[Milsurplus] DAV-2 On Off Wiring

[WA5CAB at cs.com]

Ray,

That was one of my two guesses, too.  It also eliminates one additional 
piece of wire.  But it also occurred to me, looking at the schematic, that by 
moving a couple of wires around you might also put the headset in series with 
the mic on transmit and have voice sidetone with the headset serving the 
purpose of the fixed reswistor usually found in carbon mic circuits.  Which 
someone in 1943 might have thought desirable.  But with only 1.5 volts, the 
resistor wouldn't be needed and lower mic current would result unless you went 
to a 3-volt filament supply.  That's why I asked whether anyone had ever 
seen the schematic of the base model.

In a message dated 6/17/2010 12:33:55 PM Central Daylight Time, 
RAFANTINI at salisbury.edu writes: 
> It serves no electrical purpose, there is no path to ground for the 
> secondary of the transformer or earphones when the radio is switched off. Its 
> serves a mechanical function being that the rubber covered cable that feeds 
> the headset and microphone needed a point to connection to the wire to the 
> radio section. Post photos of the wiring in the radios head and you will see 
> it's just a convenient way aid wiring and not having to install a terminal 
> strip. I don't have my DAV in front of me but believe this to be the case.
> Ray Fantini KA3EKH
> 
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net 
> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of B Smith
> Sent: Thursday, June 17, 2010 1:04 PM
> To: Milsurplus
> Subject: [Milsurplus] DAV-2 On Off Wiring
> 
> I have some questions concerning the DAV-2 On-Off switch wiring. 
> 
> Schematic link at the bottom.
> 
> On the DAV-2 set why are the receiver ear pieces  connected to the A + 
> when
> the set is turned ON?
> 
>   Why do they connect the receiver ear pieces  through the output
> transformer
> and back to A +  when the set is turned OFF.
> 
> Yes, I checked the wiring and it is wired IAW the manual.
> 
> 
> Please see:
> 
> (http://k4che.com/DAV%20Mystery/DAV-2%20Wiring.htm) 
> 
> 73
> 
> breck k4che
> 

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