Thanks for setting that straight; I guess we can say that we have a definitive answer on key retention during battery swap-outs or if the coin memory battery is dead.

That has me interested now; I will chase down the schematics to see exactly what is juiced off of that battery. Maybe the encryption board uses NVRAM (non volatile) and does not require a wetting voltage to hold the data.

The battery is actually a rechargeable Li-Ion in a miniature coin style. It ...

Encryption keys were never intended to be read back out of the module. Imagine the glaring security hole in a system if someone could temporarily gain access to a legitimate radio and to lift the encryption keys out and then to drop it back in a different radio.

It is a one-way action of writing to ...

I think it was the battery from the MX300 portables... circa 1975.

ePay has one for $55.... insane pricing.

Firstly,
I did search the forum for this particular question. The KVL T3011 keyloader was designed to use a portable radio battery. It was the very old style quarter turn twist style.. I think this was even pre-HT series. I remember having one issued to me back in the early 80's with this style of ...

Mike,
Thanks so much, I am pretty comfortable with digital logic and being able to toggle a line to strobe the data in and out of the shift registers. I did that type of design work back in the early 1980's. Now that I look at the very simplistic way that the hardware is structured I feel confident ...

I have a bunch of the HLN124D DEK heads and would like to put a few to use with a Micom 2 (five of those as well). Normally there is not DEK support for the Micom 2 but there is a serial HDLC data connection off of the back of the Micom 2 radio.

What I want to do is to use a small controller, like ...

Will,
Thanks so much, that will really help in making a custom cable end so I can jack the microphone into the MOBAT-2

One of the problems that comes up with the Mobat radio is that pin #7 is the "monitor" pin and pin #2 is digital RXD (like for programming). If you use some other Motorola mics and do not pay attention to pin-outs you can end up hanging up the mic on-hook and it takes the RXD data line to ground ...

Hi,
I am trying to adapt the HMN4069 microphone to a different Motorola radio (Micom2). I know the pinouts on the Micom2 but I have not had much luck on finding the pinouts for the microphone. Can someone please post the pinout? If I have to I can make a custom connector end to match up to the radio ...

Thanks for the guidance. I had gone through the batlabs and repeaterbuilder sites looking for details on firmware versions. I have not seen anything similar to a set of release notes and most information appears to be empirical or based on anecdotal.

I had hoped that by comparing the machine code ...

I have seen this question partially asked and partially answered in several places without a good explanation of exactly what advantages come from different Spectra PROM versions.

I know that there are certain features that become available at newer firmware versions like "Zones" on versions newer ...

I have been working as a SCADA comms engineer for +20 years and a good part of that time has been interfacing to MOSCAD SCADA RTU's. Normally we get the data converted back into serial (EIA-232) at 9600 baud and run it into an HMI (Human-Machine-Interface) software package where we map the I/O into ...

It has been mentioned, can someone post the resistor value changes for the VHF preamp?

Not having or being able to get a service manual really sucks. I could look up the values myself.

Tish, AA4HA

For a straight-up resistor change it sounds like they are just changing the gain. If I knew what it is and what it should be there would be some leeway in setting the stage amplification.

I have used the BDA approach and a "passive antenna" setup to provide cellular coverage in the tunnels under a sewage treatment plant. There are about 3 miles of tunnels under the plant (LARGE plant, major metropolitan area) and 10-12 stairways that descend down to around 30 feet below grade. It is ...

As it is impossible for me to find a set of detailed and basic service manuals for the Spectra I cannot work out the resistor changes for the receiver section on the VHF radio. I want to add the pre-amp option to a few VHF units and I understand that it is less complicated than the UHF preamp (that ...

I took a look at the schematics for a Maxtrac and see where they have a bi-directional buffer chip between the programming interface and the CPU. In theory this should be able to cope with a little bit of jitter.

Now if the stinkin computer serial port just inserts large pauses into the data stream ...

Since it appears that the RxD line on many moto products is very sensitive to timing; eg: issues with fast computers would a redesign of the RIB be a worthwhile project?

Right now it is all asynchronous from computer, through RIB to radio. When we run a faster computer or an OS that plays the ...

Does anyone have the Motorola part number for their 15-pin TDA7256? The Motorola 15-pin 7256 is actually, so I've heard, a 7255 in disguise.

Ooh! Just looked on eBay, someone's selling the TDA7255s for $9.58 plus $3 shipping. http://cgi.ebay.com/TDA7255-Integrated-Circuit-x-1-pieces-/380248757476 ...

If you have large structures like hospitals, hotels, commercial buildings, etc... You may have some pull in your fire codes to have those buildings retrofitted with radiax (leaky coax cable) running through the emergency stairwells or elevator shafts.

When IC pulls up to the scene your commo person ...