HT1550XLS DPL Issue

[W2MB]

I am having what seems to be an issue with DPL on my HT1550XLS. I have one channel setup for simplex operation on 151.7750mHz/DPL#516 on a system which consists of a mix of Motorola SP50s and Icom handheld equipment. Audio from the HT1550XLS sounds distorted on the Icom sets and the squelch on the Icom units seem to close during audio peaks from the HT1550XLS. Signals from Motorola SP50's sound fine on the same Icom devices. The HT1550XLS receives both the Motorola and Icom units without any problem. The HT1550XLS sounds fine on this channel on a Motorola JT1000 set up with DPL. The HT1550XLS sounds fine on other CSQ and PLed channels. I remember reading that there can be problems with some DPL implementations but can't remember the details. Can anyone shed some light on this for me?

[a_j_b]

I've had issues using DPL with mixed brand radios. If you are in a position to reprogram radios a TPL will probably resolve the issue.

[RKG]

I remember reading that there can be problems with some DPL implementations but can't remember the details. Can anyone shed some light on this for me?

I suspect the issue you have in mind had to do with inconsistent definitions of "normal" and "inverted", both among manufacturers and among different products within a manufacturer's line.

If this is the problem, the receiving radio won't unmute at all, and it can be correct either by inverting the receiver or programming it for the logically inverted form of the DPL in question. This issue does not yield the symptoms I believe you have described.

Rather, my guess (and all long-distance diagnoses are founded on some guesswork and have to be taken accordingly) is that your problem has more to do with waveform shape and symmetry. This can be a frustrating issue to chase down, and switching to an analog PL is a much simpler fix.

[d119]

Are you sure your bandwidth settings (2.5kHz/4kHz Narrow/Wide) are set correctly in your HT1550?

[W2MB]

Are you sure your bandwidth settings (2.5kHz/4kHz Narrow/Wide) are set correctly in your HT1550?

It is possible that it was not programmed properly, but it is odd that it sounded fine and DPL worked when monitored on a JT1000. I will have to experiment more, I believe that the device has 3 bandwidth configurations.

[com501]

Wide/Narrow issues between Motorola radios are not nearly as picky as between a Motorola radio and another brand. Kenwood, Icom and Vertex appear to be the most susceptible. On some radios, using a wide band M radio and a narrow band Non-M radio with DPL will result in no decoding whatsoever.

Check those settings!

[W2MB]

Wide/Narrow issues between Motorola radios are not nearly as picky as between a Motorola radio and another brand. Kenwood, Icom and Vertex appear to be the most susceptible. On some radios, using a wide band M radio and a narrow band Non-M radio with DPL will result in no decoding whatsoever.

I don't know if the system if the existing system is configured narrowband, but I did program the HT1550XLS in the wideband mode. I will change the bandwidth to narrow on the HT1550XLS and see if I still get the complaints of low or garbled audio. I am wondering if it is tx audio level is set to hot.