[AMRadio] NC57 design question

Larry Szendrei ne1s at securespeed.us
Mon Nov 28 08:57:55 EST 2016

On 11/27/2016 11:58 PM, CL in NC via AMRadio wrote:
> Anybody know why National, in later versions of the NC57, decided the need to add a rotary switch section to the CWO/MVC/AVC/ANL control, so that when it is in CWO or MVC only, the AGC line is shunted through the 1 meg and .01uf cap in the cold end of  the band 'E', broadcast band antenna  coil secondary?  I can see the 1 meg and cap being switched in and out for AGC reasons, but why use the cold end of the band E coil as a common point.  Surely they didn't decide to use those 2 parts just to save the cost of having to get another set of 1meg/.01 to put in the radio.  The darn wire runs from one side of the radio to the other through the harness just to switch them in and out.
> Charlie, W4MEC in NC
> ______________________________________________________________
In fact, it may well have come down to the lower cost option.  When you 
are manufacturing large quantities pennies add up. Maybe the extra wafer 
or contacts on the switch and piece of wire were less expensive than 
another resistor and cap.


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