I'm new to this list, so please forgive me if I am missing some older
information not in your post.
I also believe you are overdriving the amplifier, but the oscilloscope
display scaling is confusing us. Several things stand out at me from
your message:
* The AD9858 has a current-mode D/A
The DDS puts out perhaps a volt far to large for a preamp device. I suspect
like everyone else you are clipping. Just take a 2n3904 use it as a common
collector/buffer and bias the emitter for a clean cycle and see what level
you get.
Regrads
Paul
WB8TSL
On Sat, Jan 17, 2015 at 2:51 AM, Tom
Hello,
That Q1 is MAV1-0104 made by Mini-Circuits. This part is exact
replacement for the MSA-0104, which was in TenTec kits early.
The schematic of that pre-amp is pretty simple:
+12 V
|
[ ] (470 Ohm)
Hi
Based on the phase noise on the 15 MHz output, I would *guess* that the 5 MHz
OCXO has a floor in the vicinity of -160 dbc / Hz. That would be correct per
the MTI spec sheet. It also would make sense based on your phase noise plots.
Close in ( around 200 Hz) your multiplier and amp are
Hi
The amp you are using has about 18.5 db of gain. It’s a typical self biased
transistor style amp. From the part number, it’s got a ~ 1.5 dbm output limit
at 1 db compression. That gives you a max input level of -17 dbm when the amp
is in compression. If you want reasonable noise
Bonsoir Stéphane,
(For Stéphane's unedited reply, look in the Current state thread)
On 01/17/2015 12:36 AM, Stéphane Rey wrote:
Hi,
I've took the time to read carefully your long and detailed message
Magnus and this was very interesting. I've learned many things that have
enabled me to
Hi,
I am not clear about the little sawtooth riding on the signal, but it
looks like you are running out of headroom on the Ten-Tec preamp. The
Ten-Tec preamp would not be my first choice for the job. One of the
Minicircuits MMIC's would probably be a better choice depending upon
your
- Original Message -
From: d0ct0r t...@patoka.org
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, January 17, 2015 12:02 AM
Subject: [time-nuts] DDS on AD9852
Hello,
I would like to ask some advise about the signal distortion I get
Am 03.01.2015 um 02:43 schrieb Gerhard Hoffmann:
over the Christmas season, I have designed and built a frequency
doubler from 5 to 10 MHz and a distribution amplifier for the Lucent
KS-24361. A preliminary writeup is under
http://www.hoffmann-hochfrequenz.de/downloads/DoubDist.pdf
I
