[RFI] RFI from Astron power supply

[Jim P]

I have to say that I have observed RFI coming from my Astron RS-35M
'linear' supply. It is in the form of a pulse or 'buzz' at the line rate. It
kind of low-level and is noticable on the AM broadcast band; I don't
usually hear it on the ham bands even when using it to power the
HR rig doing the receiving.

The supply is not oscillating, but there would appear to be something
else taking place generating this 'RFI' linked to the line (AC input) side
of things.

Jim P  // WB5WPA //


----- Original Message ----- 
From: "Dave Hachadorian" <K6LL at adelphia.net>
To: "RFI Reflector" <rfi at contesting.com>
Sent: Friday, May 25, 2007 11:24 PM
Subject: Re: [RFI] RFI from Astron power supply


>
> ----- Original Message ----- 
> From: <rrath at charter.net>
> To: <rfi at contesting.com>
> Sent: Saturday, May 26, 2007 12:28 AM
> Subject: Re: [RFI] RFI from Astron power supply
>
>
> > The model is RS-35m. I have not made contact with the
> > company, I thought
> > I would ask the people that use them first; to see what
> > you have done to
> > remedy your RFI problem - - what works and what does not
> > work.
> >
> > The power company RFI guy and myself checked the S-unit
> > noise level on
> > shore power and then hooked up to his power inverter from
> > his truck. No
> > change. He then used his HF radio and a 102" whip -- for
> > receiving -- and
> > the noise level; parked just outside the building and
> > about 15' away from our
> > base radio, he had an s-7 noise reading. We then unhooked
> > the p.s. from
> > the inverter and his HF radio dropped to an s-3 noise
> > level. Re-hooked the
> > p.s. to his inverter and his HF radio jumped back up to an
> > s-7 noise.
>
> The Astron RS-35M is a very reliable analog power supply.
> I'v been using one for years with no problems. This supply
> won't generate noise unless something is radically wrong.
>
> I'm trying to understand your setup here. Are you saying
> that he had a power inverter hooked up to his battery and
> the noise level in his receiver increased when you plugged
> your RS-35M into the inverter? Power inverters are
> notoriously noisy. I'll bet the noise increase came from his
> own inverter, when it was loaded down by the RS-35M!
>
> Dave Hachadorian, K6LL
> Yuma, AZ
>