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meanwhile out in the garage ...

Discussion in 'Announcements & Open Forum' started by kopcicle, Oct 23, 2018.

  1. kopcicle

    kopcicle Sr. Member

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    IMG_0010.JPG

    Meanwhile back at the Siltronix...
    Square at lower left " 80MFD @ 400V C-1712 "A" Red to 800 ohm 10W and W/Red to ...

    Semi-circle lower right: 80MFD @ 400V C-1712 "B" Small Red to the other side of 800 ohm 10W , large red to Rect/Filter board, .01 MFD orange drop to pin 6 of V11 6GW8, 3.3K ohm to pin 6 V7 12BA6

    Triangle at upper left : 5 @ 400V W/Red to T/R relay & W/Red ?

    ---O--- at upper right" 5 @ 400V Pin 3 V11 6GW8 Blue


    I think that covers it. All I need to do now is a "clean" way to get this done. There isn't a whole lot of room here for another terminal strip but severaal ground tabs available within easy reach. The two 500V 100 MFD will replace the two 80MFD @ 400V with a two section cap and the 5MFD @ 400V will be replaced by discrete axial electrolytic capacitors.

    @nomadradio , suggestions ?



    For those of you that have a long memory or have been following along at home...

    The hidden gem in this one was the .01 ceramic disc between pins 6 & 7 of V10 , 6AV6, the AGC amp. You wouldn't believe all that goes wrong if this cap isn't present or connected.

    The even more hidden and frustrating fauld was a crack in the ground side of the main VFO variable cap. Once mechanically stabilized and soldered the VFO actually worked. Then there was an entire afternoon of adjusting the plate of the capacitor in sections to get a somewhat accurate spread that agreed with the dial. It was a choice between a complete mechanical rebuild of the VFO ( I did have the parts) or a repair of what was there. In the end a toss up and a challenge to fix what was there. In retrospect , start over was probably a better option. If you ever attempt to get this VFO to agree with the dial across .45MHz you'll understand why. In the end I go it to agree "near" channel one and channel 40 is about 17Kc low . Close enough for the girls I go out with :)
     

    Attached Files:

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  2. nomadradio

    nomadradio Analog Retentive

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    Seems to me that last one we did used a two-section F&T, LCR, JJ 100uf 500v like we use in the Tram D201. Had to drill the two holes to mount the saddle clamp.

    The two 5 uf sections? A tie strip mounts on one of the saddle clamp's screws under the deck. A 4.7uf 450V radial cap each goes to a lug with the blue wire, the other cap on a lug with the red and gray wires.

    Pretty sure that's how we did it.

    73
     
  3. kopcicle

    kopcicle Sr. Member

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    wisconson.jpeg
     
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  4. kopcicle

    kopcicle Sr. Member

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    copper.jpeg
    Picked up a foot of 2" x .250" copper from Online metals. Picked up, because even across town shipping would have been greater than the price of the metal!

    So there is the heat spreader.

    peltier.jpeg
    hummm.
    A possibly futile effort to partially circumvent the three laws of thermogawdamics.
    Do the name "Jean Charles Athanase Peltier strike a familiar note"?
    I don't think this will be much of an advantage but the "trick factor" is there.
    The internal screw bosses are 3.67mm the Peltier are 3.87mm thick.


    25mm.jpeg

    Look, I know I promised no more crap pics but I'm out of AA's for the moment.
    Just take my word for it that the spacing on the the back of the HR-2510 is 25 x 25mm.

    fans.jpg

    back to work ...
     
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  5. Rwb

    Rwb Sr. Member

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    i get the feeling its going to go from 0 to GONE in a second well maybe 6 seconds
     
  6. kopcicle

    kopcicle Sr. Member

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    Do the term "temperature compensating bias" strike a familiar note?

    temp_comp_bias.jpg temp_comp_detail.png
    You see there was this, from the two working brain cells at the NXP help and support desk...

    >>Dear "direct question that doesn't deserve a useful answer",
    Unfortunately, we have no a separate schematic doc sheet for this design. You can draw the schematic using detailed views of the layout. I attached complete document pack for this design.
    To update this case, please reply to this email.<<

    jeebuz cheeze and rice....

    Thanks to Nomadradio for the attached .pdf and for putting up with my incessant bs
     
  7. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

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    ce qui se passe autour revient autour!

    (Hint: Does Not Mean Gosh Darn It!)
    HotGates.jpg

    Amongst others...

    The PDF even gives a Thermistor variant too...
    Not as precise ... but ... when in Rome...
    Thermistor variant.jpg

    Equations are as follows...
    TrackingEQ.png
     
    #187 Handy Andy, Sep 18, 2019
    Last edited: Sep 18, 2019
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  8. kopcicle

    kopcicle Sr. Member

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    bias.jpg
     
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  9. nomadradio

    nomadradio Analog Retentive

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    So, if you get 10 mV per degree from one diode, you'll get 40 mV per degree from a series string of four, right? Well, only if all four of them are held at the temperature you're trying to compensate.

    Gotta look at the data sheet for 1N4148.

    73
     
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  10. kopcicle

    kopcicle Sr. Member

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    #190 kopcicle, Sep 18, 2019
    Last edited: Sep 18, 2019
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  11. kopcicle

    kopcicle Sr. Member

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    Then this happened
    duh.jpeg
     
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  12. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    You 3D printed a microphone and a coffee mug?
     
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  13. 357magnum

    357magnum Sr. Member

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    What doesn't Kop have ? Whiskey Tango Foxtrot !:whistle::)
     
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  14. kopcicle

    kopcicle Sr. Member

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    Screenshot at 2019-10-15 14-29-03.png
     
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  15. ButtFuzz

    ButtFuzz Anti-BS Advocate ● WO0WOO ● Reverend Doctor

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    Click on "MACHEEN!"
     
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