[R-390] LED lamp replacement

[Barry Hauser]

Instead of LED's, best bet is probably the long-life version of the standard
replacement bulb.  I think there's a reference on it and some list members
may know offhand what the number is.  As I recall, there is quite a bit of
difference in the hours spec. and not that much difference in price.
Brightness may be a bit lower, though.

Anyone know?

Barry


----- Original Message ----- 
From: "Bob Camp" <ham at cq.nu>
To: "Don and Diana Cunningham" <wb5hak at sirinet.net>
Cc: <R-390 at mailman.qth.net>
Sent: Tuesday, July 06, 2004 11:36 AM
Subject: Re: [R-390] LED lamp replacement


> Hi
>
> If you do that then you have two items to worry about. The LED's have a
> reverse breakdown voltage and you now have a half wave rectifier. That
> gets you right back into the chopped current = RFI problem.
>
> If you run them in reverse parallel pairs then the breakdown voltage is
> not an issue but you still only run current through them when the
> voltage is above about 1.6 volts on the diode. Off of a 6.3 volt AC
> supply having no current for 1.6 volts is a fairly large amount of
> chopping. You are right back to the RFI issue.
>
> I know all this sounds a bit like witchcraft but the R-390 is
> particularly vulnerable to the problem. The designers simply never
> considered there would be a source of broad band RFI *inside* the
> radio. The other gotcha is that it is such a sensitive radio that you
> can hear crud with it that other radios would simply miss in the noise.
>
> Take Care!
>
> Bob Camp
> KB8TQ