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Old April 11th 04, 11:26 PM
PJ
 
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Default Astron RS 35A

I just purchased an Astron RS 35A to go along with my new TS 2000. I was
getting some terrific line noise that I was attibuting to local line noise,
until I hooked up the TS 830.

1. Totally takes out the 830 on 7 MHZ. Turn off the 2000, and noise
disappears.
2. Noise on most bands -- not 60 hz but seems higher buzz. Probably 120 or
so.
3. Discernable roughness on CW note monitored locally. Reports from
others varies -- hard to know. 4. Tried another small power supply.
Noise does not seem to exist with it.

I'll probably send it back, but anyone have similar problems?

KD0UN


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Old April 13th 04, 12:27 AM
N0DG
 
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If it is this bad I would suspect paint or some other insulating material on
the top post connections on one of the filter caps.Be usre the contacts are
clean and tight.
Good Luck.
N)DG
Don
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Old April 13th 04, 12:27 AM
N0DG
 
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Default

If it is this bad I would suspect paint or some other insulating material on
the top post connections on one of the filter caps.Be usre the contacts are
clean and tight.
Good Luck.
N)DG
Don
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Old April 16th 04, 08:40 AM
Pete KE9OA
 
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It sounds like the rectifier diodes in you power supply radiating that
noise. Usually, this type of noise decays pretty rapidly above 600kHz, but
this supply could be using very fast diodes. Connect .01uF caps across each
diode and
(more importantly) bypass each leg of the SECONDARY of the power transformer
to ground with .1uF non-polarized capacitors. This will knock out that
noise, allowing the receiver to be usable down to about 250kHz. If you want
to tune lower than that, increase the value to .47uF.

Pete

"Temporary FL@L&ER" . wrote in message
...
On 12 Apr 2004 23:27:39 GMT, (N0DG) wrote:

If it is this bad I would suspect paint or some other insulating material

on
the top post connections on one of the filter caps.Be usre the contacts

are
clean and tight.
Good Luck.
N)DG
Don


Definately check the cap connections, also check to see that the case
cover screws have at least one external tooth lockwasher to bite
through the paint on both the cover and chassis to ensure a good
ground connection for the cover itself. Sometimes there isn't a good
bond, so you have essentially an unshielded power supply.


Use the usual techniques to reply via email.

Molon Labe!



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Old April 16th 04, 08:40 AM
Pete KE9OA
 
Posts: n/a
Default

It sounds like the rectifier diodes in you power supply radiating that
noise. Usually, this type of noise decays pretty rapidly above 600kHz, but
this supply could be using very fast diodes. Connect .01uF caps across each
diode and
(more importantly) bypass each leg of the SECONDARY of the power transformer
to ground with .1uF non-polarized capacitors. This will knock out that
noise, allowing the receiver to be usable down to about 250kHz. If you want
to tune lower than that, increase the value to .47uF.

Pete

"Temporary FL@L&ER" . wrote in message
...
On 12 Apr 2004 23:27:39 GMT, (N0DG) wrote:

If it is this bad I would suspect paint or some other insulating material

on
the top post connections on one of the filter caps.Be usre the contacts

are
clean and tight.
Good Luck.
N)DG
Don


Definately check the cap connections, also check to see that the case
cover screws have at least one external tooth lockwasher to bite
through the paint on both the cover and chassis to ensure a good
ground connection for the cover itself. Sometimes there isn't a good
bond, so you have essentially an unshielded power supply.


Use the usual techniques to reply via email.

Molon Labe!



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