Fwd: Re: [FH] Hopping questions for Andre and Hal, part two

[Nan and Sandy Sanders]

>Hi Sandy, can you put this on whatever lists it needs to go to.
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>Hi Terry,  well reminds me a bit of the old days!
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>Andre is the guy responsible for driving the 
>concept so I hope he’ll chime in and pick up the thread too.
>I’ll try to answer some of the questions you 
>asked and thanks for letting us tap into your knowledge base on
>DDS.
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>1. Arudunio clock.  Yes, this will most 
>certainly be a big problem and, as you say, at anything higher than
>a trivial hop rate drift and loss of synch will 
>occur.  Last time we though about this we 
>assumed two stage synchronization with the
>transmit side (coarse/acquire - lock and 
>tracking) and went out of our way to at least 
>think about a better oscillator/clock.  Those designs
>had the hoping timing totally independent of any 
>housekeeping (moving dat around, looking up the next
>frequency,etc.)
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>2. Artifacts in the audio bandpass — yes, we 
>experienced those in some of our previous experimenting
>Remember the snare drum?   Also, if AM is used 
>there are RF artifacts generated by the pulse like
>nature of the hop and that can creature hash in 
>the spectrum at the products of the clock and hop frequency.
>We talked about shaping the pulse to avoid those 
>— don’t think we were came to a conclusion on that.
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>3. Best way to interface the DDS with the 
>Ard.    OK - need to think about that some more.
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>4. What band — Doesn’t the ham rules pretty well 
>limit us to 420Mhz?   (FCC playing it safe again!)
>I propose we target 10m and get an STA.  We 
>don’t have to do that right now but lets keep it as
>a goal we can go after when we get our feet on the ground with this.
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>5. Target hope rate?    I vote for 10 a second 
>to start.  We can turn up the rate.
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>6. Modulation - AM was the target because it is 
>easy.  It also very tolerant and for starters we need tolerance!
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>7. Home channel,  form of the “go” signal, ID, 
>system compatibility negotiation and others — 
>arbitrary and ad hoc unless we make a standard (oh no!)
>Some time ago Paul was interested in creating a 
>standard handshake or pro signal that told the 
>other station about what your system was composed of,
>what kind of hoping/spread you were able to do, 
>the form of the go signal, etc — The idea was you looked at the other station’s
>descriptors to decide if you could talk  and if 
>so, replied with suggestions on how to proceed, 
>the other station accepted or decline based
>on preferences.  Possibly a second round of 
>negotiations began then until a common set of 
>functions supporting communications was arrived at
>or you decided you could’t talk after 
>all.  Maybe that could be revisited by interested parties.?
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>8. Code Exchange.  Once we agree upon something 
>we can all build or buy to program I highly recommend
>we set up a github repository for our 
>code.  Benefits: share code with anyone who wants to experiment,
>a place for us to share our latest/greatest 
>programming feats, a place to document and keep track of
>what we would like others to know about our 
>project.   A code repository is free or fee depending on the
>features we want.
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>If your are not familiar with git hub  it can be 
>found here: https://www.github.com
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>9. Last tuesday I wanted to talk about how 
>successful Makers group is using the simplest 
>kind of components to empower kids and
>adults to get involved.   What I call the Andre 
>FH approach equally relies on simplicity for the same reason.  But, we are
>a  pretty sophisticated bunch of hams, so whats 
>our role?   The people who designed the snap together components that make
>up the Arduino “ecosystem” are pretty 
>sophisticated too, but they know success in this 
>market is through simplicity. I suggest
>we are in the same boat.  Our success depends on 
>first doing a decent design (based on our knowledge) but making sure
>our(what I hope) emerging “ecosystem” is well 
>served by simplicity.  The widest number of people should be ok with
>trying out this project.
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>Terry,
>problem here is that I am nearly full time on 
>classes, work and professional organizations, with some time left for sleeping.
>I can devote a couple of hours every so often to 
>any ham project but it depends.
>I think  a lot of people are in that soup.
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>If you like we can pick this thread up on next Tuesday night’s tech net.
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>73
>Hal WB3KDU
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