auditwhe.blogg.se - Motorola r2670 service manual youtube

The baseline recording can be heard here. All reproduced audio recordings were taken by directly mic-ing the speaker of the XTS5000 with the SM58. The file was then replayed and fed into the External Modulation input of the R2670 and done so for all tests. this is about as close as I can get to broadcast quality audio).

Since FirstNet squashed the development for Phase 3 (which was focused on mobile data) and Phase 2 (TDMA) operation only applies to trunked systems, C4FM will remain the modulation method for conventional P25 operations.Ī baseline recording was made using a Sure SM58 microphone, recorded at a sample rate of 192 kbps and stored as a WAV file (i.e.

See above equipment that I had access to.

P25 was chosen as the digital medium to test for several reasons.

I own the R2670A and my employer owns the R8000B.

Maybe we'll see that in the R9000 (*cough* Doyle Wofford Freedom CTE *cough*).

The R8000/8100 does not have encode/decode capability for NXDN and DMR, just store and playback which made it impractical to obtain consistent base audio recordings for comparison.

The P25 encode/decode functionality of the Freedom R8000B had recently been released and my company had not purchased the upgrade yet.

The R2670 was chosen for several reasons:

This one had been aligned several weeks prior.

Unlike most APX and XPR SU's I've tested, the Astro 25 line typically hits 5% BER within 1 dB of 12 dB SINAD (not that it really matters for this experiment).

I hadn't honestly seen my XPR6550 in almost a year at that point.

The R2670A I have will support Astro (VSLEP) or P25 with it's IMBE vocoder.

I did not have access to an APX subscriber at the time.

I tend to use Motorola as the standard to which I compare everything else to.

It was the only easily accessible Astro 25 subscriber I had available with current firmware at the time.

The 7/800 MHz XTS5000 was chosen for several reasons: All audio was generated by a calibrated Motorola R2670A service monitor. the points at which we spec analog and digital receiver sensitivity to) as it is reproduced by a 7/800 MHz Motorola XTS5000 with firmware release R20.50.10 on 8CALL90 (851.0125 MHz). This test compares the audio quality of 5% BER versus 12 dB SINAD (i.e.

Performed an experiment about six months ago and figured I'd finally stop sitting on the audio. By now this has been posted in several locations (Reddit and CommTech Forums to name a few) however, I still feel that it is a good reference and really should be posted here as well.