800 MaxTrac to 900 Rx, Manual Power Control

This forum is for the discussions targeted at converting various models of Motorola equipment to operate in the 900MHz Amateur Band.

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kcbooboo
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800 MaxTrac to 900 Rx, Manual Power Control

Post by kcbooboo »

There are two new articles over on the "r-b" site: one deals with conversion of an 800 MHz MaxTrac to receive 902 MHz; the other deals with adding manual power adjustability to just about any MaxTrac/Radius.

They're both in the Motorola/MaxTrac area of that establishment, thanks to the effort of a few people who hang around here a lot too.

Bob M.








PS: that's repeater-builder.com ! (I hope nothing bad happens to me for mentioning that.)
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Max-trac
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Post by Max-trac »

Excellent articles, thanks.
re the power control mod;
I had a VHF unit that the PA had gotten wet and would put out 35w (it is a 25w unit) then shut off.
Instead of working on the PA, I decided to do the manual control mod.
I did the mod , but it didn't work.
I assumed the PA current sensing lines were a fault.
So I moved the wiper control of the mod to the output of the control circuit.
I cut the line coming from R456 and tacked the wiper to the base of Q453
Worked perfect!
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