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Re: Analog or Digital Radio Transmission by the Railroads???
Author: SPKid
Date: 04-06-2011 - 18:56
Several Class 1 railroads have purchased NXDN analog/digital radios. I believe BNSF, UP and NS now have some of the NXDN radios. The AAR has recommended the NXDN digital radios since they can be migrated to 6.25 kHz channel width, allowing even more channels for the railroad radio service. The thinking is that the new radios will not only conform to the pending 12.5 kHz requirement, they positioning the railroads for a future migration to full digital 6.25 kHz channel width. Kenwood for sure, and possibly Icom, have an NXDN radio model with the RR channels designations on the display.
The NXDN format, in my opinion, is superior to Motorola’s digital radio since the radios can talk unit to unit in the digital mode, without having to revert to the analog mode as with the Motorola MotoTurbo format.
The NXDN radios can be programmed to decode either analog or digital signals, and respond in the same format as the received signal, all without any user intervention. The delay is a little unusual in the digital mode if two radios are used side by side. The delay is caused by the encoding and decoding of the audio.
The digital quality is quite excellent, and can be shaped, and according to Kenwood and Icom, extends the range about 25%, all things being equal. I can’t attest to the 25%, but I can say from experience that the digital mode goes further than the same radio and repeater in the analog mode. The downside, if indeed it’s a problem, is that the digital mode will drop out suddenly, instead of simply getting noisy until becoming unreadable as with the analog mode. The good news is that the digital reception is very good in areas where the analog signal is noisy.
I’m using the NXDN radios and I’m very pleased with the performance. Unfortunately my radios are UHF so they won’t work for the railroad frequencies, if and when the railroads go digital.
I should also mention that the NXDN digital radios will provide unit ID and ,as an option, GPS, information for each transmission imbedded in the digital signal without the analog data squawk associated with unit ID on analog radios.
The NXDN format, in my opinion, is superior to Motorola’s digital radio since the radios can talk unit to unit in the digital mode, without having to revert to the analog mode as with the Motorola MotoTurbo format.
The NXDN radios can be programmed to decode either analog or digital signals, and respond in the same format as the received signal, all without any user intervention. The delay is a little unusual in the digital mode if two radios are used side by side. The delay is caused by the encoding and decoding of the audio.
The digital quality is quite excellent, and can be shaped, and according to Kenwood and Icom, extends the range about 25%, all things being equal. I can’t attest to the 25%, but I can say from experience that the digital mode goes further than the same radio and repeater in the analog mode. The downside, if indeed it’s a problem, is that the digital mode will drop out suddenly, instead of simply getting noisy until becoming unreadable as with the analog mode. The good news is that the digital reception is very good in areas where the analog signal is noisy.
I’m using the NXDN radios and I’m very pleased with the performance. Unfortunately my radios are UHF so they won’t work for the railroad frequencies, if and when the railroads go digital.
I should also mention that the NXDN digital radios will provide unit ID and ,as an option, GPS, information for each transmission imbedded in the digital signal without the analog data squawk associated with unit ID on analog radios.
