Motorola® MX® Information Index

Contributions and additional listings are both requested and welcome!

The "MX Series" includes several crystal based (actually channel element based) and synthesized products that were first introduced in 1975. This series of radios included the MX310, MX320, MX330, MX340, MX350 and MX360 handhelds (the last two are rare), the PX300 and PX500 packsets, the MTR300 firetower repeater, the "APCOR" emergency medical repeater (also called the paramedic suitcase radio), and several others. One of the design goals was receiver performance equal to a Micor station. Until the Saber series came out these were the top-of-the-line handheld radios. Due to the fact that the "narrowband" units are what is considered today as wideband they will be illegal to use in commercial and public safety use when the narrowband rules go into effect.

There were some MXnnn-R radios produced for the military that had two major differences - the first was a dark finish on the external metal pieces (the standard radios were just too reflective for night time and special ops use) and the entire design was "ruggedized". Even the frame surrounding the main board was different. Many of the exterior case parts and some of the internal parts are not interchangeable between a standard and a -R version.

The MX series used tiny channel elelments, the synthesized units (those with the model names ending in "S", like MX320S) used 256 x 8 PROMS. You may find these chips referred to in some literature as "code plugs". The factory PROMS are numbered with NLN5096A, NLN5096B, NLN5096C or NLN5096D and many were made without the "NLN" on the label. All were / are programmed using the R1801A suitcase programmer fitted with the RTL5070 series adapter module (the one that I saw was a RTL5070D) and the RTL4809D software package (which itself was a set of PROMs that were installed inside the suitcase programmer). The A and B chips are one time devices and once you program a channel that's it. If there are empty channels you can still program them, but you are stuck with what's there. The C and D series chips are EEPROMS and can be electrically erased and reprogrammed. I suspect the later radios that had a zone switch (and up to 48 channels) used a larger PROM.

Anyone know what the regular (non-Motorola) part number is for the chips?

Anyone know of a way to program them without the suitcase? There has got to be a way to calculate what each byte needs to be for a given frequency, and then burning that bit pattern into a chip is pretty trivial...

Anyone have a couple of photos of a desktop charger?
The standard single unit desktop rapid (one hour) charger was the NLN8858A. The NLN4038A was the 220 Volt version of it. The single unit standard rate (14 hour) desktop charger was the NLN8856A. The NLN4036A was the 220 volt version. Due to the wide variety of power plugs around the world the 220 volt chargers were delivered without a mains power plug and one was fitted locally.

The regular speaker-mic is the NMN6071B. The public safety one (used only on UHF, complete with the High/Low switch) is the NMN6072A. The 8505355K04 antenna is designed for 440-470 MHz, the 8505309N11 is for 470-512 MHz.
The military wanted a waterproof speaker-mic and that's the NMN6124B (with a velcro patch) or the NMN6125B (with a swivel clip).

If you are at all serious about the MX Series you will want to subscribe to the Yahoo group devoted to the PX and MX Series radios

MX300 Series Model Numbers
We know this table is not complete, if anyone wishes to add some details please let us know.

Sample model number: H43SXU-3180

H 4 3 S X U

Radio
Type Transmit
Power Frequency
Range Type Encryption ?

H
Hand-
held

or

Z
Special
Product 2
1 watt 2
68-88 MHz
but I've not seen one A
Channel Element
(non-synthesized) A
Non Encrypted U

3
2.5 W 3
136-174 MHz S
Synthesized X
Digital Encrypted

4
5 W 4
403-470 MHz

5
800 MHz

Sample model number: H43SXU-3180

3 1 8 0

Squelch Channel
Spacing Channel
Selector ?

1
Carrier 0
Wide Band
(15 KHz deviation) 2
2 Channels 0
?

3
PL 1
Narrow Band
(5 KHz) 4
4 Channels

6
DPL 6
6 Channels

8
8 Channels

The antennas are the same as used on other pre-SMA-fitting handhelds and the "correct" factory antennas are:

? or 85-82283J06 or NSN 5985-01-043-9372 (142-150.8 MHz)
NAD6283A or 85-82283J01 or NSN 5985-00-378-0156 (150.8-162 MHz)
NAD6284A or 85-82283J02 or NSN 5985-00-182-7352 (162-174 MHz)
? (403-430 MHz)
? (440-470 MHz)
? (470-512 MHz)
8505355K03 Public safety speaker-mic only (404-430 MHz)
8505355K04 Public safety speaker-mic only (440-470 MHz)
8505309N11 Public safety speaker-mic only (470-512 MHz)

Other parts:

KXN1039A/B or KXN1067A/B UHF receiver channel element
KXN1040a/B VHF receiver channel element
KXN1041B or KXN1099 VHF transmitter channel element
NLD6610A, NLD6621A, NLD6631A and NLD6641A are all listed as being the RF Power amp 136-150.8 MHz
NLD6633B VHF RF PA 2.5w 162-174 RF PA
RPX4253A is the Volume Control Replacement kit for the MX Series
50-05181E02 is the internal speaker
01-05951J35 replacement curly cord and connector for the Speaker Mike

MX300 Parts List and Accessories List 1.2mb PDF file Donated by A. Nony Mous

Note: All of the manuals below are out-of-print and no longer available. Parts availability is also a problem, especially for the channel elements, PL tone and DPL code elements, and the frequency and tone PROMS for the synthesized radios. See the comments above regarding the one-time PROMS and re-usable PROMS (called EEPROMS).

KJ6VU has a nice web page with some MX information at http://www.qsl.net/kj6vu/mx.html.

VK1KRF in Australia has a web page on how to substitute an inexpensive common 24 pin EPROM for the Moto code plug - but it requires disassembling an old code plug module and some careful soldering. See http://www.qsl.net/vk1krf/MX300/MX300.htm.

Another interesting page is at http://www.cahuenga.net/mx300.html.

The MX300 Series Theory and Maintenance Manual This is the starting point for understanding these radios. Moto's part number for this manual is 68P81013C70 version A (but there may be later versions, I don't know).

MX300 VHF Service Manual This covers the H23AAU 1watt, H33AAU 2.5watt and H43AAU 6 watt one through eight channel models. Moto's part number for this manual is 68P81013C71 version B (but there may be later versions, I don't know).

MX300 UHF Service Manual This covers the H24AAU 1watt, H34AAU 2watt and H44AAU 5 watt one through eight channel models. Moto's part number for this manual is 68P81013C75 version B.

MX300-S VHF Service Manual This covers the H23SSU 1watt, H33SSU 2.5watt and H43SSU 6 watt synthesized models that held up to 12 channels in each of (up to) 4 zones. Moto's part number for this manual is 68P81022C10 version A.

Servicing MX Portable Radios This is a training course handout. The last section covers the synthesized radios.

MTR300 Sales Brochure This manual covers the MBC33CKA / MBC34CKA fire tower lookout repeater radio that is based on the MX Series Handheld components built into slide-in modules and sized to fit a Spectra-Tac chassis. Note that this unit was made by Motorola Canada (hence the MB prefix in front of the C3xCKA model numbers).

MTR300 Installation Manual This manual covers the MBC33CKA / MBC34CKA fire tower lookout repeater radio that is based on the MX Series Handheld components. Moto's part number for this manual is 68P02900A35 version A.

Other manuals relevant to the MX Series are:

800 MHz manual: 68P81015C85
UHF MX300-S manual: 68P81022C15

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This web page created January 2007

Motorola®, MX, PL and DPL and a whole bunch of other names are registered trademarks of Motorola Inc.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.

	The MX300 Series Theory and Maintenance Manual This is the starting point for understanding these radios. Moto's part number for this manual is 68P81013C70 version A (but there may be later versions, I don't know).
	MX300 VHF Service Manual This covers the H23AAU 1watt, H33AAU 2.5watt and H43AAU 6 watt one through eight channel models. Moto's part number for this manual is 68P81013C71 version B (but there may be later versions, I don't know).
	MX300 UHF Service Manual This covers the H24AAU 1watt, H34AAU 2watt and H44AAU 5 watt one through eight channel models. Moto's part number for this manual is 68P81013C75 version B.
	MX300-S VHF Service Manual This covers the H23SSU 1watt, H33SSU 2.5watt and H43SSU 6 watt synthesized models that held up to 12 channels in each of (up to) 4 zones. Moto's part number for this manual is 68P81022C10 version A.
	Servicing MX Portable Radios This is a training course handout. The last section covers the synthesized radios.
	MTR300 Sales Brochure This manual covers the MBC33CKA / MBC34CKA fire tower lookout repeater radio that is based on the MX Series Handheld components built into slide-in modules and sized to fit a Spectra-Tac chassis. Note that this unit was made by Motorola Canada (hence the MB prefix in front of the C3xCKA model numbers).
	MTR300 Installation Manual This manual covers the MBC33CKA / MBC34CKA fire tower lookout repeater radio that is based on the MX Series Handheld components. Moto's part number for this manual is 68P02900A35 version A.