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Date: Mon, 02 Dec 2002 15:36:22 -0800
From: Phil Wheeler <w7ox at earthlink.net>
Organization: Outstanding
To: COLIN WHITMORE <cncwhitmore at msn.com>
Cc: Elecraft <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] K1 ATT LED flicker

As I recall, the flickering is completely normal.

Phil

COLIN WHITMORE wrote:

>Ok 'Crafters, here's one for you!  
>
>I have a K1 (s/n 942) which has the KFL1-4 (40, 30, 20, & 15), the KAT1, and the KNB1. There haven't
been any modifications to the radio, with the exception of the "blue cap" mod and any changes required
for the options that are installed. I am powering it with an Astron RS-4A supply.
>
>Some time back, while operating in very low light conditions, I happened to notice an occasional flicker
coming from the ATT LED. Usually only one or two flickers then nothing for a while (several minutes or
more). Sometimes, perhaps by coincidence, when I switched on the attenuator then switched it back off,
the flicker appeared to go away. This may be totally unrelated, as I said, perhaps by coincidence. I
should note that when the ATT LED is lit it seems to be "emitting light" without any discernable flicker.
Well, today I happened to be playing around with the display mode and when I set it to the BAT mode (ATT
off) I got a continuous flicker at a rate of about 4 flickers per second. Oh, the BAT display value was
13.4V, just in case you were wondering.
>
>I haven't crack it open to verify any values or anything.
>
>So, what say you?
>
>Cheers,
>Colin
>N0YGY
>
>K1 #942 - flickering and causing general mischief, perhaps out of jealousy for the K2?
>K2 #2833 - causing dust to accumulate onto it's little brother! With a sly snicker, I'll wager!
>

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From: "Don Brown" <DolfinDon at msn.com>
To: "COLIN WHITMORE" <cncwhitmore at msn.com>,
        "Elecraft" <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] K1 ATT LED flicker
Date: Mon, 2 Dec 2002 17:36:34 -0600

Hi

It's OK and normal. The DVM and and ATTN light use the same pin on the MPU
so the ATTN light will flicker when the MPU reprograms the pin as an input
so it can read the battery voltage. Then changes it back to an output to
drive the ATTN circuit. The time needed to read the battery voltage is very
short but long enough to make the ATTN light flicker.

Don Brown

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