Date   
Just starting out

Vladimir Grijo
 

Hi Richard,
See the attached file.
It was very usefull to me.
Regards,
Vladimir

Re: Just starting out

Nick Kennedy
 

Well, you've got several elements of it. 

The PHSNA doesn't use a local display or encoder (or any other controls).

There are two main versions. In the terminal version, all the intelligence is in the Arduino sketch and it communicates with you via a serial terminal. 

In the Windows version, the sketch for the Arduino does minimal functions controlling the DDS and reading the ADC while most of the intelligence is in the Windows program which shows your results on your PC as any typical Windows program would.

There are two major hardware components. 

First is an AD8307 log RF power detector circuit. It's in a separate box to keep noise low. Its DC output signal goes to an ADC pin in the Arduino.

The other box contains the rest of the PHSNA hardware, which includes an Arduino, a DDS, post-DDS filtering and amplification and/or attenuation if required. Most of the complexity of the different versions comes from the fact that there are designs for a couple different form-factor eBay DDS boards plus the AmQRP / Midnight Engineering DDS-60 board. Also one post-amplifier used a transistor and another used an MMIC. 

Having this set-up, your calibrated RF output from the DDS box generally goes through the DUT and then to the log power meter and its output goes back to the Arduino.  Other fixtures may be used, such as a crystal measurement fixture or a return loss bridge, depending on what you're testing at the moment.

73-

Nick, WA5BDU



On Sun, Sep 25, 2016 at 5:49 PM, lancer979@... [PHSNA] <PHSNA@...> wrote:
 

I'm starting out with an arduino nano v3.0 pro mini (on board FTDI and 5v regulator)

I'm hooked up to a 1602 LCD display on D4 to D7 and D12 to D13.

My DDS AD9850 module (125MHz clock) is on D8 to D11.

I'm using a nice AD8307 module - well shielded with an SMA connector - connected to A0.

I have a shaft encoder on D2 and D3


Is this setup anywhere close to a PHSNA as this group defines them?


I'm a little confused with the large number of options and boards members of this group are using.

I don't understand the software (arduino sketches or PC applications) or how they apply.


I hope to start out with something clean and simple then expand to more complexity.

The hope is to do frequency response measurements of filters and crystals to start out with. 


Can anyone in the group help me out?


Richard


Just starting out

Richard Wilson
 

I'm starting out with an arduino nano v3.0 pro mini (on board FTDI and 5v regulator)

I'm hooked up to a 1602 LCD display on D4 to D7 and D12 to D13.

My DDS AD9850 module (125MHz clock) is on D8 to D11.

I'm using a nice AD8307 module - well shielded with an SMA connector - connected to A0.

I have a shaft encoder on D2 and D3


Is this setup anywhere close to a PHSNA as this group defines them?


I'm a little confused with the large number of options and boards members of this group are using.

I don't understand the software (arduino sketches or PC applications) or how they apply.


I hope to start out with something clean and simple then expand to more complexity.

The hope is to do frequency response measurements of filters and crystals to start out with. 


Can anyone in the group help me out?


Richard

Just starting out

Richard Wilson
 

I'm starting out with an arduino nano v3.0 pro mini (on board FTDI and 5v regulator)

I'm hooked up to a 1602 LCD display on D4 to D7 and D12 to D13.

My DDS AD9850 module (125MHz clock) is on D8 to D11.

I'm using a nice AD8307 module - well shielded with an SMA connector - connected to A0.

I have a shaft encoder on D2 and D3


Is this setup anywhere close to a PHSNA as this group defines them?


I'm a little confused with the large number of options and boards members of this group are using.

I don't understand the software (arduino sketches or PC applications) or how they apply.


I hope to start out with something clean and simple then expand to more complexity.

The hope is to do frequency response measurements of filters and crystals to start out with. 


Can anyone in the group help me out?


Richard

Re: New file uploaded to PHSNA

dick faust
 

In case someone is interested in a "leveler" I took Sam Wetterlin's info
http://www.wetterlin.org/sam/SA/MSACal/CalAccessories.htm
and made a PCB.  I have also shared the layout on OSH Park today.
OSH Park ~ Signal Leveler

 

Attached is a schematic and BOM.

Dick K9IVB

Re: New file uploaded to PHSNA

K5ESS
 

Marcus,

Yes, I have modified the DDS board for differential output and use the Mini Circuits T1-1T transformer.

Best Regards

Mike K5ESS

 

From: PHSNA@... [mailto:PHSNA@...]
Sent: Thursday, September 08, 2016 1:59 AM
To: PHSNA@...
Subject: Re: [PHSNA] New file uploaded to PHSNA

 

 

Funny,

 

I've also almost done the same thing. Yesterday I send my AD8008 amplifier board with a modified version of the ALC (http://www.cwtd.org/May_6-2014.html) to OSHpark. I changed the peak detector and added a control pot to the first op amp and removed the second one. The third one is still there.

 

I intend to use the board with the experimenters board as v2.0 of my homebrew RF generator. However I have modified my DDS board to use differential output with a Mini Circuits T1-1T transformer. Do you use an modified DDS board or not?

 

My solution lacks your clever mounting solution.

 

Br

Marcus, SA5PMG

 

On Thu, Sep 8, 2016 at 5:09 AM, <PHSNA@...> wrote:

 


Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the PHSNA
group.

File : /K5ESS/AD8008 amplifier/AD8008 Amplifier for the PHSNA Experimenters Board.pdf
Uploaded by : nothdurftm <k5ess.nothdurft@...>
Description : Describes an add-on amplifier for the Experimenters board. Essentially a clone of the DDS-60 amplifier.

You can access this file at the URL:
https://groups.yahoo.com/neo/groups/PHSNA/files/K5ESS/AD8008%20amplifier/AD8008%20Amplifier%20for%20the%20PHSNA%20Experimenters%20Board.pdf

To learn more about file sharing for your group, please visit:
https://help.yahoo.com/kb/index?page=content&y=PROD_GRPS&locale=en_US&id=SLN15398

Regards,

nothdurftm <k5ess.nothdurft@...>

 

Re: New file uploaded to PHSNA

Marcus Gustafsson
 

Funny,

I've also almost done the same thing. Yesterday I send my AD8008 amplifier board with a modified version of the ALC (http://www.cwtd.org/May_6-2014.html) to OSHpark. I changed the peak detector and added a control pot to the first op amp and removed the second one. The third one is still there.

I intend to use the board with the experimenters board as v2.0 of my homebrew RF generator. However I have modified my DDS board to use differential output with a Mini Circuits T1-1T transformer. Do you use an modified DDS board or not?

My solution lacks your clever mounting solution.

Br
Marcus, SA5PMG

On Thu, Sep 8, 2016 at 5:09 AM, <PHSNA@...> wrote:
 


Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the PHSNA
group.

File : /K5ESS/AD8008 amplifier/AD8008 Amplifier for the PHSNA Experimenters Board.pdf
Uploaded by : nothdurftm <k5ess.nothdurft@...>
Description : Describes an add-on amplifier for the Experimenters board. Essentially a clone of the DDS-60 amplifier.

You can access this file at the URL:
https://groups.yahoo.com/neo/groups/PHSNA/files/K5ESS/AD8008%20amplifier/AD8008%20Amplifier%20for%20the%20PHSNA%20Experimenters%20Board.pdf

To learn more about file sharing for your group, please visit:
https://help.yahoo.com/kb/index?page=content&y=PROD_GRPS&locale=en_US&id=SLN15398

Regards,

nothdurftm <k5ess.nothdurft@...>


New file uploaded to PHSNA

PHSNA@...
 

Hello,


This email message is a notification to let you know that
a file has been uploaded to the Files area of the PHSNA
group.


File : /K5ESS/AD8008 amplifier/AD8008 Amplifier for the PHSNA Experimenters Board.pdf
Uploaded by : nothdurftm <k5ess.nothdurft@...>
Description : Describes an add-on amplifier for the Experimenters board. Essentially a clone of the DDS-60 amplifier.


You can access this file at the URL:
https://groups.yahoo.com/neo/groups/PHSNA/files/K5ESS/AD8008%20amplifier/AD8008%20Amplifier%20for%20the%20PHSNA%20Experimenters%20Board.pdf


To learn more about file sharing for your group, please visit:
https://help.yahoo.com/kb/index?page=content&y=PROD_GRPS&locale=en_US&id=SLN15398


Regards,


nothdurftm <k5ess.nothdurft@...>

Re: Output Impedance?

Asadullah Mir
 

Hi Nick!

 I too was wondering how theS22 is +- 50Ohms.

On the other hand I am wondering why was an MMIC used in the first place. I can get equally good results if I directly use the 9851 output. A match with a 4:1 balun or in my case UNUN does the impedance match.

Any idea why an MMIC was used? I just adds to harmonic and other distortion.

 

I think some more explanation is called for.

I guess you might remember that many moons ago I pasted some pictures of SNA I built from scratch. I was considering posting it to the group but wanted to improve is somewhat and be ready to answer questions regarding the HW/SW.  I could not get around to doing it due to some bit of illness. ( It was all assembly so hard to remember the details)  During this time I decided to learn some embedded C and as an exercise to rewrite the SNA SW in C. I also did not like the slow serial connect to the Graphic LCD ( GLCD!) etc. S0 I decided to use a 3.2 inch GLCD. This one has a 16 bit parallel data interface so the old 32 pin IC would not do and I switched to a more modern C8051F020 from Silicon Labs.

I was looking at the output of the AD9851 and decided that I don't really need the MMIC. I have a few AD9851 boards with the filter built in and decided that a single ended signal take off would do.

I have used a 200 Ohm R on the output of the AD9851 board removed the filter and used a 4:1 Ruthroff UNUN The output is over the top. Enough to do any old testing of networks.

The output level is calculated as follows. ( excluding the attenuation of any built in LP filter. I have removed mine)

The Peak I out is 10mA.  The 200 ohms at the output and the 50 ohms reflected as 200 ohms at the output of the SNA = total 100 Ohms. The 10 mA x 100 ohms gives a peak of 1000 mV and 0.707 V rms output which reduces to .707/2 =353 mV rms at the SNA terminals ( UNUN). This equals +4dBm

Enough for my needs. The out impedance is 50 Ohms. I intend to build a few small external filters for use in different applications. Sweep scan is variable from 480 Hz to 50 MHz. I think the fastest  scan is 300mSec. Slowest is several seconds.

 

I will try upload the pictures and schematic and SW as soon as I am happy with the details. It is written in C except a few fast routines for the GLCD  in Assembly.  I have used no library routines as  all is home brew. and the SW is as efficient as I could make it. This is an 8051 U-controller so some people might not be familiar but it is the best uC  in the world. ( In my view, that is)

I think the real DIY guys should find it interesting.


 73


Azzythehillbilly

Re: Resistor value on the PowerMeter board

Pravin
 

Hi Philippe,
                         R3,R8&R12 should be 6.8 Ohms only ( not K) and R9 should be 51 ohms . I have assembled the board at least an year ago and it works perfectly with these values. Hope it helps. 73
DE (AB9XC)
(Pravin)


On Sep 1, 2016, at 10:15 AM, n5ib@... [PHSNA] <PHSNA@...> wrote:

 

 Hello all, Hello Jim,

I am soldering components on the RF Power Meter board III.

I discovered my bag with 6.8R contains in fact, 6.8K resistors. My question is this one. I was wondering, for the three resistors R3 , R8 and R12, if the value of 6.8 ohms is critical.  Same question for R9 of 51 ohms.
If yes , Jim, how do you explain these values? 

Best regards, Philippe - F4GRT

 

 

Resistor value on the PowerMeter board

Philippe.Creis@...
 

Hello all, Hello Jim,

I am soldering components on the RF Power Meter board III.

I discovered my bag with 6.8R contains in fact, 6.8K resistors. My question is this one. I was wondering, for the three resistors R3 , R8 and R12, if the value of 6.8 ohms is critical.  Same question for R9 of 51 ohms.
If yes , Jim, how do you explain these values? 

Best regards, Philippe - F4GRT

 

Re: Output Impedance?

Nick Kennedy
 

Well, I was following along with your reasoning and it made sense to me. From the diagram of the internals of the MMIC in the data sheet, it appeared the output is taken from the collector(s), so it made sense that the resistance would be determined by the external collector resistor.  But having a high return loss looking in does imply an inherent 50 ohm source resistance. Somehow(?)

The schematic I'm looking at is different.  I need some more versions. This one is Rev 6.06 of May 4, 2014. It does have an ERA-3+, but it has an RFC in series with the 270 ohm biasing resistor, essentially eliminating its effect on Rg. 

And the pi attenuator in this revision has resistances of 82, 93.1, 82 ohms, which will give 50 ohms looking in if there's a source resistance of 50 on the other end.

Oh - I see that it specifies values of 150, 39, 150 as a -6 dB option for the -12 dB attenuator shown.

73-

Nick, WA5BDU

On Sat, Aug 27, 2016 at 12:47 PM, mirasad314@... [PHSNA] <PHSNA@...> wrote:
 

Hi Nick sorry about that I checked my calc with S22=>21db

The impedance calculates to >48 Ohm. Which is great.
Sorry about that.
(  (270 || 50 ||150) +39  || 150)  = 48.61 ohms.  is the correct way.

Thanks
73



Re: Output Impedance?

Asadullah Mir
 

Hi Nick sorry about that I checked my calc with S22=>21db
The impedance calculates to >48 Ohm. Which is great.
Sorry about that.
(  (270 || 50 ||150) +39  || 150)  = 48.61 ohms.  is the correct way.

Thanks
73


Re: Output Impedance?

Asadullah Mir
 

Hi Nick
I was looking at the drawing  by Jim Gianco N51B  and Jerry Haigwood W51H
The output  attenuator is two 150 Ohm and one 39 Ohm R.
The source is ERA-3+  which has a bias resistor of 270 Ohm.
Essentially since the output impedance of the MMIC is rather high the shunt of 270 Ohm prevails so this attenuater has one side fed from source impedance of 270 ohms and looking in from the output side the impedance calculates to 71 Ohm.
this is (270 || 150) +39) || (150) Ohm.

Return loss on output of ERA3 is >quoted at 21db at 1 GHz so if I assume output impedance of 
50 ohms
then (  (270 || 50 ||150) +39  || 150)  = 63 ohms.


I think there is another  output  type too and I think a quick mental calculation showed that one to be 73 Ohm but I will check a post a little later.

 I might be wrong
73

Azzy

( Was AP2AM.  Haven't got new CS yet))

Re: Output Impedance?

Nick Kennedy
 

I get a little confused as to which designation refers to which schematic.  Does the version you are looking at have a transistor amplifier or a MMIC?  Or does it use a DDS-60?  

Following the amplifier, what does the attenuator look like?

I think they were all designed to be close to 50 ohms.

73,

Nick, WA5BDU

On Fri, Aug 26, 2016 at 11:26 PM, mirasad314@... [PHSNA] <PHSNA@...> wrote:
 

Looking at the schematic of PHSNA II it seems that the output impedance is close to 73 ohms rather than 50 Ohms.

Am I right and why so?


73


Azzy


Output Impedance?

Asadullah Mir
 

Looking at the schematic of PHSNA II it seems that the output impedance is close to 73 ohms rather than 50 Ohms.

Am I right and why so?


73


Azzy

Re: My PHSNA building & testing experience

Nick Kennedy
 



On Tue, Aug 23, 2016 at 10:19 PM, rex.vk3pk@... [PHSNA] <PHSNA@...> wrote:
 

Hi all,
I have just completed building &bench testing my PHSNA.  Packaging is still to be done.
I am using a DDS60 & a Mini Pro. & a level detector board by SV1AFN.

I made a couple of small changes.
a) I did not use a 100 Ohm trimpot as I did not have one on hand.   In addition, the output of the AD8307 is very unlikely to exceed +2.5 V (+15dBm), therefor I changed R1 & R2 on the regulator to 510 Ohm's to give me aAVref of 2.534.   The code was changed accordingly. After calibration, this gives a slop of 0.1056 approx  Ie. more counts/dB   That works good.


​Sounds good. I allowed for up to 2.6 V output (+18 dBm) and my slope is 0.0998.​
 


b)I used a SARK110 to do the calibration using the preset levels of -73.-63,-53,-43,33,-23,-13 & -10dBm
   After calibration it is very accurate around the higher levels, but gives an error of about -1.5 dBm at the -73 dBm. level.      Why is this so????


​A guess might be that you are near the noise floor, especially with the detector circuit not in a box yet.​
 


c) After calibration , I adjusted the gain of op-amp 1 on the DDS50 board. to give me an output level of -10dBm.  All good.  I did note that the input into op-amp 1 (190 mV p-p) & the output of op-amp1 (560mV p-p) is quite clean looking (using a Tektronix 100 Mhz. CRO),  however, the output of op-amp2 the output is far from sinusoidal (1024 mV p-p).  Is this normal.  The gain of op-amo 2 is about 4, so I would have expected about 2000 mV p-p and a clean looking sinusoid.   


​That definitely doesn't sound right. I also use a DDS-60 board and my output is a good looking sinusoid.
 


d)  I expect to run my gear of my station supply, which is 13.2V, so the regulator on the PHSNA board gets pretty hot.   So, I added a DC-DC pre-regulator to drop the V+ voltage to about 8.5 volts, which of course will be the Vsupply of the op-amp.   I would not have thought that the op-amp would be saturating at that supply voltage.    In fact, increasing the supply voltage made little difference to the look of the sinusoid.


​The manual for the DDS-60 says supply voltage can be 8 to 16 VDC, so you are in the right range.

73-

Nick, WA5BDU​
 




This may help some constructors.  In the mean time I would welcome comment on the distortion of the
sinusoid in op-amp2  and the level error near the lower calibration point.

Lee VK3PK  


My PHSNA building & testing experience

Lee de Vries
 

Hi all,
I have just completed building &bench testing my PHSNA.  Packaging is still to be done.
I am using a DDS60 & a Mini Pro. & a level detector board by SV1AFN.

I made a couple of small changes.
a) I did not use a 100 Ohm trimpot as I did not have one on hand.   In addition, the output of the AD8307 is very unlikely to exceed +2.5 V (+15dBm), therefor I changed R1 & R2 on the regulator to 510 Ohm's to give me aAVref of 2.534.   The code was changed accordingly. After calibration, this gives a slop of 0.1056 approx  Ie. more counts/dB   That works good.

b)I used a SARK110 to do the calibration using the preset levels of -73.-63,-53,-43,33,-23,-13 & -10dBm
   After calibration it is very accurate around the higher levels, but gives an error of about -1.5 dBm at the -73 dBm. level.      Why is this so????

c) After calibration , I adjusted the gain of op-amp 1 on the DDS50 board. to give me an output level of -10dBm.  All good.  I did note that the input into op-amp 1 (190 mV p-p) & the output of op-amp1 (560mV p-p) is quite clean looking (using a Tektronix 100 Mhz. CRO),  however, the output of op-amp2 the output is far from sinusoidal (1024 mV p-p).  Is this normal.  The gain of op-amo 2 is about 4, so I would have expected about 2000 mV p-p and a clean looking sinusoid.   

d)  I expect to run my gear of my station supply, which is 13.2V, so the regulator on the PHSNA board gets pretty hot.   So, I added a DC-DC pre-regulator to drop the V+ voltage to about 8.5 volts, which of course will be the Vsupply of the op-amp.   I would not have thought that the op-amp would be saturating at that supply voltage.    In fact, increasing the supply voltage made little difference to the look of the sinusoid.



This may help some constructors.  In the mean time I would welcome comment on the distortion of the
sinusoid in op-amp2  and the level error near the lower calibration point.

Lee VK3PK  

Generic Network Analyzer mailing list

 


After it becoming apparent that there was a need for a mailing list dedicated to a generic discussion of network analyzers, I've gone ahead and created one. 

https://groups.io/g/svna

In no means should this be an attempt to demean the hard work of Those who are key to the PHSNA, but rather an effort not to clutter up the PHSNA list with irrelevant traffic. 

Thanks!
Bob

Re: Sweep output debugging

Marcus Gustafsson
 

Hi all,

wanted to share my latest proceedings of my PSHNA build on an experimenters board.
Short recap: I first got MAV-3 instead of ERA-3 MMIC although when I got hold of ERA-3 I never got them to work properly.

So I decided to go with a 2N5109 solution instead, however the output dropped around 5dB over the 1-60MHz span, see below:


So this made me curious on the utilizing the Rset input on the DDS with an ALC so I built the DDS-60 ALC http://www.cwtd.org/May_6-2014.html from the CWTD webpage. And got this result when adjusting the ALC for 0dBm output at 60MHz.

I think I settle for this for now and move on to other projects.

However I'm toying with the idea of skipping major parts of the ALC and letting the Arduino read the AD8307 and control the Rset with LP-filtered PWM output to the MOSFET, or just use a digital potentiometer directly.

Best regards
Marcus, SA5PMG