[time-nuts] Advise on building a DIY GPSDO?

[Bob Stewart]

As a victim of the "I'm gonna build a GPSDO" virus, I think the cautions are well worth mentioning.  Building a decent GPSDO sounds like such a simple thing, but it slowly turns into a rabbit hole as you discover you need ever better test equipment, and a microscope, and hot air rework station, and gaining the skills in designing the electronics and laying out boards.  And then there's the time.  I've got over 2 years invested in nothing but this GPSDO project.  I'm retired, so I'm not talking about an hour or two after work, either.

I wouldn't discourage anyone from doing it, if they have a good idea what it's going to cost going into it; both in terms of time and money.  Suddenly discovering that you really, really need a Cs standard else all the work you've done is wasted, is a big shock.

I'd have to agree with others that the best path to take is to find a proven design and build it.  Then decide whether you truly want to come up with something of your own.  Just remember the cost.

Bob

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On Mon, 4/4/16, Tom Holmes <tholmes at woh.rr.com> wrote:

 Subject: Re: [time-nuts] Advise on building a DIY GPSDO?
 To: "'Discussion of precise time and frequency measurement'" <time-nuts at febo.com>
 Date: Monday, April 4, 2016, 11:18 AM
 
 The preceding questions
 always come up when a newbie comes up on the list wanting to
 build their own GPSDO. They are all good questions from an
 engineering/management viewpoint, but this latest incident
 reminded me of conversations I had with my father some 50+
 years ago when I wanted to tackle some project and needed
 some resources. His most common question was why do you want
 to do this? My usual poorly thought out answer (hey, I was
 an adolescent at the time) was simply "because I want
 to". I would then get the obligatory lecture on needing
 a better reason and having a plan, but then he would often
 provide some subset of the resources I asked for ($$) so
 that I could proceed. Naturally, I resented these probing
 interrogations into my motives and poor project management
 skills, but learned to accept them as the cost of doing
 business with the old man. Being an engineer himself, he
 understood that whether or not the project was a success
 that I would learn something from the enterpr
  ise. 
 
 I'm
 not saying that the questions posed are not relevant and
 important, as well as useful; I just wonder if we are
 discouraging the learning process that most of us went
 through to get where we are.
 
 Tom Holmes, N8ZM