Am new to the board and new to MTR's. Our county is switching over from Master II and III"s. Have played with the new bases a couple days now.
Quite the experience learning to allign. Just wondering if anyone has the answer to adjust the pl deviation to be around .5k using the wireline option. It seems it is only adjusted when total dev in the allignment is adjusted.
We were using 0db in = 4k out. Also found I can only make that work in 2wire configuration and need to go a couple db lower to make it work for the 4w configuration.
Any contributions would be most helpful.
MTR 2000 pl deviation
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Hmmm, I wish I had one here right now to test with. I've never noticed any difference in PL level between repeated audio, and wireline audio. Out of curiosity, what level are you getting using the wireline? I have to fire up my other computer & look at a codeplug now...
Todd
Todd
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Welcome to the /\/\achine.
Welcome to the /\/\achine.
Here's what I've found. When you receive a MTR it is set for an auidio out level which is fairly low before distorting the pure audio. Can only get to about 3k mod. By adjusting the tx mod in the alignment one can get clean audio at 4k, but this also adjusts the pl up as well.
It seems the audio and pl are tied together in this radio which is a very poor design to me compared to all other base,repeaters I've ever worked on from motorola or any other brand. Motorola didn't seem to have an answer for me when I spoke with them.
It seems the audio and pl are tied together in this radio which is a very poor design to me compared to all other base,repeaters I've ever worked on from motorola or any other brand. Motorola didn't seem to have an answer for me when I spoke with them.
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Dan562
- Posts: 533
- Joined: Mon Aug 23, 2004 7:30 pm
- What radios do you own?: Kenwood, Yaesu, ICOM, Motorola
MTR2000 PL Deviation
It's been quite a while since I've aligned TX audio levels on a MTR2000. I believe there's a TX ALC Wire Line parameter in the RSS that needs to be Disabled while setting up the levels. Then once your satisfied with the alignment Re-enable the ALC parameterr on the Wire Line. The Wire Line ALC is used to compensate for any degradation in the 600 Ohm TRC Wire Lines between the Console and the Base Station.
I do not remember any of /\/\'s products ever having a seperate deviation potentiometer for the PL signal encoding, going all the back to the MOTRAC product line in the late 1960s and into the 1970s. The theory was in the 1960s and the 1970s if +/- 750 Hz TX PL would not open a receiver's PL decoder with a 250 Hz sensitivity at 6 dB Quieting, there was something definitely wrong with the resonant Reeds or the electronics. Of course with the all solid state Infrastructure and Subscriber product lines of the 1980s, 1990s and into the 2000s, /\/\ engineering have developed the PL or CTCSS to TX Deviate at +/- 500 Hz and still be decoded on the receiver's PL circuitry. I believe that's why it's called subaudible signaling.
As far as the /\/\ standard TX Audio level was always +/- 3~3.3 KHz Deviation for pure AC sinewave at 1 KHz audio fed into the transmitter or at 2/3rds deviation level. Any thing above that level started to develop a "clipped or distorted" waveform causing harsh TX audio.
I do not remember any of /\/\'s products ever having a seperate deviation potentiometer for the PL signal encoding, going all the back to the MOTRAC product line in the late 1960s and into the 1970s. The theory was in the 1960s and the 1970s if +/- 750 Hz TX PL would not open a receiver's PL decoder with a 250 Hz sensitivity at 6 dB Quieting, there was something definitely wrong with the resonant Reeds or the electronics. Of course with the all solid state Infrastructure and Subscriber product lines of the 1980s, 1990s and into the 2000s, /\/\ engineering have developed the PL or CTCSS to TX Deviate at +/- 500 Hz and still be decoded on the receiver's PL circuitry. I believe that's why it's called subaudible signaling.
As far as the /\/\ standard TX Audio level was always +/- 3~3.3 KHz Deviation for pure AC sinewave at 1 KHz audio fed into the transmitter or at 2/3rds deviation level. Any thing above that level started to develop a "clipped or distorted" waveform causing harsh TX audio.