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FW: IMG00040-20100814-2011.jpg

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  • Dale Putnam
    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
    Message 1 of 2 , Aug 14, 2010
    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


     
  • Stephen Wandling
    Hi Dale, 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
    Message 2 of 2 , Aug 14, 2010
    • 0 Attachment
      Hi Dale,

      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
      each dit?

      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?

      72
      Stephen
      VE7NSD

      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)
      >
      > IMG00040-20100814-2011.jpg
      > <http://groups.yahoo.com/group/AT_Sprint/attachments/folder/793199313/item/588193680/view>
      > IMG00040-20100814-2011.jpg
      > <http://groups.yahoo.com/group/AT_Sprint/attachments/folder/793199313/item/588193680/view>
      >
      >
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