[TenTec] Corsair II thump

[Mike Hyder -N4NT-]

Once upon a time some Astron power supplies had a floating output, neither 
positive nor negative was connected to the chassis.  For laboratory work, 
this was just fine.  But with radio transmitters, problems sometimes arose 
because RF energy could enter through the negative post and go directly to 
the voltage regulator circuitry.

Astron became aware of this and suggested grounding the negative post to the 
chassis.  I did it by taking the post out, removing the insulators, cleaning 
paint from around the hold and reinstalling the post with no insulation. 
Many reported they had never had a problem with their Astrons but I did and 
apparently it was common.  Below is my correspondence with Astron:

      To:  "Ten-Tec Reflector" <tentec at contesting.com>
      Subject:  [TenTec] Astron Power Supply (RS-35) from the horse's mouth
      From:  "Mike Hyder -N4NT-" <Mike_N4NT at charter.net>
      Reply-to:  Discussion of Ten-Tec Equipment <tentec at contesting.com>
      Date:  Tue, 5 Dec 2006 21:04:25 -0500
      List-post:  <mailto:tentec at contesting.com>

[TenTec] Your semi-annual Astron tip...

People come and go from this reflector. This is a reminder that many
troubles with Astron power supplies can be cured by grounding the negative
post to the cabinet.  I did it by removing the insulators from the negative
post, scraping some paint from around the hole and putting a lockwasher on
the post when reinstalling.  Below is my correspondence with them about it.

Merry Christmas,
Mike -N4NT-

----- Original Message -----
From: "ASTRON" <sales at astroncorp.com>
To: "Mike Hyder" <N4NT at chartertn.net>
Sent: Tuesday, November 20, 2001 6:06 PM
Subject: Re: RS-35 in an RF environment

MIKE.

1ST CHECK YOUR AC OUTLET GROUND IT MUST HAVE GOOD CONNECTION

2ND. MEASURE FROM THE -13.8V TERMINAL TO CHASSIS, IF NO DIRECT CONNECTION,
RUN A PIECE OF WIRE FROM -13.8V TERMINAL TO CHASSIS.

JANE

----- Original Message -----
From: Mike Hyder <N4NT at chartertn.net
To: <eastron at astroncorp.com
Sent: Tuesday, November 13, 2001 7:56 AM
Subject: RS-35 in an RF environment

Several people have advised me that Astron had a service bulletin for the
Astron RS-35 (and possibly other models) which advised to strap the negative
post of the supply to the cabinet to reduce or eliminate problems caused
when RF energy affects the supply's regulation.  This is in particular a
frequent problem in the amateur radio service.

Could you confirm such bulletin and either email it to me or point me to the
URL that will allow me to view it, please?

Many thanks,
Mike Hyder


----- Original Message ----- 
From: "Paul DeWitte" <kb9lie at gmail.com>
To: <tentec at contesting.com>
Sent: Wednesday, December 03, 2008 9:13 AM
Subject: [TenTec] Corsair II thump


>I did a bit of playing with the sidetone adjustments. That did nothing to
> help.
>
> I have been using an Astron SS30M power supply with a breaker in line. I
> tried a 962 TT supply and the noise is less.