Date   

Re: Building the power meter

Garey Barrell
 

OH, Now I understand. The schematic shows it over by Pin 6 of U1. On the board it's over by the A/D connector.

Better a feedthrough cap at the box wall.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

Garey Barrell wrote:


Jim -

I don't understand. There no pads for C5. According to the schematic C5 is in parallel with C4 (same value) and
they're only a fraction of an inch apart?? No connector involved. If you really want 0.2, why not just put a 0.22 in C4??

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

n5ib@... wrote:



Good catch, Don.
I updated the BOM to add C5. You probably would want to parallel C5 with another capacitor (.1 or .01) right at the
connector body itself.
Jim, N5IB
On Sun, 3 Nov 2013 07:49:29 -0800 (PST) Don Lewis <dlewis11193@... <mailto:dlewis11193@...>> writes:

Jim, Please, ...Is C5 left off the Power Meter BOB? (.1uf)?
Thank you, -Don


Re: Building the power meter

Garey Barrell
 

Jim -

I don't understand. There no pads for C5. According to the schematic C5 is in parallel with C4 (same value) and they're only a fraction of an inch apart?? No connector involved. If you really want 0.2, why not just put a 0.22 in C4??

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

n5ib@... wrote:




Good catch, Don.
I updated the BOM to add C5. You probably would want to parallel C5 with another capacitor (.1 or .01) right at the connector body itself.
Jim, N5IB
On Sun, 3 Nov 2013 07:49:29 -0800 (PST) Don Lewis <dlewis11193@... <mailto:dlewis11193@...>> writes:

Jim, Please, ...Is C5 left off the Power Meter BOB? (.1uf)?
Thank you, -Don


Re: Building the power meter

N5IB
 


Good catch, Don.
 
I updated the BOM to add C5. You probably would want to parallel C5 with another capacitor (.1 or .01) right at the connector body itself.
 
Jim, N5IB
 
 
 
On Sun, 3 Nov 2013 07:49:29 -0800 (PST) Don Lewis <dlewis11193@...> writes:

Jim, Please, ...Is C5 left off the Power Meter BOB?   (.1uf)?
Thank you, -Don


Re: Building the power meter

Don Lewis
 

 
Jim, Please, ...Is C5 left off the Power Meter BOB?   (.1uf)?
 
 
Thank you, -Don

From: "n5ib@..."
To: PHSNA@...
Sent: Thursday, October 31, 2013 7:16 AM
Subject: [PHSNA] Building the power meter

 
One important thing to remember about the AD8307 rf detector is that it is VERY sensitive. It will measure down around -70 dBm, which is one ten-billionth of a watt! Or 71 millionths of a volt.

So you have to take extra special care to keep stray rf away from it. First and foremost is a VERY well shielded enclosure. One of those cast aluminum boxes is probably best, but the "minibox" style will be OK if the halves fit tightly together. I used an "Altoids tin on steroids" with a tight fitting slip-on lid, from PaperMart.com.

Anything coming into the box (other than the signal, of course) needs to be well bypassed for rf, hence the posts you&apos;ve read recently about feedthru capacitors.
Best bet is to keep the power supply (battery) inside the box. Then the only other penetrations are for input signal and DC out to the Arduino. You can probably get away without a feedthru cap for the dc output if you use an rf type connector and bypass it very close to the box wall with a couple of caps, maybe a 0.001 uF in parallel with a 0.1 uF There is another bypass cap on the PC board, but don&apos;t rely on that one.

If you use an analog meter with yours, the meter represents a big hole in the box (unless its one of those great mil surplus full-metal-jacket types). For a plastic meter, maybe some copper foil tape or real aluminum foil duct tape can be applied to the back to cover most of the gaps.

Jim, N5IB



Re: Atta Boys

Gene Dorcas <gene@...>
 

I ordered my Funduino about the same time. I don’t know if it was from the same company but I received an email from them saying there would be a delay since they were out-of-stock.

 

Gene, W5DOR

 

From: PHSNA@... [mailto:PHSNA@...] On Behalf Of Jay
Sent: Saturday, November 02, 2013 9:07 PM
To: PHSNA@...
Subject: [PHSNA] Atta Boys

 

 

Fellow builders,

Most of the time, I fail to recognize the folks
that support us in our building efforts. These
are the companies that provide excellent service
and response to our parts requests. I'd like to
give an "Atta Boy" to:

Chipworld on ebay I had received 2 of the
AD9850 modules within a week of ordering.
KitsandParts Diz and his XYL had my order in my
hands in a matter of days.
AllElectronics My order for meters took 2 days.

As always, I have no connection with any of these
companies, other than being an extremely
satisfied customer.

I am still waiting on my Funduino to arrive. It
supposedly has left the USPS in Chicago and is
enroute to parts unknown. It is interesting that
Chipworld could get my modules to me in less than
a week, and my Funduino has not been heard from.
Both orders were placed within a few minutes of
each other.

Happy building!!!
Jay
AJ4AY
Mobile, AL


Atta Boys

Jay Henson
 

Fellow builders,

Most of the time, I fail to recognize the folks
that support us in our building efforts. These
are the companies that provide excellent service
and response to our parts requests. I'd like to
give an "Atta Boy" to:

Chipworld on ebay I had received 2 of the
AD9850 modules within a week of ordering.
KitsandParts Diz and his XYL had my order in my
hands in a matter of days.
AllElectronics My order for meters took 2 days.

As always, I have no connection with any of these
companies, other than being an extremely
satisfied customer.

I am still waiting on my Funduino to arrive. It
supposedly has left the USPS in Chicago and is
enroute to parts unknown. It is interesting that
Chipworld could get my modules to me in less than
a week, and my Funduino has not been heard from.
Both orders were placed within a few minutes of
each other.

Happy building!!!
Jay
AJ4AY
Mobile, AL


Builder Alerts - summary and photos posted

N5IB
 

Look in the files section for a PDF file containing the two known builder alerts for the SSNA PC boards.

Jim, N5IB


New Test File

Jerry Haigwood
 

Hi Guys and Gals,

     I have created a test file that outputs a 10 MHz signal.  The file is in the Files Section of this Yahoo group.  It is titled “Test_10_MHz_Signal.ino.”  You can use this file as a check out file once you get the SSNA board built.  This file can also be used to calibrate the DDS signal.  On line 38 of this file is a denominator of 125000000.  You can vary this value until the 10 MHz signal is zero beat with WWV.  If you have an accurate frequency counter, you can use it to measure the output of the 10 MHz signal for calibration.

Jerry W5JH

"building something without experimenting is just solder practice"

 


Re: Some initial testing & success

N5IB
 

 

---In PHSNA@..., <phsna@...> wrote:
The left two legs of the LM317L being crossed and the grounded end of D1 are the only issues I've found thus far.  It wasn't hard to scratch off the 4 skinny foils connecting the D1 anode pad to ground, which I did since my diode was already soldered in, although the in-line connection would be fine too.

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

Thanks for the report Nick. Glad to hear my SNAFUs didn't hold you up too much  :^))

If any of y'all opt for Nick's method to deal with D1, be sure to do a continuity test and make sure that leftmost lead of D1 is NOT grounded. The bottom side foil does not have a ground trace, but the clear margin around the pad was significantly reduced for some reason, so the possibility of a solder bridge on the bottom is increased.
Use an ohmmeter and test.

I'm back at the home QTH, so before too long will post some errata and photos.

Whoever is the first "lab rat" to complete a power meter, please post :^))

Jim, N5IB


Some initial testing & success

Nick Kennedy
 

OK, I got as far as getting the DDS to produce some  output,  so that's pretty good.


The left two legs of the LM317L being crossed and the grounded end of D1 are the only issues I've found thus far.  It wasn't hard to scratch off the 4 skinny foils connecting the D1 anode pad to ground, which I did since my diode was already soldered in, although the in-line connection would be fine too.

After I got the voltages looking good, I plugged in the Arduino board.  I'd previously loaded it with a "sketch" that varies the voltage on a pin using PWM, so I checked that pin with my scope and saw that the Arduino was running OK. Step 1 good.

Next I downloaded the test program from the site and managed to load it into the board. I think it would be good if this program would start up by programming the DDS to a known frequency output, even before any serial I/O with the user occurs. Or one of us can make a separate sketch to do that.

I hadn't tried the recommended Term232 before, but I got it running.  First issue was that my laptop installed the Arduino's USB/RS232 converter as COM11 and Term232 only goes through COM8.  I managed to use the device manager to change the port number.

I established serial communications between the laptop using Term232 and the Arduino and saw the opening screen.  One useful thing is to configure Term232 to echo typed characters locally, or you're typing blind.

I chose generator mode and asked for 7000 kHz (7 MHz).  I knew the DDS was at least powered up because an LED was  ON.  I tuned the station receiver to 7.000 MHz but didn't hear anything.  Maybe it needs a bit of an antenna.  I clipped short test leads to the two pins of J4, which is the alternate wave output.  Still no sounds.

There were a couple things I had to correct.  See the view of the DDS board in DDS image.PNG on the site.  The two pin header at the upper left had no shorting jumper -- it needs one to put the board into serial programming mode. 

Still no sound.  Experimentally I removed the jumper from near the upper right corner that says to produce square waves when connected and then I heard the sound in the receiver.  Yea! That's always fun.

At this time, the two programming jumpers at the left are installed and the one at the upper right is not.

I was able to move the frequency up and down with the 8 & 2 keys.  I gathered from the menu that arrow up and down might be an alternative way of doing this, but only the number keys worked for me.

BTW, after making some changes or needing to start over, press the RESET button which is on the corner of the board right next to the USB connector.

The DDS frequency is about 90 Hz higher than shown in my receiver, before calibration.  So pretty close.  Didn't need to tune around to find it.

I haven't yet built the filter and amplifier section.  That's next.

73-

Nick, WA5BDU



BUILDER ALERT!! - SSNA - D1 - ALERT

N5IB
 

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: Parts and Request

Jerry Haigwood
 

Hi Jay,

     You guys are blazing the trail here.  My power meter was built ugly/manhattan style.  I am not sure how Jim built his.  So, my pictures probably won’t help very much.  I would recommend soldering the 8307 IC directly to the PCB.  If built right, this power meter should be useful up to 500 MHz.  You should be using UHF building techniques.  That means short leads and no sockets on the 8307.

Jerry W5JH

"building something without experimenting is just solder practice"

 

From: PHSNA@... [mailto:PHSNA@...] On Behalf Of Jay
Sent: Thursday, October 31, 2013 3:21 PM
To: PHSNA@...
Subject: [PHSNA] Parts and Request

 

 

Fellow builders,

P2, P3 & P4 on the power meter board are two pin
male headers with no polarizing tabs. I am
planning to get a female header Mouser
#517-850-01-19 (19 female positions). With a
Dremel tool or good knife, I can cut 2 pins away
from the header and create J3, likewise J4. One
pin is sacrificed in the process, but there are a
lot of female pins left to work with. There is
very little cost difference between the female
header and the shells and pins. YMMV!

I have a request for Jim and/or Jerry, and anyone
that has finished their power meter and/or the
SNA. Post pictures of the final results,
particularly the power meter insides.

Vy 73 to all,
Jay
AJ4AY
Mobile, AL


DIP socket etc.

Ted KX4OM
 

Okay, ignore those links to my web site. I added some pertinent photos to the Photos section of the group showing the construction technique of my original meter (plus I changed my account for the group to show my call.)

73,
Ted, KX4OM


Re: Question on the power meter board ...

Ted KX4OM
 

The local Ace Hardware stores here in Georgia have brass and tin stock. I prefer to use tin as it is easier to bend and solder. I've made a few shielded compartments in rigs using PCB stock for the walls and floor, and then soldering on a "tin roof" with edges that overlap the walls. I did that for the VFO compartment of a 40m receiver based on Dave Benson's SW-40+ transceiver. It was easy to make adjustments by unsoldering three edges and bending the tin up 90 degrees.This link shows that VFO with the tin and PCB combination.

http://www.kx4om.com/Projects/40m%20Superhet/40m_superhet.html

73,
Ted, KX4OM

--- In PHSNA@..., <n5ib@...> wrote:

Yes, That was the intent. To allow you do do at least some shielding around the front end components. I have one in the works at the home QTH and will post photos when I'm done, but that will be at least a week.

I had built a prototype (homemade PCB) without shielding and it workes fine, but I thought... maybe more is better :^))



I have some 1/32" PCB stock I was going to try, if that was unmanageable then brass shim stock could be bent into sort of a quonset hut affair top and bottom.



Jim, N5IB


Re: AD8307 socket

Ted KX4OM
 

I not only used a DIP socket for the AS8307 in my build some years back, I soldered the socket to a homemade "Manhattan" board which I glued to the main board of the AD8307. I enclosed that whole part of the circuit in a shielded copper clad homebrew box with feedthru caps for power. That way, I didn't have to worry about a completely shielded unit for the log power meter. I don't use it (so far) above 30MHz, and it seems to be fine. As Jim says, soldering the chip directly to the board is better practice.

You can see my build of the original meter on my site at www.kx4om.com.

73, Ted KX4OM

--- In PHSNA@..., <dtjay@...> wrote:

Is it ok to put the AD8307 in a socket or better to solder it in?

tnx
John
K3YJP


BUILDER ALERT!! - SSNA - LM317L - ALERT !!

N5IB
 

Nick found a layout error.
Jerry caught my original mistake back on the prototype.
I fixed it, and then it snuck back in, dagnabbit.
This applies to both the 5109 and the ERA versions of the SSNA
*****************
You will need to criss-cross the ADJ and OUT leads of the LM317L.
*****************
With the flat of the package facing as drawn on the silk screen, the lead closest to U1 IS CORRECT.
The middle lead and the lead closest to the AREF pin need to be crossed.

When I get back home in a couple of days I'll take a photo and post it. If any of you want to post a photo right away, go ahead.

Jim, N5IB


Parts and Request

Jay Henson
 

Fellow builders,

P2, P3 & P4 on the power meter board are two pin
male headers with no polarizing tabs. I am
planning to get a female header Mouser
#517-850-01-19 (19 female positions). With a
Dremel tool or good knife, I can cut 2 pins away
from the header and create J3, likewise J4. One
pin is sacrificed in the process, but there are a
lot of female pins left to work with. There is
very little cost difference between the female
header and the shells and pins. YMMV!

I have a request for Jim and/or Jerry, and anyone
that has finished their power meter and/or the
SNA. Post pictures of the final results,
particularly the power meter insides.

Vy 73 to all,
Jay
AJ4AY
Mobile, AL


LM317L pinout?

Nick Kennedy
 

The board is laid out for the LM317L pinout as being IN-ADJ-OUT from L to R.  The data sheet I'm using shows it is ADJ-OUT-IN.  Is there more than one pinout available for this regulator?  Or am I just looking at it wrong?  Wouldn't be the first time.


73/TU,

Nick, WA5BDU


Re: AD8307 socket

N5IB
 

 



---In PHSNA@..., <phsna@...> wrote:
Is it ok to put the AD8307 in a socket or better to solder it in?

I'd recommend no socket. Keep everything short and sweet in the rf front end.

But that being said, the prototype I did on the homemade PCB did use a socket and did not seem to suffer. It is an expensive chip compared to many we use (unless you scored a free sample from AD) so I understand the temptation to socket it. Go ahead and socket the op amp, since everything around it is nearly dc.

The SMT version has been rumoured to perform better, and that may be partly because of the nice short lead arrangement.

Jim, N5IB


AD8307 socket

 

Is it ok to put the AD8307 in a socket or better to solder it in?

tnx
John
K3YJP