Thanks for the scope images. Can you walk me through what we are seeing
here? I see a continuous lower horizontal trace, two sets of short
traces above that and then a single medium length trace above them. How
many dits are we looking at? Can I assume that the peak voltage of the
longest/lower line is about -0.45V? What is the peak positive swing on
If its not too much trouble, since Chris simply keyed the continuously
and hence is showing the RF, (if I understand correctly), could you also
supply a similar image? Then we can compare apples with apples.
And, maybe it would be informative if Chris sent us an image with his
transmitter keyed with dits at 20 wpm, as you have?
Dale Putnam wrote:
> [Attachment(s) <#TopText> from Dale Putnam included below]
> The tx current is a clue, and what is happening at the input to U8 pin
> 6 and the output of U8 1 & 13 is more of interest.
> The attached is a trace of TP1, and the output of U7 pin 16, and U8
> pin 6. This is with the scope set for .2v per div. and keying with the
> keyer set to 20wpm with the paddle stuck on dits. The wave form is a dit.
> The difference between a 3b and a 3b.1 in this area is minimal, in
> concept. There has been adjustments made, but the circuit works
> similar. The keying shape remain, and the impedance is better matched.
> The following email will contain the trace of the output of U8 pin 13
> and 1.
> I think we are close here.
> --... ...-- Dale - WC7S in Wy
> Attachment(s) from Dale Putnam
> 1 of 1 Photo(s)