Batboard

Glen W Christen

If you go the isolation route, don't forget the control head and fusing BOTH leads. Some functions are referenced to chassis.

Glen W Christen

Regarding colored cases, years ago in the days of the HT220, Motorola had a bright orange housing as an option. The local RR reserved it for their supervisors so that they didn't mysteriously 'disappear' into someone elses hands. There was also an option for a bright yellow housing for mobile microp...

Glen W Christen

Male RJ-45 Female 9-pin

1 goes to Pin 2
2 goes to Pin 3
3 Jumpered to 4
7 goes to Pin 5

Glen W Christen

The PT200 was a conductor's pack set which used the same boards (separate T & R), with a 5 watt PA as an option. The battery pack was a collection of D-cells (11?) and would last for weeks which made them popular with railroads. I worked on many, including an HT200 that fell into a creek and was...

Glen W Christen

There was even a warning included with the cables with a new radio. You MUST have both radio power and ignition power tap the same power point or all kinds of strange things would happen.

Glen W Christen

Years ago one of our customers took a lightning hit on their tower. The result was three antennas blown clear off the tower and the power company's transformer blown off the pole. The strike hit the building, vaporized the meter panel and blew a 4-foot hole through the wall but didn't start a fire. ...

Glen W Christen

Haven't found the plain Syntor, but the Syntor X memory module p/n is HLN1125B. The IC itself is 51-97014B01 (2k X 8 EEPROM, 24 pin. I think the module was the same for both.

Glen W Christen

The Mocom 70 came out in late 1969, using the identical head for the MOTRAC. The initial run was low band, then VHF, which used the same exiter and PA with a varactor tripler to provide a 30 watt UHF transmitter. Later models used the same chassis with a MICOR PA deck to give a 75 w UHF, 100 W VHF, ...

Glen W Christen

Not that it matters, but the speaker is for a Micor, which makes the case about 30 years old (or more, since it came out in 1969)

Glen W Christen

If I remember correctly, when the H.E.A.R. system started in Iowa bout 1976, it designated Hospital Emergency Administrative Radio.

Glen W Christen

The 1327 model is at least 30 years old. I think you've probably gotten all the goodie out of it that there was in it.

Glen W Christen

Thanks!

Glen W Christen

In spite of many years in the business, I've only worked on a few Spectras. Which capacitors are the ones that the above writer referred to in regard to the fail 001 message?

Glen W Christen

It's been a long time since I used one, but if I remember right, there were several functions that were internal options but the front panel still had the indictor LED's. Maybe you don't have that function at all.

Glen W Christen

Early model MSF's were not PC programmable. The only way to program them was with the R1800(?) suitcase programmer and the on-board software. What age is the unit? The serial number would tell you the manufacture date.

Glen W Christen

GM300/GM120 was strictly DOS - no Windows version. It was a successor of Maxtrac, which was paralleled with the M100 (Radius line) and were M's first low-tier synthesized mobile products.

Glen W Christen

If I remember correctly the first "Conductor's Pack Set" was the PT100, which used the separate Tx & Rx boards of the HT100. Some were high power, with the external PA, but all that I worked on used D cells and would last for weeks in railroad use. I've seen it both low band and VHF: L...

Glen W Christen

It's like Marley seeing the ghosts of Christmas past after almost 40 years in the business.

Glen W Christen

If it is a Motrac or Mocom 70, unless you have a very high-level signal generator, you might even have to take the cover off the front end and inject signal stage-by-stage, working from back to front for an initial tune-up, then inject it as normal and complete your fine-tuning. These units were ver...

Glen W Christen

If you replaced a selenium stack (Yes, they STUNK) with silicon diodes, your power about doubled. I remember when we had to install a 100 W dynamotor (Model 140 D) in the "trunk" of a Pinto. There was no room for anything else, and you wanted the engine well wound up before you hit the PTT.

Glen W Christen

More history: The predecessor to the MCX100 was the good old MICOR. It was limited to the same channel configurations as the standard Micor, but had a chassis extension which allowed it to be used on 12 Vdc, 72 V dc, and 110 V ac, or all three, depending on which power supply modules were installed....

Glen W Christen

I ground the clips and eliminate the issue. FYI, the DTMF mike uses a mechanical plunger to activate an internal switch and does not need a ground.

Glen W Christen

Also, the base end is likely duplex so that the control center can have priority to transmit.

Glen W Christen

No separate adj for DPL/PL. Deviation set is under maintenence in the software.

Glen W Christen

HT600 & P200 will not run on the other model: I've had no luck with anything faster than a 486.

Glen W Christen

Years ago the Illinois Highway Patrol had yellow mikes on their MOTRACS. Some Mot salesmen managed to get their hands on a few and made sure to make them highly visible and never had a problem with speed stops.

Glen W Christen

The local railroad dropped an HT100 (yes, 100) from a bridge into the river about June. Late September, someone saw it lying on the mudbank and took to to the yardmaster in a bucket of water. I drained the water and let it dry. When I applied power, it had squelch noise but I gave it last rites anyw...

Glen W Christen

VHF railroad Consolette model number would be something like L43BBB-1900 for carrier squelch, -3900 for PL in 30 watts, 4 freq. L53BBB would be 60 W, and even a few L73BBB were built in 100 watt. Even earlier version had a MOTRAC in a similar housing.

Glen W Christen

The service manual for it is contained in the GR300/GR500 repeater manual. The i50 is a BASIC INTERCONNECT REPEATER CONTROLLER. The manual shows no optional settings, other than to accomidate different radiosl

Glen W Christen

They also use different software for programming. (standard)

Glen W Christen

I have found that whenever this unit gets hit (unless it is totally destroyed) that the controller board is what is toast. I finally got smart and started using sockets.

Glen W Christen

Thanks for the info.

Glen W Christen

Does anyone have the part number for U101 - the Rx mixer. Stamped M1216? Appreciate any help you can give me.

Glen W Christen

Unfortuneately, the only training Ihad on these was the school of hard knocks and the telephone to talk to M.

Glen W Christen

When these were first in service, they were for IBM field service techs. Each station was tested via computer daily, and if it failed a test, you were called out. The one I was responsible for was checked at 0200 local for the first couple of years, and when if failed, I was called. NOT fun.

Glen W Christen

Better to know that you don't know than to do your own like a sheriff did last week - NO fuses in the lightbar feed, or in the radio. Luckily it DIDN'T go up in smoke.

Glen W Christen

You might also try by-passing all of the wires to ground with a small capacitor, such as a .01 uF. This used to fix many problems with high-power, low-band units when they were popular.

Glen W Christen

Sometimes moving the TEST jumper on the control board will allow you to TX and thus troubleshoot.

Glen W Christen

The first use for these transistors were for the MICOR audio output way back in 1969.

Glen W Christen

Both the Micor and Mocom 70 came out in late 69, early 70. I remember because that was when I started in the business and didn't yet know enough to be impressed! They didn't even need a power supply that sang.

Glen W Christen

The HT600 was the first. The HT50/P100 came later, and the MT1000 evolved from the HT600.

Glen W Christen

The M3 uses the standard HLGT/Function/LLGT as default. They can be reprogrammed to different tones if needed for system operation

Glen W Christen

FYI most intrinsically safe batteries have an internal fuse. If you short it accidently, the fuse goes and you have a brick, so there's many ways to destroy a perfectly good battery.

Glen W Christen

I only worked on a couple of the very early ones for DPL repeat problems. Motorola had to provide a mode (low freq bandpass) since they retransmitted the PL but had too much roll-off for DPL

Glen W Christen

I'm not sure of your actual hookup, but the M3 remote function tones can be programmed using MSEDIT if you could determine exactly what you need to mix and match.

Glen W Christen

VHF Radius maintenence manual 68P801050C80-O Operating instructions 68P801050C65 Programming instructions 68P801051C15 UHF Radius instruction manual 68P80157C55-O Radius P100 and Motorola HT50 are identical except for color. However, early models used different software p/n's but they later combined...

Glen W Christen

I have had a lot of these units in service for years - the ones with recurring problems were the ones sold with interconnect, when a long call would generate tremendous heat on the PA. Also found out the hard way that if you wanted reliable service you HAD to have the A+ set at 13.8. Lower voltage w...

Glen W Christen

The Mocom 70 does use an audio output transformer. One side is grounded via pin 5 and the other goes to the control head, pin 3, via front plug, pin 3. You might check for audio at the yellow and yellow/blue wires at t he transformer to eliminate cabling and control head. If you have audio there, sh...

Glen W Christen

#19 is designed for unswitched input
#20 is PTT ignition control
Both Motrac and Mocom 70 used the same scheme - you wanted to turn off the filiments in the Motrac or it would kill the battery - so #20 provided that function.

Glen W Christen

The first that I ever saw of this type of scrambler was in 1969 when Motorola provided an SP (Special Purpose) system to the Cedar Rapids IA PD. They were used on both Motracs and tube model radios but weren't used very long - the Collins Radio engineers who designed the Apollo communications had no...

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