Alfredo Mendiola Loyola

Hello,

If I use a TCXO oscillator with a frequency accuracy of 1ppm with an AD9851 which have activated the 6x Multiplier, will the multiplied frequency have the same accuracy of 1ppm?

Example:
Input: TCXO 10 Mhz with 1ppm
Output: AD9851 60 Mhz with X ppm

Will the value of X be 1 ppm ?

Regards
Alfredo
OA4AJP

Re: Si570 Set Frequency

Alfredo Mendiola Loyola

Ambrogio,

The Arduino Sketch Worked with my si570 Circuit.
I had to use the i2c scanner to find the I2C address of the Si570.

The modified source code is in:
https://github.com/oa4ajp/Si570_v5

73
Alfredo Mendiola
OA4AJP

Re: MMIC Amplifier Bias calculation

Nick Kennedy

If the inductor has a core material other than air, such as powdered iron
or ferrite (and it probably does), the DC current through it could saturate
the core material. That would cause the inductor to become non-linear or
have much lower than marked inductance.

If you know the manufacturer and part number of the inductor you might be
able to look up what value of current would cause it to saturate. Otherwise
you could wind your own inductor on a toroid and use published values of
its properties to be sure you're avoiding saturation.

73-

Nick, WA5BDU

On Fri, May 3, 2019 at 8:17 AM Alfredo Mendiola Loyola via Groups.Io
<mendiola_loyola=yahoo.com@groups.io> wrote:

Good Morning,

I'm using this calculator (
https://www.changpuak.ch/electronics/mar_era_bias.php) to get the values
of
the Capacitors, Resistance and Inductor for my Minicircuits MAV-11BSM
amplifier.

The calculator gives me a capacitor value of 68pF and an inductor of 1.6
uH.

What I don't understand is this statement in the calculator:
*******************************************************************
" Make sure the inductance does not saturate at the current of operation "

The calculated current is 60 mA, and the inductance calculated is 1.6uH.
How do I know if the inductor saturates at 60 mA of Current ?

Parameters:
**********
Supply Voltage: 8
Amp Type: MAV-11BSM
Min Freq: 50 Mhz

Output:
*******
R = 41.67 Ohms
L >= 1.592 uH
C >= 0.0637 nf ( 64pF => 68pF) {Usar 0.1uF}
P = 0.15W
I = 60 mA

Re: MMIC Amplifier Bias calculation

Alfredo Mendiola Loyola

I'm still designing the schematic before buyinh the components.
RegardsAlfredo Mendiola Loyola

On Friday, May 3, 2019, 9:25:22 AM GMT-5, Ambro IW2FVO <ambrogio.riboli@...> wrote:

hi Alfredo,
is your si570 working well with the sketch ?
Just to know .
regards,
Ambro
iw2fvo

Re: MMIC Amplifier Bias calculation

Ambro IW2FVO

hi Alfredo,
is your si570 working well with the sketch ?
Just to know .
regards,
Ambro
iw2fvo

MMIC Amplifier Bias calculation

Alfredo Mendiola Loyola

Good Morning,

I'm using this calculator (https://www.changpuak.ch/electronics/mar_era_bias.php) to get the values of
the Capacitors, Resistance and Inductor for my Minicircuits MAV-11BSM amplifier.

The calculator gives me a capacitor value of 68pF and an inductor of 1.6 uH.

What I don't understand is this statement in the calculator:
*******************************************************************
" Make sure the inductance does not saturate at the current of operation "

The calculated current is 60 mA, and the inductance calculated is 1.6uH.
How do I know if the inductor saturates at 60 mA of Current ?

Parameters:
**********
Supply Voltage: 8
Amp Type: MAV-11BSM
Min Freq: 50 Mhz

Output:
*******
R = 41.67 Ohms
L >= 1.592 uH
C >= 0.0637 nf ( 64pF => 68pF) {Usar 0.1uF}
P = 0.15W
I = 60 mA

Re: What is the difference between a DDS Type 1 and Type 2 ??

Pravin

No they are different in layout and pin arrangement . Same set of chips .

73
DE AB9XC
(Pravin)

--------------------------------------------

On Fri, 4/26/19, David Slipper <softfoot@...> wrote:

Subject: [PHSNA] What is the difference between a DDS Type 1 and Type 2 ??
To: "PHSNA@groups.io" <PHSNA@groups.io>
Date: Friday, April 26, 2019, 11:09 AM

Are they different modules or chips ??

Rgds
Dave

Re: What is the difference between a DDS Type 1 and Type 2 ??

Terry VK5TM

And the "Type 1" "Type 2" designation is just someone's arbitrary designation, not an "official" one you will find on any of the sites selling the modules.

Re: What is the difference between a DDS Type 1 and Type 2 ??

K5ESS

Yes. I noted that some sites disagree on which is a Type I or Type II in the attached PDF.
Mike
K5ESS

-----Original Message-----
From: PHSNA@groups.io [mailto:PHSNA@groups.io] On Behalf Of William Kimber
Sent: Friday, April 26, 2019 5:53 PM
To: PHSNA@groups.io
Subject: Re: [PHSNA] What is the difference between a DDS Type 1 and Type 2 ??

A quick word of warning,

There is SoftwareControledHamRadio.io group who have an Antennae
Analyser that uses the same modules but who have numbered them oppositely.

Cheers,

Will

ZL1TAO

On 27/04/19 7:43 AM, K5ESS via Groups.Io wrote:
Dave,
They are different modules. Either might have either AD9850 or AD9851 DDS chips. See the attached file. The file also shows an adapter board that can be used when needed. The modules are becoming rather expensive particularly the Type I (three rows of seven pins).
Mike
K5ESS

-----Original Message-----
From: PHSNA@groups.io [mailto:PHSNA@groups.io] On Behalf Of David Slipper
Sent: Friday, April 26, 2019 12:09 PM
To: PHSNA@groups.io
Subject: [PHSNA] What is the difference between a DDS Type 1 and Type 2 ??

Are they different modules or chips ??

Rgds
Dave

Re: What is the difference between a DDS Type 1 and Type 2 ??

William Kimber

A quick word of warning,

There is SoftwareControledHamRadio.io group who have an Antennae
Analyser that uses the same modules but who have numbered them oppositely.

Cheers,

Will

ZL1TAO

On 27/04/19 7:43 AM, K5ESS via Groups.Io wrote:
Dave,
They are different modules. Either might have either AD9850 or AD9851 DDS chips. See the attached file. The file also shows an adapter board that can be used when needed. The modules are becoming rather expensive particularly the Type I (three rows of seven pins).
Mike
K5ESS

-----Original Message-----
From: PHSNA@groups.io [mailto:PHSNA@groups.io] On Behalf Of David Slipper
Sent: Friday, April 26, 2019 12:09 PM
To: PHSNA@groups.io
Subject: [PHSNA] What is the difference between a DDS Type 1 and Type 2 ??

Are they different modules or chips ??

Rgds
Dave

Re: What is the difference between a DDS Type 1 and Type 2 ??

David Slipper <softfoot@...>

Many thanks

On 26/04/2019 20:43, K5ESS via Groups.Io wrote:
Dave,
They are different modules. Either might have either AD9850 or AD9851 DDS chips. See the attached file. The file also shows an adapter board that can be used when needed. The modules are becoming rather expensive particularly the Type I (three rows of seven pins).
Mike
K5ESS

-----Original Message-----
From: PHSNA@groups.io [mailto:PHSNA@groups.io] On Behalf Of David Slipper
Sent: Friday, April 26, 2019 12:09 PM
To: PHSNA@groups.io
Subject: [PHSNA] What is the difference between a DDS Type 1 and Type 2 ??

Are they different modules or chips ??

Rgds
Dave

Re: What is the difference between a DDS Type 1 and Type 2 ??

K5ESS

Dave,
They are different modules. Either might have either AD9850 or AD9851 DDS chips. See the attached file. The file also shows an adapter board that can be used when needed. The modules are becoming rather expensive particularly the Type I (three rows of seven pins).
Mike
K5ESS

-----Original Message-----
From: PHSNA@groups.io [mailto:PHSNA@groups.io] On Behalf Of David Slipper
Sent: Friday, April 26, 2019 12:09 PM
To: PHSNA@groups.io
Subject: [PHSNA] What is the difference between a DDS Type 1 and Type 2 ??

Are they different modules or chips ??

Rgds
Dave

What is the difference between a DDS Type 1 and Type 2 ??

David Slipper <softfoot@...>

Are they different modules or chips ??

Rgds
Dave

New to group

David Slipper <softfoot@...>

Hello all.

I am very interested in this project.

Dave

Re: Si570 LVDS Output Impedance

Clifford Heath

On 23 Apr 2019, at 11:12 am, Alfredo Mendiola Loyola via Groups.Io <mendiola_loyola=yahoo.com@groups.io> wrote:
I will use a 1:4 transformer with center tap to connect the output of the si570 (LVDS).
The secondary of the transformer (Center Tap) will be connected to the differential outputs of the si570
The primary of the transformer will be connected to a 3dB PI attenuator to get 50 ohm at the input and output of the attenuator.

The si570 datasheet states that the LVDS model has an output of 0.7 vpp {swing (diff)}

If I use a 1:4 transformer (Coilcraft PWB-4-BL) what will be the output peak to peak voltage at the transformer Primary?
1:4 impedance is 1:2 voltage ratio. 0.7Vp-p would reduce by 2:1 to 0.35Vp-p, which is 0.12Vrms.
Into 50 ohms that's about -5dBm.

Clifford Heath.

Re: Si570 LVDS Output Impedance

Alfredo Mendiola Loyola

Hello,

I will use a 1:4 transformer with center tap to connect the output of the si570 (LVDS).
The secondary of the transformer (Center Tap) will be connected to the differential outputs of the si570
The primary of the transformer will be connected to a 3dB PI attenuator to get 50 ohm at the input and output of the attenuator.

The si570 datasheet states that the LVDS model has an output of 0.7 vpp {swing (diff)}

If I use a 1:4 transformer (Coilcraft PWB-4-BL) what will be the output peak to peak voltage at the transformer Primary?

73.
Alfredo Mendiola Loyola
OA4AJP

Re: Si570 LVDS Output Impedance

Nick Kennedy

For that purpose, I'd try to assure 50 ohms by following the output with an
attenuator. I wouldn't assume a specific source resistance internal to the
Si570.

Another issue if you're trying to use the si570 in a signal generator type
of application is that the Si570 has a square wave output. However, if as
you say you are interested in a single channel use, you can LPF that signal
into a sine wave.

73-

Nick, WA5BDU

On Mon, Apr 22, 2019 at 6:28 AM Alfredo Mendiola Loyola via Groups.Io
<mendiola_loyola=yahoo.com@groups.io> wrote:

Hello:

My goal is to get a single channel output with exactly 50 ohms impedace.

By using a transformer 1:4 if the outputs of the si570 doesn't have
exactly 50 ohm I will get at the output of the transformer an impedace
higher or lower than 50 ohm.

I'm working with UHF sgnales 430 mhz.

73
Alfredo.
OA4AJP

Re: Si570 LVDS Output Impedance

Alfredo Mendiola Loyola

Hello:

My goal is to get a single channel output with exactly 50 ohms impedace.

By using a transformer 1:4 if the outputs of the si570 doesn't have exactly 50 ohm I will get at the output of the transformer an impedace higher or lower than 50 ohm.

I'm working with UHF sgnales 430 mhz.

73
Alfredo.
OA4AJP

Re: Si570 LVDS Output Impedance

Ambro IW2FVO

https://www.sdr-kits.net/documents/PA0KLT_Manual.pdf

and look at fig. 7 on page 13/21 for impedance / transformer connections.

I am using the Si570 as a VFO for my airband AM receiver too with good results. I did try it last week !
Used also for : Two meters FM receiver and for APT (137 MHz ) 40 KHz IF FM receiver.
all the best !
73, iw2fvo
Ambrogio

Re: Si570 LVDS Output Impedance

Clifford Heath

The Si570 data sheet says: "Available LVPECL, CMOS, LVDS, and CML outputs".
So the correct output coupling depends on which one you use.

LVPECL (fastest) requires 50 ohms termination to Vdd-2.0V.
LVDS and CML require 100 ohm differential (not supply-referenced).
CMOS swings within about 0.4V of the rails.

Clifford Heath.

On 22 Apr 2019, at 12:39 pm, Clifford Heath via Groups.Io <clifford.heath=gmail.com@groups.io> wrote:

Check that you get the right impedance ratio - remember that it is the
square of the turns ratio.

I haven't checked the data sheet to see if the Si570 output is DC (ground)
referenced. If not, I would decouple the CT to ground with a capacitor
anyway. But check the data sheet.

Clifford Heath

On Mon, 22 Apr 2019, 02:29 Alfredo Mendiola Loyola via Groups.Io
<mendiola_loyola=yahoo.com@groups.io> wrote:

Hello,

If I connect a Center Tap of an 1:4 Transformer (Secondary) to the LVDS
outputs I will get a 50 Ohm output impedance on the Primary?

Schematic:

I understand that the output impedance of each output of the si570 is 100
Ohm (LVDS), When I connect each output of the si570 to the transformer
Secondary I will get 200 ohm and 50 ohm on the Primary (200 4 = 50 ohm).

Do I have to connect the center tap of the secondary to ground?

Transformer Datasheet:
https://www.coilcraft.com/pdfs/pwb.pdf
Model: PWB-4-BL

73
Alfredo Mendiola
OA4AJP