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Heathkit Chippewa amplifier

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AE7IX:
Hi All
I just acquired a Heathkit Chippewa amplifier from a good friend who had passed recently, this amp has not been fired up for nearly 20 years so this will be a fun project to bring this old beauty back on line.
Here are a couple of pictures of the unit and the power supply, I will post more as I clean it up and bring it online.

AE7IX:
Ok, got it up and running today, ran just the filaments for about an hour then  turned on the high voltage and keyed it with no drive in SSB mode and adjusted the idling plate current with the bias adjustment to 180 mA per the instructions and let it make heat like that for a couple of hours.
The tubes do have the blue glow so they are a little gassy, 1 is a little brighter blue than the other.
I put it in line and tuned up on 3.915 and  slowly started bringing the power up over about an hour, 60 watts drive gives me about 1000 out, so far so good.
Here's a few more pictures with the cover off while I was bringing the tubes up.

KE7TRP:
Jim, So glad you got the beast up and running!   1k is pretty good. 

I guess you got the 220 volt line run and installed? 

I really like that power supply he built.  Looks like a bud case.  I will be on tonight so I can hear this thing!

Clark

AE7IX:
More pics of the input circuit

KE7TRP:
Jim, The Amp sounded awesome on the air. Its very clean and has a loud voice.  If you ever got into running AM, That is the amp to do it. We need to make an AM night. You can run that amp at 300 watts AM all night and the only thing that's burned up is your electric bill :)

After looking at the recent photos, Its clear that the block of resistors is the input pad.  This seems to be in line all the time on this KW-1.  Even if you choose the tuned input.  I followed the pad output right to the mica cap, then to the ceramic feed through and then over to a choke and to the grids of the 4-400s.

This would mean that you can run 100 watts into the amp without issue.  I think you are not seeing Grid drive on the meter at 50 to 60 watts as there is not enough drive to show Grid.  On my Tbolt you really have to drive it to see any grid.

On my Johnson thunderbolt, You can choose "tuned" inputs or "RES" for resistive.  In the RES position you can run 60 watts or so input without any trouble but on the Tuned input mode, You do NOT have the pad inline. So Max drive is 10 to 15 watts PEP.   I ran this with 10 watts in and got full power 1000 watts out.  You better make sure your exciter is clean with that kind of gain!

I wonder about making a modification to the Tbolt so the Pad is always inline like the KW1.  I will have to look over the schematic when I have time. 

C

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