[ARC5] ARC-5 receivers - running from a 60V B+ supply.

[John Hutchins]

Leslie -
Interesting there is an ARC5 and ARC-5radio group,,,,,
Hutch

On 10/20/2011 4:34 AM, Leslie Smith wrote:
> Hello list-members,
> Recently the topic of power supply voltage was discussed, both for the
> transmitters and receivers.
>
> I experimented with running the receivers on 60 and 90V B+ supplies.
> The result of my observations are available at "yahoo" groups, in the
> group ARC-5radio, including the circuit I used to generate the 60V B+
> supply from 24V AC (used as the filament supply).  The address is
> "www.groups.yahoo.com"  There is no space between ARC-5 and radio in the
> group name.
>
> When I first used the ARC-5 receivers I knew nothing about their
> history, or that a full tech manual was available.  I quickly found a
> circuit diagram, and that was my basic starting point.  Had I known more
> I might have taken a different approach to generating the B+ supply -
> for example I may have favoured running the filaments from a DC supply
> rather than the 24V AC system I chose.  Still 24V 1 amp transformers are
> common enough.
>
> Briefly I found that a nav. band receiver (R-23 or BC-453) behind a 3
> transistor xtal controlled converter was comparable in performance to a
> modern commercial receiver on 80 meters, with a 60V B+ supply.  The only
> mod I made to the ARC-5 receiver was in the HF and CW oscillator plate
> circuits.  I soldered a 33k resistor across the plate dropping resistor.
>    More detail is available in the yahoo group files area, including a
> photograph of the prototype power supply.  The key point, so far as the
> mod is concerned is to know that the HF oscillator dropping resistor is
> inside the oscillator coil can.
>
>
> If anyone has difficulty getting access to the yahoo group I can send a
> copy of the circuit diagram via an email.  Just let me know.
>
> 73s,
>
>    Leslie Smith
>    vk2bcu at operamail.com
>