Checking AM in Johnson Ranger

[W4AMV]

The CW portion of this restoration looks ok.  Achieving nearly 50 W output at line V of 110. Next, is the AM section. I have no mic! Sorry! So, I was going to drive the 2pin port of the mic jack with an ol HP audio oscillator ( the infamous HP 200CD). Attenuate the level and raise the port Z so it looks like a D104 mic. My question, I see that the Ranger uses only the shell of the connector as ground. Is there any issue in grounding the unused port? I suspect that the challenge was to keep RF out of the mic port. Since the TX is terminated there is little radiation. In any case, how did the D104 connect to the shell and if it did, where does one find those 2 pin male D104 mic connectors with the appropriate threaded connector?   

Tnx!!, W4AMV

[Pete, WA2CWA]

The CW portion of this restoration looks ok.  Achieving nearly 50 W output at line V of 110. Next, is the AM section. I have no mic! Sorry! So, I was going to drive the 2pin port of the mic jack with an ol HP audio oscillator ( the infamous HP 200CD). Attenuate the level and raise the port Z so it looks like a D104 mic. My question, I see that the Ranger uses only the shell of the connector as ground. Is there any issue in grounding the unused port? I suspect that the challenge was to keep RF out of the mic port. Since the TX is terminated there is little radiation. In any case, how did the D104 connect to the shell and if it did, where does one find those 2 pin male D104 mic connectors with the appropriate threaded connector?   

Tnx!!, W4AMV

http://www.kcom.us/OldHeathkitParts/miccon.htm

http://www.kenselectronics.com/lists/micplug.htm

http://www.newark.com/cooper-interconnect/80mc2m-np/connector-din-audio-plug-2way/dp/76R0775

http://www.onlinecomponents.com/wirepro_80-mc2m.html?p=12794933

[KB2WIG]

I pulled the 2 pronger out and stuck a 4 pronger in its place. Ya can always stick the old one back in.

klc

[KD0HUX]

 ALLIED ELECTRONIC SELLS   MALE AND FEMALE  2PIN CONNECTORS

[Dave K6XYZ]

I saw the 2 pin connectors today at Radio Crap.

[W4AMV]

Thanks ALL, for all the information!!!

[WA3VJB]

(avatar)

Dave that's  GREAT avatar !

All you need is a little wisp of smoke coming up ...

[Dave K6XYZ]

Thanks Paul......
Believe it or not, that KWM-2 I had torn down took a bath and when I was done with all the restoral work it was one of the best I have ever done.
A gent in California owns it now.
I didn't think to make some smoke when I took the picture....good idea.
I'm getting ready to restore a B&W 5100B so I'll make sure to have the camera standing by when the REAL smoke lets itself out!!!

[W3GMS]

I pulled the 2 pronger out and stuck a 4 pronger in its place. Ya can always stick the old one back in.

klc

I did the same thing on mine for several reasons.  The mic grounding on the Ranger relies on the set screw hitting the spring which the shield of the mic cable is attached to.  Oxidation builds up in time and this offers a poor ground return.  If you swap out the 2 pin for a 4 pin female connector, you solve that problem buy allowing one of the pins to be ground.  This is a much better solution over the long term.  I believe the 4 pin connector fit right in the same hole without enlarging the hole. 

Here is the pin out on my 4 pin connector:

Pin 1 = Ground
Pin 2 = Mic Audio
Pin 3 = High level mic audio which allows external processed audio to be fed 1 stage in.
Pin 4 = PTT


If you use the PTT scheme in the mic cable and are using a High Impedance mic like the D-104, make sure the PTT voltage is free of AC ripple.  If not, the AC ripple will couple into the very high impedance line and create a possible low level hum.   

Just some thoughts!

Regards,
Joe, W3GMS