I had a noisy varactor experience too: in my Tek 492 one day I noticed an
increase in the 0 beat noise and the PLL not working. When I replaced the
2.2GHz conversion varactor all was back to normal.
On Fri, Oct 19, 2012 at 6:54 AM, Tom Curlee tcur...@sbcglobal.net wrote:
I'll second the
Rick,
thanks for the hint. I had a 2x 45 pF SOT23 diode at hands that works
fine. The frequency could be adjusted without any changes to the
circuit. Now as the 10811 is back in the 8662A, the diode will most
likely keep living happily in there.
John,
it's a bit tricky. First of all, you
Hi
Varactors are typically biased through very large decoupling resistors. The
amazing part isn't that they get noisy, it's that they ever are quiet :)..
In most circuits if they ever leaked at the rated max leakage spec, you
would see all sorts of trouble.
Bob
-Original Message-
From:
Hi TJ,
The Jupiter receivers I have are the standard part, and like you I have found
detailed design info hard to come by.
All I can suggest for your issue is to use a small microcontroller to send the
commands to the receiver at power up, then go to sleep until the next power
cycle.
I have
Hi TJ,
I recently ran into a similar issue with a Jupiter T. No NMEA output. What I
found was the unit came up in Motorola Binary @ 9600 and sent only an
initial string out.
The solution here was to use a PIC. (I was actually working with a PIC done
by Tommy Sullivan called 3DFIXLED)
Here
There is an MSP430 port of GCC that works fine, and mspdebug is able to
write the code to the chip via the programming hardware that comes on
the Launchpad boards. TI also provides several free IDEs with code size
limits, if you prefer that route. Definitely not as easy for a beginner
as an
I've just re-read this post after looking at the replies.
If the 365 is Time locked and showing and offset of 2.98E-13 then it looks
to working fine, and I would suspect that it is the frequency counter
oscillator that is drifting.
Is the frequency counter free running or locked to any other
Using the arduino infrastructure can be dirt cheap! The arduino itself is
just an Atmel atMega microcontroller with the arduino bootloader burned into
the bootloader section of the controllers flash. For embedding you can buy a
DIP atmel atmega328 chip already burned for less than $5. There are
On Thu, 18 Oct 2012 13:03:14 -0700, Hal Murray wrote:
It's a typical low-cost GPS via USB navigation unit. It's not a timing
receiver.
I was wondering why there wasn't someone on the list suggesting this
Trimble (The A4 board) $87
eb* 290730738839
From the desc. it needs a 48v PSU.
But
I wonder if the glass case got a crack in it or if the kovar seal
was failing. Maybe a failed solder joint (which gets fixed when you
install the new diode). I've never heard of a noisy varactor before either.
Rick
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I do not know the circuit in question but could you unsolder the varactor,
solder in a 10pF cap and look at the output?
The frequency would not be stable but if the varactor was the culprit, you
should see less noise.
My 2ยข anyway
DaveH
-Original Message-
From:
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Here is a copy of the header FYI:
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Slightly off topic: the oscillator transistor has some 1854-
part number, but is actually a 2N5179 selected for some minimum
fT at 30 mADC collector current. When the oscillator starts up,
before the ALC takes effect, a fairly large DC current can flow
and some 2N5179's don't have enough
I didn't notice any damage, nor was there a visibly bad solder joint.
However, I couldn't reproduce the excess noise with a quick bench test
at 30V / 100k neither.
DC-wise there are a few microvolts only. Same with the SMD diode.
Exept, when the original glass diode is exposed to light. With a
Hi
The normal 10811 package has several openings in it. Light *might* get in
there. A micro volts level of noise can mess up your phase noise if it's
AC noise at a low frequency.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of
Dear Group,
Good afternoon. I just realized that my two HP 5065As have been running for
about a month and their operation has been closely monitored. Now I assume both
clocks are stabilized. I want to start doing some phase and time comparisons
between them and with respect of a TrueTime 5 MHz
Date: Fri, 19 Oct 2012 07:27:39 -0700
From: Keenan Tims keenan.t...@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Fwd: Re: Contact: Jupiter GPS questions
Message-ID: 5081635b.9050...@gmail.com
Content-Type: text/plain;
As I mentioned, the varactor is equivalent to the Motorola MV1650. I
have a bunch as well left over from building VCXOs. :-)
David
On 10/19/12 3:37 PM, Rick Karlquist wrote:
Slightly off topic: the oscillator transistor has some 1854-
part number, but is actually a 2N5179 selected for
Edgardo,
You do use the C-field adjust to put a 5065A On frequency. The Factory
values are a moot point after all these years!
Just incrementaly adjust the c-field control in small steps while
observing the frequency comparison.
The only thing that might happen is that you reach one end of the
Rick, Adrian, I think there are a number of possibly material related areas
that could cause a varicap to go noisy but I have no experience of them
First a reversed biased diode makes quite a good particle detector :-)) and
remanent radioactive atoms in say the glass could cause localised
Back in the dark ages while dinosaurs roamed the earth, I worked for a music
audio company outside of Seattle, WA called Tapco (they are now Mackie).
They were making PA amplifiers and I and three other people were doing final
test and burn-in.
Had one that had a bit of a 60Hz hum on the
It's been a few years since I really dug into the FRK and M100 but I do
remember this particular common problem.
You power the unit up and after the normal warm up period it locks and
stays locked.
Then if you cycle the power the Lamp refuses to light.
Has anyone figured out the most likely cause
Hi Corby,
Will it start when it gets cold ? How long do you have to let it cool before it
will re ignite ?
Perhaps the lamp oscillator has a problem where it will not oscillate when hot
with the momentary lost of power.
BillWB6BNQ
cdel...@juno.com wrote:
It's been a few years since I
Hi Rob,
The counter is free running and it has option fitted 4 fitted, a XOCO. After
it was suggested I check the specs on the counter I obtained them and found
that up to 2 Hz @ 10 MHz is in spec ( 6 months after Cal ) 200 Hz @ 1
GHz is in spec I was a bit disappointed
I usually run
Bill,
When plugged in cold and after the lamp starts I can cycle the power and
the lamp will re-ignite up to about 4 minutes into the warmup.
After that the lamp won't start.
Maybe the lamp heater is set too hot or the lamp oscillator is heat
sensitive?
Corby
There was some discussion of the DTS-207X recently. There is a DTS-2010 on
ebay for $265. Anyone know about this model? The usual searches come up
empty.
Orin.
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thanks
-pete
On Fri, Oct 19, 2012 at 12:16 PM, George Race geo...@mrrace.com wrote:
Pete, I have been trying to answer you but your server is denying access to
my mail.
Here is a copy of the header FYI:
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