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Maco 750

donemad

Active Member
Jun 21, 2008
104
1
26
Anyone know the value of the resistor that ties to the input from the radio where the jumper goes? This one is burned. Looks like may-be someone tried to drive it.............Thanks for any help....
 

Your welcome, The CB tricks site has a good library of amp, antenna, and radio information.
 
750 maco

If it is the resistor on the keying circuit input looks like a 47 ohm here is link to schematic.

http://www.cbtricks.com/Amp/maco/maco_750b/graphics/maco_750b_sch.pdf
Also there is a jumper that runs from pins 2 to pin 6 on the pre-driver and the other two drivers that connect to the finals, but I can,t seem to see what that is! Is it a resistor or coil? .....talking about the 47 ohm, what wattage is it? Also that resistor or coil looks like a 22ohm resistor, but what wattage? But it may be a coil, can,t tell, it is burnt to bad.........thanks for any help
 
Also there is a jumper that runs from pins 2 to pin 6 on the pre-driver and the other two drivers that connect to the finals, but I can,t seem to see what that is! Is it a resistor or coil? .....talking about the 47 ohm, what wattage is it? Also that resistor or coil looks like a 22ohm resistor, but what wattage? But it may be a coil, can,t tell, it is burnt to bad.........thanks for any help

Schematic does not give me wattage for the resistors, 1 or 2 Watt would be a safe bet.

the 22 thing is a choke, 22 microhenry choke most likely, do you see how the 22 symbol is different than the 47 resistor symbol?

http://www.cbtricks.com/Amp/maco/maco_750b/graphics/maco_750b_redraw_sch.pdf

Link to better schematic, first one had some flaws in it.

I can not tell for sure but if it is a 22 thingy it is an choke on the pins two and 6 most likely. Maybe some other member will post who has a Maco 750, I have the baby brother the Maco 200 sitting on the shelf in the shack.
 

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