XPR XPR8400 question and help on a weird behavior

[mproy]

Hello

Disclaimer: I have 15+ years of Motorola portable radio programming experience, but I am fairly newbie to Repeater programming (had very good success with XPR8300 and MotoTRBo 14).

I recently purchased a XPR8400 repeater from a local radio shop (via ebay as it was cheaper believe it or not) and program it using CPS 2.0 2.21.61.0.

After some tweaking of hang time (as we could hear for almost a full second some dead noise after tx) to 1000ms, I have had great success reading, configuring it for an FM pair of frequencies (as assigned by ISED Canada). The portable radios were BPR40.

question 1 I then copied channel 1 to channel 2 and modified it to respect the second set of authorized ISED Canada frequencies.... BUT the repeater would not "trigger" on RX (TX from the portable radios). I moved position 2 to 1. Wrote and it now worked... but no longer the "old" channel 1 now in position 2. Should I understand the XPR8400 will only work with one set of FM channel at a time and the second channel would be for DMR only? Or did I miss something?

Question 2 When I used the second set of frequencies with cp200 and cp200d radios in analog mode, on several occasions but not everytime, the repeater (via RX it got maybe) it would transmit garbled audio long after the user transmitting had let go of the trigger. Almost like if the key had been stuck open... This occured with two different users transmitting (not related to only one radio) among a group of 8-10 users. Could the radio side programming be causing this behavior? Or should I look at the repeater side? Is there a self test or a test I can perform on the repeater to ensure it is "up to snuff" and not defective (obviously buying from a reputable company I assume it was ok as not listed bad, but...?)

Thank you in advance

M.P.

 

[dickie757]

What is antenna setup? Separate rx/tx or thru duplexer?

 

[cavmedic]

Its only going to operate on the first channel only in either D or A, now if you have the dynamix mix mode entitlement, then the repeater must be set for that and then it should be 1 or 2 i believe... its been a while.

 

[dickie757]

Next thing i see, not exactly wrong, but questionable....457.075 rx and 452.0375 tx.

I know they dont have to be set 5 megs off exactly, it looks like an easy mistake.

If you are running a duplexer, ch1 and 2 are so far away from each other, it will never work.

 

[mproy]

Not using a duplexer. Using two seperate cable/antennas FG4500

The frequencies were as per assigned! Could it be the problem?

"Its only going to operate on the first channel only in either D or A, now if you have the dynamix mix mode entitlement, then the repeater must be set for that and then it should be 1 or 2 i believe... its been a while."

So what's the purpose of having two channels if only the 1st will work? Another mode than Analog FM or Digital?​

 

[cavmedic]

Not using a duplexer. Using two seperate cable/antennas FG4500

The frequencies were as per assigned! Could it be the problem?

"Its only going to operate on the first channel only in either D or A, now if you have the dynamix mix mode entitlement, then the repeater must be set for that and then it should be 1 or 2 i believe... its been a while."

So what's the purpose of having two channels if only the 1st will work? Another mode than Analog FM or Digital?​

It’s literally two mobile radios in a box. One mobile is a receiver and the other is the transmitter interfaced together. It’s the same CPS used for the XPR lineup.

The help files in CPS go over everything.

 

[RadioGuy7268]

The XPR repeater has functionality for external "channel steering" through the backplane GPIO pins. That gets deep into the weeds, but it's explained in the Trbo setup guide.

The typical repeater ( typical as in 99.97 % of the time!) is going to repeat one single channel. Portable keys up on that particular channel, communication is relayed through the repeater. Simple.

The XPR8400 can be set up with either Ch1 as Digital, or Ch1 as Analog. That's the typical use. The repeater defaults to Ch1 when powered on.

You can purchase a DMM EID for the XPR8400 - Dynamic Mixed Mode Entitlement license. That would allow you to assign "mixed mode" to Ch 1, and then you could operate it as either Analog or Digital (one or the other, depending on which mode was received first - never both at the exact same time.) BPR40 is an analog only radio. DMM is probably a waste of time for your setup.

As far as the repeater channel programming - what are the portables set up as? The repeater and portables need to work together. The portable's transmit freq is the repeater's receive, and the portable will receive what the repeater transmits - provided the programming is correct on both sides. Does the portable match the License?

If you are using a split antenna system, how far apart (physically) are the 2 antennas? Are they mounted to the same tower/ building ? Who designed the system? Was desense ever mentioned/considered?

 

[mproy]

I have setup several xpr8300 in the past (using cps 16). Same antenna config... 53' truck one antenna on the right and one on the left. Antennas are at the end of a fiberglass mast.

No desense was never considered, as it was never a problem before.

I have programmed thousands of cp200, bpr40, xpr portable radios in both analog and digital configs and some of them for repeater use. All with great success. So I am familiar with the portable tx to repeater's rx and repeater's tx to portable,s rx. That's the easy stuff.

The problem occured only with the one set of devices and frequencies. The other set of devices and frequency *the problem was not noticed*.

As was said before, maybe it was the frequency split... because I know the portables are capable. But because it is intermittent its difficult to confirm.

As for the Channel A and Channel B / two channels in CPS2, I assumed you could program 2 x analog and/or digital channels. As cps2 allows me to do so.

 

[otobmark]

Normal repeaters don’t scan channel positions. I use 1 channel for DMR, and have a second programmed for FM. I have to manually select the channel using CPS at repeater site or by shorting pins on the back of the repeater. I thought about making a remote switch to connect to the rear of the repeater which I could control by IP or even DTMF on separate receiver. I never did it. If repeater is IP connected then you can change channels with management software peer to peer or through network if it’s on one. Not sure about newer firmware but originally you could only IP connect to the repeater when it was in digital mode (not FM or Mixed). I would be great if that has changed. Basically subscriber radios will have no effect on switching “channels”.

For 99% plus of conventional repeaters they are essentially single channel in use. If you want to play cool games get a mmdvm based ham repeater which “scans for modes” etc. Not a good or even maybe legal commercial solution.

 

[dickie757]

... 53' truck one antenna on the right and one on the left. Antennas are at the end of a fiberglass mast.

So, the width of a trailer? Take the horizontal distance, and make it the vertical with 0' horizontal distance and you will be happier. The antennas are too close horizontally. Stack them on top of each other, with receive on top. That is how I remember receive freq....it is higher, both in integer and height.

The problem occured only with the one set of devices and frequencies. The other set of devices and frequency *the problem was not noticed*.

Garbled, late audio is the problem? Kinda like FM doubling? Check to see if some kind of privacy inversion b.s. is programmed into subs.

And finally, there are ways to make a repeater change channels, but I have no clue how a xpr8x00 does it. I know how to do it with trc and *Ithink* dtmf.

You need to get another repeater for the other freq pair.

 

[mproy]

So, the width of a trailer? Take the horizontal distance, and make it the vertical with 0' horizontal distance and you will be happier. The antennas are too close horizontally. Stack them on top of each other, with receive on top. That is how I remember receive freq....it is higher, both in integer and height.

Correct or about 8ft.

Interesting. I will dig some more.

Garbled, late audio is the problem? Kinda like FM doubling? Check to see if some kind of privacy inversion b.s. is programmed into subs.

Subs of the repeater? Or the actual portables? Since this is only happening (noticed) on some of the radios.

And finally, there are ways to make a repeater change channels, but I have no clue how a xpr8x00 does it. I know how to do it with trc and *Ithink* dtmf.

You need to get another repeater for the other freq pair.

10-4. That seems general concensus. I was just "excited" at the idea of supporting two pairs of channels with one repeater.

Again, thank you all for your input

 

[dickie757]

Subs of the repeater? Or the actual portables? Since this is only happening (noticed) on some of the radios.

Subs=subscribers and actual portables and HTs and walkie talkies and mobiles and control stations and base stations. Everything but a repeater

Please explain the problem again

 

[mproy]

I used the repeater with 5 and 8 portable radios (two sets each with different frequencies).

Under one (5) all were BPR40 radios and 1 cp200d. Everything worked flawlessly. I even measured the output strentght and it was right on 25W, as per config.

Copied channel 1 to channel 2. Modified Channel 2 for the second pair of frequencies. After finding out, the repeater would not work with both channels concurrently under FM/UHF channels work, I moved channel 2 to position 1.

Under this scenario (8) all were CP200 and 2 cp200D radios. 98% of all communications were fine between all parties. Then - and this is not one radio, but at least 4 different ones did it - after transmitting, the repeater would "stay on" and transmit garbled undeciferable communication, robot like. The same radio would rekey and it would not do it. Sometime later, not a fix period of time, the issue would occur again.

I'll look at privacy... but wouldn't that do it all of the time for one given radio?

 

[kk6rq]

Correct or about 8ft.

Interesting. I will dig some more.



Subs of the repeater? Or the actual portables? Since this is only happening (noticed) on some of the radios.



10-4. That seems general concensus. I was just "excited" at the idea of supporting two pairs of channels with one repeater.

Again, thank you all for your input

"subs", meaning Subscriber Units. What LMR ppl call users' radios. Also referred to as "SUs"