Motorola 1928-2008...900MHz MX300 in 1975?

[MTS2000des]

Worth reading, could not help but note the technical inaccuracy "Motorola's 1975 MX300 series of portable radios operated in the 900MHz band..."
correct me if I am wrong, but there NEVER was a 900MHz MX300 as the 900 band wasn't used until the late 80's or early 90's and the MX series would just have been going out of production. I know there was an MX300 800MHz Privacy Plus radio...Intelligence...anywhere?

http://www.motorola.com/mot/doc/6/6800_MotDoc.pdf

[MT2000 man]

Well, your absolutely right about that, I've never heard of a 900MHZ MX either. Looks like a typo to me.
However, a good read nonetheless. Thanks for sharing !
Mike

[Jim2121]

But then it comes up again? http://giti.nectec.or.th/download/Bali/ ... stones.pdf

EDIT: I have to agree with the MT2000man.... it does make good reading
http://www.motorola.com/mot/doc/6/6496_MotDoc.pdf

[RADIOMAN2002]

Maybe not an MX but they did make an expiremental cell phone using MX technology in 1975. Looked the the first incarnation of Motorola's Dyna-Tac.

[bernie]

My two bits worth:
I note that the picture has the light duty battery, as well as the long case.
I would not be surprised if this was a prototype that never went on sale.
The 900 equipment is very similar to the 800 equipment.

[Batman]

the wimax 802.16e allowing mobile hand off interests me.

has lots of possibilities if it can be implemented on the ISM bands.

[MTS2000des]

My two bits worth:
I note that the picture has the light duty battery, as well as the long case.
I would not be surprised if this was a prototype that never went on sale.
The 900 equipment is very similar to the 800 equipment.

but someone correct me if I am wrong, but the FCC did not open the 900MHz band for SMR use until the late 1980's? (1987 seems to stick in my mind)...heck the current (and soon to be history thanks to re-banding) 800MHz band plan wasn't approved until 1982. So how could Motorola be selling MX radios on a band that didn't exist (as far as SMR use) when I was born (yeah I'm 32, will be 33 this June. Proud Gemini...Ironic as the MX was my favorite series, and the "STX Gemini" was a variant!)?

Every 800MHz MX360 I've seen was made in 1983 or later. I still say it's a typo. The MX series did come out in 1975, have seen a VHF MX320 with a serial number dating back to November of 1975, but it was VHF, not 800, and certainly didn't do trunking! Did the MX-S models not arrive until the early 80's? I had a VHF low power, low split (136-150. ex-military radio on 2m ham in the early 90's. My first "real" Motorola portable, and it was the cat's ass. It could hear better than any YaeComwood of the day, and out-talked any 5 watt Jap radio of the time, thanks to the real metal frame.

I'd love to see some early literature on the MX series. IIRC GE even "copied" the design of the MX series with the MPR/MPS series in the early 80's, all the way down to the modular construction, size, twit-on batteries, etc.

[bernie]

My two bits worth:
I think that you are probably right.
I have been in the 2 way radio business since 1968.
After working for a GE 2 way shop, which was also a RCC, I went to work as a Motorola field tech in Hawaii in '72.
I have participated in some of the early work in the 820 band. I installed a 120 W Micor Community Repeater at various sites on Oahu, for survey purposes in the early '80s. Before we installed our first beta test trunking system.

There are "Conventional" systems in the 800-900 bands, as well as trunking.
I know that there were field trials in the 800-900 bands in the early '70s. I saw the vehicles in the parking lot by the parts department in Schaumburg, and asked about the strange antennas, looked like stacked UHF 5 DB gain antennas. They discovered that too much gain on a mobile antenna is not necessarily a good idea.
I would not be surprised if Motorola had a valid license for mobile operation in this band which was used mostly for point to point.
I presume that Motorola likely had some input to the FCC regarding the new channel plans for the 806-820 band, likely had trunking in mind.

Before there were channel plans, you found two channels, put a radio on them. You still see this in VHF public safety channel assignments.
I find no mention of a 800 MX in the old parts book, but that does not mean that they did not build something for beta testing. There are probably very few people left at Motorola that would know what the old stuff was for, including the Museum. I think the MX was built at Plantation FL.

The MX is still my favorite. Back in the day when the MX was a current model I built my MX from several scrap units.
My first one was built from some units that were given to me. Several had no problem what ever for the first 20 floors or so, the last inch was brutal, for some reason the shop refused to repair them, then there was one that looked like it came out of the box, which it did a few days before it went for a swim off a pier. The insides were green after it was recovered a few weeks later.
I made my UHF MX 320 2 channel with talk around. My GMRS, as well as the shop repeater.
The 320 is supposed to be 2 ch max. I used the diode matrix on a VHF flex strip.
Contrary to Motorola's admonitions I used an ICM crystal in the channel element for my channel.
I scrounged my shop channel element from sales. Total cost: one ICM rock.

The early MX batteries especially the low capacity battery which is in the picture were extremely short lived.
Plastic cells , which I was told were made by Motorola. The "colometer" battery charger was also quite troublesome.

There were also problems with after market batteries: Should a public safety officer use his MX 360 for a truncheon, the locking cam would break away from the battery, the Genuine Motorola would not fail, it would break the bottom of the radio off. The MX trunking radios were not synthesized, if you had just one in your fleet, you were forever stuck on the first 5 channels of your trunking system, which can be problematic on a busy 15 or 20 channel system.

[3-SAM-12]

Here is the video version of the PDF,


http://www.youtube.com/watch?v=CMc7ppAIzik

[DJP126]

My two bits worth:

There are "Conventional" systems in the 800-900 bands, as well as trunking.
I know that there were field trials in the 800-900 bands in the early '70s. I saw the vehicles in the parking lot by the parts department in Schaumburg, and asked about the strange antennas, looked like stacked UHF 5 DB gain antennas. They discovered that too much gain on a mobile antenna is not necessarily a good idea.
I would not be surprised if Motorola had a valid license for mobile operation in this band which was used mostly for point to point.
I presume that Motorola likely had some input to the FCC regarding the new channel plans for the 806-820 band, likely had trunking in mind.

Before there were channel plans, you found two channels, put a radio on them. You still see this in VHF public safety channel assignments.
I find no mention of a 800 MX in the old parts book, but that does not mean that they did not build something for beta testing. There are probably very few people left at Motorola that would know what the old stuff was for, including the Museum. I think the MX was built at Plantation FL.

The MX trunking radios were not synthesized, if you had just one in your fleet, you were forever stuck on the first 5 channels of your trunking system, which can be problematic on a busy 15 or 20 channel system.

There was a program in the R1801 for testing the trunked MX portables. IIRC the application was MXT

[Hoseman292]

FWIW I have owned a early 800 MHz trunked MX360(?) which I purchased reaaaally cheap at a hamfest probably in 1988 or '89. If I remember correctly, it was not synthesized and used those pesky channel elements that were so hard to come by. Like most of the MX radios that I've picked up over the years, I never did anything with it and I'm quite sure it's boxed away somewhere. A question for the more senior batlabber's out there, can you recall any early trunked systems where the MX was used?

These days it's hard to walk away from a mint condition MX selling for $5 until you take into consideration the work required to make it operational. I purchased my first MX in 1986 for around $150. It was a powerful, solid radio and I carried that thing everywhere I went. Although the newer equipment will run circles around it, I would love to see an MX which could be programmed using ordinary RSS.

[bernie]

My two bits worth:
The first Motorola 6809 trunking systems had 5 channels. 120 W tube type amplifiers. Been known to function for weeks at a time. The controller key switches had to be left in service enable or it would crash, no watch dog, so it had to be physically re booted.
The mobile was a Micor, the portable was the MX360T.
Only problem was that for ever more anyone that ever used an MX or Micor was restricted to the original 5 channels.
Network services had a box on the order form: Synthesized or not.
Since the original radios were not , this particular subscriber was not ever assigned to higher channels.
Problem was: sales did not exactly know what the "Synthesized" Y/N box was for, so it was always checked NO, mysteriously when I expanded the busy system to 10 channels, immediately no subscribers were operating on the new channels.

The Micor was soon replaced with the Syntor.

[Big Towers]

I don't know about 900Mhz MXs, maybe for another country? But, I personally used many of the MX series portables on 800Mhz conventional in the late 70s. We operated a two state conventional 800Mhz repeater system made from Micor repeaters and tied together with tertiary UHF link radios. The MX was the portable for us to get, micor mobiles, and micor consolettes for base stations. As with Bernie, ICM crystals worked just fine. Conventional MXs were hard to come by, lots of trunked versions floating around. But once the MTX-800 and 810s came out, the crystal controlled MXs became history, as did the whole system when 800Mhz channels became just too valuable.