[GreenKeys] Interference

[Bob Camp]

Hi,

It's not uncommon to see low pass RFI filters installed in series with 
the keyboard contacts or with the keyed line. You should be able to get 
the RFI down well below the level that it bothers a radio without a lot 
of work. The one thing you don't want to do is to mess with capacitors 
around the selector magnets. They can resonate with the inductance in 
the magnets and make for some really weird distortion.

For some reason my model 28's have vacuum tube loop keyers in them but 
no polar relays. I must not be living well ....

	Take Care

		Bob Camp
		KB8TQ



On May 7, 2004, at 2:06 AM, Tom Elmore wrote:

> I' am trying to solve some local interference I am getting in my 
> receiver
> when receiving RTTY signals. I hear what sounds like relay contact 
> arcing
> probably coming from the polar relay in my model 28 ASR. It is only
> noticeable on weak signals and I wonder if it degrading them at all. I
> placed a .01 capacitor across the keying line between my TU and RTTY 
> machine
> but it didn't help so I need to continue looking.
>
>
> Thank You
> Thomas Elmore
> Anchorage, Alaska
>
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