[ARC5] First Post and Questions

[J Mcvey]

hello Bobby,
On of the first things I look for on military surplus is signs of modification.The fact that the power plug has been replaced with an octal tells me that someone used that unit for SOMETHING.Since the BC-457A not natively in the Ham band, they probably messed with the oscillator ( coil inside the shield) and the tank ( ceramic tower). Now the next question is: How skilled was the ham who did the modification? I've seen everything from a functional setup to "oh my God, what were they thinking".  The ferrite was supposed be attached to an adjusting screw assembly at the top of the "tower". 
In the original system design, the underside "select relay" and the antenna relay are wired in parallel and were intended to stay engaged while the transmitter was selected for use . They were not used for keying. Keying, was effected in the BC-456 modulator by "hot keying" the B+ though a relay! You can do the same with your supply. 

Since your BC-457A has already been "compromised" it would be interesting to power it up with a "home brew supply" to see what frequency they tuned it to. 
Of coarse the down side is that the dial is incorrect and will need to be re-calibrated to the new frequency unless you want to use a frequency counter all of the time.

 

    On Tuesday, July 4, 2017 8:50 AM, AKLDGUY . <neilb0627 at gmail.com> wrote:
 

 Leslie wrote: "Also, Neil wrote (in Wikipedia) that there are 3 different versions of these sets - (or four if you count the "K" series) and there are significant (but small) differences between the versions."
I did not write the Wikipedia article, but I have contributed to it. What you mention was pretty much done before I even started.
73 de Neil ZL1ANM
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