[TenTec] best power supply for Orion II and other items

[Mike Hyder -N4NT-]

The 35 amp linear Astron supplies used a floating output so they could be 
used with either positive or negative ground applications.  For our use, the 
negative post of the Astron should be grounded to the unit's 
cabinet/chassis.  I think the Astron supply is good but if the negative 
output post is not grounded to the cabinet/chassis then RF energy gets into 
the regulator circuitry...

Follows my correspondence with Astron some years ago:
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 hole 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: "John Molenda" <cdistflatfoot at gmail.com>
To: "TEN TEC DISCUSSION" <tentec at contesting.com>
Sent: Sunday, November 21, 2010 3:50 PM
Subject: [TenTec] best power supply for Orion II and other items


> Hello , I have been having some trouble with rfi and strange impulse
> noise on RX I have traced it down to a bad power supply .  I will be
> replacing this power supply with another to power my Orion II and a
> couple other items so a ps with a high amp rating of say 35 or so might
> just be what I need .  Who makes the best ps I have been looking at the
> alinco products and like them I have had trouble with astron but have
> very good luck with Pyramid Ps.  any suggestions I am replacing a 963
> for the curious . any suggestions ?  thanks John kb2huk
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