Monday, July 23, 2012

TCVCXO PCBs Received

I just received another set of boards from

This time they are my corrected TCVCXO boards. The board will provide a Temperature Compensated, Processor I2C Corrected, 10MHz Master Clock for the Propeller Microcontroller (see previous post).

Top Side
Back Side
This board is 0.34 x 0.5 inches with 0603 components. If you click on the microscope photos above, the resulting image will be about 400 times actual size.

 I should have it loaded with parts within the next few days.


A Friends Voice From the Past

A voice heard from 45 years ago.

Saturday I was reprogramming my Prop Receiver with new User Interface (UI) Code. The previous UI code did not provide an intuitive controls for the BFO and VFO Frequencies with the two knobs that are available. It had previously been a rush-job, just to have something to demonstrate as a working receiver at Salmoncon (which was the previous weekend).

Prop Receiver on the Left

Now, to test and try the new UI code, I connected the Prop Receiver to an Antenna, a 250 foot long wire that I previously posted a blog. For the test I programmed the default Frequency to 20 meters. With a little twisting of knobs I found the sweet spot for the BFO and was tuning across the band. I heard several stations on CW, and then higher up the band on SSB. I tuned across a signal and recognized a very distinctive friends voice from my past, of 45 years ago, Randy - KH6IB.

I switch the antenna over to my IC-730 and tuned up on near the Frequency that I thought was where I heard Randy on the Prop Receiver. My Prop Receiver Frequency was un-calibrated and therefore I had to do a little searching on the IC-730.  But on 14.227MHz his distinctive voice was heard again. I sent BREAK and waited for his QSO to end. Randy asked for the Breakers, I jumped in with my call - "Whiskey Alpha Zero Uniform Whiskey Hotel". Randy came back with, "the Whiskey station please try again". We made contact, and had a short reminiscing QSO before the band went south. This was my first real on-the-air QSO with Randy.

Actually, Several years ago, Randy and I chatted on EchoLink.

In 1967, while in the Navy, Randy and I were attending the Precision Measurement Equipment Laboratory (PMEL) school at Lowry Air Force Base near Denver CO. I think Randy was a little ahead of me in the six month training schedule, but we meet because of his Ham Radio. A few weeks earlier his Mother had sent him his SB-101 transceiver to use in his barracks. Being a previous Novice, I gravitated to the sound of CW and SSB coming from his room. We spent the rest of our tour/training time at Lowery; walking to-and-from the chow hall and class, chatting about Ham Radio, and his race cars. After graduation and leaving Lowry, I was sent to the East Coast to a Submarine Tender and I think Randy was sent to the West Coast and Vet Nam - I never saw Randy again.

Here I am Aboard The Submarine Tender
 H. W. Gilmore AS-16
So for me, Ham Radio has again brought a voice and a friend from the past.

Oh, The Prop Receiver seems to work well, even though I have not checked the receiver sensitivity yet. And, I have not tried to energize the Band Switch Relay and then try the low bands and lower sideband (below the 11MHz IF).


Tuesday, July 17, 2012

Salmoncon 2012

Salmoncon 2012 has come and gone. The weather was overcast and a little light rain, but no one seemed to notice.

There were three days of great presentations, demonstrations and wonderful Ham Radio conversations.
One of many Technical Conversations
On Friday the SOTA group activated Little Mt Si.

The main events were on Saturday and Sunday, but many of the die-hard's were on site Thursday through Monday. I think the sign-in-sheet only listed about 60 attendees, but I think there were more.
Saturday Morning Parking

The long distant traveler was John - N0AR and his family from Minnesota.
John's Family
The following are only excerpts from Salmoncon, there are just too much to report and I may have some events out of order as reported here.

Jeff and I were up early on Saturday to set out the Fox for the Fox Hunt (see below).
Early Saturday, 
Jeff with the Fox Hanging Stick
We had planned to set them out late Firday night, but too many late activities prevented the effort.

Saturday Morning was started with Curt - WR5J cooking a wonderful breakfast (with a little help from John's Boys). I remembered Curt's breakfast from last year, so I made sure I was up on time.
Curt Making Breakfast
About Ready to Eat
The Crew is Ready to Eat
After Breakfast and Introductions, the first event was the Fox Hunt - thanks to Jeff - KO7M. The instruction for the Fox Hunt were deliberately vague as scoring was based on the Factoids Collected during the hunt. The hunters ware also instructed to "Expect the Un-expected" for the hunt.
Bob and Ben Team Up for The Fox Hunt
DF Loop and Ready to Hunt
Jacob with the KX3 and a Wire Loop
The only detail that was provided; was the approximate frequency used by the Fox - about 10.1395MHz. It as also shown that the Fox can be heard on simple one wire loop antenna and portable radio (the KX3 and FT-817 receivers were a very good choices).
Doug, Alan, and Jacob
Trying to get the First Fix on the FOX?
After about a half hour, many hunters realized there were more than one Fox, in fact there were three, each sending it's own CW ID in coordinated time sequence with the other Foxes. Jeff and I created the Foxes using the Propeller Microprocessor, therefore anything and everything devious was done in software. Other details of the hunt will be left out of this blog, to encourage others to attend next year.
Wayne and Sandy Getting Their First FIX
A Fox Hunting with one Radio is like Canoeing.
Later that day, awards were given to the Hunters with the most facts about the Hunt.

After the Fox Hunt, Jeff - K07M, gave a presentation on the Propeller Microprocessor showing its architecture and how it could be used in Amateur Radio - the Fox Hunt was a good example.
Jeff - Getting Ready for Presentation
Jeff's - Propeller Presentation
Lyle - KK7P and Rich - AC7MA presented an update on the KX3, Note with at least three, the KX3 was well represented in the Fox Hunt.
Lyle and his KX3 on the Fox Hunt
Bob - AD7PB, gave a presentation on his Homebrew Mag Loops and had several examples for demonstrations. He demonstrated how tuning was as simple twist of the knob near the center hand-hold of the loop. He went through the design process for the loop, picking the dimensions for a particular group of bands. I enjoyed the insight, and now plan to create a Mag Loop for my use.
Bob and His Homebrew Mag Loop
Charlie - N7KN and Roger - K7RXV, gave a presentation on building Tennis Ball Launcher and a demonstration/shootoff followed.
Charlie and Roger - Tennis Ball Launchers

After the Shoot Out
Rich, Roger, myself and Tess
Tess can not wait for the next shot

Jeremy - NH6Z gave a interesting presentation and update on the Open SDR project.
Jeremy Demos Open SDR
There were other presentations, many more short demonstrations and technical discussions that continued through out the weekend.

With John - N0AR's three boys attending Salmoncon, Tess was in "Boy Heaven". She had lots of Ball and Play Time.
Joe, Tess and a Ball
What could be better!
Play Hard, . . . then Rest Hard,
Tess Is In Little Boy Heaven!

Now, . . . only 364 more days until next Salmoncon!


Tuesday, July 10, 2012

Prop Controlled Receiver - Success

In the past I have blogged about the QRSS, WSPR, and OPERA Beacons that I have created with the Propeller Microprocessor (Prop). The Processor generates the RF signal that is passed through a LowPass Filter to remove Harmonic, and then connected to an Antenna. For some experiments a Homebrew Power amplifier was used to increase the processor generated RF signal from 7 milliwatts to 150 milliwatts. I have received many reports (or Spots) from many stations around the world. I think the farthest was from Australia at about 12,000 miles. I consider my Propeller Beacon a fun and very successful project.

And Now,  . . .

I have been playing with the idea and trying to receive signals with the Propeller. A simple direct conversion receiver using a SA612 mixer would require a Local Oscillator at the received frequency. The Propeller can generate RF frequencies from; 0 to 128MHz, with an amplitude of about 3Volts Peak-to-Peak. Which is a little more than needed by the SA612, but it can be attenuated with simple resisters if needed.

My original plan was to construct a simple direct conversion receiver daughter board for the Prop. But, Jeff - KO7M pointed out that the N3ZI Double Conversion Receiver using two of the same SA612 chips, was available as a kit (this was actually several months ago). I put the kit on order, and it has been setting around waiting for my User Interface (UI) project to be completed (or at least working). The receiver kit needs two RF signals, one for the VFO and one for the BFO (about 11.055MHz). The BFO is normally supplied by a Crystal. I plan to replace the BFO Crystal with another RF signal from the Prop.

For the High Band (above IF) and Upper Side Band, the injected frequency is the BFO frequency (IF) plus the intended (displayed) receive frequency. For example, for USB: the VFO = BFO + Received Freq, for LSB: VFO = BFO - Received Freq.

For the Low Band (below IF) and Lower Side Band, the injected frequency is the BFO frequency (IF) minus the intended (displayed) receive frequency. For example, for USB: VFO = BFO - Received Freq, for LSB: the VFO = BFO + Received Freq. (I think that is correct?)

Obvious the VFO should be adjustable so the receiver can be tuned to the desired received frequency. But, maybe not obvious, is that small adjustment of the BFO can be used to adjust the band width of the received signal. In both cases a handy way of adjusting either or both frequencies is necessary. And that is where my UI comes in, it has knobs and buttons that can be programmed to control two Prop RF signals which will be supplied to the receiver.

Note: Sadly, I think the N3ZI Receiver Kit is no longer available.

Prop Controlled Receiver - Left
Prop Transmitter - Right
Today's Success !!

I have one Prop running ko7m's Keyer Program and another controlling the double conversion receiver. The test distant between the transmitter and receiver was only about 12 feet, but it works !

With the receiver connected to an antenna, I have received other signals with this set up; WWV and other Amateur stations.

The Receiver is mounted under the Prop on the left, the two SMA coax cables connect the VFO and BFO. Two of the corner holes of the receiver match the hole pattern of the Prop board (nice). The Keyer Transmitter is on the Right.

This weekend at Salmoncon, Jeff and I will demonstrate some of our Prop projects. Maybe, we will have time attempt to do real QRP DX'ing with our Props.

Many more experiments and improvements are planned.

For now, . . . it all just, fun and games, with the Prop !!


Wednesday, July 4, 2012

Under the Microscope

Cutting Under the Microscope
I think I have past a personal milestone on my forever quest to build ever smaller projects.

I noted the passing, when I realized it was much easier to cut-out my paper models of a new small PCB under the microscope.

The scissors look like huge shears under the microscope.

This new TCVCXO board is required due to pin mounting hole miss-alignment (my error) on the previous PCB. This time I am using the cut-out TO MAKE SURE it is correct.

Alignment Conformation
A straight pin pushed through the holes ensure hole alignment. The fifth pin is at an odd, non-standard location and has caused me trouble.

Note: for scaling, the protoboard holes are 1.0mm in diameter and on 1/10 inch centers.

The paper cut-out now confirms the new PCB layout

This paper image is the same that I would use to create a Homebrew Toner Transfer PCB (if that was my goal) but for this board I will be using the service of (again).

The five Crystal Pin Sockets (see previous post) are installed and ready to receive pins from the new TCVCXO board.

Pin-Sockets Installed
I took this pin-move opportunity to shrink the TCVCXO board even smaller, it is now only 0.34 X 0.5 inches, which is smaller by about 25 percent.

I do enjoy making projects as small as my abilities and eyes allow.

The two bottom Pin Sockets supply I2C Signals (jumper wires will be added on the back side), the next two Pin Sockets supply GND and 3.3Volts (the Propeller board already has them connect to VDD and VSS), and then the new TCVCXO board supplies its 10MHz output to the single Pin Socket (upper Center) to the Processor Crystal Input. The Processor multiplies its input by eight, to supply its internal required 80MHz clock frequency.

The sixth pin socket shown in the photo (upper right) is one of the the standard 5MHz Crystal sockets, which will not be used with the 10MHz TCVCXO board installed.

This is a proven circuit, I am just trying to get the final implementation right.


Tuesday, July 3, 2012

Part Quest

Crystal Pin Sockets
Several days ago, I received my order for Crystal Pin Sockets (see previous post) and have not had time to use them yet. I have been busy working on some projects, and trying to get ready for Salmoncon.

The smaller Crystal Pin Sockets will be used in Propeller Projects, Homebrew PCB Projects, and the larger (longer) ones will be used in Manhattan and Ugly Style Projects. The 2-Pin Header and the single Machined Pin/Post are shown for scale. The crystal leads will be cut to length as necessary for the project.

The Stash
These are by far the smallest mechanical devices in my bag of project parts. And, they are probably the most expensive per weight, at $0.20 each they are several times the price of GOLD. But, . . I only need a few :-)

The first photos shows several styles and sizes that I have obtained. The smaller ones are the style that I had in mind for my initial Part Quest, they fit into 1mm plated holes, and do not protrude much beyond on the backside of the PCB. Others were some initial trial parts.