[R-390] Ending The Moment Of Silence

[Steve Goode]

I must have missed something.  Where do we find the mod details?

K9NG



----- Original Message ----- 
From: "David Wise" <David_Wise at Phoenix.com>
To: <r-390 at mailman.qth.net>
Sent: Thursday, January 20, 2005 6:19 PM
Subject: [R-390] Ending The Moment Of Silence


> I did it!
>
> I have perfected a mod that eliminates the carrier level
> disturbance when switching the R-390/391/390A AGC rate.
> Only the front panel wiring changes.  It is 100% compatible
> with standard IF decks and those with the Lankford AGC mod.
> This is how Collins should have done it, it would have cost
> them next to nothing.  Like the carrier level pot, the
> engineer just didn't think it through.
>
> The mod I posted earlier had side effects that ultimately
> caused me to reject it, although it was very compact and
> easy to do.  This mod borrows an idea, but otherwise it's
> totally new.  I have tested it extensively, and the
> ergonomic improvement is just fantastic.  You'll never
> realize how obnoxious and fatiguing the stock AGC switch
> is until you try this.
>
> Pros:
> No more "Moment Of Silence" (SLOW to MED)
> No more blasting (MED to SLOW)
> Same time constants as before, or season to taste
> Compatible with existing modules
> Reversible (no holes)
> No "box on the side", it's all internal
> Works with decks that have a bad C551
>
> Cons:
> Needs a new AGC switch (2-pole vs 1-pole)
> Needs a piece of sheet metal (if you want it to be neat)
>
> Performance:
> OLD
> FAST-MED: Dip, Nothing, or Surge, depending on signal levels
> MED-SLOW: Severe Overload for 1-2 seconds
> SLOW-MED: No Signal for 1-2 seconds
> MED-FAST: Nothing
>
> NEW
> FAST-MED: Nothing!
> MED-SLOW: Nothing!
> SLOW-MED: Nothing!
> MED-FAST: Nothing
>
> (Lest someone accuse me of advertising hype, I will qualify the above
claims
> to the extent that at very high signal levels (over 80dB), you may detect
> a slight surge on MED-SLOW and SLOW-MED, but it's barely perceptible
except
> under artificial laboratory conditions, where it becomes merely
"perceptible".)
>
> Cost: About $15 and a couple of hours.
>
> Well?
>
> Dave Wise
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