[ARC5] Re: Pipsqueack info desired

[Mike Morrow]

Jack wrote:

>The BC-616 box does a couple of things. First off, is that
>for the first second of the transmit cycle, the radio is
>keyed on the channel selected by the control box, with MCW.
>For the rest of the cycle, the transmitter is switched to channel one
>with no tone.

Jack, thanks for pointing out the details of this.  I'd in the past examined the BC-616 diagram the Mike Hanz has posted, but I never did a detailed look at how the three relays in the BC-616 coordinated together.

After looking at Mike's diagram again, I see it works just as you said:

1.  BC-608 contactor closes and relay 22A starts the dynamotor, selects TONE (MCW, 1000 cps) mode, and keys the transmitter selected on the BC-451 control box until relay 23A drops out after a time delay determined in part by resistor 26 and capacitor 27 across the coil of relay 23A.

2.  When relay 23A drops out, relay 24A energizes to de-select the transmitter that is selected on the BC-451, select CW mode, and key the transmitter in the number 1 rack position for the remainder of the 14 second per each minute keying cycle.

So it takes about one second for relay 23A to drop out...that's good to know info that I've never come across before.  I've never tried to energize any of the control relays in my BC-616, but I'm tempted to do a quick experiment.  I suppose the one-second tone sent on the active command frequency was intended to indicate to those on that frequency that a Pipsqueak transmit period on transmitter number 1 frequency was about to begin.

>I am pretty sure that this does NOT apply to the SCR-522 pipsqueak
>setup, as all this switching is done in the BC-616.

I don't have my SCR-522 manuals with me now, but I seem to recall that there were modifications made to the SCR-522 which affected how it responded to BC-608 contact closure, so an early model might be different from a late model with respect to whether a particular channel was auto-selected during contactor closure.  Guess I need to look that up.

>I'd like to see the tech manual on the RC-96 system, anyone have
>a copy?

I'd like to know if the BC-608-A when attached to a SCR-522, i.e., no BC-616 relay box, was still known as an RC-96.

The BC-608-A and BC-616 don't seem too rare at all, or to bring much interest at auction.  Every piece I've ever seen appears to be NOS.  I've never seen a RC-96 manual, so that may be the rarest component. 

I have to wonder if in practice this system saw any *significant* use in USAAF aircraft.  Apparently it was intended for fighter aircraft only.  I would bet any actual installations would been predominently attached to an SCR-522 rather than a SCR-274-N.

Mike / KK5F