MaCo 300

[385]

got a maco 300 base amp today and need tuning instructions.
2 knobs on the front and one on the right side
on the front left knob says tune
the front right says load
and the one on the right side says tune
Will post pics asap.
Thanks 385

[385]

Ok I figured out how to tune it...Kinda...Do you start with the tune or load?
Now does anyone now how much input it will take?
It has 5 2057 tubes in it and all the reading I done yesterday I could only come up with a DK input of 3-5 watts.
It came with a Pres.Washington base and D-104 and it all works. The recieve is a little low on the washington but other than that not too bad for $150.00

[NCMidnight]

Ok I figured out how to tune it...Kinda...Do you start with the tune or load?
Now does anyone now how much input it will take?
It has 5 2057 tubes in it and all the reading I done yesterday I could only come up with a DK input of 3-5 watts.
It came with a Pres.Washington base and D-104 and it all works. The recieve is a little low on the washington but other than that not too bad for $150.00

Turn the amp on and let it warm up for 10 mins or so.
Next turn your radio power up and adjust your tune and load to the highest dead key within reason, using short 10-15 sec key's. Tubes aint cheap!
Then turn your radio down to the normal dead key that you use.
Adjust the "load" to a lower operating level to where you get max swing or lower then max. on the watt meter.

This is just general. I did own a Maco 300 myself at one point when I first got into radio, and sold it.. Im still kicking my self in the butt for it.. Great amps IMO. I didnt know what I had at the time..

[385]

Thanks NC Midnight, Maybe I can explain this better. This one has only 5 tubes all 2057's I'm putting 3w DK and swinging 15-20w into the amp from the radio, then I adjust the load to max on the watt meter, then the tune to max, then the tune on the side to set the amp's DK which on low is about 50w swinging to around 150w and on high is 100w swinging to 500-600w. Does this sound about right? Theres a guy in texarkana that told me about a matcher adjustment in the back thats adjusted with an allen wrench but cant remember exactly what he said about it, something about the DK of your radio. What about the DK and swing input on this amp. How much? Thanks 385

[razor717]

what is the match screw on the back for on these maco300's
Thanks 73's

[Nagant]

IIRC it functions as your input standing wave tuner.

[Rooster173]

Use the load on the back to match your swrs many people don't know that. Tune or load first either way tune to the max never tune down from max power. Consider this all that extra power is going elsewhere when you detune a amplifier to less than max power. Also i recommend one and a half watts to no more than two and a half watt deadkey to ensure your amplifiers life. Tubes for macos are surely not cheap. I wish you all the best. Rooster