[Drake] AC3

[Garey Barrell]

Rick -

The 'extra' pigtails are no doubt 'field changes' prompted by the arrival of the R-4 / T-4X.  The 
AC-3 was designed for the TR-3, and the original single pigtail was for the speaker.  However, the 
AC-3 had no provision for the keying contacts and ALC input from an external linear amplifier 
required by the T-4X.

So when you got your T-4X, if you had a linear amplifier, some just moved the speaker pigtail over 
to the linear keying contacts, since the speaker was no longer used.  Some added another for the ALC 
input.  Sounds like in your case the guy may have still used the supply with a TR-3 and so needed to 
keep the speaker pigtail as well!

The AC-4 came along a little later, adding the ALC and linear keying connectors.  The outer cabinet 
was for safety reasons.  Half the HV was present on the can of one of the Twist-lok electroytics, 
protected only by a cardboard sleeve.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>


Rick Stealey wrote:
> I am not sure if all AC3s were this way but I have one where the AGC lead is a pigtail out of the Jones plug.
> In fact there are 3 pigtails - speaker, AGC, and........ I am having a "Rick Perry" here, forget what the third one is for.
> It seems to me as if the AC3 is a better design, as it doesn't trap transformer heat inside the case.
> Rick  K2XT
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