[ARC5] IIRC Stinson?s solution to sidetone issue

[Ronnie Hull]

I have used Dave’s method in my SCR274N station and use that switch for “netting” and it works well!
I do however, want to install a inter phone box. Who has one they will part with?

W5 Sum Ugly Mug

Ronnie

“A 20wpm Extra”

Sent from my iPhone

> On Feb 11, 2019, at 7:06 AM, David Stinson <arc5 at ix.netcom.com> wrote:
> 
> (Think I made the attachment too large.  Trying again)
> 
> Thanks to Brian Clarke and Mike Hanz for jogging my memory.
> I reviewed the diagrams over coffee this morning to blow the dust
> off the creeky stuff in my old and rapidly-emptying head.
>  
> The SPDT relay(s) in the receiver rack are picked by the PTT buss. 
> The Common contact is connected to the Receive Audio busses
> and their associated switching.  The Normally Closed contact
> is connected to the Receiver’s pin 2, Audio Out.
> The Normally Open contact is connected to the Sidetone buss
> supplied to the receiver rack.
>  
> Thus, in “Receive” mode, the radio’s Audio Out feeds the rack
> audio busses and the Sidetone buss is open-circuit.
> In “Transmit” mode, the receiver Audio Output is open-circuit
> and the Sidetone buss is connected to the Rack Audio buss
> with its associated switching (and also out to the RX Control Head).
> In order to provide a means to Net the TX-RX, a small toggle switch
> on the display stand open-circuits these relays, allowing the receiver
> BFO (if properly aligned) to be used for netting.
> See photo attached.  The switch obviously mounted in a scrap
> adaptor box is for netting.  Please forgive the “frumpy” look;
> in the middle of refurbishing some sets.
>  
> Left the Sidetone buss open-circuit in all modes.
> Did experiment with Sidetone attenuation schemes, but all seemed
> to affect the Modulation envelope to some degree.
> I confess I did not try very hard; to do this “by the book” would
> require the addition of an Interphone box to the display.
>  
> Of course, I can’t speak for anyone else, but the point of my 
> displays is to tell a story to hams in hopes of sparking interest.
> Those hams, mesmerized by the latest shiny things, tinkling
> bells and flashing lights (more expensive thingies to break
> and give the makers a Repair revenue stream)
> are only half-curious to start with.
> Getting them to stop the “Hamfest Zombie March” long enough
> to talk about the sets is hard and getting harder.   Adding an interphone
> box would make the display even more “busy,”  giving it an
> unbalanced look. 
>  
> And there is this:  In story-telling, there is an axiom:
> “If a character does not advance the story,
>  the character should be cut.” 
> An interphone box would be of great interest to you and me,
> but it would not “advance the story” when trying to ignite
> a spark in a newbie.  An Interphone box adds a complicating
> element that would need further explanation.  Trust me;
> getting them to stand still long enough to talk about the bare set
> is hard enough.  Start adding elements and their eyes will glaze-over.
> Remember the goal, and Montgomery Scott’s admonition:
> “The more complicated they make the plumbing,
> the easier it is to stop-up the drain.”
>  
> GL OM DE Dave AB5S
>  
> <ATAARAnet.jpg>
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