[ARC5] Waking up Command Receivers

[Brian Clarke]

Be very careful of your first awakening of a Command receiver that was designed in the 1930s and built in the early 1940s. I have worked on many such awakenings. I have found that most of the carbon resistors have drifted more than +20%; in many places that’s no big deal, but around the oscillator and the AVC line, not so good. Almost all potted capacitors will be faulty – they were designed and manufactured over 80 years ago. I have repotted using newer, higher-Voltage rated capacitors when I suspect the radio will be inspected. If the radio will go in the box with me when I go, I just wire in the new capacitors right at the tube sockets.

 

73 de Brian, VK2GCE

 

From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net] On Behalf Of Mark K3MSB
Sent: Monday, 5 July 2021 10:49 PM
Cc: ARC-5
Subject: Re: [ARC5] Waking up Command Receivers

 

Alternatively, you could just use a 28V dynamotor powered off of a 24 V supply  (or build a 28V linear supply as I did).  28V Supplies are pretty cheap on Amazon (just be sure to bypass the output lines as these are switching supplies).

 

In Feb 2020, using a stock BC-453B,  I logged 68 NDBs during a weekend listening sprint with the receiver connected to my 160M INV-L antenna.

 

73 Mark K3MSB 

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