L3276 et al

[TX_Shooter]

Is there a difference between the L3276, L3276A, and L3276AC?

I've got two manuals for the L3276 (6880802B90-O, 2003 and 2008), but neither shows how to connect an L3276AC to an XTL2500 radio (pin to pin), which apparently is how this base is able to connect 3 desktop units to it, all in parallel, but also channel steer it (or so they say). They did not specify what their desktop units are, other than to say that they're CPI units. I didn't think that the XTL2500 could be externally steered like that.

Thanks,
TXShooter

[d119]

XTL doesn't support external channel steering, so you're correct on that.

These are OEM'ed by CML Emergency Services. You might try contacting Motorola SSC and see if someone has an application note on how to interface these to the XTL. Otherwise, you just need to sit down with the L3276 manual and the XTL pinout and make it work.

It shouldn't take more than an hour to figure it out and implement it if you've got all the correct connectors, pins, etc.

[TX_Shooter]

XTL doesn't support external channel steering, so you're correct on that.

I've seen an XTL5000 mobile inside of an XTL-5000 Consolette, and conversely an XTL7500 inside a Consolette, both of which could be channel-steered, but I suspect that was via a digital buss from the AIB.

It shouldn't take more than an hour to figure it out and implement it if you've got all the correct connectors, pins, etc.

I can't quite recall but I think that I've seen factory molded cables connect the L3276AC to the XTL2500. Unfortunately, not knowing how its pinned is a hindrance, and thus I'm going to have to go about this the hard way. I'm guessing the L3276AC is just a Tone-Keying adapter, and it just translates a 2-wire with EIA tones on it to a regular 2 or 4-wire audio with a relay to key the radio?? Is that too far fetched of an idea to assume?

Thanks,
TXShooter

[d119]

I've seen an XTL5000 mobile inside of an XTL-5000 Consolette, and conversely an XTL7500 inside a Consolette, both of which could be channel-steered, but I suspect that was via a digital buss from the AIB.

Correct. THAT kind of channel steering is happening on the SB9600 side of the house, and requires the consolette housing and associated internal electronics.

I can't quite recall but I think that I've seen factory molded cables connect the L3276AC to the XTL2500. Unfortunately, not knowing how its pinned is a hindrance, and thus I'm going to have to go about this the hard way. I'm guessing the L3276AC is just a Tone-Keying adapter, and it just translates a 2-wire with EIA tones on it to a regular 2 or 4-wire audio with a relay to key the radio?? Is that too far fetched of an idea to assume?

Not at all too far fetched. In fact, that's exactly what's happening. The L3276 takes PTT, TX audio and RX audio from the radio, buffers it, and allows whatever is placed on the line input going into the 3276 to tone key the radio. It also provides a standard 600 ohm interface to the radio from whatever is on the line, and this is what desksets, dispatch consoles, telco interfaces, etc. want to see.

There's a little bit more it can do (COR-based audio gating, channel steering using different function tones, put the radio in monitor mode, etc), but the basic premise is 2175Hz HLGT + 1950Hz FT + Voice&2175HzLLGT = tone keying.

[TX_Shooter]

I've seen an XTL5000 mobile inside of an XTL-5000 Consolette, and conversely an XTL7500 inside a Consolette, both of which could be channel-steered, but I suspect that was via a digital buss from the AIB.

Correct. THAT kind of channel steering is happening on the SB9600 side of the house, and requires the consolette housing and associated internal electronics.

Just out of curiosity, would an L3208A handle the conversion from EIA tone to SB9600 in order to channel steer the XTL7500?