[Boatanchors] Heathkit HO-10 Sweep (???) Problem

[Al Parker]

Hi Bill,
    Without looking, it's a shot from the hip, but sounds like the input
is getting "hum modulated".  Since it's not from the p.s. as it's been
recapped, then maybe it's heater to cathode leakage in one of the tubes.
    Just a wild guess.
73,
Al, W8UT
(any word on the swap?)

----- Original Message ----- 
From: <wd0x at adelphia.net>
To: <boatanchors at mailman.qth.net>
Sent: Sunday, March 26, 2006 5:51 PM
Subject: [Boatanchors] Heathkit HO-10 Sweep (???) Problem


> I'm hoping there is a simple solution to a sweep problem (at least I
think it's a sweep issue) I'm having with my newly restored Heathkit HO-10
monitor scope.
>
> I've completely re-capped all of the paper & electrolytics, re-tubed,
cleaned and treated pot and switch contacts with DeOxit, and still can't
get a steady trace on the CRT with no input to the scope.
>
> The horizontal sweep control will adjust the "wavy" line trace I get and
will eventually speed it up to the point where it is steady (but a bit
fuzzy) when the control is full clockwise.
>
> With the sweep control full CCW, I get a very sharp trace but it
resembles a sine wave NOT a perfectly flat line.  It is difficult to get
the trace to stop "moving" unless the control is full clockwise.
>
> When I transmit a steady CW carrier into the scope, the top and bottom
of the display are "wavy" NOT flat like I think it should be.
>
> Any suggestions as to where to look would be appreciated. 73, Bill, wd0x
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