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Title: Heathkit SB-610 scope users Post by: WB4AQL on August 04, 2013, 05:06:47 PM Hello everyone. Are y`all real happy with your SB-610 pattern? Mine seems to have all the functions, but the trapezoid pattern is tall and narrow. It`s all there, it just seems compressed.
The sinusoidal pattern is only clear with steady tone modulation (whistle). Not like I`m used to with my Tektronix scope. Voltages are good. I`ve replaced a few out of tolerance resistors. Maybe just the nature of the beast? Title: Re: Heathkit SB-610 scope users Post by: wa5ddz on August 05, 2013, 04:05:23 PM Yep--- I think you got it right "the nature of the beast". It's no
where close to my B+K scope. What happens when you move the ''' Horz Gain ''' control ? Mine is in line with a Dx-60 and is used more for a reference than anything else. And that green flashing screen just looks good. Title: Re: Heathkit SB-610 scope users Post by: WB4AQL on August 06, 2013, 11:35:48 AM The horizontal gain control will spread the sinusoidal trace or narrow it. The pattern is more discernable if the horizontal gain is increased. It seems to have no effect on the trapezoid pattern.
Title: Re: Heathkit SB-610 scope users Post by: W1RKW on August 09, 2013, 11:30:09 AM You're probably seeing non-linearities in the way the trapezoid pattern is derived on the SB-610 using the feedline connections.. If the SB-610 is connected via the feedline and using the trapezoid pattern function the audio from the modulated RF is detected or demodulated then feed to the deflection plates in the SB-610. The non-linearity could start there. Not sure what the SB-610 does to filter out the audio for the RF going to the other deflection plates. I don't have a schematic. Sampling RF and audio separately in a plate modulated rig using an o'scope is the best way as you've found out. I think the SB-610 provides the trapezoid feature for "looks". AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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