I realize many people on the list are going to be familiar with the
equipment and process, but it's interesting to see write-ups like this
receive publicity on a larger scale. Especially when the article cautions
... get sucked into hacking frequency references and you may become a time
nut
Rick wrote:
optimum noise figure is a function of the ratio between base
spreading resistance and (beta)(r-sub-e). If base spreading
resistance is high, you make r-sub-e high by reducing collector current.
I replied:
reducing transistor current to raise the noise resistance causes
You can try to build a poor man's choke ring:
http://www.mauve.gr/var/DIY_Choke_Ring_GPS_Antenna.htm
On Thu, Jul 23, 2015 at 7:38 PM, Alan Ambrose alan.ambr...@anagram.net wrote:
Hi, is there any benefit in adding a ground plane to these simple timing
antennas? e.g. GPS-TMG-26N
OTOH, the other cure for high base spreading resistance is
to simply parallel multiple devices. This avoids the bad
side effects you mention. The other key noise parameter
in a BJT is RF current gain, and this cannot be cured
by any circuit design tricks.
Rick Karlquist N6RK
On 7/23/2015 8:29
Hi
On Jul 23, 2015, at 1:38 PM, Alan Ambrose alan.ambr...@anagram.net wrote:
Hi, is there any benefit in adding a ground plane to these simple timing
antennas? e.g. GPS-TMG-26N
http://www.antenna.com/apg_products.cgi?id_num=11740
In which case, how big? And I'm imagining immediately
On Thu, 23 Jul 2015 17:38:00 +
Alan Ambrose alan.ambr...@anagram.net wrote:
Hi, is there any benefit in adding a ground plane to these simple
timing antennas? e.g. GPS-TMG-26N
http://www.antenna.com/apg_products.cgi?id_num=11740
In which case, how big? And I'm imagining immediately
Hi
If your 10 MHz is the result of a “divide by 2 then divide by 5” approach, the
output will not be
a 50/50 duty cycle square wave. The best way to fix that is to move up the
chain and play
with the dividers. You need to re-aragne them so the final divider is a divide
by 2.
When you do so,
Was a good week for eLORAN I was able to check out much of my equipment.
Next possible test may be 6-7 August. Not firm.
Possibly from Dana Indiana. One of the original actual LORAN C sites.
Wildwood NJ was and is a test site and at lower power and a shorter antenna
I believe.
I did send my
Symmetry is based on the biasing of the sinewave feeding the gate that you
are trying to create a sinewave from.
Jerry N9XR.
On Jul 24, 2015 7:19 PM, skipp Isaham via time-nuts time-nuts@febo.com
wrote:
Hello again,
First off, I want to thank everyone who replied direct and through the
group
On 7/24/2015 11:58 AM, Brooke Clarke wrote:
Hi Charles:
Does hFE (DC) have much relevance to this? Would hfe (AC) be the
important one?
Only insofar as DC current gain is an upper bound on AC current gain.
If your operating frequency is less than f-sub-t divided by beta,
then DC current
skipp wrote:
[the 10MHz output is] not even close to being symmetrical. The waveform
on-portion (duty cycle) appears (surprising to me) to be much less than 20%
Now I'm under the assumption that proper rounding or conversion of the non
symmetrical 10 MHz square to a sine wave will be a bit
Brooke wrote:
Does hFE (DC) have much relevance to this? Would hfe (AC) be the
important one?
It depends on whether you are more interested in the 1/f noise, which
causes most of the phase noise in oscillators and the additive
(residual) PN in amplifiers, or the in-band noise. As I said
Hi Charles:
Does hFE (DC) have much relevance to this? Would hfe (AC) be the important one?
Mail_Attachment --
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Charles Steinmetz wrote:
Rick wrote:
Hello again,
First off, I want to thank everyone who replied direct and through the group
regarding my recent 10 MHz square to sine wave conversion info request.
I obtained a mini-circuits 10.7 MHz low pass filter from Ebay cheap
enough and I also plan on rolling my own based on some of the
Hi
On Jul 24, 2015, at 11:54 AM, Attila Kinali att...@kinali.ch wrote:
On Thu, 23 Jul 2015 17:38:00 +
Alan Ambrose alan.ambr...@anagram.net wrote:
Hi, is there any benefit in adding a ground plane to these simple
timing antennas? e.g. GPS-TMG-26N
15 matches
Mail list logo
