[R-390] Collins trim cap settings..?

[Jordan Arndt]

Thanks Larry...

For further clarity, if the adjustment slot is at 90 degrees to the front panel, the cap should be at mid-range...

The reason I'm asking is that I've read of a number of different ways to set T401 and then the trimmer caps, and I'm hoping to find a standardized method.

Even the method I've used for years doesn't work on the S-W I'm working on now, so I'm trying to find if there is an actual fault in it or simply a mis-adjustment...

Thanks again and 73...Jordan...
  ----- Original Message ----- 
  From: Larry H 
  To: Jordan Arndt 
  Cc: R-390 Forum 
  Sent: Monday, December 06, 2021 6:04 AM
  Subject: Re: [R-390] Collins trim cap settings..?


  Hi Jordan,  If you are looking at the 2nd osc unit with the trimmers closest to you (normal installed position) and the tuning tool slot is running left and right (parallel to the front of the unit), the trimmer is adjusted in the minimum or maximum  position.  So, if the tuning tool slot is parallel to the sides of the unit (running front to back), it is set at half value.


  Regards, Larry


  On Mon, Dec 6, 2021 at 4:43 AM Jordan Arndt <Outposter30 at shaw.ca> wrote:

    Hi group...

    I hope this request will make sense to some of you all...

    I recall that there is a way to determine how to set the trim caps for 
    mid-range by the position of the capacitors value printed on the rotor, but 
    I don't recall how exactly.

    It has something to do with the position of the printed value on the cap in 
    relation to the "band" printed next to the adjustment opening for each cap.

    Does anyone know how to make that determination...?

    I'm hoping so..!!

    73..Jordan VE6ZT






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