[TenTec] Re: Orion - Jupiter Microphone Connections

[Joe Giacobello]

Well, it's interesting that this subject has just come up, because I am 
in the midst of trying to wire up a D104 to use with the Orion.  I got 
off  on the wrong foot because I didn't have the addendum that corrected 
the wiring errors shown in the manual.  Since the instructions didn't 
make sense to me, I wired it up the way I thought it should work, and my 
audio was attenuated, tinny and the PTT had about a 1/2 second delay 
before the audio came on.  Consequently, I wrote TT service and received 
the following reply:

"We are aware that the drawing is incorrect, there is an addendum 
included with the manual that states this fact.  Audio ground should go 
to pin 2 and shield should go to the shell. PTT should be between pin 3 
and shell and NOT between pin 2 and 3."

Well, since the shield and audio ground were already connected to pin 2, I merely connected a short piece of braid between Pin 2 and the connector shell.  There was only slight improvement in the audio quality and the PTT still had a delay.  I haven't gone to the next obvious step and disconnected everything from pin 2.  I'll do that tonight and let you know what happened.

73, Joe




NJ0IP wrote:

>Maybe it's not quite so simple, guys.
>
>To be honest, I'm confused.
>My first take would have been to tie the mic's "-" to the case ground.
>Some of you have suggested that.
>I'm suggesting that this is wrong.
>
>One of our BCC contest stations attempted to use my ORION in the recent 160m
>ARRL DX contest (SSB) but after 2 hours of failing to get their setup to
>work with the ORION, they aborted the plan.  They cut the 4-pin mic
>connector off, soldered an 8-pin on, and used an FT-1000,  Some of you may
>be thinking that the hams there didn't know what they were doing, but if you
>view their setup which they purpose-built on site just for the contest, and
>consider the fact that they set yet another new world record, then maybe
>you'll believe me that these were first class hams.
>
>The problem incurred was strong hum and very scratchy audio (when
>transmitting).
>
>I had the team forward their exact configuration to me (connection between
>the heil headset, the IBM notebook - through an audio line isolator - and
>into the front-panel mic jack).  I forwarded the drawing to Ten-Tec.
>
>The reply was that this has happened a few times before and been cured by
>separating the mic's (-) from the case ground.
>
>With that, I rest my case.
>
>73
>Rick
>
><SNIP>
>As to internal grounding, microphone connections and RF, I suspect that
>radiation back into the associated equipment or cables is the culprit.
>Grounding won't solve it unless one is at the electrical end of a 1/4 wave
>or 3/4 wave ground pole.  As to inserting a transformer, this is simply a
>frequency limiting device (it won't pass RF) so the RF induced into the mike
>cable won't get into the rig. I don't advise this approach as impedance
>matching, common mode rejection, and associated humm pickup may prevail.
>
>
>73
>Bob, K4TAX
>
>
>
>
>_______________________________________________
>TenTec mailing list
>TenTec at contesting.com
>http://lists.contesting.com/mailman/listinfo/tentec
>
>
>  
>