[ARC5] Command Set Field Day

[Leslie Smith]

Hello Wayne & list-members,

The question was:  Will a Q-Multiplier help the selectivity for R-27 or
BC455 receivers?

I run a "super-gainer" (ie superhet without IF) -  IF at 1700 kHz. 
Regen detector, of course.

The detector uses a "Q" multiplier, rather than the more-common
"tickler" etc detector.
Solid state.  Using this as a point of comparison (since I have only one
tuned circuit at the IF frequency) my guess is "yes",
a "Q" multiplier in the 40m set will work.  Addition to the set:  1 10pF
capacitor (and some connection point).
The IF for the R-27 is 2830kHz, almost twice my IF frequency, but there
are more tuned circuits in the R-27 than in my set.
The original "Q" multipler cct came from "Amateur Radio Techniquest" by
Pat Hawker/Tony Langdon.
Slips in an out of regeneration very nicely.  

The other factor that will influence this scheme is stability of the
local oscillator.
Drift in the LO will show up in the received signal, of course.

73 to all in the new year.

  Les
  vk2bcu at operamail.com


On Wed, Jan 2, 2013, at 9:35, hwhall at compuserve.com wrote:
> > The selectivity of the 40 meter receiver is much too broad (purposely)
> and really can't be much improved on, although it is certainly fun to use.
> 
>  Would a simple Q-multiplier help the selectivity enough? I see a
>  1-transistor (old PNP type) Q-mult in the 1964 ARRL Handbook. Battery
>  powered and a single coax lead to an i.f. tube plate. The article was
>  for a 455-500 kHz i.f. but that can be altered I imagine.
> 
> Wayne
> WB4OGM
> 
> 
> 
> -----Original Message-----
> From: Kenneth G. Gordon <kgordon2006 at frontier.com>
> To: Tim <timsamm at gmail.com>
> Cc: ARC-5 List <arc5 at mailman.qth.net>
> Sent: Tue, Jan 1, 2013 3:02 pm
> Subject: Re: [ARC5] Command Set Field Day
> 
>  
>  
>  
> On 1 Jan 2013 at 13:29, Tim wrote: 
>  
> > Hi - Thanks - Yes, Amen to all of that!  A bit dicey to operate
> during 
> > crowded conditions but perfect for casual Camp Ops...and Vintage
> Field 
> > Day (different weekend!).  Best of all, no synthesizer, digital
> phase 
> > noise in the sidebands and NO MENU's!  Ha..  But the Fun Meter is 
> > pegged.... 
>  
> Yes! Indeed! I'm with Mike on this one: show the ignorant how to do it. 
>  
> Actually, I have found the selectivity of the 80 meter receiver to be
> quite  
> adequate under most conditions, especially if you modify the first IF for 
> adjustable regeneration. This requires two pieces of #12 THHN at the tube 
> socket, and a pot in the cathode circuit. 
>  
> A nice audio filter of some type also helps a lot. The various "Range"
> filters  
> provide a pitch that is much too high (1020 Hz) for me, though. I use
> either  
> the old CWF-2 filter, or the modern equivalent by Vectronics. Those are
> set  
> to about 750 Hz. 
>  
> The selectivity of the 40 meter receiver is much too broad (purposely)
> and  
> really can't be much improved on, although it is certainly fun to use. 
>  
> Using one or more of David's converters with a BC-453 or R-23/ARC-5 will  
> work very well indeed, with plenty of adequate selectivity. 
>  
> BTW, Tim, I also own and operate an AN/GRC-109. I am extremely  
> interested in your various home-brew inverter power supplies for both the 
> ARC-5 and the '109. 
>  
> Are you going to be able to finish those any time in the near future? 
>  
> You have an excellent website, by the way. 
>  
> vy 73, 
>  
> Ken W7EKB 
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