[ARC5] Volume control - ARA receiver

[Kenneth G. Gordon]

On 12 Jul 2016 at 0:00, Mike Morrow wrote:

> It would be much better to connect your proposed external control
> panel to the receiver through the receiver's rear apron
> connector...just like the system was designed to support. 
> 
> Mike / KK5F

I absolutely agree, Mike.

In fact, an accessory which was made and sold by Fair Radio Sales back in the 1970s did 
exactly that: it was a gray-painted box containing a power supply, 
audio-impedance-matching transformer, a speaker, controls for BFO OFF/ON and RF gain, 
all connected via a matching connector to the receivers' rear-apron connector.

I have two of those here and can supply photos if anyone is interested.

That connector can be easily made with some of those "small" banana pins mounted in an 
epoxy based form. What one does is to insert the pins into the rear-panel connector through 
a thin piece of cardboard to prevent the epoxy filler from getting into the receiver's 
connector, then surround those pins with another bit of thin cardboard, then fill that with the 
epoxy filler, let it set, unplug the "new" "connector", then solder the necessary wires to them. 
Works a treat.

I will also repeat what I have said here before about the AF output capability of the "ARC-5" 
receivers: if the impedances are CORRECTLY matched, there is enough audio output to 
rattle the shack windows. And I am not kidding.

There is zero need for incorporating any sort of audio preamp or post amp.

It is amazIng to me what errors hams have achieved by simply not investigating things more 
closely.

Ken