Maxtrac model curiosity

[sataraid1]

I have some questions concerning Maxtrac naming and model numbers. One is a specific instance of two very confusing radios, the other is more general.

I have two 2-channel VHF radios. One is D33MJA7304BK, the other is D33MJA73A5CK.

According to the model numbers, one has an 04 control head (2-channel), and the other should have an A5 (16/32 channel) control head.

In reality, they both have 2-channel control heads.

Normally, I would just think that one radio got a control head "downgrade" at some point, but what's odd is that the radio that *should* have had the 16 channel head also has the brain-dead 5-pin HLN9123A board. Even if there *had* originally been a 16 channel head on it, it would have been useless, right? Why would Motorola build a 2-channel radio and then sell it with a multichannel head?

Also curious is the fact that the D33MJA7304BK radio has a 16-pin board in it.

Is there any rhyme or reason to the use of 5-pin or 16-pin boards in radios that would otherwise be considered identical? I found it strange that the older B model had a more sophisticated board in it than the later C model did.

I'm also curious about why some radios have the full model number on the faceplate (ie: Maxtrac 50, 800, 900 etc.) yet other identical radios do not. Is this merely a cosmetic change made sometime during the production run?

Thanks, and sorry if this all needs to be filed under "clueless newbie", but after reading so many model decoding charts, my brain is starting to smoke and thought maybe I'd see if someone could give me some plain-english clarification.

[Bill_G]

Sounds to me like both radios might be Frankensteins. Do the serial numbers read from the radios match the printed labels?

[Satelite]

Hello :
Hacked radios = possibly.
Motorola did in fact produce a 16 channel mobile using the HLN9123 5 pin logic bd.
I still today see them run across my bench for repair ocasionly.
They were not that rare of a radio around here in Iowa .
I have reinitiated the 5 pin HLN9123 bd to 16ch with scan in vhf and uhf versions.
Satelite

[sataraid1]

Sounds to me like both radios might be Frankensteins. Do the serial numbers read from the radios match the printed labels?

The codeplugs in both radios agreed with the model and serial numbers, and all the components are internally consistent as far as dates go. There really aren't any of the telltale signs of mismatched parts. (Not conclusive, I know.)

The 16 pin radio appears to be quite old. All the parts inside were labeled 1986 or 1988, and the firmware chip says "v 5.04" but doesn't give the part number. Is it safe to assume that this is an earlier version of the HLN5569A?

[wavetar]

It does sound to me like the 5-pin was originally a 16-channel (they did exist, as was mentioned) which got a 2-channel head installed at some point. Don't read much into the 'B' and 'C' revisions, as they varied between the 2 & 16 channel versions. The serial numbers contain a date code. IE - 428PPC1234...the middle 'P' is the year...'Z' being 1999 so counting down from that gives 1989 as the year of manufacture. The 'C' means first two weeks of February of that year. If you look, you should find the 5-pin unit to be older than the 16-pin, although there was an overlap with existing stock as well.

[sataraid1]

It does sound to me like the 5-pin was originally a 16-channel (they did exist, as was mentioned) which got a 2-channel head installed at some point. Don't read much into the 'B' and 'C' revisions, as they varied between the 2 & 16 channel versions. The serial numbers contain a date code. IE - 428PPC1234...the middle 'P' is the year...'Z' being 1999 so counting down from that gives 1989 as the year of manufacture. The 'C' means first two weeks of February of that year. If you look, you should find the 5-pin unit to be older than the 16-pin, although there was an overlap with existing stock as well.

When I got the radio from a local fire department, it was only programmed with one mode and set to monitor only. I added a second mode, but I had no reason to think it would accept more. I guess I need to try to add more and see what happens. It would be nice to just add more and swap control heads, but I'm sure it's never that easy.

[sataraid1]

I have reinitiated the 5 pin HLN9123 bd to 16ch with scan in vhf and uhf versions.

Is this procedure documented anywhere? I've seen how to perform upgrades on boards with swappable firmware EPROMs, but not without.

[Satelite]

Hello:
Not sure if its documented here or not but i do have reinitiation sheets on step by step procedure i can email to you if you pm me your email address.
Would need to know what logic bd your dealing with as to 16 pin or the 5 pin and what the prom version on the bd is .
[email protected]
Satelite

[RADIOMAN2002]

I have run into all combinations of those radios. I bought about 50 Maxtrac series radios at state auction, some were 5 pin others were 16 pin, some with the extended eeprom others not. Motorola used whatever board was available at the time of manufacture, and just adjusted the firmware chip and heads accordingly. I was able to blow out both versions to 32 channel with MDC, but did have to install the extended eeprom in some to do it.

[sataraid1]

I have run into all combinations of those radios. I bought about 50 Maxtrac series radios at state auction, some were 5 pin others were 16 pin, some with the extended eeprom others not. Motorola used whatever board was available at the time of manufacture, and just adjusted the firmware chip and heads accordingly. I was able to blow out both versions to 32 channel with MDC, but did have to install the extended eeprom in some to do it.

So what we're saying is that radios with components that differ from what the model number indicates aren't *necessarily* hack jobs, correct?

Does this also mean that two radios with the same model number could have two different (5 vs 16 pin) logic boards?