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    hum developed in my dynatuner fm 1

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    richard j

    Posts : 1
    Join date : 2011-05-08

    hum developed in my dynatuner fm 1

    Post by richard j on Sun May 08, 2011 5:12 pm

    I have developed what i believe is a 60 cycle hum in my dynaqtuner fm 1. The tuner sounds great except for the background hum. the signal is clear and crisp. Would appreciate any suggestions.

    richard j

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: hum developed in my dynatuner fm 1

    Post by tubes4hifi on Sun May 08, 2011 7:46 pm

    most likely power supply capacitors going bad . . . .

    baddog1946

    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: hum developed in my dynatuner fm 1

    Post by baddog1946 on Mon May 09, 2011 8:57 am

    Time to upgrade the PS is my call. I did 5 of these tuners this spring and that was a problem I solved in 3 of them with a PS replacement.

    Pooch

    Posts : 53
    Join date : 2009-12-01
    Age : 66
    Location : Wa

    Re: hum developed in my dynatuner fm 1

    Post by Pooch on Mon May 09, 2011 5:50 pm

    Baddog,
    Love the picture! Nekked with a bottle between the legs cheers
    Gordy

    j4570

    Posts : 141
    Join date : 2010-08-30

    Re: hum developed in my dynatuner fm 1

    Post by j4570 on Mon May 09, 2011 7:42 pm

    Baddog,

    5 FM 1's in Costa Rica? That seems like too many for a small place. And 5 in the spring alone. Must be some serious Dynaco fans down there.

    Luddite

    Posts : 235
    Join date : 2009-02-04
    Age : 66
    Location : Texas

    Re: hum developed in my dynatuner fm 1

    Post by Luddite on Tue May 10, 2011 12:26 am

    Richard,

    I also had the same problem and cured it by replacing the power supply cap with a cap board. I built my own cap board, but here's a link to one that is complete and ready to be installed : http://home.comcast.net/~netminer/CAPBOARD.html

    Best Regards,
    Charlie

    baddog1946

    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: hum developed in my dynatuner fm 1

    Post by baddog1946 on Tue May 10, 2011 8:52 am

    Hi:
    Yep 5 of them, and you are right there is only a few good stations down here but I got carried away when I won 3 low ball auctions on eBay I hadn't planned on and ended up with 6 of them!!
    I was going to try and follow an article I read that recommended I have 2 or three for parts on hand. I actually ended up with enough parts to finish 5 but one was so cannibalized it is only a few parts now. I will send a picture of them later today.
    I have one completely rebuilt tuner including motherboard and all new parts, two with new power supplies and various other mods like new PEC modules, caps and resistors, one FM-3 I kept 100% original and one is an FM-1 with the stereo upgrade that is a dog's breakfast made with stock stuff that was left over.
    It does seem like a lot of work but down here in the jungle there is not much to do at night (I don't drink) so I got into it and ended up with 5 tuners. I'm not sure what I will do with them but I am coming back to Canada in July and may bring a couple to sell. They all seem to be working well. I might add that the completely rebuilt one with new motherboard and a homemade dipole antenna is very good it pulls in stations from Nicaragua about 150 miles away without interference at night. Too bad they don't have any good stations. Luckily Costa Rica has a few good stations and one great jazz station.
    I am now thinking I will do an original ST-70 I have and am toying with exactly where to go with it.
    BTW
    This forum keeps me going with all the DIY'ers who support it not to mention Bob our Guru who has the patience of a saint.
    cheers
    Baddog

    baddog1946

    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: hum developed in my dynatuner fm 1

    Post by baddog1946 on Tue May 10, 2011 12:15 pm

    Hi
    Here are the pics of the5 FM-3's I rebuilt.
    http://s1212.photobucket.com/albums/cc446/baddog1946/

    Tom

    Posts : 166
    Join date : 2011-04-04

    Re: hum developed in my dynatuner fm 1

    Post by Tom on Tue May 10, 2011 1:30 pm

    Dog,

    Please tell us that you're spending at least some
    of your daylight hours surfing there in paradise
    and not just tinkering with antique radios!!!!!!

    Stuck here in FL,
    Tom

    Sad

    mantha3

    Posts : 298
    Join date : 2010-11-10

    Re: hum developed in my dynatuner fm 1

    Post by mantha3 on Tue May 10, 2011 4:20 pm

    Post a "For Sale" here if you end up looking to sell 1. These look to be in good shape and re-done well.

    baddog1946

    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: hum developed in my dynatuner fm 1

    Post by baddog1946 on Tue May 10, 2011 5:40 pm

    As a Canadian I never learned to surf. We do have world class fishing here though. check my website for some fishing pics. I will post a radio or two for sale here in July when I come back to Canada for a vacation. Its a nightmare to ship stuff from here. Stay tuned (pun intended)

    www.lafinisterra.com

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