Date   
Power Meter Build Photos (SOIC)

N5IB
 

I've posted a photo album with the first few pics of the SOIC version power meter under construction. Especially note the detail of the inductor L1.

Jim, N5IB

Power meter J1

Jim Pruitt <wa7duy@...>
 

What are builders using for J1, rf input, for the power meter?  Or are you just hooking the coax directly?  I had wanted to use a SNB connector there but get the impression that most do not use a jack there at all.  I like to use interconnects rather than hooking cables directly and wonder what others do in that situation.
 
Thank you.
 
Jim Pruitt
WA7DUY

Re: BUILDER ALERT!! - SSNA - D1 - ALERT

Michael McShan <n5jky@...>
 

I've just now gotten time to begin with the PHSNA build.  On the ERA-3+ board, the D1 pad is NOT connected to the ground plane.  The fine connecting traces only continue part way to the pad from ground.  I've studied the board under high magnification and confirmed the lack of ground connection with a continuity tester.

FYI,
Mike N5JKY
OK City

On Oct 31, 2013, at 8:22 PM, n5ib@... wrote:

Y'all thank Nick... he found another one... this one's mysterious. The anode end of D1 is clearly connected to the ground plane on the top side. On the bottom side the layout doesn't show a ground plane connection, but the margin around the pad is reduced. Both conditions are in error. The layout file ended up showing BOTH a clearance margin and a filled plane connection. Don't know how that could happen.

Here's the fix...
Connect and solder the left (non-banded) lead of  D1 and the right lead of F1 together as "flying leads", but DO NOT solder them  to the PC pads.  Leave them elevated above the board. If you choose to not use F1 at all, you can just connect D1 from its normal banded-end pad to the left pad of F1, skipping the two middle pads entirely.

Once again, when I get home I'll post a photo.

Jim, N5IB


Re: Power meter J1

Jerry Haigwood
 

Hi Jim,

   The power meter must be built into a shielded box.  The circuit is so sensitive that it picks up stray RF.  Just turning mine on causes the meter to register a power level.  It cannot be built into the same box as the SSNA or things will not function correctly.  Therefore, I used a BNC connector for the RF input.  The power supply is an internal 9V battery to prevent RF from coming in on the DC lines.  It is a good idea to also shield the back of the analog meter.  For DC output, I used Tip jacks.  However, another BNC might be good also.

Jerry W5JH

"building something without experimenting is just solder practice"

 

From: PHSNA@... [mailto:PHSNA@...] On Behalf Of Jim Pruitt
Sent: Tuesday, November 05, 2013 10:02 PM
To: PHSNA@...
Subject: [PHSNA] Power meter J1

 

 

What are builders using for J1, rf input, for the power meter?  Or are you just hooking the coax directly?  I had wanted to use a SNB connector there but get the impression that most do not use a jack there at all.  I like to use interconnects rather than hooking cables directly and wonder what others do in that situation.

 

Thank you.

 

Jim Pruitt

WA7DUY

Scalar Network Analyzer vs Wobbulator

Tom Herbison
 

Hi everyone,


A friend of mine told me about this group, because I have been involved in doing something very similar, and I think maybe it would be useful to exchange ideas.

My project is a Raspberry Pi Wobulator, which is effectively the same as the PHSNA, except it uses a Raspberry Pi, and a rather hastily designed and built buffer amp/detector stage. My project also uses a AD9850 based DDS module to generate the RF, and an "off-the-shelf" ADC module (based on the MCP3424 chip) to measure the response of the circuit under test.

If anyone is interested full details of the Raspberry Pi Wobbulator are on my blog:

www.asliceofraspberrypi.co.uk

The design, construction, software development and testing are all covered if you look back through the blog posts.

... and I've set up a Yahoo group for it as well called "rpiwobbulator"

I hope to develop the Raspberry Pi Wobbulator into a simple plug-in module for the Raspberry Pi.

73 de Tom MI0IOU

Re: BUILDER ALERT!! - SSNA - D1 - ALERT

N5IB
 

I've just now gotten time to begin with the PHSNA build.  On the ERA-3+ board, the D1 pad is NOT connected to the ground plane.  The fine connecting traces only continue part way to the pad from ground.  I've studied the board under high magnification and confirmed the lack of ground connection with a continuity tester.
 
---------snip-----------
 
Mike's right. I just examined my several boards and verified that the pad IS grounded on the top side on the 5109 version but NOT on the ERA version. The little grounding tendrils look like they got started but didn't close the deal. This gets curiouser and curiouser. I'm going to spend a little quality time with a microscope this morning and check other pads that are supposed to be grounded.
 
Given the reduced clearance margin around the pads, the possibility of a solder bridge remains high, and that pad is right on the power bus. So I'd recommend that you still treat it like an extraneous ground and use the fix detailed in the Builder Alert.
 
Jim, N5IB
 
 

Re: Power meter J1

N5IB
 

On Tue, 5 Nov 2013 20:01:30 -0800 "Jim Pruitt" <wa7duy@...> writes:
What are builders using for J1, rf input, for the power meter?  Or are you just hooking the coax directly?  I had wanted to use a SNB connector there but get the impression that most do not use a jack there at all.  I like to use interconnects rather than hooking cables directly and wonder what others do in that situation.
 
-----snip------
 
A short piece of RG174 from the board to a chassis-mounted connector. 
 
Most folks no doubt will use a BNC. If you do be sure to use the kind that grounds the shell with the mounting hardware. There are some that have an insulating sleeve that leaves both terminals floating. Then you have to ground the shield terminal separately, and it's not as RF tight.
 
Notice that there are two grounded pads on either side of the RF input pad, and they have larger diameter holes. My scheme is to tease the braid into two strands to solder on either side. Another, mechanically more secure, method is to fold the braid back over the outer jacket, loop some hookup wire once around and solder the wire to the pads and the braid. I'll take a picture of that to add to the photo shoot.
 
A good quality RCA jack would be OK (It was good enough for Collins Radio, I believe)
I flirted with the temptation to use an SMA, since I have some SMA attenuators, fittings, and terminators with my TAPR/TenTec VNA.
 
Bringing the A/D signal out can be done with another BNC/RCA/SMA. Or as other have suggested, a feed-through capacitor. And as Jerry said, he has success with a pin jack (bypassed at the box wall).
 
Jim, N5IB
 
 
 
 

Re: Power meter J1

William Kimber
 

Thanks for that info, Jim.

I was wondering how it was done, didn't seem to be a pc layout for a socket on the board.  I was waiting for board to arrive to confirm. The toroids I ordered from Diz have arrived. They were sent only a few days before boards were posted.

Any thoughts as to next project?

How about LC meter with different frequencies?  and/or Q meter.  There are most of the basics of them in the Arduino/AD8950 combo.

Cheers
Will
ZL1TAO

----- Original Message -----
From: n5ib@...
Sent: 11/07/13 02:16 AM
To: PHSNA@...
Subject: Re: [PHSNA] Power meter J1

On Tue, 5 Nov 2013 20:01:30 -0800 "Jim Pruitt" <wa7duy@...>
writes:
What are builders using for J1, rf input, for the power meter? Or are
you just hooking the coax directly? I had wanted to use a SNB connector
there but get the impression that most do not use a jack there at all. I
like to use interconnects rather than hooking cables directly and wonder
what others do in that situation.

-----snip------

A short piece of RG174 from the board to a chassis-mounted connector.

Most folks no doubt will use a BNC. If you do be sure to use the kind
that grounds the shell with the mounting hardware. There are some that
have an insulating sleeve that leaves both terminals floating. Then you
have to ground the shield terminal separately, and it's not as RF tight.

Notice that there are two grounded pads on either side of the RF input
pad, and they have larger diameter holes. My scheme is to tease the braid
into two strands to solder on either side. Another, mechanically more
secure, method is to fold the braid back over the outer jacket, loop some
hookup wire once around and solder the wire to the pads and the braid.
I'll take a picture of that to add to the photo shoot.

A good quality RCA jack would be OK (It was good enough for Collins
Radio, I believe)
I flirted with the temptation to use an SMA, since I have some SMA
attenuators, fittings, and terminators with my TAPR/TenTec VNA.

Bringing the A/D signal out can be done with another BNC/RCA/SMA. Or as
other have suggested, a feed-through capacitor. And as Jerry said, he has
success with a pin jack (bypassed at the box wall).

Jim, N5IB

Re: Scalar Network Analyzer vs Wobbulator

Graham <planophore@...>
 


very cool Tom.

I have had a similar thought, in fact there are adapter boards to allow you to use arduino shields on the PI.

<http://www.cooking-hacks.com/documentation/tutorials/raspberry-pi-to-arduino-shields-connection-bridge>

for anyone who might be interested.

While I like the PI I am also a big fan of the BeagleBoard Black, kind of like the PI on steroids. Interestingly there is also an adapter "cape" for the Beableboard and BeagleBoard Black that lets them emulate the GPIO connector of the PI, AB Electronics in the UK



for anyone who might be interested.

This last item brings the compatibility of the PI and the BeagleBone Black closer together and makes them more complimentary than competitors, at least to my way of thinking.

I have two sets of the PHSNA boards and my thinking is I will build one and use on an Arduino as intended and adapt the other for use on a PI or BeagleBone.

I have signed up for your new group and I am now off to have a good thorough read of your blog.

cheers, Graham ve3gtc


On 13-11-06 10:45 AM, asliceofraspberrypi@... wrote:
 

Hi everyone,


A friend of mine told me about this group, because I have been involved in doing something very similar, and I think maybe it would be useful to exchange ideas.

My project is a Raspberry Pi Wobulator, which is effectively the same as the PHSNA, except it uses a Raspberry Pi, and a rather hastily designed and built buffer amp/detector stage. My project also uses a AD9850 based DDS module to generate the RF, and an "off-the-shelf" ADC module (based on the MCP3424 chip) to measure the response of the circuit under test.

If anyone is interested full details of the Raspberry Pi Wobbulator are on my blog:


The design, construction, software development and testing are all covered if you look back through the blog posts.

... and I've set up a Yahoo group for it as well called "rpiwobbulator"

I hope to develop the Raspberry Pi Wobbulator into a simple plug-in module for the Raspberry Pi.

73 de Tom MI0IOU

Re: Power meter J1

Jerry Haigwood
 

Hi Will,

    Jim and I have several products in the pipeline we are working on.  In fact, I tend to jump ahead sometimes and have to be reeled back in.  While we can’t say much about these efforts just yet, we will announce them when they are ready for prime time.  Stick with us and you will have fun building stuff and end up with some useful test equipment/radio gadgets.

Jerry W5JH

"building something without experimenting is just solder practice"

 

From: PHSNA@... [mailto:PHSNA@...] On Behalf Of Will
Sent: Wednesday, November 06, 2013 3:18 PM
To: PHSNA@...
Subject: Re: [PHSNA] Power meter J1

 

 

Thanks for that info, Jim.

I was wondering how it was done, didn't seem to be a pc layout for a socket on the board.  I was waiting for board to arrive to confirm. The toroids I ordered from Diz have arrived. They were sent only a few days before boards were posted.

Any thoughts as to next project?

How about LC meter with different frequencies?  and/or Q meter.  There are most of the basics of them in the Arduino/AD8950 combo.

Cheers
Will
ZL1TAO

> ----- Original Message -----
> From: n5ib@...
> Sent: 11/07/13 02:16 AM
> To: PHSNA@...
> Subject: Re: [PHSNA] Power meter J1
>
> On Tue, 5 Nov 2013 20:01:30 -0800 "Jim Pruitt" <wa7duy@...>
> writes:
> What are builders using for J1, rf input, for the power meter? Or are
> you just hooking the coax directly? I had wanted to use a SNB connector
> there but get the impression that most do not use a jack there at all. I
> like to use interconnects rather than hooking cables directly and wonder
> what others do in that situation.
>
> -----snip------
>
> A short piece of RG174 from the board to a chassis-mounted connector.
>
> Most folks no doubt will use a BNC. If you do be sure to use the kind
> that grounds the shell with the mounting hardware. There are some that
> have an insulating sleeve that leaves both terminals floating. Then you
> have to ground the shield terminal separately, and it's not as RF tight.
>
> Notice that there are two grounded pads on either side of the RF input
> pad, and they have larger diameter holes. My scheme is to tease the braid
> into two strands to solder on either side. Another, mechanically more
> secure, method is to fold the braid back over the outer jacket, loop some
> hookup wire once around and solder the wire to the pads and the braid.
> I'll take a picture of that to add to the photo shoot.
>
> A good quality RCA jack would be OK (It was good enough for Collins
> Radio, I believe)
> I flirted with the temptation to use an SMA, since I have some SMA
> attenuators, fittings, and terminators with my TAPR/TenTec VNA.
>
> Bringing the A/D signal out can be done with another BNC/RCA/SMA. Or as
> other have suggested, a feed-through capacitor. And as Jerry said, he has
> success with a pin jack (bypassed at the box wall).
>
> Jim, N5IB

Re: Scalar Network Analyzer vs Wobbulator

Tony Abbey
 

Hi Graham (and Tom)

I believe I was the friend who pointed Tom in the direction of this group. I have bought a couple of the pcbs off Jim to go with my Pi and am intending to use them with the Chipkit Pi which uses a pic32 and gives the Pi  some Arduino connections. The Pi programs the pic32 and also the GPIO is replicated on the top surface of the Chipkit Pi. So AFAIK you get the best of both worlds together. Since the Chipkit Pi is only around 20 english pounds, it is quite a lot cheaper than that shield from cooking-hacks at 40 euros, and gives quite a lot more flexibility. It also can be used stand-alone once programmed from MPIDE on the Pi. It would be interesting to see what speed the 2 different ADCs can be pushed to. Anyway that's a bit off topic. As soon as I get the boards built I will be taking the best of both sites to use the Pi as a very pretty but cheap network analyser. There's suddenly so much of this its quite difficult to keep up!

73s

Tony - G3OVH



---In phsna@..., <planophore@...> wrote:


very cool Tom.

I have had a similar thought, in fact there are adapter boards to allow you to use arduino shields on the PI.

<http://www.cooking-hacks.com/documentation/tutorials/raspberry-pi-to-arduino-shields-connection-bridge>

for anyone who might be interested.

While I like the PI I am also a big fan of the BeagleBoard Black, kind of like the PI on steroids. Interestingly there is also an adapter "cape" for the Beableboard and BeagleBoard Black that lets them emulate the GPIO connector of the PI, AB Electronics in the UK

<http://www.abelectronics.co.uk/products/15/Breakout-boards/36/Beaglebone-Black-to-Raspberry-Pi-Cape>

for anyone who might be interested.

This last item brings the compatibility of the PI and the BeagleBone Black closer together and makes them more complimentary than competitors, at least to my way of thinking.

I have two sets of the PHSNA boards and my thinking is I will build one and use on an Arduino as intended and adapt the other for use on a PI or BeagleBone.

I have signed up for your new group and I am now off to have a good thorough read of your blog.

cheers, Graham ve3gtc


On 13-11-06 10:45 AM, asliceofraspberrypi@... wrote:
 

Hi everyone,


A friend of mine told me about this group, because I have been involved in doing something very similar, and I think maybe it would be useful to exchange ideas.

My project is a Raspberry Pi Wobulator, which is effectively the same as the PHSNA, except it uses a Raspberry Pi, and a rather hastily designed and built buffer amp/detector stage. My project also uses a AD9850 based DDS module to generate the RF, and an "off-the-shelf" ADC module (based on the MCP3424 chip) to measure the response of the circuit under test.

If anyone is interested full details of the Raspberry Pi Wobbulator are on my blog:


The design, construction, software development and testing are all covered if you look back through the blog posts.

... and I've set up a Yahoo group for it as well called "rpiwobbulator"

I hope to develop the Raspberry Pi Wobbulator into a simple plug-in module for the Raspberry Pi.

73 de Tom MI0IOU

Re: Scalar Network Analyzer vs Wobbulator

Nick Kennedy
 

I also did a version of the PHSNA with the Raspberry Pi.  I'd had a PIC 16F88 board interfacing with the W7ZOI / W7PUA log power meter for a number of years and then got the PI and decided to get it to talk via serial link to the PIC and create a date file of dBm versus frequency to plot on the PC. 

Oh yeah, the PIC was also controlling a NJQRP DDS30 / DDS60 signal generator of course.  Works very well, but I hope this new version will possibly work even better as I'm going to shield things better, not use an analog meter, etc.

If I'd been starting from scratch I probably would have omitted the PIC and just had the PI do everything, although I'd have needed to add an ADC chip to it.


73-


Nick, WA5BDU

Unfiltered Output from DDS Module

N5IB
 

Threw caution to the winds and hacked a DDS module this evening. Haven't given it a full checkout yet, since I haven't finished my new SSNA. There's been a PDF file posted for a while in the files section with an annotated photo of what needs to be removed.

Posted a new photo album showing the before and after. I made a little fixture by hammering a piece of #12 wire flat then filing a notch in the end that fits across the SMT devices. Wrapped the wire around my soldering iron tip and crimped it with pliers. It was very easy to heat both sides of the part and lift it with tweezers.

I'll update when I get a chance to test it well. That has to wait until I finish a SSNA board with its LPF.

Caveat molitor...

Jim, N5IB

Re: Unfiltered Output from DDS Module

Nick Kennedy
 

I bypassed the internal filter last night too.  I have two solder irons and put a tip on each side, then lift.  Sometimes the part goes into the 4th dimension and sometimes it sticks to the iron and I tap it with the other one to knock it off.  Either way, it's gone,.
 
I used the photo instructions from site.  Nicely done.  I installed the jumper with a piece of wire from a ribbon cable.
 
Now to do the transformer and amplifier.
 
73-
 
Nick, WA5BDU

Re: Unfiltered Output from DDS Module

W0PWE
 

I performed a successful filter-ectomy and bypass tonight as well. Output stage is all put together but my output is low. With 50 ohm load I would expect 70.7mv RMS for -10dBm but I'm only getting about 15mv.


Input to the 12dB pad is 57mv so the pad is OK anyway. I'm seeing about 86mv at the input to the 10db pad. Input to the 3db pad is 125mv and output from the DDS card is 245mv all in RMS. All readings at 10MHz. Oh yea and if it isn't obvious I'm building the 2N5109 version. 


I will go back to the bench and check everything for a third time but if you guys get yours put together maybe you could take a few readings that I can compare to. Thanks - Jerry - W0PWE



---In phsna@..., <kennnick@...> wrote:

I bypassed the internal filter last night too.  I have two solder irons and put a tip on each side, then lift.  Sometimes the part goes into the 4th dimension and sometimes it sticks to the iron and I tap it with the other one to knock it off.  Either way, it's gone,.
 
I used the photo instructions from site.  Nicely done.  I installed the jumper with a piece of wire from a ribbon cable.
 
Now to do the transformer and amplifier.
 
73-
 
Nick, WA5BDU

BUILDER ALERT !! SSNA - UNO USB PORT - ALERT !

N5IB
 

Don reports a possible issue with clearance above the USB connector on the UNO.
Pins at the end of the header connector that accepts the DDS module can touch the shell of the USB connector. He put a bit of tape on the top of the USB shell.

I'm going to suggest a slight change  in how you mount the headers that will give  a mm or so extra clearance, and should eliminate the need for tape. This will be most easily accomplished if the male header strips that connect to the UNO are the VERY FIRST PARTS installed on the SSNA board. No board modification will be required.

Look in the files section for an udated Builder Alert PDF file (rev08NOV2013)

Jim, N5IB

Re: Unfiltered Output from DDS Module

N5IB
 

 

---In PHSNA@..., <j.b.hall@...> wrote:

I performed a successful filter-ectomy and bypass tonight as well. Output stage is all put together but my output is low. With 50 ohm load I would expect 70.7mv RMS for -10dBm but I'm only getting about 15mv.


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


Double check the two bifilar transformers. I've been behind my time line. I wanted to get some photos out to show the winding configuration. The footprint for each transformer has one square pad and two round ones. The square pad is where the two leads from the joined windings go. The "bottom of one winding joins the "top" of the other.


I'll try to get crackin' on those photos of the transformers.


Jim, N5IB





Re: BUILDER ALERT !! SSNA - UNO USB PORT - ALERT !

Michael McShan <n5jky@...>
 

I always used tape on the USB shell and made sure the pins of the header were trimmed short.  Mine seem to have sufficient clearance.  You can also not push the board all of the way down and leave 1-2 mm clearance.  This is not an uncommon problem with Arduino shields.

Mike N5JKY

On Nov 8, 2013, at 8:29 AM, n5ib@... wrote:

Don reports a possible issue with clearance above the USB connector on the UNO.
Pins at the end of the header connector that accepts the DDS module can touch the shell of the USB connector. He put a bit of tape on the top of the USB shell.

I'm going to suggest a slight change  in how you mount the headers that will give  a mm or so extra clearance, and should eliminate the need for tape. This will be most easily accomplished if the male header strips that connect to the UNO are the VERY FIRST PARTS installed on the SSNA board. No board modification will be required.

Look in the files section for an udated Builder Alert PDF file (rev08NOV2013)

Jim, N5IB


Winding and installing bilfilar transformer T1 and T2

N5IB
 

Just posted a pictorial and description of how to wind and install the transformers. Look in the Files section for a PDF.

Jim, N5IB

Re: Winding and installing bilfilar transformer T1 and T2

Michael McShan <n5jky@...>
 

One comment about winding the toroids.  Be sure to study the PC board layout for the inductors before you start winding so that the leads begin and end on the right side (says one who had to re-wind one toroid this morning).

Mike N5JKY

On Nov 8, 2013, at 10:45 AM, n5ib@... wrote:

Just posted a pictorial and description of how to wind and install the transformers. Look in the Files section for a PDF.

Jim, N5IB