[AMRadio] Heath HO 10 Monitor Scope

Peter Markavage manualman at juno.com
Sun Feb 24 14:13:26 EST 2008

For starters, check the resistors in the cathode and plate circuit of the
6C10 Horizontal amp. section. Try a new 6C10. Check the input (2 mfd) 
and output (.22 mfd) caps for leakage. You might also check the 6BN8 RF
Demodulator section and components.

Pete, wa2cwa

On Sun, 24 Feb 2008 10:11:07 -0800 (PST) John King <k5pgw at yahoo.com>
> Have replaced bad 3RP1 cathode tube in my HO 10 and
> tested all other tubes. Have changed the two
> .15 at 1600VDC capacitors.
> It is working however not up to PAR. All controls
> work. The current problem is that when in the
> trapezoid pattern monitoring AM transmitted signal,
> the horizontal width of the trapezoid doesn't
> completely fill out to a symetrical point. The
> horizontal position and horizontal gain pots work
> except that there doesn't seem to be enough horizontal
> gain to cause the trapezoid to fully display the full
> signal.
> I have a properly working SB 610 that shows clearly my
> transmitted AM signal. The HO 10 doesn't fill out the
> trapezoid symetrically to a point.
> I suspect a resistor in the horizontal gain circuit
> having changed value or maybe a suspect capacitor. Are
> there any commonly known culprits that cause this loss
> of horizontal gain? Naturally, I am lazy by nature,
> and would rather "pick your brains" than use my feeble
> brain. What are your thoughts based on your vast
> knowledge and EXPERIENCE??? Thanks and 73, John, K5PGW

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