Mating a Fisher 440 Amp to a 490-T Tuner

Discussion in 'Fisher' started by audmod01, Jun 6, 2017.

  1. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

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    Joe -- An easy way to make a ground plane without adding any weight to the unit is to tape down appropriately cut strips of aluminum tape (used to wrap heating and air ducts) in the area where the tuner/preamp, and power amp chassis mount to the cabinet, and then mount those items down over the tape. The tape is conductive, simply and easy to install, and perfect for these types of applications. When the chassis touches the tape the ground plane is formed.

    Your mini-console looks really cool!!

    Dave
     
  2. audmod01

    audmod01 AK Subscriber Subscriber

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    Dave;

    Thanks for the compliment. I had thought of possibly adding a thin sheet of aluminum under each chassis, but tape is another option I had not thought of. I have some of the aluminum tape, which is actually fairly thick, so I think I will use it. It certainly can't hurt anything and may avoid some stray RF interference or noise impulses getting into the circuits.

    I spotted some lift and securing handles made for boats that I might use on the ends of the cabinet. These have very sturdy construction suitable for lifting heavy loads and do not put excess stress on their mounting hardware. Ordinary drawer pulls do not have the strength I believe is necessary for carrying this cabinet with all the equipment inside.

    Joe
     
    Last edited: Oct 8, 2017
  3. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Something like a mooring cleat. These work real good for lifting handles if you get the 4" ones. 3" are too small for most hands. Put one on each corner and wrap line around each pair then bind the line so you have rope handles. You could even use Eyebolts with Fender washers behind the nuts, and run the line between them. Then do some fancy rope work on the cabinet.

    Marine Tie Down.JPG
     
  4. audmod01

    audmod01 AK Subscriber Subscriber

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    Larry;

    Thanks for the suggestions! Hope and pray that Dee gets well soon and that Jesus will sustain all of you through this ordeal!

    Joe
     
  5. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Thanks Joe. Today she's awake about 50% of the time (they cut back the sedation, but left the pain meds going.) She's PISSED that she has an E-tube, NG Tube and all the other associated stuff, and wants it out now. Staff had to restrain her hands to keep her from pulling the E-Tube out(definate NO-NO!). She tries to write notes but all it ends up as is scribbles, that even I can't understand (and I'm pretty good at deciphering Dr writing. HAHA!). I'm gonna bring up her laptop, start up Wordpad and let her type it out with 1 finger (her normal speed).
     
  6. audmod01

    audmod01 AK Subscriber Subscriber

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    I had to deal with a setback today. I examined the two sides of the cabinet that I had stained and left to dry. It turned out that the foot of the saber saw I was using left an imprint on the surface of the wood and the stain did not enter that part of the wood like it did elsewhere on the surface. I wound up having to completely strip the stain by using progressively finer sandpaper until I got the surface nice and smooth again and reapplied the stain. So now I get to wait another day or two before I can proceed with the rest of the assembly and adding the back board the top will hinge to. We had a cool front over the last two days with night temperatures down into the 40s and 50s and back up in the day but less than 70 degrees. Today it is to rise to 82 for a high. We will have a high tomorrow in the low 90s, but another cool front arrives Saturday night with lower temperatures up to low 70s by Monday or Tuesday. This is not exactly conducive to wood working.

    Apparently when sawing a wood surface if the foot of a saw is rubbing against the wood it is going to leave some damage behind. My friend suggested I use a strip of painter's masking tape (the blue kind) to provide a cushion between the saw foot and the wood. I had also thought about applying some Kraft paper on the wood surface, taping it down on the back side of the piece, before clamping my straight edge and beginning the saw effort with the saber saw in the future. That would avoid even getting any tape adhesive residue on the wood. I also had to deal with a spot on the wood where the store had applied a bar-code label and it left adhesive behind. I had removed the bar code label and thought I had successfully removed the adhesive from it using some mineral spirits. Unfortunately it did not. Instead the mineral spirits just thinned the adhesive and allowed it to seal the surface in that spot and prevented the stain from penetrating. So that spot required extra attention in sanding to make sure I got below the surface level that had the adhesive penetration in it.

    I am learning as I go on this. Lessons learned the hard way tend to stay with us better, so I don't think I will repeat this error. I qualify for 30 lashes with a wet noodle again!:whip:Such is life!

    Joe
     
  7. gadget73

    gadget73 junk junkie Subscriber

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    probably more about the wood fibers being compressed. I've seen where the saw foot leaves a shiny track behind sometimes.
     
  8. audmod01

    audmod01 AK Subscriber Subscriber

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    Gadget;

    That is exactly what happened. If I had looked closely before applying the stain I might have seen it. I found this area of compressed wood fiber tracks on the cut-away parts of the boards for the front panel, where the tracks left happened to fall on the remains of the board that I would not be using. The only way to recover from this was to sand down to an undisturbed area of the wood and then apply stain. Apparently when the wood fibers are compressed this way it just does not permit stain to penetrate the area like it does in undisturbed areas of the wood surface. Sanding the panels was a lot of work, but at least I managed to get it done and re-stained the cabinet sides. I have yet to put them on the cabinet. That will come somewhat later in the process.

    Joe
     
  9. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Joe; I've found with my reciprocating trim saw (big sucker on a stand that weigh's 200lbs total) that if the foot has a spring loaded pivot (or just a swivel on the foot) to just bring it down until the front barely touches the wood that the foot will float on the wood and not "dig in".
     
  10. audmod01

    audmod01 AK Subscriber Subscriber

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    Larry;

    I think it is mostly my fault because the saber saw I was using does not weigh much by itself. I was leaning against it and holding it firmly against the straight edge to keep a good straight cut, but probably exerted too much downward pressure on the saw and consequently against the wood. The wood is Birch and may be softer than some wood types. One of my friends suggested that next time I cut wood in this way that I place a sacrificial thin paneling plywood over the wood I am cutting and let it take the punishment of the saw movement. Clamping the two together may also help prevent splintering. I was successful in not splintering the wood and I think the choice of blade I used was helpful in that regard.

    Joe
     
  11. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Yep. 2 problems. 1.) Birch is soft, almost like pine but it doesn't have the pine tar. 2.) Try and use less downforce, just enough to keep the saw from bouncing on the wood, and use more lateral force, but not enough to bog down the blade/motor. Slow and steady is actually faster, let the blade do the work not your back/shoulder. Pushing too hard will actually clog the blade as it doesn't get a chance to clear all the debris from between the teeth. Then you get burning of the wood in places.

    Your friend is right with regard to the doubling of pieces. A piece of cheap luaun plywood will take the bruising of the saw and allow no or very little splintering of the main piece. Even a piece of scrap veneer will do the trick too. You can also cut from the reverse side or use a downstroke cut blade to minimize splintering on the showing side. Downstroke blades are kind of hard to find tho. You can also try steaming the seam from the saw before staining. Sometimes it works on the compressed wood.

    You're doing good Joe. Keep it up!
     
  12. gadget73

    gadget73 junk junkie Subscriber

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    downstroke blades don't always do so well with a hand saw though. Instead of pulling the saw table against the wood it tries to push the saw away from the wood as it cuts. It tends to get really jumpy. Cutting it from the back side works fine though, any damage from the saw table is where you don't see it anyway.
     
  13. audmod01

    audmod01 AK Subscriber Subscriber

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    Today I removed excess stain from the side panels and the front panel. I cut and mounted the board the top hinges will mount to and currently have it clamped down and glue curing between it and the frame for the cabinet. By clamping it down I can make sure nothing warps as the glue dries. It is secured to the frame with #8 X 1 1/4" screws plus Elmer's glue. I placed the side panels alongside the cabinet frame to make sure I was getting the board for the hinges mounted squarely and even with the tops of the sides. After the glue cures I will remove the changer base and stain the inside surface of the hinge mounting board. I will do some light sanding with fine sand paper before applying the stain.

    I hope to get the sides and the front ready to assemble to the cabinet frame soon. Today may be the last good day for several days out to do any cabinet work. We will get a cold front this evening along with rain and temperatures will be below 70 degrees for at least until Wednesday next week.
    Hinge Support web 01.jpg
    Joe
     

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