Does anybody know hvad The values from 0-127 stands for in watts in The cps for The gm1200?
Say i only want to transmit from 446-447 mhz The it should be ok to only put The values for 438.01250 and 449.01250 to 127?
Then it wont be able to transmit on otter frequencys, but kan use All The power on one frequency.
Or is i totalt messing it here?
Transmitter output values gm1200
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jens ledet
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Re: Transmitter output values gm1200
There are no guaranteed mappings from calibration values to watts - that's the whole point of a calibration value; it varies from radio to radio.
If you turn the calibration value all the way up, you WILL be overdriving your transmitter - causing distortion, widening the spectrum to interfere with other channels, distorting the digital data, and potentially burning out your transmitter.
Really: Don't mess with calibration values unless you have the equipment to do a proper calibration.
If you turn the calibration value all the way up, you WILL be overdriving your transmitter - causing distortion, widening the spectrum to interfere with other channels, distorting the digital data, and potentially burning out your transmitter.
Really: Don't mess with calibration values unless you have the equipment to do a proper calibration.
This is my opinion, not Aeroflex's.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
Re: Transmitter output values gm1200
There are two different things you are talking about but they are related.
One is the power calibration level at the various frequency which essentially provides a flat output across the rated frequency range.
The second is the power out adjustment ...usually set first and set at the mid-point frequency. The power " flatness " is set after that at the various frequency adjustment points ..usually around ten but it varies based on radio type. You typically see the drive values start low and gradually increase with frequency.
Some radios let you select a high, mid and low power and have those levels adjustable and set by mode or channel ( the GM300 is not one of those radios )
If you only want five watts you should be able to set the power out adjustment for that value and the uP adjusts the drive based on the frequency and flatness values.
You should only have to do the full calibration if the PA is replaced but on radios this old it may not be a bad idea as the components age.
overdriving the PA past a certain point can cause spurs on the output and shorten the life of the output stages as well. Usually better to run low than high ...a better antenna is the preferred approach as opposed to higher power.
One is the power calibration level at the various frequency which essentially provides a flat output across the rated frequency range.
The second is the power out adjustment ...usually set first and set at the mid-point frequency. The power " flatness " is set after that at the various frequency adjustment points ..usually around ten but it varies based on radio type. You typically see the drive values start low and gradually increase with frequency.
Some radios let you select a high, mid and low power and have those levels adjustable and set by mode or channel ( the GM300 is not one of those radios )
If you only want five watts you should be able to set the power out adjustment for that value and the uP adjusts the drive based on the frequency and flatness values.
You should only have to do the full calibration if the PA is replaced but on radios this old it may not be a bad idea as the components age.
overdriving the PA past a certain point can cause spurs on the output and shorten the life of the output stages as well. Usually better to run low than high ...a better antenna is the preferred approach as opposed to higher power.
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jens ledet
- New User
- Posts: 29
- Joined: Mon May 26, 2014 4:12 am
Re: Transmitter output values gm1200
Think you for reply. 
In The gm 1200 i Can select high and low power for each Channel in The conventional mode.
Them are only gonna transmit within 1 mhz so i thougt That maybe it Would be Wise to only set The Twofrequencys that covers that area to max, or what ever is good for The radio.
I have not done anything yet
I have ben told That 0 is max and 127 is 0 output. Is that correct?
Kind regards jens
In The gm 1200 i Can select high and low power for each Channel in The conventional mode.
Them are only gonna transmit within 1 mhz so i thougt That maybe it Would be Wise to only set The Twofrequencys that covers that area to max, or what ever is good for The radio.
I have not done anything yet
I have ben told That 0 is max and 127 is 0 output. Is that correct?
Kind regards jens
Re: Transmitter output values gm1200
The CPS/RSS values vary from radio to radio as to what impact they have. Motorola was never consistent on that.
Normally I would just align per the manual and adjust down from there for the actual operating power levels you want.
The radio is designed for a wide frequency operation no matter what your requirements are and I would not just max the value of any adjustment without a good reason.
Normally I would just align per the manual and adjust down from there for the actual operating power levels you want.
The radio is designed for a wide frequency operation no matter what your requirements are and I would not just max the value of any adjustment without a good reason.