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Help me find C13 on FT-101EE

Discussion in 'Ham Equipment' started by 443, Feb 29, 2012.

  1. 443

    443 W9WDX Amateur Radio Club Member

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    Ok, I got this old Yaesu, and it was working good, had a problem when switched to 160 meter blows fuse, found C131, replaced it with 1000pf silver dipped mica cap...

    Below it is a burned up capacitor, I mean burned up bad. I have seen notes to replace C13 (80pf 1000V) cap, as it could go bad, and wondering if it looks like a big ass electrolytic or not because the only capacitor I see in the area that various web pages have said to find C13 is C131 which is the cap to fix the 160M fuse blowing problem...



    Anyway, I just need to locate this damn C13 cap in here and change it out, for some reason I have not been able to find any 80pf cap in this area, only a burned up beyond recognition electrolytic cap that I cannot figure out what it is/was for or any idea what value, see pic, please help! Thanks in advance 73.
     

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  2. 443

    443 W9WDX Amateur Radio Club Member

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    Ok, I found C13, it was under the "lip" on the edge of the chassis up against the chassis wall and had a piece of clear vinyl hose or something around so I wasn't sure what it was. It has a Yaesu part number on it, checked it with my cap meter, shows good, around 85pf.

    So now I need to figure out what that burned up electrolytic capacitor is/was.... looking at schematics, it's attached to ground (chassis gnd) on one side and the other is connected to 2 large resistors, mounted to a standoff strip, has a wire going back to one of the pins of the driver tube.
     
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  3. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Look on the Schematic for C-109, 2.2uf@450 volts on the main chassis... i think
    I do not have a sch here, and the only chassis I have left is 60 miles away....

    73
    Jeff
     
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  4. 443

    443 W9WDX Amateur Radio Club Member

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    I am having trouble finding a full blown schematic of the PA area of the chassis, only the little part around the final output tubes...

    This capacitor comes off Pin 8 of the Driver tube and goes to Chassis Gnd.

    Looking for C109 on the schematics, but to no luck yet thanks.
     
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  5. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    OK, found a Sch online, go here
    http://hamradio.online.ru/ftp2/man_sch_ft101.pdf
    Download it.
    Go down towards the bottom, shows 12by7a driver, follow the line off pin 8.

    73
    Jeff
     
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  6. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    couple of resistors, a choke, and then look for C109...see the +/_ next to the electrolytic cap...to the right and slightly below the 12by7a.

    You can get a complete replacement set of caps here.Yaesu FT-101E HF Transceiver Capacitor Replacement Kit | eBay

    Not bad for $35 bucks.......
    73
    Jeff
     
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  7. 443

    443 W9WDX Amateur Radio Club Member

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    Thanks for the info Jeff, but this capacitor only goes from Pin 8 then to ground, the C109 in that schematic shows it passing through 2 resistors and a choke or something before it connects back to pin 8, so either the schematic is wrong and the part is right, or C109 isn't the right cap (though from it's large size and obviously Electrolytic composition you would think it must be). Wish someone had a radio to look inside of and confirm for me. I will keep looking for some other schematics. I think the one you posted the link to is for the oldest FT-101, (no suffix), so it may indeed have been a different schematic than my radio (the EE model, should be same as E/EE/EEX)
     
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  8. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    If I get down in the Valley this weekend, I will look, I have a E chassis in storage....just have to get down there to look at it.
    The only cap I see that comes off of pin 8 to ground directly is C-8, 4700 Pf.


    73
    Jeff
     
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  9. 443

    443 W9WDX Amateur Radio Club Member

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    Yep, C8 is in there, comes off of Pin 8 as well, but right at the pin, then goes to ground at the pin socket ring, then there is a little wire that goes to a standoff with 2 large red colored resistors mounted on it. The busted cap connects to where the largest of the 2 resistors and the wire back to pin 8 of the driver tube meet (+ side of cap) then to ground on the other end of the cap same place the largest resistor grounds to, soldered onto part of the chassis under the big band selector switch that runs all the way to the back of the radio.

    Thanks again, I will keep looking for pics, surely I can find one somewhere, just having hard time.
     
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  10. 443

    443 W9WDX Amateur Radio Club Member

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    There is a schematic for the E model on this page, that has handwritten next to the cap in question C151 10. But I didn't see C151 on the parts list in the FT-101E service manual so ???

    The Yaesu FT-101E Transceiver

    Thanks
     
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  11. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Very good detective work, It don't show a voltage rating, so lets go look at the replacement caps for the 101 e that Simpson sells on E-Bay.....and he show`s 1, 10 uf Electrolytic@ 350 Volts.
    Unless some one shows up with a picture, maybe you could send him an E-mail and just ask him to be sure....but I would say that you have found it!
    I did not get to make a run down to storage this weekend, other things got in the way.

    73
    Jeff
     
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