this is an mod that will work with all Nucleus Transmitters ....the mods listed would not work my units had no nic cards and no tx from ext low settings so i did a small work around i hope this helps
most of the info from repeaterbuilders site will work but the ptt and some units need an freq reference also in order to work.. please use the info from both to get you past any issues you may have.
thanks for looking . i edited the question i had out after figuring out how to get around it ..
Motorola Nucleus Transmitter 900MHZ
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Motorola Nucleus Transmitter 900MHZ
Last edited by n8obu on Mon Jan 03, 2011 3:15 pm, edited 2 times in total.
Re: Motorola Nucleus Transmitter 900MHZ
ok after lots of views and no replys i desided to trash the ten nucleus transmiters i had for our groups 900 mhz linking project.. issue fixed!!!!!! 
ok its not that easy we are hams!!! i desided i had one scu that acted the way i thought it should so i desided to rethink the whole issue of my scu's not being the same as the ones listed at repeater builder's site..
so i took the one that would key on ext key request low the only one that even list's it as an choice in the menus.. and metered out the back plane and find out were the key request changed at the exciter while it has told to transmit .. i did find it and knowing that it goes from 5vdc to ground while the transmiter is keyed up now.. i pulled the working scu and swaped it out with an non working one and using my 12volt test light{ better than shorting it to ground not knowing what was going to happen it is an test light!} i strobed that point and it will key up and pass audio just as i needed it to using the maxtrack mods listed so i pulled the test light out of line and just grounded the pin and yes it transmits as needed this is the good .. now the bad i am sure we bypassed a few of the safety controls it has built in... the power supplys are smart so they will save them selfs and the amps shut them self down too if they see a hi swr or any issues yes i tested them... . so i dont care about the rest the scu's i have have no cnet addon so there are more steps that had to be covered to make these units happy .. i will now list them
1. there is no hi stabs so you need to add your own the choices found under the opt1 key are 1 meg ,5 meg, 10meg, hit the opt1 key than the up arrow1 time hit... enter... use... tog ...to get to your choice than hit... enter... than ...exit {yes there are more choices there but they dont apply to our config so skip them} you can feed in you freq ref in the front or j30 in the rear.
2.to enter freq you must turn on dipswitch 1 on the scu behind the bnc cant miss them.. if you have your glasses on!
2.1 if you dont know the password turn on dip switch 2 let it boot up one min.. then turn off the power supplys and turn off dip switch two then the pass word will be ...6000...hit ...enter... your in!
2.3 to set your new freq hit... tx... than enter two times enter your freq ie 92752500 look to see the point is at the 927.52500 spot while its scrolling you need to add zeros until it is after 927.there. than hit... enter... is should be scrolling your freq with ch1 in the window now! smile! and hit... exit... two times
2.4 setting your output power is easy? starting at the ready display hit tx than the down arrow than.... enter... should scroll your output power will be at 100watts {if you did a reset using switch two listed in 2.1}.. to change it hit ...enter... enter you wanted wattage can be from 100 to 300 in 25 watt steps 100 for testing ...enter 100 hit enter now set at 100 watts ..
2.5 modding the scu to pass audio you need to cut an trace on the scu it is an easy task with the scu laying down on the table chips facing down and with the bnc on the front to your right count up 11 gold tabs on the left edge from the bottom it should be the last one before the line up notch cut it there.there is an thin trace going up at an 45 from it[ ya cant count down from the top the boards have a drifferent pin count but the trace is the same one if you go by the line up notch] simple!
2.6 you can test with an mic pluged in to your maxtrac.. but you must unplug it when setting your repeater controler audio it loads down the audio while the mic is pluged in
ok its not that easy we are hams!!! i desided i had one scu that acted the way i thought it should so i desided to rethink the whole issue of my scu's not being the same as the ones listed at repeater builder's site..
so i took the one that would key on ext key request low the only one that even list's it as an choice in the menus.. and metered out the back plane and find out were the key request changed at the exciter while it has told to transmit .. i did find it and knowing that it goes from 5vdc to ground while the transmiter is keyed up now.. i pulled the working scu and swaped it out with an non working one and using my 12volt test light{ better than shorting it to ground not knowing what was going to happen it is an test light!} i strobed that point and it will key up and pass audio just as i needed it to using the maxtrack mods listed so i pulled the test light out of line and just grounded the pin and yes it transmits as needed this is the good .. now the bad i am sure we bypassed a few of the safety controls it has built in... the power supplys are smart so they will save them selfs and the amps shut them self down too if they see a hi swr or any issues yes i tested them... . so i dont care about the rest the scu's i have have no cnet addon so there are more steps that had to be covered to make these units happy .. i will now list them
1. there is no hi stabs so you need to add your own the choices found under the opt1 key are 1 meg ,5 meg, 10meg, hit the opt1 key than the up arrow1 time hit... enter... use... tog ...to get to your choice than hit... enter... than ...exit {yes there are more choices there but they dont apply to our config so skip them} you can feed in you freq ref in the front or j30 in the rear.
2.to enter freq you must turn on dipswitch 1 on the scu behind the bnc cant miss them.. if you have your glasses on!
2.1 if you dont know the password turn on dip switch 2 let it boot up one min.. then turn off the power supplys and turn off dip switch two then the pass word will be ...6000...hit ...enter... your in!
2.3 to set your new freq hit... tx... than enter two times enter your freq ie 92752500 look to see the point is at the 927.52500 spot while its scrolling you need to add zeros until it is after 927.there. than hit... enter... is should be scrolling your freq with ch1 in the window now! smile! and hit... exit... two times
2.4 setting your output power is easy? starting at the ready display hit tx than the down arrow than.... enter... should scroll your output power will be at 100watts {if you did a reset using switch two listed in 2.1}.. to change it hit ...enter... enter you wanted wattage can be from 100 to 300 in 25 watt steps 100 for testing ...enter 100 hit enter now set at 100 watts ..
2.5 modding the scu to pass audio you need to cut an trace on the scu it is an easy task with the scu laying down on the table chips facing down and with the bnc on the front to your right count up 11 gold tabs on the left edge from the bottom it should be the last one before the line up notch cut it there.there is an thin trace going up at an 45 from it[ ya cant count down from the top the boards have a drifferent pin count but the trace is the same one if you go by the line up notch] simple!
2.6 you can test with an mic pluged in to your maxtrac.. but you must unplug it when setting your repeater controler audio it loads down the audio while the mic is pluged in
Last edited by n8obu on Mon Jan 03, 2011 3:17 pm, edited 2 times in total.
Re: Motorola Nucleus Transmitter 900MHZ
ok i am posting a few bad pictures of the mods needed the only real change are we needed to add an reference freq to our nuc's and get an working ptt point that was the hang up from the repeater builders mods our scu's do not have nic's for freq refererence we add it with a ptt that works i have converted three of these and two are now in service and working well ..
this is were we tie in the maxtrac ptt goes here
this is were we put in our audio from the maxtrac
most the menus are not the same from the one listed on repeater builder site there are many flavors of these pigs but this work around will cover most built .
i hope this helps someone if you need help just ask i will do what i can mike bayard n8obuhttp://www.cmen.us/
scu cut trace
this is were we tie in the maxtrac ptt goes here
this is were we put in our audio from the maxtrac
most the menus are not the same from the one listed on repeater builder site there are many flavors of these pigs but this work around will cover most built .
i hope this helps someone if you need help just ask i will do what i can mike bayard n8obuhttp://www.cmen.us/
scu cut trace
Last edited by n8obu on Mon Jan 03, 2011 3:10 pm, edited 2 times in total.
Re: Motorola Nucleus Transmitter 900MHZ
this is were we grabed our 14vdc for the freq reference and maxtrac so run two wires from each point
yes you can power your reciever from here too
Last edited by n8obu on Mon Jan 03, 2011 3:12 pm, edited 1 time in total.
Re: Motorola Nucleus Transmitter 900MHZ
Excellent work Mike - thanks for posting this info.
Only one problem - the colored text on the pics is so small i cant read it(my eyes are getting old & tired).
Any way you can fix that?
Only one problem - the colored text on the pics is so small i cant read it(my eyes are getting old & tired).
Any way you can fix that?
fineshot1
NJ USA
NJ USA
Re: Motorola Nucleus Transmitter 900MHZ
reposted them they were a lot bigger in my 22" monitor good luck
Re: Motorola Nucleus Transmitter 900MHZ
Thank you - much bettern8obu wrote:reposted them they were a lot bigger in my 22" monitor good luck
fineshot1
NJ USA
NJ USA
Re: Motorola Nucleus Transmitter 900MHZ
Glad you got it going.
I have two Nuc transmitters with the newer exciters. These will program right in the 927 part of the band. Modulation mods have not been done but is very easy. I have one complete and ready to go on the air. I installed a 800 meg Maxtrac as the receiver and a nhrc controller. It works great. Along with the Nuks i also got the antennas. Some are receive at 902 and some are tx at 927, these are thicker. I have had it on the air without cavaties just using seperate antennas about 10 feet apart.
If anyone is looking for a nuk let me know. I have two.
Walt
I have two Nuc transmitters with the newer exciters. These will program right in the 927 part of the band. Modulation mods have not been done but is very easy. I have one complete and ready to go on the air. I installed a 800 meg Maxtrac as the receiver and a nhrc controller. It works great. Along with the Nuks i also got the antennas. Some are receive at 902 and some are tx at 927, these are thicker. I have had it on the air without cavaties just using seperate antennas about 10 feet apart.
If anyone is looking for a nuk let me know. I have two.
Walt
Re: Motorola Nucleus Transmitter 900MHZ
Glad to hear there working ya should post the unwanted one in the for sale fourm