Re: [softrock40] Checking si570 calibration witha frequency counter?
> ----- Original Message -----Hi Alan, when I built it I remember taking the probes to some section
> Subject: [softrock40] Checking si570 calibration witha frequency counter?
>> Can someone kindly remind me how to check the cal of a si570 in a
>> built Ensemble II receiver is spot on with a frequency counter please?
>> I set it up perfectly with a frequency counter locked to a GPS
>> reference when I built it ages and ages ago, but today, for some
>> reason, it locked up and "went berserk". I had to reset the si570 to
>> factory cal and it's now a tad off. When I set it with the frequency
>> counter it stayed absolutely spot on for, oooh, two years or more? Thanks.
> The easiest way is
> http://sites.google.com/site/g4zfqradio/calibrating-the-softrock-si570-usb-controller It's years since I used a
> counter to do it. I've forgotten how I made the correction. (Except
> when we used PICs to set the Si570.)
> What do you mean "absolutely spot on"? +/- 0.5Hz?
> Even that would not be considered absolutely spot on by many these days:)
> The Si570 is not bad but I've not had one I'd describe as
> absolutely spot on for more than a few minutes.
> 73 Alan G4ZFQ
and reading the frequency output into the counter and trimming it with
the software, unless I am getting confused with something else?
Anyway, have set it up with the info in the link to the RWM signal on
14996KHz and it's fine now. It must have been something in the build
instructions because I doubt I'd have poked about without some
concrete info to go by, I'll pull up the pages later. Once set up on
the Softrock which is on 24/7 it stayed within 2 or 3Hz as far as I
I view the Time-Nuts forum, but am far from a "nut" myself, they are
WAY out of my league :) Too easy to become very anal about that sort
of thing <LOL>
Chris Wilson. 2E0ILY