipment. Until Alinco’s release of the DJ-G29T, there has never been any amateur gear manufactured for 900Mhz. The only option was to seek out commercial 900MHz gear that could be converted to the amateur frequencies.
One thing I’ve learned is that there is no real band-plan for 33cm. The ARRL has one, the Indiana Repeater Council has one, and then there is what people use in your local area. The standard repeater split is -25, but in some areas you’ll find a -12 split in use. Here in Indianapolis, due to interference, our 900Mhz repeaters use odd splits. Depending on the gear you choose, programming and operating certain splits can be tedious.
I started my search on the Radio Reference classified and of course ebay. For the most part, the only commercial 900MHz equipment you’ll find on ebay is from Kenwood and Motorola. However, recently EF Johnson has made an appearance. The following is a summary of my experience with the different radios I’ve picked up:
Motorola MTX9250 – My new favorite 33cm HT. The size is very nice and the audio is fantastic. I’ve received great signal reports and it seems to do a better job from inside builds that the EFJ 5100’s. Requires hex editing of CPS in order to open up the ham bands. I have not encountered and unlock conditions across the band. Of course, your mileage may vary as I’ve heard of some radios do better that others.
Motorola MTS9000 – This unit is by far one of the best radios I’ve found. Handles both -25 and -12 splits. The only issues I’ve found is that the VCO doesn’t lock to allow receive in the bottom portion of the band. That hasn’t been an issue, especially since those frequencies are reserved for weak-signal SSB. Requires hex editing of the RSS in order to program frequencies in the 33cm band.
Motorola MTS2000 – This radio has issues transmitting above 924MHz, which makes using some of the simplex frequencies a problem. For a repeater only radio, its been great as it also has no issues with the -25 and the -12 splits. Also requires hex editing of the RSS in order to program frequencies in the 33cm band. Model 1 units only have a top display with a limited number of characters. Model 2 have a full front panel display, without the DTMF keypad. And lastly the Model 3 units have a full display/keypad. I have a Model 1 and a Model 3.
Motorola GTX900 Portable /w keypad – The unit I have will not transmit in the middle of the band (915MHz), which makes it unusable to me as our local repeater used the -12 split and the input is in the middle of the band. It would work fine in an environment where a -25 split is used or a -12 split in a different part of the band. The GTX900 was designed to be a trunking radio. After conversion to conventional it has some wierd characteristics like:
- The channel selector knob on the top does not work. Channels have to be selected via the keypad.
- You must have one trunking group programmed as well as one trunking personality. So one of your channels is wasted out of the gate.
Motorola GTX900 Portable (basic) – I have two of these units. They have proven to be functional radios.
Motorola GTX900 Mobile – I use this unit as my primary 900Mhz rig in the shack. I have a Motorola desk mic connected to it. It works great. It does have some characteristics of the GTX 900 keypad portable in that the channel selector on the right side of the display does not work, you have to switch channels with the buttons on the left side of the display. Not a big deal, but a little odd.
Kenwood TK-931 – This unit is very nice. I like the operational controls, etc. Unfortunately its capability in the 33cm band is still up in the air. It does handle the -12 and -25 splits, but only one at a time (radio-wide) and only in certain parts of the band. Programming this radio is odd, in that you have to configure two groups inside one system, one for TX the other for TX, then enable system scan to make it work. Very odd. I’ve since disposed of this unit.
Kenwood TK-481 – I’ve had this unit for quite a while and only recently decided to sit down and figure out how to program it. The Kenwood radios do not allow direct TX/RX frequency entry via their programming software. Instead you have to enter FCC channel numbers and they use a third-party program (KW900EZP) or hex-edit the saved file to get the radio into the ham bands. I chose to use the KW900EZP program. Basically you enter in the FCC channel number with the appropriate ending portion of your target frequency, then save the file. After that, you run the KW900EZP program which convers the 938.xxx entries into 927.xxx entries. You can then re-load the file and write it to your radio. Newer versions of the KW900EZP program even allow you to program in odd splits.
EF Johnson 5100 – Recently these radios have shown up on ebay for a decent price. I have four of them, purchased for $40 each. That deal only got you the radio and an antenna. However they use the same battery and other accessories as the Motorola XTS5000. I happen to have access to batteries, mics, etc., so I was good to go. The software required to program them is called PCConfigure. There are a couple of versions depending on the firmware on the radio. I was unable to reliably read/write a radio with the older firmware (using the 1.x PCConfigure). I ended up flashing the radios to a newer firmware and then using the 2.x PCConfigure. These radios have some very nice features and even a few that the Motorola series do not have. If you can find someone, usually a radio tech, with the PCIssue lab software you can enable these radios for FPP (front panel programming). This radio is definitely one of my favorites and I continue to play with it.
Kenwood TK-981 – I purchased one of these units from eBay recently. I’m happy to report that it was as easy to program as the TK-481. So far it works extremely well and I’ve purchased additional units for installation in both of our cars as well as an extra unit. I’m contemplating purchasing two additional units to begin work on a 33cm repeater.
If you have any questions regarding any of the above radios, please drop me a line. I’m happy to share what I’ve learned and help get you onto this great band!