Azelio,
I was lucky, it was just the opamp, so the TB is happily driving the
MV89 again. Back to three cornered hat testing!
The DAC is no more than PWM, so I'm guessing the reference (5V, not as I
thought 4V) and DAC output are sampled by the CPU to get the PWM output
close to what's required.
One interesting thing: the Trimble oscillator is now dead (ignoring
EFC). I had tried it after the MV89 failure, and it apparently didn't
like more than +/-5V.
Cheers.
and maybe that the DAC's output feeds an OPAMP first, if so then
replacing the OPAMP should fix the problem...
On Thu, May 16, 2013 at 12:10 PM, David Hooke
<[email protected]> wrote:
OK.
This MV89 is mounted on a PCB with SMA connectors for the EFC, REF and
10MHz. I connected the EFC from the TB to the REF out of the oscillator, not
for very long, and things haven't been quite right since then.
I should not play in the workshop after drinking wine with dinner!
It'll be interesting to see how Trimble designed the DAC. There doesn't seem
to be much more than a 4V reference, a quad opamp and a bunch of RCs. I
guess that as long as it's monotonic, accuracy is not overly important.
Cheers.
david
Fess up David. Tell the story.
LOL,
Tom
----- Original Message ----- From: "Burt I. Weiner"
<[email protected]>
To: <[email protected]>
Sent: Wednesday, May 15, 2013 11:54 AM
Subject: [time-nuts] Embarrassing stuff...
David,
I'm sure it's nothing compared to what I did many years ago to my
Singer FM-10C Synthesizer. You tell us your story and I'll tell you
mine. You're among friends. Every time my life flashes before my
eyes it's mostly embarrassing stuff.
Burt, K6OQK
From: David Hooke
<dhooke-re5jqeeqqe8avxtiumwx3w-xmd5yjdbdmrexy1tmh2...@public.gmane.org>
Subject: Re: [time-nuts] three cornered comparison tools
Hi All,
I've managed to blow up the DAC output on my TBOLT; it now has about
0.5V 42kHz ripple on it. I think I know how I did this, but it's too
embarrassing to share in public.
Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California U.S.A.
[email protected]
www.biwa.cc
K6OQK
_______________________________________________
time-nuts mailing list --
[email protected]
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
