[R-390] Ending The Moment Of Silence

[Bob Camp]

Hi

Only the obvious question -

Is it easily reversible ?

	Take Care

		Bob Camp
		KB8TQ


On Jan 20, 2005, at 7:19 PM, David Wise wrote:

> 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
> _____________________________________________________________
> Win a new Icom IC-756PROIII and help QSL/QTH.net
> Details at: http://mailman.qth.net/index.html
> _____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390
>