[Boatanchors] Globe Scout 40A

[L L bahr]

Garey,

It is possible to use the capacitor you suggest with an adapter plate.  The caps you mention are the same as sold by Peebles but Peebles also sells one with slightly more capacitance then 365 pf if you want to use a bigger one for "Loading". (This transmitter goes on 160 meters and using 365 pf variables is kind of insane especially for "Loading").  WRL got away with this by installing an "L" network behind the pi-network).  The problem with using modern caps as replacements is the two mounting holes on each side of the tuning shaft on these new caps are directly in line with the tuning shaft (horizontally).  The Globe Scouts all used a variable cap similar to what you describe, but the two mounting holes, one on each side of the tuning shaft, are a little lower then being in-line with the tuning shaft.  The bottom line is you can't just bolt one of these new caps to the front panel of the Globe Scout.  As I suggest, you can make a small adapter and then use one of these new caps.  (Just flush mount the new cap to a small, say 2 inch x 2 inch aluminum plate 1/8th inches thick by using the new caps mounting holes.  Then bolt the adapter plate to the front panel using the front panels existing mounting holes.  The two screws going from the adapter plate into the new cap need to be recessed with flush mount heads on them.  There is plenty of space and room behind the variable caps to accommodate such an adapter plate.  Also, both variable caps are the same variable cap.  (Plate Tuning and Loading).  They are interchangeable. 

Lee, w0vt



----- Original Message -----
Lee -

Is this a possibility??

<http://www.midnightscience.com/catalog5.html#part2>

73, Garey - K4OAH
Glen Allen, VA

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L L bahr wrote:
> Steve,
>
> I think the bottom line is your capacitor is not aligned properly.  (The rotor plates are not spaced equally between the stator plates).  I am almost certain this is your problem. I bought a new 40A as a kid and never had a problem, so I know the spacing is tight but it will not arc if the capacitor is in good shape.  I recently in the last 4 weeks had the sam issue as you while restoring a 65.  In my case the capacitor was really bent beyond repair.  I was lucky enough to find a replacement but it too was misaligned. Very carefully using a VOM while bending the plates, I was able to get the capacitor so there were no longer any shorts as I rotated the rotor.  Since then I have used the Globe Scout 65 daily without a single arc ever occurring.
>
> Now for a replacement.  First try and repair yours as I did to my damaged replacement cap.  If that works, fine, you are done.  Secondly if you can't do the repair, then just maybe you might get super lucky and find a replacement out of a junker.  I personally think this will most likely not happen unless you get super lucky.  If I was going to have to replace the cap with a non WRL cap here is what I was going to do.  As you are aware the two mounting taped screw holes for the WRL cap are not in line with the tuning shaft but rather slightly down on either side of the tuning shaft.  Until I found a usable exact replacement,  I was going to take an easy to get 430 pf air variable from Peebles Originals and then bolt a 1/8th inch aluminum plate to the Peebles capacitor with flush mounted bolts recessed into the aluminum adapter plate. Then I was going to mount the adapter plate housing the new air variable to the front panel with two tapped screw holes mating up with the front
>    panel mounting holes.  There is plenty of space behind the front panel for all this to happen.  I was going to use a 430 pf cap rather then a 365 pf cap as it would give me more range and there is little size difference or cost between a 365 pf and 430 pf cap.  This adapter thing could easily have worked out and from the front panel, you would never know anything like this has been done to your rig.  You would have no extra holes in the rig and the new cap would work just fine.
>
> But again,  I know the spacing is really tight on the original cap, but if it is in alignment, it will not give you any arching problems.  I realize this is hard to believe, but I have had enough experience with many Globe Scouts to know the original caps are perfectly suitable for the rig.  Granted not much to spare but they won't arc if spaced correctly.  Just go in there and try and fix the old cap.  Put an ohmmeter on the cap, have it wide open, slowly close it until the ohmmeter shows short, then take a small blade screwdriver and slightly move each rotor plate one at a time to see if the short goes away.  Then this is the plate out of alignment.  Then slightly really bend it.  Now move the rotor in again a little more and if the thing shorts out again go through the same process.  I was lucky enough to finally get the cap to never short out anywhere.  Once this happened I never had an arcing problem while using the rig.
>
> Good luck.  Hope this helps you out.
>
> Lee, w0vt
>