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Maxtrac 144-174 split?

Posted: Tue Dec 12, 2017 12:01 am
by Xnke
So I'm in the middle of converting one of my VHF Maxtracs to 2 meter amateur operation and was checking the RF board. Instead of finding a 4322B 146-174 split board, I found a 4322C 144-174 RF board.

Does there exist a part number or RSS version that will allow me to use the 144-174 split that the RF board will do?

Re: Maxtrac 144-174 split?

Posted: Tue Dec 12, 2017 7:13 am
by Satelite
Hello:
I'm not familiar with a 144 to 174 split but yes the 146 to 174 split but.
I recall rf bd numbers 4322B and 4322C being pretty much the same bds just that the B and C was newer revision of bd only.
However new revision could have given the 144 bottom end that I wont say yes or no because I honestly don't know.
But id bet my last dollars its still the same conventional rss that reads and programs it.
If your not aware of the shift key trick to get out of band programming down to 144 MHz then read on.
True when you read a maxtrac radio it does normally specify 146 to 176 MHz and wont let you enter directly an out side freq below or above the 146 to 174 split.
But if you wanted for example 144.500 MHz = Do this = With the shift key pressed and held only for the numbers and DO NOT press shift key for the dot in the freq entered youll get the radio to accept the out of band freq you want if not too far out of band for rf bd to lock on yet.
So for example 144.500,with the shift key trick would look like this on screen when you enter it into the maxtrac !$$.%)) but after programmed radio will read as 144.500.
If you look at number 1 on your computer key bd youll see that a 1 in shift key is ! and 2 is @ and 3 is # and so forth just remember DO NOT enter the dot after 144 in shift key enter it as a dot . not shift >
Hopefully I was of some help.
Thank you
satelite

Re: Maxtrac 144-174 split?

Posted: Thu Dec 21, 2017 12:16 pm
by Karl NVW
The bandsplits are caused by both the synthesizer programming and RF switch filtering on the PA board. The traditional splits of 146-162 and 162-174 were normal in the USA, and I recall seeing a compromised third version built just for Uncle Sam's 136-150.8 window.

Re: Maxtrac 144-174 split?

Posted: Thu Dec 21, 2017 4:26 pm
by Satelite
Hello:
I'm confused.
My American Motorola Maxtrac repair manual shows only:
VHF range one as 136 to 162 MHz and VHF range two as 146 to 174 MHz for USA,
Doesn't make much sense to make a radio for uncle sam in 136 to 150.8 MHz when VHF range one covered that plus.
And 146 to 162 when usa has 136 to 162 MHz doesn't make sense either.
162 to 174 would be odd with VHF range Two already covering that plus too.
Never know bout Motorola though soooo ????
Satelite

Re: Maxtrac 144-174 split?

Posted: Sun Dec 24, 2017 5:56 pm
by uman18
I had about 25 surplus Maxtracs that came from the South Pole, Antarctic program. all were 136-162 split.

Re: Maxtrac 144-174 split?

Posted: Wed Apr 18, 2018 6:16 pm
by Karl NVW
The ones I remember might not have had FCC T/A, they were being used in other countries.