MTX 9000 on Ham 900mhz
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MTX 9000 on Ham 900mhz
Thanks to all who helped me get the software able to program my B5 MTX 9000. Got it to take frequencies in the 927.9125 and 902.0000. But i cant seem to transmit. The VCO locks on RX fine at 927.9125 can rx from my other B3 MTX 9000 no problems clear as a bell. But i cant Xmit below about 940.0000 mhz without the Fail 001. I have performed the big bang to take the Fractional-N synthesizer down to 6000 and i still cant get it. Does everyone think i might be able to bang it down to maybe 5500 or maybe 5000 and think that might solve my VCO lock problem? Thanks a bunch. This board rocks!
Fail 001 is a VCO out of lock condition, so you *may* have to adjust the VCO crossover point to get the radio operational on the 900 ham bands.
Write this frequency down just in case you need to reenter it though.
Both the UHF and VHF models require a different VCO crossover adjustment if you change RF boards to later revisioned models.
I'll have to go back into the service menu myself and take a peek at things as well as I am curious since this is usually one setting that rarely needs or gets 'adjusted' once it's out of the factory.
Write this frequency down just in case you need to reenter it though.
Both the UHF and VHF models require a different VCO crossover adjustment if you change RF boards to later revisioned models.
I'll have to go back into the service menu myself and take a peek at things as well as I am curious since this is usually one setting that rarely needs or gets 'adjusted' once it's out of the factory.
Adjusting VCO Crossover Point
Forgive the sillyness. What does anyone suggest to set the VCO crossover point on the radio? I believe i can set that in the labtools as well however i dont have it open in front of me.
If you enter the wrong value in the VCO crossover box, the radio will 'NOT transmit or receive, you MUST first copy the frequency listed so you have a reference point that works you can return to.
It's late here as well, so I have nothing fired up so that I can review the RSS, but if you change the value in the VCO crossover, you should have an up to date service manual that corresponds with the exact controller model number your radio has, and its crossover data, otherwise, you'll be on a hunting expedition to find the proper working value to place there.
If you have an SRN for that controller model, you should use the value that's listed for that number only, be it an 'A', 'B' or 'C' Etc...revision.
An improper value will cause the VCO to track inside or outside its intended band split, and cause all your alignment data to be incorrect as well, which includes TX power, squelch settings for different channel spacings, PL deviation and more.
Many times, the differences are slight, but it can be quite the opposite as well.
I did a crossover change a while back and found the receiver performance sucked as it rose from .18uV to .47uV!
That's a HUGE jump in deafness!
All from ONE supposedly minor 'adjustment'.
Not to mention that the TX would no longer lock on frequencies outside of the 450 Mhz range of a 403-470 split model II.
It's late here as well, so I have nothing fired up so that I can review the RSS, but if you change the value in the VCO crossover, you should have an up to date service manual that corresponds with the exact controller model number your radio has, and its crossover data, otherwise, you'll be on a hunting expedition to find the proper working value to place there.
If you have an SRN for that controller model, you should use the value that's listed for that number only, be it an 'A', 'B' or 'C' Etc...revision.
An improper value will cause the VCO to track inside or outside its intended band split, and cause all your alignment data to be incorrect as well, which includes TX power, squelch settings for different channel spacings, PL deviation and more.
Many times, the differences are slight, but it can be quite the opposite as well.
I did a crossover change a while back and found the receiver performance sucked as it rose from .18uV to .47uV!
That's a HUGE jump in deafness!
All from ONE supposedly minor 'adjustment'.
Not to mention that the TX would no longer lock on frequencies outside of the 450 Mhz range of a 403-470 split model II.