XPR8400 PL Disabled w/ Flat Audio

[omegacom]

Hey All,

New to the forum, looks like lots of smart people here... wondering if anyone has run across this. I'm building an analog repeater network with XPR8400's using external controllers, so I've disabled the internal repeat path. I need discriminator Rx audio out of the accessory port so I can detect multiple PL tones externally, so I enabled that in the CPS. Whats strange is if I set Tx PL in the analog channel and I key the transmitter with the accessory port it doesn't work, I get carrier only.

The network has been designed so that users send unique PL tones that either puts them on the UHF backbone, or keeps them on the VHF drop, and the VHF drop transmits the same PL tone regardless.

I'm not sure if Moto was just thinking if someone is using the unfiltered audio option, why would they possible need a Tx PL tone, but in my unique case I do.

I saw that Mars has modified some codeplugs, maybe that's an option to get this to work.

Any help would be great,

Thanks,

Jesse

 

[Notarola]

Since the radio is in flat 'mode' the pl is not sent because radios using PL and voice use emphasis/deemphasis. Flat mode is used for data type transmissions. to fix the issue set the radio to normal TX and you should have no troubles with your repeater.

the rear pinouts can be found here if you need them.

http://communications.support/threads/10673-Disappointing-Conclusions

 

[omegacom]

Right, however in the accessory config I have one option, filtered audio or unfiltered audio (if you select filtered audio you get the option of having pre/de or not, but that's a moot point since I need unfiltered audio). Since I'm using an external PL decoder, I need unfiltered audio. I just tried it with filtered audio, and it doesn't work, which is what I expected since there should be a 300Hz to 3 Khz passband filter enabled when filtered audio is selected. Once I enable unfiltered audio it seems to kill the internal PL generator, even though it's not greyed out in the CPS and there is nothing in the help files that say this is a result.

Also in the pinout thread, pin 14 is Rx audio, not necessarily discriminator audio, since that's settable in the CPS.

Tried Firmware R02.40.01 Codeplug 14.00.07 and R02.40.12 Codeplug 14.01.03, both exhibit the same issues.

Going to try some older firmware revs and a 8300 and see what happens.

Thanks,

 

[omegacom]

XPR8400 R01.09.00 Codeplug 11.00.11 does the same thing

XPR8300 R01.03.03 Codeplug 03.01.04 does the same thing.

Also if you turn the internal repeat path on, while using "Flat Unquelched" Audio Type it passes PL from the Rx to the Tx internally, and ignores the Tx PL field. (on both the XPR8400 and 8300)

In the help screen for "Audio Type": "This feature selects the configuration of the audio output line" Motorola needs to change this to: "This feature affects the entire audio handling of the repeater"

I'm really in trouble, this is going to be a $20,000 mistake as I've built out a whole network based on the internal PL generator functioning while getting discriminator audio out the auxiliary pins

 

[com501]

You will have to encode PL externally and insert it into your transmit path, probably.

 

[omegacom]

Ya that's what I'm currently working on as a solution. It's getting messy as I have links that need to key the VHF transmitter (which needs Tx PL) so I have to use an aux input to the tone board to get it to generate PL. But the tone board has muting circuits that turn on when the aux input is used, and this system designed is supposed to be full duplex, so I have to modify the tone board and bridge those out. So much for a simple wiring harness, lol

 

[Notarola]

I was going to make the same suggestion. Since you can decode the PL externally it would be easy to tie it to a matching encoder.

 

[escomm]

OP needs an MTR3000 to do what he wants, XPR8400 will not support this configuration as discussed.

MTR3000 will let you split the TX and RX and you can have flat RX and regular TX or regular RX and flat TX or whatever combo you like. Injection of external PL on an MTR3000 is done through the low speed data input on the DB25, pin 13.

 

[Notarola]

very good point escomm, the MTR is a fantastic rptr and a staple of the RF industry. I was replying to help the issue since the member indicated he already has the XPR8400s. If a external PL encoder/decoder is chosen I highly recommend the Com-spec encoders and decoders. They operate extremely fast especially on decode (analog and digital) along with very low input PL levels needed. I have used them in similar aplications in the past. In my case it was multi PL decode to two tone paging encoding.

 

[omegacom]

Thanks for the replies guys, I'm using a Zetron Model 38A for decode/encode, though I have used the Com-spec boards in the Daniels/Codan AC3E and they work well. At this point I have a working prototype, it's much more complicated and mess then what I originally envisioned, but it gets the job done without buying more parts. The one thing I wish was that the PL encode fields would be greyed out in the TRBO Cps if unfiltered audio type has been selected, it's very misleading as it currently stands. I noticed the PL decode still sets the PL / Talkgroup Detect accessory output, so that would have to remain. Thanks all.

 

[Notarola]

I am happy you were able to get things running to your satisfaction. As you have discovered often the CPS displays weird setting conflicts, this is primarilly because the cps main features are checked for conflicts but when you select something off the beaten path you fall between the cracks. There are two primary causes for this. First the programmers never even see a radio so they have no real idea of the setups and connections used. Second sloppy or lazy programming.

 

[Jutod]

I just ventured down the same path as the original poster of this thread.

In my case I was adding an external controller to the analog side of a Trbo DMM (Dynamic Mixed Mode) channel in an XPR8400. In a DMM channel, if you leave the internal repeat path enabled, and set the analog RX criteria to CSQ (carrier squelch in the DMM channel settings), it will by default disable the internal controller and audio path and for analog users only. However it will leave the internal path intact for digital users. I then had to add an external PL decoder in order for the digital users not to key the analog side of the repeater. After that when trying to use the internal PL encoder, I realized this does not allow the PL Encoder internal to the repeater to work (even though in the codeplug it was set to TX PL of ZA). So I had to add an external PL encoder so the analog users didn't have to hear the digital noise. Of course the RX Audio type has to be set to unfiltered and un-squelched flat audio (in order to capture the PL from the transmitting radio). Then I ran the raw unfiltered audio through the high pass filter of the external PL decoder (I used a TS-64) to remove the user's PL. I left the repeater set to pre-emphasis for the TX audio (as most transmitted audio needs to be, so the user radio can do de-emphasis on receive).

The reason I had to do this is because Moto has a bug in the DMM channel operation on the analog side of it. Basically it will never do CW ID for analog users. I found that analog users on the mixed mode channel could talk all day and repeater would never ID. For digital users the ID worked fine. So that is why I had to add an external controller for the analog side of the DMM channel. I reported the issue to Moto, both officially and un-officially. In other words.... I opened a case on a repeater that was still in warranty about it. And I used to do development for Moto for many years (including the Trbo line), so I have several friends in Schaumburg Engineering I still talk too, therefore I mentioned it to them as well. But Moto obviously wasn't interested in fixing it. So I moved on with my own solution.

So in summary, a XPR will do what the guy wants, and it doesn't have to be a MTR. It just has to be programmed and wired correctly including the addition of an external PL decoder/encoder.