David C. Partridge wrote:
> I'm waiting to see what Magnus Danielson has to say, as it was he after all
> who suggested adding caps in parallel to the pull-downs, and also series
> resistors.
>
> Thinking about it retrospect, I think he may have meant the series resistors
> to go between the pull-d
Magnus is on vacation and has some (net) connectivity problems. I would
expect him to be back online within a day or two.
--
Björn
On Wed, 2008-07-16 at 18:27 +0100, David C. Partridge wrote:
> I'm waiting to see what Magnus Danielson has to say, as it was he after all
> who suggested adding
I'm waiting to see what Magnus Danielson has to say, as it was he after all
who suggested adding caps in parallel to the pull-downs, and also series
resistors.
Thinking about it retrospect, I think he may have meant the series resistors
to go between the pull-downs and the chip, rather than where
Hal Murray wrote:
> [Context is filtering on inputs from switches.]
>
> Could somebody tell me why we are doing anything fancy at all? What's wrong
> with just a simple pullup?
>
>
Pull down required because of thumbwheel switch encoding.
> I can think of two cases that might be interesting.
>
[Context is filtering on inputs from switches.]
Could somebody tell me why we are doing anything fancy at all? What's wrong
with just a simple pullup?
I can think of two cases that might be interesting.
One is signal integrity. There might be enough crosstalk to cause troubles.
This is a 4
John Miles wrote:
> Right; when the thumbswitches are toggled, the RC integrators will slow down
> the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise
> fail to reliably with slow edges -- it probably comes down to the
> "complementary" thing, where both halves of a totem pol
John Miles wrote:
> Right; when the thumbswitches are toggled, the RC integrators will slow down
> the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise
> fail to reliably with slow edges -- it probably comes down to the
> "complementary" thing, where both halves of a totem pol
John Miles wrote:
> Right; when the thumbswitches are toggled, the RC integrators will slow down
> the edges into pins 9-11. Sometimes CMOS parts will latch up or otherwise
> fail to reliably with slow edges -- it probably comes down to the
> "complementary" thing, where both halves of a totem pol
HC family.
-- john, KE5FX
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of David C. Partridge
> Sent: Tuesday, July 15, 2008 11:07 AM
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] Fre
: [time-nuts] Frequency divider design critique request
I don't know about sending edges that slow into a CMOS chip. Is that
considered kosher for HC-series logic?
-- john, KE5FX
> -Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] Behalf Of David C. Pa
; To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] Frequency divider design critique request
>
>
> Magnus,
>
> Was the attached what you had in mind?
>
> Thanks
> Dave
>
___
tim
Magnus,
Was the attached what you had in mind?
Thanks
Dave
-Original Message-
From: Magnus Danielson [mailto:[EMAIL PROTECTED]
Sent: 10 July 2008 23:07
To: time-nuts@febo.com; [EMAIL PROTECTED]
Subject: Re: [time-nuts] Frequency divider design critique request
From: "Da
Bruce Griffiths wrote:
>> I was only thinking that maybe there ought to be a buffer from the input
>> to the rectifier, or else higher frequency energy will escape out
>> towards the
>> source. At least some isolation should be there.
>>
>>
>>
If one uses a common base stage to drive the d
Magnus
>> Magnus
>>
>> A minimalist approach for the 5MHz to 10MHz doubler could use a full
>> wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz
>> shunt trap to minimise the 5MHz content in the output.
>>
>
> Actually, it depends on weither you would like to get a 10 MHz or
From: Bruce Griffiths <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] Frequency divider design critique request
Date: Sat, 12 Jul 2008 12:11:03 +1200
Message-ID: <[EMAIL PROTECTED]>
> Magnus Danielson wrote:
> > Why not? It basically solves a problem most of us has, and only
David Partridge wrote:
> CPLD - wassat? OK, OK I have some idea, but that's about all I know.
> Anyway these are probably BGA stuff which I couldn't hope to hand solder
anyway
Many CPLD's are leaded. Only the high-pin count CPLD/FPGA's are BGA.
> Chris Hoover,
Christopher, per favor.
> You
Magnus
A minimalist approach for the 5MHz to 10MHz doubler could use a full
wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz shunt
trap to minimise the 5MHz content in the output.
If the doubler components were perfectly matched (unlikely) the
fundamental trap could be omit
Magnus Danielson wrote:
> Why not? It basically solves a problem most of us has, and only a few tweaks
> away and it solves it fairly generically. The only think it doesn't do well is
> handling 5 MHz souces rather than 10 MHz. Having that would solve many
> problems. While not achieving full metro
Magnus Danielson wrote:
Hej David,
Magnus Danielson:
1) Please could you clarify what you're proposing with the series resistors?
I get the idea about 10nF in parallel with R24-R26, though I'm not sure what
the benefit is? Those MUX control pins are going to sit pretty hard on 5V
or pulle
Jim Lux wrote:
> At 10:41 AM 7/11/2008, David C. Partridge wrote:
>> M
>> All,
>>
>> CPLD - wassat? OK, OK I have some idea, but that's about all I know.
>> Anyway these are probably BGA stuff which I couldn't hope to hand solder
>> anyway - it's enough of a stretch for me to think of hand solderi
At 10:41 AM 7/11/2008, David C. Partridge wrote:
>M
>All,
>
>CPLD - wassat? OK, OK I have some idea, but that's about all I know.
>Anyway these are probably BGA stuff which I couldn't hope to hand solder
>anyway - it's enough of a stretch for me to think of hand soldering this SMT
>board.
CPLD ->
From: "David C. Partridge" <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] Frequency divider design critique request
Date: Fri, 11 Jul 2008 18:41:52 +0100
Message-ID: <[EMAIL PROTECTED]>
Hej David,
> Magnus Danielson:
>
> 1) Please could you clarify what you're
Magnus Danielson:
1) Please could you clarify what you're proposing with the series resistors?
I get the idea about 10nF in parallel with R24-R26, though I'm not sure what
the benefit is? Those MUX control pins are going to sit pretty hard on 5V
or pulled down to ground.
2) You said:
>I am su
Bob Paddock wrote:
>>> There are usually some BNC bulkhead connectors on eBay that terminate
>>> in SMA/SMB/SMC pigtails, which are great for panel mounting.
>>>
>
> Not directly related to this design, but it made me wonder about something.
>
> If you are building a multiple output system a
>> There are usually some BNC bulkhead connectors on eBay that terminate
>> in SMA/SMB/SMC pigtails, which are great for panel mounting.
Not directly related to this design, but it made me wonder about something.
If you are building a multiple output system and channel phase to channel phase
was
John Miles wrote:
> I am not a big fan of BNC connectors on the PC board itself, because I
> am not a big fan of attaching PC boards directly to panels in most cases.
>
> There are usually some BNC bulkhead connectors on eBay that terminate
> in SMA/SMB/SMC pigtails, which are great for panel moun
:30 PM
>To: 'Discussion of precise time and frequency measurement'
>Subject: [time-nuts] Frequency divider design critique request
>
>As I've mentioned before, I've been working on the design of a frequency
>divider to go with my TB.
>
>The idea is 10MHz sine
On Fri, Jul 11, 2008 at 11:33:53AM +1200, Bruce Griffiths wrote:
> [EMAIL PROTECTED] wrote:
> > Hi David,
> >
> > It looks like your design is pretty far along, so maybe it's too late for
> > this suggestion, but one thing you might consider is replacing the 7400
> > series logic with a 5V CPLD p
> The CPLD's (unlike the FPGAs) are single chip solutions.
There are many single chip FPGA solutions today from several different
companies.
If you are in the US and near a Avnet office you can pick up a Actel
Igloo Icicle
eval. board/programmer for $49. They are giving them out at the Actel
Pow
Magnus Danielson wrote:
> I would consider a dedicated 1 PPS output.
>
> I would consider a synchronise feature with a PPS/synchronise input. It should
> be wise to not directly wire it to the counter resets, but provide an arm
> button and maybe a very simple arrangement to indicate "left", "on ma
[EMAIL PROTECTED] wrote:
> Hi David,
>
> It looks like your design is pretty far along, so maybe it's too late for
> this suggestion, but one thing you might consider is replacing the 7400
> series logic with a 5V CPLD programmable logic device.
>
> This could offer several advantages:
>
> 1) any
Hi David,
It looks like your design is pretty far along, so maybe it's too late for this
suggestion, but one thing you might consider is replacing the 7400 series logic
with a 5V CPLD programmable logic device.
This could offer several advantages:
1) any issues (such as jitter) could be addr
Hej Magnus
Magnus Danielson wrote:
> David,
>
>
>> As I've mentioned before, I've been working on the design of a frequency
>> divider to go with my TB.
>>
>> The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave
>> into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade se
From: "David C. Partridge" <[EMAIL PROTECTED]>
Subject: [time-nuts] Frequency divider design critique request
Date: Thu, 10 Jul 2008 21:30:56 +0100
Message-ID: <[EMAIL PROTECTED]>
David,
> As I've mentioned before, I've been working on the design of a f
I am not a big fan of BNC connectors on the PC board itself, because I am
not a big fan of attaching PC boards directly to panels in most cases.
There are usually some BNC bulkhead connectors on eBay that terminate in
SMA/SMB/SMC pigtails, which are great for panel mounting.
http://cgi.ebay.com/eB
In my best "HAL 9000" voice;
Hi Dave. Dave, what are you doing ? Dave we need BNC connectors. Those SMB's
are hard to work with. Dave, are you intending to have those SMB's stick out
through a panel ? Dave ? Dave, let me suggest that you layout the connector
pattern so either one can be used
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