[ARC5] T-19 Update

[Christopher Bowne]

Will have to check that out on a schematic..wonder why they (ARC) would key so 
many parts of the circuit in CW and MCW, seems like osc plate and final screens 
would be enough, along with the antenna relay.




________________________________
From: David Stinson <arc5 at ix.netcom.com>
To: Christopher Bowne <aj1g at sbcglobal.net>; ARC-5 List <arc5 at mailman.qth.net>
Sent: Thu, December 20, 2012 7:49:17 PM
Subject: Re: [ARC5]  T-19 Update



-----Original Message-----
>From: Christopher Bowne <aj1g at sbcglobal.net>

>
>IIRC, the modulator BC456 and MD7 modulator power units only actually key the MO 
>
>plate and final screen voltages to transmit on CW and MC ,with the 1625 plates 
>having HV on them  whenever the dyno is running, which is continuously in CW and 
>
>MCW. 

Very respectfully, this is not correct.
The dynamotor runs continuously in CW and MCW,
but all High voltages are applied through the
modulator's internal keying relay to the divider
and that relay closes only on PTT and key closure.

The ARC-5 MD-7 modulator plates do have High Voltage on them
any time the dynamotor is running, but the Mod. screens
are also keyed by the relay.

Regards,
Dave S.