Monday, December 28, 2009

Code Practices

I have been planning to do more code practice and I want to buy a KX1 or similar transceiver. But I am very rusty, and for me, my code speed does not justify the investment. I would be embarrassed to put myself on the air.  I try to listen to code while at my bench and workstation, and sometimes have received fun QSO's to try to copy - I am getting faster.

Yesterday I decided to do something about obtaining a MP3 player to contain code lessons as I think I would like to practice while away from the shop and radios, and maybe in the car. Thinking to myself that an investment of, .  . say $150 for an MP3 player would be OK.

Boy, was I pleasantly surprised! (where have I been?)

At Staples, a more than adequate MP3 player (Coby) was only $29, and an even simpler players was only $19, both had 2G's of memory. I went for the $29 version because it had a built in USB connector, like a memory stick. Once pluged in, files are transfer as easy as file copy!

Now, all I need are some MP3 code files. Sometime ago, I found a WEB site that would generated CW MP3 downloadable files from typed text, I'll have looked but can not seem to re-find it.

So, Here-is-to faster code copy,  .  .  .  and you may hear me on CW someday - de WA0UWH K


Daves Power Meter

Yesterday, Dave - W7AGJ came by my Shop. He had been to RPC (PC Recycling) in Seattle to buy a heat sink for a Home Brew Power Meter that he is building,

The large (about 6x5 inch) heat sink needed some of it's fins milled off of one side to provide a flat surface to mount to a the side of an enclosure he was planing to use. A lot of mill chips later, the heat sink was ready to mount. But, the aluminium enclosure was painted which prevents direct contact - after taping a mask (or shield) a paint patch, the size of the heat sink, was removed with the sand blaster.

Before leaving we discussed the frequency response of capacitors, Dave will need several for his voltage divider and detector circuit of the power meter. His goal is to provide reliable response from HF to 70cm (450mHz).

Using my AIM-4170B it was easy to see the effects of lead length and the different types of capacitors - it was not looking good for my best and available junk box capacitors above 150mHz. Dave is hoping to select the diode, capacitor type, lead length and construction methods to minimise the need for radical calibration chart - we will see. One idea, is to use several; Parallel, Surface Mount or Mica Capacitors.

Dave will no doubt want to scan his new project with an analyser with a greater frequency range than that which is possible with an AIM-4170B (1-181mHz).

I will continue to follow this project.

NOTE: RPC as mentioned above is a great place to find parts for Home Brew QRP project,  re-purposed PC boards/equipment/parts are abundant for only very few dollars.


Saturday, December 26, 2009

Loop Antenna - Continued

I have measured the wire length or the inside of the conduit at 5.7m (18.70 feet) and calculated 1.81m (5.95 feet) Diameter (see previous post).

I re-scanned the antenna with the tuning Cap (4-47pF) at Maximum and again at Minimum. The both results are shown on the following graph.

Scan with Tuning Cap at Max and Min
Scale: 2 to 18mHz

The tuning Cap can vary the Resonant Frequency between 7 and 16mHz, just right for a 30m loop. This is very close to resonate frequencies as computed via a online calculator by Bruce Carter Loop Antenna Page.

All of the above was found experimental, now I an trying to justify it with math.

I know the impedance as seen at the feed point can be set by changing the turns ratios of the input toroid, The input impedance value is not critical for just looking at resonates, but it will be corrected before obtaining the final results. Currently the match is:

75 ohm input * (2 T Sec / 4 T Pri )^2 = 18.75 ohms output

According to what I have read on the Internet, the input impedance for a loop antenna is closer to 5 ohms. I should need a high turns ratio, like:

75 ohm input * (2 T Sec / 8 T Pri )^2 = 4.65 ohms output

With the tuning cap set to minimum, I would think the antenna would look like a dipole and resonate at:

22.88mHz = ( 300m / (5.7m * 2 * 1.15)

But, I measured 16.43mHz, maybe this is because the ends of the dipole are folded back in a circle and provide capacitance between the ends.  Also, there is probably more self inductance due to the coil shape?

Note: I know that using a 12 AWG wire for the element is not the best for performance, but for design investigation it works just fine.  Later it maybe replaced with stand alone copper pipe.

I need to do more experiments and investigate this further.


Thursday, December 24, 2009

Loop Antenna

A year or so ago, I started experimenting with 30m Loop Antenna.

Not knowing exactly what I was doing I started with Grey PVC Conduit and Electrical Box Fittings. I used two 10 foot sections bent into a circle with a square box fitting at the bottom and a tee pull-box at the top. The loop is about 19 feet in circumference (a little was cut off to remove the bell ends). Bending was done last summer in the hot sun. I have made two of these and have done different experiments on each - and, have learned something new at each revision.

Top of the loop Tuning 4-47pF Cap

The Bottom Box, with Toroid Core for Matching
(sorry, my old camera can not take a good photo for here) 

Somewhere I had read that a single loop antenna had a very low impedance feed point 180 deg from the top or from the tuning capacitor.  I used 12 AWG as the element inside of the conduit, looping through the conduit from the top, down to the toroid and back up to the top (that was fun!?).

 Loop Schematic
(Now measured at 18.70 feet Circumference)

 30m Loop As-Built

Experientially, I found a 4x2 turn toroid would provide a close match to my 75 ohm feed source, I used my AIM-4170B to check the feed performance.  Also, during the  experiment I found that 4-47pF cap would resonate the loop at 30m (10.140mHz). With a little tweaking of the toroid turn count and ratio, I should be able to get a low 1:1 SWR.

With Good SWR - Showing about 1.6:1
Scale = 9.5 to 10.5mHz

A Well Behaved Feed Point, Showing nothing strange over a Wide Range from 2 to 18mHz
(Note: above 20mHz nothing too strange happens)

When I did all of this, I only had QRSS station and Grabber running,  I did not have WSPR to make proper antenna comparison measurement. But. it did work well for both QRP QRSS Transmit and Grabber operation.

Recently, I have been reading Joachim's blog, where he describes the DCTL (Distributed Capacitance Twisted Loop) antenna.   Well, my antenna looks somewhat like a DCTL antenna, only it has a lump capacitor at the top. I have started thinking I should rewire it with 300 ohm twin lead and driving it with my toroid transformer.

The next experiment,  is going to use 300 ohm Twin Lead for the element. My concern is not the actual resonate frequency, only it's feed point behaviour, I can fix the resonate frequency later by change the loop size or a tuning cap.

My goal is to build a loop that is simple and easy, and that will be easy to keep in tune.


I have measured the wire length or the inside of the conduit at 5.7m (18.70 feet) and calculated 1.81m (5.95 feet) Diameter.


A tribute to a Lost Friend

Yesterday, I learned of the death of a previous flying friend - Arden Johnson (of N2425Q), he pass away in March 2009.  We had a "falling out" many years ago, and only spoke to each other a couple of times since. I wished that we had resolved our differences - but due to distance and other factors that did not allow two stubborn old-men to take the time to try.

In some way I thought we would resolve our differences someday, as I still have a metal file that he lent me. Each time I saw it in my tool cabinet, I remember I needed to return it - thinking that I could use it as an excuse to chat.

Looking back now, I can see that Arden may have tried, by asking us to their house to help resolve a new issues at the Airpark, we went to their house, but the Airpark was no longer important as we had just bought our new Ranch and was very busy with it. He left the door open for making amends, but due to other immediate Ranch issues, I just did not walk through.

It is strange how final death is, things un-said or un-done can not be corrected - no matter how hard you would want to try.

Sorry - my Friend.


Sunday, December 20, 2009

December 2009 - eBuild-A-Thon and BBQ

The December 2009 eBilld-A-Thon and BBQ has come and gone, a great day of working and chating with fellow HAMs about electronic projects.

Two new visitors from the SkyValley Ham Club came by to see the Shop:
  • Dave Zehrung - AA7L and his young grandson (I think) Brandon Williams - KF7EZE
Brandon is a new HAM and has plans to build some VHS antennas and maybe a HS dipole. Because Brandon represents a younger adult, Tess (my dog) was in heaven, Brandon was someone to play ball with.

Dave - W7AGJ from SkyValley came by, he wanted more information on my Cordless Soldering Iron - he was looking for proper specification for describing it to Santa.

The Beacon Hunt

The hidden QRSS "Beac-in" was located by Jeff - KO7M within about 15 minutes of his arrival, using a portable Elecraft KX1 Transceiver with a clip lead from the antenna jack to his umbrella frame (it was raining). Jeff used low RF gain on the Transceiver and signal strength to Home in on the Beacon. Later, Jeff admitted that physcology was also used, as he looked in places that he thought I would have used for the hiding place. For the next hunt, I will try to make the hunt and physcology much harder.

For being the first to find the Beacon, Jeff will receive the prize -  A pick of one of my QRSS/WSPR marker beacons, or a custom copy that we build during the event. He chose a custom copy - more on that later.

The Projects 

Roger - K7RXV brought a very special KIT for all to enjoy, his kit was the fixings for Russian Mushroom and Potato Soup. He started just after arrival, he was busy chopping, cutting and saute'ing bits-n-pieces for what seemed like several hours, it was ready on-time for lunch. It was excellent, I highly recommend it! I plan to save the above link to the recipe for another time. Good job Roger!

Roger - Working at his Cook KIT

Jeff - KO7M brought his Elecraft KX1 Transceiver, we enjoyed listing to CW QSO's and his operations. We had to ask him to connect it up to some speakers for all to hear.

Jeff - Transceiver Operation

John - KC7NVE brought one of his KITs, A Scout Regen Receiver (I think) to start the build process, on arrival John had a sack of parts and boards. When he left, his parts were all labeled, organised and sequenced for easy access for the later build process. Not only is John a great HAM, he is an amazing organiser.

John - Labeling Parts for his KIT

Doug - W7RDP brought the chassis of a KIT he was starting, it needed holes drilled, punched, and the heat sink tapped. Doug spent most of his time at the Drill-Mill and helping with other projects.

Doug - Supporting Jeff's Marker Build Project

At the Mill/Drill

More Hardware Discussions in the Shop

Jeff - Hard at Work on a small SMD


Thanks to: Carolyn (my sister) for helping with cookies and Tacos; and Roger for the Potato Soup. We had enough food for an army - I was stuffed.

Lunch Break

The Beacon Hunt Prize

For Jeff's Beacon Hunt prize, we went through the complete project, from a custom modified PCB layout on the computer screen, to a finished working Marker Beacon. We changed the layout to include his CALL on the artwork for the PCB. We used the Toner-Transfer Method to build the PCB. I installed the first part, Jeff installed all of the rest, using the schematic and a previous working beacon as a guide.

Marker, Still Under Construction

Jeff - Hard at Work under to Magnifier

On the first turn-on, only a chirp was heard on the receiver when the key was pressed. We inadvertently used an old junk battery that was sitting on the bench that was almost dead.  The circuit board was double-sided taped to the battery and had to be removed. With a new battery, we tried it again - this time nothing! It did not make a sound at the receiver.

It is now trouble shooting time! Jeff compared the voltages between the working Beacon and his new Beacon, all voltages were the same. Because we used a new untried crystal in this Beacon, it was suspect - maybe it just would not oscillate. Remember this circuit is made of all surface mount components, and therefore it is somewhat difficult to check individual components.  When a circuit has never worked before, it is sometimes difficult to know where to start troubleshooting.

We decided to remove the crystal and replace it with another. While cleaning the pads with solder wick to receive the second crystal, the series capacitor moved. That is, one half of the capacitor fell off, with the other end still soldered to the board. This was surely the problem - a cracked capacitor. We may have cracked the capacitor while prying the circuit off of the the old battery.

We replaced the capacitor, and did a trial press fit of the crystal in place - it worked! About this time, my Soldering Iron was low on battery charge, and therefore we had to wait for it to charge, to see the real results (don't ya just hate that?)

In the end, after the crystal was properly installed, a quick twist of the tuning trimmer put the Marker on frequency (10.140100mHz) . The Project was a success!

Other Topics

Sometime during the day we discussed a QRSS Beacon balloon launch (see previous post),  many aspect of a balloon project are still up-in-the-air (no pun intended). To be successful, we will need to enlist as many US Grabber as available. From our Seattle area, the upper wind is just right for a long flight across the US.

Jeff also brought in his fantastic Valve (Tube) Regen Receiver. There has been a lot of talk about valve receivers on the WEB recently and I had forgot how enjoyable it is to look at the glow of a valve while in operation. From that dull red glow comes the magic that got me into HAM Radio in the first place, many years ago. It was good to hear and see Jeff's receiver.

The Dull Red Magic Glow of from Valve Receiver,
Unlike smoke, the Glow is something that you DO enjoy letting out of a Component.

(I think John may have a better photo, I'll see if I can get a replacement)

Update: Thanks to John the following four photos are added.


 Now, . . . This is What The Magic Is All About!!

ReGen Receiver In Operation

Jeff - Working with his Regen Receiver


Because the winter evening come early in Seattle, the group left about 5pm - I enjoyed the day of having the guys at the Shop.

Tess enjoyed the attention and playing ball with all of the guys, she was dead tired by the end of the day.  After going bed, I don't think she moved all night.


Wednesday, December 16, 2009

December 2009 - pQRP P&C

Last night I went to our monthly Puget Sound QRP (pQRP) P&C (pie and coffee) meeting.

For the event the group decided to do a White Elephant Gift Exchange, supposedly giving something from our junk box. I checked my junk boxes for an appropriate gift to take - it was something that I would have liked to have received, and wraped it for the exchange.

At the meeting and after dinner, I was one of the last to pick a gift from the gift pile, I selected a small package and was surprised. It was a Soft Rock 40 Kit (a receiver) - Very nice gift from someone that has an very impressive junk box. But, sad to say, in keeping with the rules of the White Elephant Gift Exchange, my Soft Rock Kit was taken by Alan K6ZY (the next in line to pick a gift), Dang!  ;-(

OK, as per the rules, I had to pick another gift, again I picked a small gift and to my surprise, it was a TAK-40 Kit  (a Transceiver, parts and boards). Again, some of the guys at the meeting must have very impressive junk boxes.  Yet, not knowing exactly what a "TAK-40" was, after the meeting and at home, I spent several hours on the web reading and learning all that I could about it.  Sometime early the next morning I got to sleep.

Well, I am thankful to who ever provided the Gift, I will put it to very good use, I may even spend some time increasing my code speed  - Thanks.

  • After reading much more on the web, The TAK-40 looks like it is going to be a bit of a project, to find; construction details, modification details, and all sorts of information to ingest and digest.


Monday, December 14, 2009

Normal Weather in Seattle

Good, we are back to normal winter weather in Seattle, cool (40F) and a little wet.

But, please no more very low temps, see previous post.

Sunday, December 13, 2009

December 2009 - eBuild-A-Thon and BBQ


This Saturday, Dec 19, 2009, as before, my Shop is available by Invitation for Building Electronic Projects, see link:

Let me know if you have a special demonstration that you would like to present, it can be scheduled so all will know.

Note: Due to the extremely cold weather and the heaved ground under the front concrete slab, the normal front door is ajar and will not open - use the large High Bay door.

For this event, I am looking for a volunteer to "Meet Greet", take names and take project photos, I missed doing so at the last event and was not able to include everyone in the follow-up report. Anyone interested?

Unlike most similar events, there will NOT be the usual "talk-in" frequency,  but in keeping with my interest of Beacons, there is instead a QRSS "Beac-in" frequency to help guide your way at 10.140050mHz (+- a few).  For a real map see the link below.  Also, once you arrive, there is a prize for the first person to find the actual Beacon, hidden on the 40 acres. If found, don't reveal it's location, while others try. Bring your DF equipment and join in the fun.

The beacon was not found last month, so we well try again!

Due to the possibility of cold unpredictable weather, the outside "BBQ" will be replaced with indoor Tortillas and Fixings (or other snacks), bring additions to share if your like. For brave soles, the wood outdoor fire pit/BBQ is available if you tend the fire.

If wanted, as before I will re-demo PCB generation for new comers, Etch and SMD soldering. If you would like to try your hand at this, junk boards will be available.

Please bring "Show and Tell", Build Projects, QRP Rigs, Small Tools, Magnifiers and Laptops (WIFI, Internet and Laser Printer are available).

See this link for All the Details, Map, and RSVP:


Saturday, December 12, 2009

Cold Weather in Seattle

In 32 years living near Seattle, I have never seen it this cold! - For the last few weeks the night time temp has be around 10F with daytime temps about 20F. Normally we get two weeks of cool but nice clear weather in November, but now it is very clear and very cold. One night I measure 7F.

I have often told newcomers to Seattle, that we normally get 4 inches of snow (some years) and the mud puddles will freeze maybe once each winter - so far this is a very unusual year. Note: last year we got 29 inches snow, measured on my picnic table (the table in my photo with my dog Tess)

The ground has frozen and has heaved in large patches, my whole gravel drive way has heaved and now has ditches along the edges where none were before. We have had heaving before, with 2 inch sharp spears of ice crystals, pushing up through the surface, but this time the whole ground has heaved as one solid mass.

The covered porch/drive slab of concrete in front of my Shop had moved up enough that my shop man-door will not open. The slab is about 8 inches think in that area and I would have not thought that ice would have formed under it. The door is about 24 feet under the cover area.

In the main shop high bay area, I have the remains of my "ET Phone Home" QRSS Transmitter timer mechanism which is a 4 foot x 6 inch tube full of water which is now ice - now froze solid! pushing up it cover. It is located about 16 feet inside the shop.

The weather man says that it should start warming up soon, I sure hope so!

I am thinking I could use some of that "Global Warming" right now.


Wednesday, December 9, 2009

WSPR Listening on 40m

The last several days I have be working through some mindless boring legal issues, and have not had much time for Ham Radio. - So my WSPR receiver is doing all of the radio work for me.

My long wire and Kenwood R-2000 with the audio connected to Ubuntu 8.10 workstation has been working in the background while I work the keyboard - Look ma - Ham Radio at 11,000km with no hands!

(sorry I deleted the include WSPR report table, it did not format well in my blog)

On 40m
See the on-line pre-formated Report at

Now QSY to 80m - as of 200912112150
See the on-line pre-formated Report at

Now QSY to 600m - as of 200912122330
See the on-line pre-formated All Spot Report at


Thursday, December 3, 2009

Listening on 500kHz

Most of the day my receiver (R-2000) was tuned for WSPR on 500kHz, my lonely red flag shows up on the LF/ULF WSPR map near Seattle. There is only one transmitting station, N4QLB, in the US - I was hoping to a least log it. But no Joy.

Listening in Seattle,  .  .  .  .   .

I listened to 500kHz for two days - nothing but four bogus spots with bad CALLs and/or Grids -  so, now Rx QSY to a higher band.


Wednesday, December 2, 2009

Catching Up with Ham Radio

The last few days I have been very busy with tedious non-Ham Radio activitives, on this short break from that, I will dump what is in my head.

I put together an external Audio Isolation Transformer for my 30m Grabber Direct Conversion Receiver.  This should remove the 60 and 120Hz hum-bars as displayed on the 30m Grabber. The transformer is not exactly a 600 Ohm Audio transformer, but it will work for now.

I also put in a Stereo Jack with the correct wiring so that I can now do away with the previously used adaptor. I made the mistake when building the receiver by not installing a stereo jack in the first place.

The temporary fix if ready, it works on my bench, now all have to do is find time to goto the receiver site and plug it in.

Also, I was reading Joachim's blog, where he describes the DCTL (Distributed Capacitance Twisted Loop) antenna - it is recommended reading.  I like loop antennas!, with my new understanding of the DCTL, I may try it.


Friday, November 27, 2009

Frustrations with Audio

Frustration with Linux Audio System is getting the best of me.

I have been working with Large UNIX Systems for more than 30 years - I have specified, configured, installed and managed many multi-multi-million dollar UNIX systems and nothing is as frustrating as "audio set up and configuration" on a simple Linux system - currently I am using Ubuntu 8.10 with many (maybe conflicting) audio subsystems. I started out looking at  and using Linux for a personal workstation when it was still called Minx.

My problem is there does not appear to be a simple solution to this problem. I do not like MS Windows, but at least the sound system on most Windows systems - just WORKS.

Several years ago, with an older Linux (Red Hat) system - sound was not easy to configure, but it was not difficult either. Now, everything about a Liunx sound system is just plain HARD.

Currently, I would grade the XP Windows Sound System with an "B+", and would grade the Linux Sound System (Ubuntu 8.10) with an "F".

I have OSS, ALSA and PulseAudio all installed which maybe the problem, but nothing suggests that another configuration is more correct.

One minute the Linux sound system appears to work, then the next nothing works, a reboot is necessary to correct the problem, restarting the daemons does not seem to fix the problems. Simple configuration change do not take place when you expect, they may take effect sometime later, when you are not expecting changes. It is difficult to keep up with what is happening to the sound system.

The Linux Sound system is all magic, there is nothing that I have found that diagrams the sound system and attempts to provide help when things do not work.  The forums describe the Linux sound system as delta's on previous information - it is hard to collect enough information to configure the sound system - when it does not work as published.

I would like a simple app that diagrams the sound system from input jacks, to kernel, to application and onto output jacks, with diagnostics showing where sound is coming from and going to.

I am sure for new Linux users, this is as frustrating as anything.  It will cause users to return to MS Window. From what I have seen, the Linux Sound System is the most effective externally generated advertisement for Microsoft that exists to date.

Sorry for the Rant, .  .  .  .  maybe I will figure it out someday.


WSPR 2.0 Working at Remote Location


I now have WSPR 2.0 working on my remote Data Centre Direct Conversion Receiver.

The DC receiver is used as both a QRSS ARGO Grabber and now a WSPR spot database reporter, both at the same time.

The audio is decode by the two programs, both running on Ubuntu 8.10, WSPR runs native on the console window, while ARGO runs under "wine" in a virtual (xvnc4server) window.  The virtual window is necessary as ARGO uses screen scrapes (or captures) to obtain images, that are used for the Web Server Grabber presentation. A non-virtual window application would often be covered by pop-up's or other normal window elements that obliterates the resulting Grabber image.

WSPR 2.0 supports CALLs with a suffix, for my remote receiver I use WA0UWH/R as it's ID, as shown near Seattle on the WSPR map.

My goal is to also report PropNet spots via the same systems.

While I was setting up WSPR (as described above), I did an experiment. I inserted a amall transformer into the computer sound card input line - the "hum bars" seen on the ARGO and WSPR console windows went away! I think a ground loop exists between the computer and the antenna. The coax is grounded at the base of the antenna.

Now I need to redesign the receiver output circuit to include proper ground loop isolation (a fix to be done another day).


Wednesday, November 25, 2009

PCB Software Review

I just did a quick review of AutoTRAX for my potential use to make Hobby Toner Transfer PCB's.

It was looking good until I looked at the copper pour implementation.

See previous reviews.


Sunday, November 22, 2009

November 2009 - eBuild-A-Thon and BBQ

WOW, the November 2009 - eBuild-A-Thon and BBQ has come and gone, we had several projects being worked in different parts of the Shop at the same time -  I could not keep up with all of the very interesting projects, activities and chats. Sorry, photos were not taken.

The QRSS "Beac-in" (not talk-in) beacon was not found, no one brought DF equipment - therefore the prize will be saved for the next event in December.

By my count, there were 22 people that came by to work on projects or just chat throughout the day. Unfortunately, I did not get a complete list of names and calls, forgive me if I don't mention your name or project. Next time I will try to have a official "meet and greeter", to help with names, notes and project photos.

Roger K7RXV brought his network analyser, but I think he worked mostly on a PCB case for an Intermod Meter.

John KC7NVE brought his Transceiver, Portable Antenna and Laptop, to demonstrate station operations in; SSB, CW, and WSPR modes.

Doug W7RDP brought his Lineman Crimping tool for demonstration and use, Doug brought  a section of very small (1/8 inch) hard-line. It will be used for future project intra case connections.

Lyle KK7P worked on a PCB case for one of his  projects, by the count of the accumulated  punched circles at the base of the punch he was a very busy person. I am looking forward to see the resulting case and finished project.

The Next Day Photo
I love the evidence of intent work

Thanks to Lyle, we will now have many large "manhattan style" PCB construction components.

Alan K6ZY worked on repair of a watt meter via meter replacement and face plate adaptor.

For a while, there was competition for the punch access with so many PCB projects needing holes punched. Die changes were coordinated for best overall effective use.

Thanks to my sister, Carolyn, Lunch was served adhoc and projects were continued though out the day.

Tess (my dog) thought it was great - she had so many people that were willing played ball with her - she was exhausted by the end of the day, but she loved every minute.

Thanks to all for a enjoyable event.

I had a great time at Eldon's eBuild-a-Thon today.

Eldon, your shop facility is, like, awesome, dude. Totally.

And the hospitality was superb. Thank you, than a big thanks to Carolyn
as well.

I'm hooked!


Lyle KK7P


Just wanted to mention Richard L's Thames & Komos Radio Ace medium and shortwave dual-triode regenerative receiver he took to a past Build-A-Thon does work. It seemed to not work at the past Build-A-Thon because it has much poorer sensitivity than we expect from regenerative receivers. But today Richard turned it on in the low lands of Snohomiosh county and received multiple BCB (AM broadcast band) stations. Selectivity seems good for a simple receiver.

I'm hypothesizing using B+ = 12 volts on a 12AU7 handicaps the tube. (Or is it a 12AT7 or 12AX7?) Unlike most one or two active device receivers I've played with, an adjustable antenna loading coil did not improve volume on the AM BCB.

Annie, Richard, and I very much regret missing the Build-A-Thon. Richard is in pain from extensive (3-hours) dental work yesterday. I've not fully recovered my strength from mild food poisoning on Thursday. After describing a past Build-A-Thon to some e-pen-pals, some (hams in Kentucky, and Japan, and a technical university professor in Lima, Peru) have emailed me with very positive comments.

Very best regards and wishes to all,

Steven, KD7YTE


Thursday, November 19, 2009

Small DPDT Switches

I have several projects needing very small configuration switches (611-AYZ0202AGRL) , which arrived today.  The switches are much smaller than I had thought, even though I had the specs. These switches will be fun to use and will be seen in future projects.

It is interesting to note that the new small DPDT SMT switch on the right has almost the same terminal spacing as the old large SPDT switch on the left, yet the switch body is maybe 1/10th the overall size.


WSPR 2.0 is Now Available

The new version of WSPR 2.0 is now available.

With the new version, proper support for station CALL suffixes are supported. I my case this means that I can run one (receive only) version at my Web Server Site 24x7 as WA0UWH/R and another at my home QTH (receive/transmit) adhoc as WA0UWH. I will use the "/R" as an indicator for Remote - until someone has a better idea.

Also, this version is available native on Linux, which was a cludge via wine before.  My Web Server is Ubuntu therefore I will beable to use the Linux version on that system.

WSPR is available at:

Tuesday, November 17, 2009

Printed Inductors - Continued

To learn more information about Printed Inductors (see previous post) I decided to check the self-resonate frequency - by disconnecting the capacitors. This experimental coil is self resonate at 22.2mHz.

Scale = 1 to 41mHz
 Resonate at 22.2mHz

Above 60mHz all kinds of strange minor resonate modes occur.

Note: Flat-topping on the graph is over range.


A Balloon QRSS Idea - Continued

To support a QRSS Beacon Balloon effort (see previous post), I checked with the local Welding Gas Supplier, a large standing tank of Helium is about $110 plus tank rental.  The tank can be rented for about a week (used at parties) for a few dollars, or by the month for commercial accounts at $20 / month.  To purchase a tank it is about $450 with refills at the same $110 rate.

I think the rental rates includes a regulator.  But, to buy a tank would require an additional $45 for a regulator.

I need to do some more Beacon Balloon planning before investing in Helium.


Monday, November 16, 2009

Printed Inductors

Today I started experimenting with Printed Inductors, which is something that I have always wanted to try. The idea is to print and etch inductors directly on the PCB, many commercial products and some kits use this technique.

For my first experiment I created a 25.5 Turn Inductor with a single 5mil spiral trace, 12mil centre-to-centre spacing, within a 1 inch diameter. The tuning capacitors are soldered to the upper two pads.

 A Tuned Tank Circuit

Note: it is difficult to see the spiral with the naked eye, it is just a blur of shiny copper.

This is the Centre of the Spiral Conductor

My goal was to resonate at my favourite QRSS frequency of 10.140mHz. With the help of a 47pF cap and a parallel 4-50pF trimmer, resonates was obtained on the desired frequency.

I thought the distributed capacitance of the spiral and of the 32mil double sided PCB would kill the Q of the circuit, but it seems to do well as indicated on an AIM-4170B Analyser. But, this will need more investigation.

Scale = 8 to 12mHz

I may have to plan a project using this technique for the tuned inductors.

As I have time, more experiments and information on Printed Inductors will follow!


November 2009 - eBuild-A-Thon and BBQ


This Saturday, Nov 21, 2009, my Shop is available by Invitation for Building Electronic Projects as before, see link:

Unlike most similar events, there will NOT be the usual "talk-in" frequency,  but in keeping with my interest of Beacons, there is instead a QRSS "Beac-in" frequency to help guide your way at 10.140050mHz (+- a few).  For a real map see the link below.  Also, once you arrive, there is a prize for the first person to find the actual Beacon, hidden on the 40 acres. If found, don't reveal it's location, while others try. Bring your DF equipment and join in the fun.

Due to the possibility of cold unpredictable weather, the outside "BBQ" will be replaced with indoor "Hot Dogs" (or other snacks), bring additions to share if your like. For brave soles, the wood outdoor fire pit/BBQ is available if you tend the fire.

If wanted, I will re-demo PCB generation, Etch and SMD soldering. If you would like to try your hand at this, junk boards will be available.

Please bring "Show and Tell", Build Projects, QRP Rigs, Small Tools, Magnifiers and Laptops (WIFI, Internet and Laser Printer are available).

See this link for All the Details, Map, and RSVP:


Sunday, November 15, 2009


I have started a companion Power Amplifier (PA) for my 43uW QRSS Transmitters, the circuit, as bread boarded, produces about 27mW via Push-Pull output into a 75 ohm load, from a 9Volt Battery, and up to 250mW at 18Volts (two 9Volt Batteries).

In the Experimental Methods spirit of EMRFD, this is a experiment with the following goals:
  • Small as possible (because I like to work on very small things). 
  • Small enough to fit into the centre insulator of my 30m Dipole.
  • Low part count.
  • Low output Harmonics.
  • High Efficiency.
  • Minimum Input Matching Requirements.
  • Minimum Antenna Matching Requirements.
  • Low Idle current between QRSS FSK or CW transmitted messages.
  • Flexible DC Power Requirements, 9 to 18 Volts.
Note: I do not have means to measure or evaluate success of all of the above requirements.

It is of my own design and uses a JFET driver and two 2N7002 FETs for PA's (the black specks seen between the two Toroids). For more power two 9Volt Batteries can be used in series.

Unlike the Oscillator's which uses small 5mil traces, the PA will use a more standard 12mil trace.

I still may do more experiments with different Toroid Turns Ratios for better performance.

The Current Bread Board Configuration.
The 75 ohm Load is standing air cooled :-) on the right.

The PA is designed to support both FSK and CW QRSS from the Oscillator. It is currently a jumble of wires and SMT components, but I have on the computer the PCB layout for a more civilised configuration on a 1x2.2 inches PCB using all SMT parts, including SMT POTs.


Above is a sample output from my local Grabber with CW mode selected on the Bread Boarded QRSS Transmitter.

Currently, the largest component will be a switch, which is used to change modes. It is the smallest switch that I have in the junk box. It is a SPDT, which works OK, but what I really need is a DPDT switch for proper operation.

The Junk Box SPDT Switch

I checked with Mouser, and plan to order a much smaller SMT 611-AYZ0202AGRL DPDT switch.

When finished, I plan to join the Oscillator and PA on a single PCB as a complete Fun and Flexible QRSS Transmitter.


Finished - Small Trace 5mils 30m QRSS Transmitter

I received in the mail a KID2 Keyer to finish the Small Trace 5mils 30m QRSS Transmitter (see previous post).

This circuit produces 43uW of QRSS FSK power into a 75 ohm load on 10.140080mHz from 9Volts at 4.5ma.

The goals of this experimental project was to:
  • build the smallest PCB that I could produce using my current Home Brew techniques
  • use all SMT parts (except Crystal, Battery and Keyer)
  • use smaller than industry standard trace sizes (used 5mils)
  • use no more parts than necessary
  • build a real and useful working circuit

This transmitter will be installed in the centre insulator of a 30m Dipole (see previous test)

Note: the frequency dose not seem as "hand proximity" stable as other similar circuits that I have produced. I think the lack of stability is due to the very small (5mil) traces used, each small trace contributing a small amount of Inductance to each component and therefore hand proximity capacitance is more determinately effective. More tests are needed?


Monday, November 9, 2009

Soldering Iron Casualty - Work Lamp

I worked on a SMT QRP RF Power Amp Circuit until very late last night, near the end, my cordless Soldering Iron was just keeping up, if I let it set in it's charger every few minutes. It was very late (early AM) when I quit. To avoid a low battery for the next day (today), the last thing that I did was make sure that the Soldering Iron was on Charge mode.

This morning, I grabbed the Soldering Iron - fully charge and started work - on the very first try the work lamp blew out, with a bright flash. Too much charge or an old lamp on my new Soldering Iron. Dang!

The replacement lamp is about $5.00 and it would take several days to arrive.

The lamp probably draws about 250ma, which is a waste of my cordless Soldering Iron Charge.

I think, I am going to look into wiring up an LED - I normally do not need the light to see the work.  For me, the light brightness is an indicator of heating status.

So, now I have yet another project!


Wednesday, November 4, 2009

Soldering Iron Fix

While working on a SMT project, my finger was getting tired of holding the "heat" button on my new Soldering Iron. See previous post.

Sometimes the Iron would NOT heat up as fast as normal, and the work light would not be as bright.  Wiggling the switch would correct the problem, but a lot of pressure was necessary to hold it ON.

I had a similar problem before, and noticed then that the plastic button seemed to be melting on the inside at the point where it pushes on the copper spring switch.  When pressed, the copper spring is pushed down onto a screw head to make electrical contact. To help avoid the button from getting hot and melting, I place a small piece of heat tape over that area of the spring. I thought that was going to solve the problem - but NO. The  heat from the copper spring was being generated by the "bad contact" between it and the screw. And the added pressure needed was still making my finger tired and the strain would cause my hand to shake (a little) - which is not good for SMT work.

This had to be fixed!

I though, I may have to replace the switch with something with a more positive contact. Why did "they" make such a dumb switch for this thing?

I decided to take it apart and fix it, again. I could see where the contact seemed to be marred from heat, but what to do about it? What I need is something that would help make a better positive connection.

I found it - I placed a small drop of NOALOX - an Anti-Oxidant Joint Compound, on the head of the phillips screw, see the black dot at centre of photo.

Now the Soldering Iron works like a champ, I can still recommend the Iron, but suggest, fixing the switch contacts before use.

The back side point of my plastic switch button has been melted a little, but still acceptable, I may need to find a replacement.

Also, I think a small dot of NOALOX on the Tip wire holes will be beneficial, or at least that what I am trying.

OK, the implementation of switch is not dumb, it just had bad contacts.


A Balloon QRSS Idea

My micro watt QRSS Transmitter is so small, light and inexpensive, I should "Fly it on a Balloon"?

See previous post.
  • At 25K feet, I wonder what range could be expected of 43uW QRSS transmitter?
  • I wonder what the Rules/Regs are regarding an experiment like this?
  • I wonder if I could get special permission from the FCC to have an MEPT transmitter out of my reach/control - until the battery runs out?
  • Just wondering, does the FCC have jurisdiction over 43uW Transmitters?
  • A centre feed 1.5 wave 30m Antenna could be the trailing support.
  • I need to do some more checking.
  • Would anyone like to join me on this adventure?

My Small Trace 5mils 30m QRSS Transmitter

My small trace (5mils) 30m QRSS Transmitter board has been loaded with most of the parts (see previous post). Still needs a Crystal, Keyer, Battery, and Antenna connections.

So far, no screw-ups, and no shorts!

Now, awaiting the KID2 to arrive in the mail.

QRSS Tx Almost Finished


Tuesday, November 3, 2009

Industry Standard Small Traces

Today I read that "Industry Standard Small PCB Traces" are normally as small as 6mils.

Because I like small things, I wanted to try to build a circuit with even smaller traces.  The circuit I choose is a new iteration on my Micro Power QRSS Transmitter - the same circuit that was used on the QRSS test that I ran last week.

I have re-designed the board for ALL 1206 SMD parts, using 5mil traces and 8mil clearance. I would have liked to use smaller parts, but 1206 size parts are the smallest that I have available. The traces do not need to be this small, I am just doing it to see if I can? - It is kind of a QRP thing for the Home Brew PCB Fabrication process!

The Toner Transfer and Etch process went well - The board DC Resistance checks OK, without loss of connections or shorts.

The size of the board is 1000mil x 850mil,
shown here at about 4X actual size.

The signal traces between pads are 5mils wide, 8mil clearance.
The GND Grid is 5mil Traces on 20mil Centres.
The Font is 3pt.

The major components of the circuit are; a 5 Volt Regulator, Crystal, 2N3904 Oscillator, and a KID2 QRSS ID'er.

Note: SMD 1206 parts are: 12mils long and 6mils wide.

The next step is to mount the parts - which could be a real challenge, . . . . for tomorrow.


Tin Plating with Solder

Tin Plating with Solder on Home Brew PCB Projects.

On a previous post, a viewer ask via a comment; how did I do a "Solder Wipe"? as shown on one of the example HB PCB Projects.

At the time, I used a Soldering Iron with a little bit of solder and moving back-and-forth over the traces coating each with solder and then while the board is still hot, "Wipe" the solder with a cloth. This produced satisfactory results - but, you have to be quick!

Because I like the looks of bare copper for my projects, "Solder Wipe" is not used very often.

Now, many of my projects are showing their age as the copper tarnishes. I need to start using something more protective on all of my projects.

While removing parts and cleaning-up several old junk board (see below), that are going to be re-used for a SMD solder technique demonstration, I noticed that Solder Wick produced a nice clean dry finish, if it was rubbed over the traces with the heat of the soldering iron.

It looked great! I tried it on the rest of the board - with fantastic results.

Without and With Solder Plating

I recommend using a short section of used "Solder Wick" to tin plate (solder plate) new HB PCB projects before parts are loaded.

Used-Wick stays together and provides the small amount of needed solder, New-Wick tends to fall apart (see top left) before it collects enough solder to stay together. Do this task quickly, as you do not want to heat the board more than necessary - it will get HOT.

Be Careful, it is HOT

A little bit of liquid "Rosin Flux" helps the plating process (I use MG 835-100ml).

After plating, and Alcohol cleaning,  a quick buff with Scotch Bright removes the shiny surface and avoids the reflections that are so distractive while loading parts.

Note; more Alcohol cleaning is necessary after using Scotch Bright as the LEAD from the solder mars the PCB between the traces.

CAUTION: Remember,
this is "LEAD" that you are touching!

With previous HB PCB (without plating) I always liked to rub a little liquid "Rosin Flux" over the entire board before loading - it gets sticky (rosin is tree sap) and must be dried first, but it provided excellent soldering conditions for SMD parts - I still may continue this practice, even with Solder Plated PCBs. Note: I think rosin will also help seal the edge of the fibreglass PCB.

Now, . . . . if I could only find a way to do a decent Home Brew PCB Solder Resist Mask to seal the board?


Monday, November 2, 2009

A new QRSS Contact

This morning while working in my shop getting frustrated with progress on trying to get a new DC Receiver working, I abandoned work for a while.  I plugged the computer sound card back into the R-2000 general coverage receiver and turned the dial. I noticed a several signals as reported by ARGO on the computer screen, that is normal noise within the sound card and the ground loops from the receiver, I really need to get a better interface. Most of the displayed signal lines on the screen are steady and associated with 60Hz.  Nothing unusual here.

A minute or so later, I check the screen - there was a single perfectly formed QRSS3 "C" on one of the hum lines!!! What, did I touch something that caused the receiver to jump frequency in time with a perfect QRSS3 "C" - I don't think so.  Where did it come from???  I continued to watch, nothing suggested it was anything but a 60Hz hum line.

Several minutes later, on the same line was a perfect QRSS3 "O"!!!

Now this has my interest!

Who would be sending QRSS3 letters at such a slow rate??, And what was the rate??

I started a timer and put the Grabber into capture mode, and waited, and waited - Eleven minutes later - a perfect QRSS3 "N" - WOW - I have to watch this! Someone is sending some very slow QRSS - I am excited - I have to figure this out!

I can't touch anything - not even the dial - I'll just have to wait!!

At the next Eleventh minute, right on schedule, I could see the leading edge of a letter, BUT at that very moment my "WSPR" transmitter obliterated the receive signal. I did not get that letter.

Who ever is doing this must have an synchronised clock and is transmitting single QRSS3 letter at the begining of minute interval. This has really got me interested! WSPR transmits precisely on even two minutes intervals and then receive-only for (in my case) 20 minutes.  To avoid having WSPR obliterate another letter, I turned WSPR off. I checked my (other) standard local Grabber, I could see the same signal there - but a little weaker - a different antenna is used and maybe my long wire on the R-2000 had an advantage at the right direction.

I computed the time for the next letter, and waited. Right on schedule, A perfect QRSS3 "W" was recorded. I now have "CON_W" received over a 50 minutes period. I wonder what the message would say and to/from whom?

Ten minutes later, a perfect QRSS "A" was received - the first part of a CALL?? - maybe the first few letters, was the last part - I checked the QRZ data base for "WA something CON" - the QRZ database does not have option letter search (that I know of) - no joy.

Ten minutes later, a perfect QRSS "0" (zero) was received, although the frequency was shifting down - NOW this is part of a CALL! - Checked the QRZ database again with "WA0CON", checked Google - still no joy.  I will just have to wait for more of the message.

Now, I started wondering, who would transmit QRSS3 at such a slow rate?  Who ever it was must be on a battery because I could see the tell-tale frequency shift of a heavy loaded transmitter - transmitting a long "zero" for that last received letter.

What could have been the letter that I missed, while my WSPR was transmitting?? an "R", "K", or a comma?? - What kind of message could this be??

I started thinking about my old beacon messages, which consists of something like the following:




BUT, I don't have anything that transmits single characters at 10 minute intervals - or, do I?

There, On the shelf, was the previous weeks experiment, the dead 9Volt battery QRSS Transmitter, with the battery still attached, just as I retrieved it from the cold, wet, centre-insulator of the dipole several days go. See previous experiment.

To make sure this was NOT transmitting, I pulled the battery clip off - the signal went away! Dang!

The extremely low battery voltage must have put the KID2 Keyer (PIC) into some kind of very slow mode, as the characters were being generated one per 10 minute intervals. This is not a normal KID2 Keyer or QRSS mode! Transmit power must have been extremely low, the warmth of the shop must have re-activated the battery (a little), when I turned on the shop heat this morning.

For about 90 minutes, this was a very exciting chase, with a little bit of a let down, but that is what ham radio is all about, chasing signals, even when they are your own!

It was a real rush, even though it was from my own system.

But, I will never ever trust dead batteries again!


Thursday, October 29, 2009

Toroid Wire Stripping

I have always had a problem stripping very short lead-ends from toroid coil wires, this is especially a problem for surface mounting a coil.

I have asked the question on several forums of; "how others do it?", but until now, nothing was an acceptable method for my fingers.
  • I have tried burning the end with a torch - wire will not take solder afterwards.
  • Folded Sand Paper - works good for long leads, but not for short SMD board mounting.
  • Scraping with a blade between finger or thumb - Fingers are too fat, blade too sharp, wire is too small and wiggly.
  • And, many other forum suggestions.

There are two problems with toroids winding that must be resolved;
  1. How to keep the wires tight and secure while working with it.
  2. And then, how to remove the insulation on very short leads.
  • Use Hot Glue, filling the centre will prevent the wire movement.
  • The technique that I use is; Fill the centre with Glue, and squeeze it between fingers, using a strip of Teflon Mat Sheet as a release medium (otherwise the Glue will stick to skin and it will HURT!). 
  • The pressure between your finger and thumb pvides a nice looking indent on the surface of the the glue.
  • Glue that overflows, can be pulled off around the edge of the toroid.
  • Note: I don't think the Hot Glue will degrade the performance of the toroid even at High Frequencies.

Fill the Centre with Hot Glue
Fold the Teflon
Mat Sheet
Squeeze Between Fingers
Caution - It can be HOT!

  • Scrape the leads "at the edge of a block of wood!"
  • Rotate the toroid as necessary, it only requires scraping on the four sides of each wire, doing two wires (or more) at a time.

Turn 180 Deg, Scrape the other side

Turn 90 Deg, Scrape the two other sides of each lead

It seems simple and silly now, but why didn't I think of that, I have been doing it "the hard way" for a very long time.

The results - a Good looking, stable Toroid, filled with Hot Glue, and ready for though-hole or surface mount.

Toroid - Ready to Mount

Building toroids, with short leads, are now fun again!


One of my Hot Glued Cores was used in a QRP transmitter final stage, RF current was enough to heat the core, and melted the glue which ran onto the surface mount parts below. I now do not recommend using Hot Glue for high current or heated cores.