Thinks for the tip. Have you used this on an actual tbolt?
Yes, I am using this squarer on my Tbolt. You may see my application here:
http://www.braddye.com/gps_do.html
Best regards,
Brad Dye
Editor, AAPC Wireless Messaging News
P.O. Box 266
Fairfield, IL 62837 USA
Telephone: 618-847-8118
One problem that is evident when a simple longtailed pair
(differential amplifier) is used to convert a sine wave to a square
wave is the tilt that is evident in the waveform when the output
transistor is conducting. This is due to feedthrough from the input
signal via the emitter base
The attached circuit uses lower capacitance Schottky diodes than the
BAT45 to reduce the capacitive feedthrough so that a much smaller value
compensation capacitor can be used.
It also draws a relatively constant current from the supply and the
capacitive coupling between the diodes ensures
Hi
What is the resulting square wave going to be used for?
A simple biased ACMOS gate is adequate for a lot of applications. A 0.1 uf cap
to couple the signal to the input. A 120K to B+ and a 100K to ground for bias
on the same input. Square wave comes out the other side. One usually
My intention is to divide the signal by 10 and feed it as an external
frequency reference into my old HP counter. Hopefully this will increase
it's stability.
As for the circuits i have tried, there have been so many. Most of them are
variations of each other as i experimented on a breadboard.
] Squaring Tbolt 10Mhz output
My intention is to divide the signal by 10 and feed it as an external
frequency reference into my old HP counter. Hopefully this will increase
it's stability.
As for the circuits i have tried, there have been so many. Most of them are
variations of each other as i
What is the model of the old HP counter?? Lets have a look
at the receiving end of the arrangement. In my experience
the use of an external frequency reference with HP test
boxes has been painless, not needing any extra circuitry
between the reference and the input.
Regards;
Greg
On
This has also been my experience. Even 5245's. Typically 1 or less volts.
On Thu, Mar 24, 2011 at 10:31 AM, Greg Broburg semif...@comcast.net wrote:
What is the model of the old HP counter?? Lets have a look
at the receiving end of the arrangement. In my experience
the use of an external
The counter is an HP 5381A 80 Mhz. According to the manual it will take up
to 2Mhz as a reference input. Just for fun, i tried feeding it the 10Mhz and
it didn't like it.
On Thu, Mar 24, 2011 at 10:31 AM, Greg Broburg semif...@comcast.net wrote:
What is the model of the old HP counter?? Lets
James Fournier wrote:
My intention is to divide the signal by 10 and feed it as an external
frequency reference into my old HP counter. Hopefully this will increase
it's stability.
As for the circuits i have tried, there have been so many. Most of them are
variations of each other as i
The HP 5381A uses a Mostek MK5009 timing
generator and it operates at 1 MHz. It has a crystal
oscillator amplifier internally and this is used by
HP as the basic timebase. There is a pin made
to receive an external 1 MHz clock which is made
for TTL. The input on the 5381A is coupled directly
to
I'm not sure everything can handle the 10Mhz signal.
Bingo.
LM339 (National data sheet)
Response time:0.5 us
CD4049B/CD405B (from TI data sheet)
Rise time is 80 ns
Fall time is 30 ns
Those are typicals at 5 V with a 5V input signal.
The LM399 says low power which usually means
what is the output drive circuit and what is the drive
level / source impedance from the Thunderbolt?
Greg
On 3/24/2011 2:10 PM, Hal Murray wrote:
I'm not sure everything can handle the 10Mhz signal.
Bingo.
LM339 (National data sheet)
Response time: 0.5 us
CD4049B/CD405B (from
of precise time and frequency measurement
Subject: Re: [time-nuts] Squaring Tbolt 10Mhz output
what is the output drive circuit and what is the drive
level / source impedance from the Thunderbolt?
Greg
On 3/24/2011 2:10 PM, Hal Murray wrote:
I'm not sure everything can handle the 10Mhz signal
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Greg Broburg
Sent: Thursday, March 24, 2011 5:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Squaring Tbolt 10Mhz output
what is the output
Hi Brad,
Thinks for the tip. Have you used this on an actual tbolt?
On Thu, Mar 24, 2011 at 5:48 PM, Brad Dye b...@braddye.com wrote:
Here is the solution that I chose:
http://g4hup.com/DFS/Iss2/SQ66M7.htm
Best regards,
Brad Dye
Editor, AAPC Wireless Messaging News
P.O. Box 266
Hello All,
I'm trying to square the 10Mhz output from a Thunderbolt GPSDO, and failing
miserably. I'm still very new at this so please forgive my ignorance. I
thought it was going to be easy. I have tried diodes, comparators,
op-amps, Schmidt trigger buffers,regular buffers, inverters, and
Feed it through a 10M0 Hz crystal filter (easy to make
out of one crystal) then put the output of the filter into
a fast comparator. It is commonly done in certain
types of DDS synthesizers. Is that clear enough or do
you need a picture?
Greg
On 3/23/2011 6:57 PM, James Fournier wrote:
Hello
James Fournier wrote:
Hello All,
I'm trying to square the 10Mhz output from a Thunderbolt GPSDO, and failing
miserably. I'm still very new at this so please forgive my ignorance. I
thought it was going to be easy. I have tried diodes, comparators,
op-amps, Schmidt trigger buffers,regular
James wrote:
I'm trying to square the 10Mhz output from a Thunderbolt GPSDO, and failing
miserably. I'm still very new at this so please forgive my ignorance. I
thought it was going to be easy. I have tried diodes, comparators,
op-amps, Schmidt trigger buffers,regular buffers, inverters, and
One problem that is evident when a simple longtailed pair (differential
amplifier) is used to convert a sine wave to a square wave is the tilt
that is evident in the waveform when the output transistor is
conducting. This is due to feedthrough from the input signal via the
emitter base
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