WWVB remodulator for the Spectracom 8170...
On Tue, 18 Jun 2013 10:52:24 -0400
paul swed paulswedb@gmail.com wrote:
Interesting the HC will work all the way down to 2.2V so everything can be
run from 3 Volts.
I don't have a spec sheet at hand, but are HC types speced down to 2.2V?
I thought it was something around 3V
No idea as to the effect of the xtal oscillator maybe the 3.9 M R needs to
be changed.
Probably not. the 3.9M resistor is to give the oscillator circuit
(which is an unbuffered inverter) a DC bias. Its value is usually not
critical.
It also appears that the HC chip may doing the lions share of current
consumption. Spec sheet says up to 20 Ma. Hard to believe actually.
As long as it's mA not MA, it is indeed believable ;-)
HC used quite a bit of current. Especially when toggling at high speed
(where as high speed is to be seen relative to the 70s when these chips
were designed).
As for driving lengths of wire over distance it needs to be a buffer chip.
74hc244. But that seems like serious overkill it can drive 20 ma per port.
If it's just a single signal, why not use a pair of digital mosfets like
FDV302P/FDV303N? These can drive a big load (680mA speced, with good cooling)
and are can be interfaced with 3V logic.
Attila Kinali
--
The people on 4chan are like brilliant psychologists
who also happen to be insane and gross.
-- unknown
Thanks Attila Burts looking to separate the rcvr/remodulator. I am fine.
Yes indeed I did look up the hc specs. I thought it was a 5v logic
actually. I knew it was not at all like the 74c series.
Regards
Paul
On Tue, Jun 18, 2013 at 5:21 PM, Attila Kinali attila@kinali.ch wrote:
On Tue, 18 Jun 2013 10:52:24 -0400
paul swed paulswedb@gmail.com wrote:
Interesting the HC will work all the way down to 2.2V so everything can
be
run from 3 Volts.
I don't have a spec sheet at hand, but are HC types speced down to 2.2V?
I thought it was something around 3V
No idea as to the effect of the xtal oscillator maybe the 3.9 M R needs
to
be changed.
Probably not. the 3.9M resistor is to give the oscillator circuit
(which is an unbuffered inverter) a DC bias. Its value is usually not
critical.
It also appears that the HC chip may doing the lions share of current
consumption. Spec sheet says up to 20 Ma. Hard to believe actually.
As long as it's mA not MA, it is indeed believable ;-)
HC used quite a bit of current. Especially when toggling at high speed
(where as high speed is to be seen relative to the 70s when these chips
were designed).
As for driving lengths of wire over distance it needs to be a buffer
chip.
74hc244. But that seems like serious overkill it can drive 20 ma per
port.
If it's just a single signal, why not use a pair of digital mosfets like
FDV302P/FDV303N? These can drive a big load (680mA speced, with good
cooling)
and are can be interfaced with 3V logic.
Attila Kinali
--
The people on 4chan are like brilliant psychologists
who also happen to be insane and gross.
-- unknown
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On Tue, 18 Jun 2013 17:51:29 -0400
paul swed paulswedb@gmail.com wrote:
Thanks Attila Burts looking to separate the rcvr/remodulator. I am fine.
Yes indeed I did look up the hc specs. I thought it was a 5v logic
actually. I knew it was not at all like the 74c series.
That's the HCT which are 5V (the T denotes TTL compatible).
I just checked it. NXP specs the HCMOS family as 2-6V, with 5V typical
(recomended conditions, not absolute maximum ratings).
So it is indeed safe to run them down to 2V.
Weird.. where does that 3V in my mind come from?
Attila Kinali
--
The people on 4chan are like brilliant psychologists
who also happen to be insane and gross.
-- unknown
Don't know but thats what the wwvb clock rcvrs run on 2 aa batteries.
On Tue, Jun 18, 2013 at 6:10 PM, Attila Kinali attila@kinali.ch wrote:
On Tue, 18 Jun 2013 17:51:29 -0400
paul swed paulswedb@gmail.com wrote:
Thanks Attila Burts looking to separate the rcvr/remodulator. I am fine.
Yes indeed I did look up the hc specs. I thought it was a 5v logic
actually. I knew it was not at all like the 74c series.
That's the HCT which are 5V (the T denotes TTL compatible).
I just checked it. NXP specs the HCMOS family as 2-6V, with 5V typical
(recomended conditions, not absolute maximum ratings).
So it is indeed safe to run them down to 2V.
Weird.. where does that 3V in my mind come from?
Attila Kinali
--
The people on 4chan are like brilliant psychologists
who also happen to be insane and gross.
-- unknown
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
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and follow the instructions there.
Hi
The clock receivers (like a watch IC) likely are made on a low leakage / low speed process. You don't get a lot of speed, but you get enough at low voltage to do the job. Current drain is generally in the microamp range.
Bob
On Jun 18, 2013, at 6:16 PM, paul swed paulswedb@gmail.com wrote:
Don't know but thats what the wwvb clock rcvrs run on 2 aa batteries.
On Tue, Jun 18, 2013 at 6:10 PM, Attila Kinali attila@kinali.ch wrote:
On Tue, 18 Jun 2013 17:51:29 -0400
paul swed paulswedb@gmail.com wrote:
Thanks Attila Burts looking to separate the rcvr/remodulator. I am fine.
Yes indeed I did look up the hc specs. I thought it was a 5v logic
actually. I knew it was not at all like the 74c series.
That's the HCT which are 5V (the T denotes TTL compatible).
I just checked it. NXP specs the HCMOS family as 2-6V, with 5V typical
(recomended conditions, not absolute maximum ratings).
So it is indeed safe to run them down to 2V.
Weird.. where does that 3V in my mind come from?
Attila Kinali
--
The people on 4chan are like brilliant psychologists
who also happen to be insane and gross.
-- unknown
time-nuts mailing list -- time-nuts@febo.com
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Weird.. where does that 3V in my mind come from?
Metal gate cmos.
Ed
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Attila Kinali
Sent: Tuesday, June 18, 2013 18:11 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB remodulator for the Spectracom 8170...
On Tue, 18 Jun 2013 17:51:29 -0400
paul swed paulswedb@gmail.com wrote:
Thanks Attila Burts looking to separate the rcvr/remodulator. I am fine.
Yes indeed I did look up the hc specs. I thought it was a 5v logic
actually. I knew it was not at all like the 74c series.
That's the HCT which are 5V (the T denotes TTL compatible).
I just checked it. NXP specs the HCMOS family as 2-6V, with 5V typical
(recomended conditions, not absolute maximum ratings).
So it is indeed safe to run them down to 2V.
Weird.. where does that 3V in my mind come from?
Attila Kinali
--
The people on 4chan are like brilliant psychologists
who also happen to be insane and gross.
-- unknown
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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On 06/18/2013 03:04 AM, paul swed wrote:
Exactly as Bob says. Though at the time I built the costas loop I did not
build the remodulator. Just time. Pun intended.
But indeed they add together for those that need both time and frequency.
If you just want time the remodulator is far far simpler.
I have looked at your schematic, and I understand what it does. What I
don't get is why you have just not added the "second arm" of the Costas
loop into the 8170 architecture. I just don't have the 8170 schematic,
but what I am trying to say is why didn't you just add the missing
pieces? Too hard?
It's almost as if you built a new frequency receiver from scratch.
Cheers,
Magnus
Magnus I certainly can and did in my earlier release some 6 months ago. But
thats very specific to one rcvr type. This is a general approach that keeps
you out of the insides.
Recovering from a severe flu
End for tonight.
On Wed, Jun 19, 2013 at 4:22 PM, Magnus Danielson <
magnus@rubidium.dyndns.org> wrote:
On 06/18/2013 03:04 AM, paul swed wrote:
Exactly as Bob says. Though at the time I built the costas loop I did not
build the remodulator. Just time. Pun intended.
But indeed they add together for those that need both time and frequency.
If you just want time the remodulator is far far simpler.
I have looked at your schematic, and I understand what it does. What I
don't get is why you have just not added the "second arm" of the Costas
loop into the 8170 architecture. I just don't have the 8170 schematic, but
what I am trying to say is why didn't you just add the missing pieces? Too
hard?
It's almost as if you built a new frequency receiver from scratch.
Cheers,
Magnus
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