4-State QRP Group "MagicBox" solid state Transmit/Receive System

This turned out to be a very satisfying weekend project. Although I must admit I put in several hours inventorying and organizing all components which made for a very smooth process of "stuffing" the circuit board.

There are images of the finished board
below.

Probably the more challenging part of this kit will be machining the housing for it. The template provided with the kit is not drawn to scale. So I'll need to make some careful measurements before going to the drill press.

I'm really excited about this unit because it will give me the chance to explore running a separate transmitter and receiver for the first time since my novice days back in the 1960s. Only now, instead of a manual ceramic and copper knife switch to switch between receive and transmit modes, I've got this slick solid state device that will make it appear almost as if I am running a transceiver.

Beginning work on digital T/R switch

Today I've started work on the Four State QRP "Magic Box" digital transmit/receive switch.

First photo below shows bagged components and construction manual.

Second photo shows component tracking sheet used to ensure correct picking & placing of each component.

NS-40 is completed

This was a very simple build, having just a handful of components. This is a Four State QRP transmitter designed by N0SM.

The view below shows the completed board mounted in an aluminum case which still needs some customization to give access for power and antenna connections.

NS-40 QRP transmitter status

Worked this weekend to complete the NS-40. I decided to do a modification that allows me to swap crystals instead of being limited to the one provided in the kit. The idea came from Jay - W5JAY. Now all I need to do is find a supplier with a reasonable cost.

NS-40 QRP transmitter status

Worked this weekend to complete the NS-40. I decided to do a modification that allows me to swap crystals instead of being limited to the one provided in the kit. The idea came from Jay - W5JAY. Now all I need to do is find a supplier with a reasonable cost.

Next kit project: Four State QRP Group Station

For my next QRP kit project I chose the recently introduced Four State QRP Group Station which consists of a separate superhet receiver & transmitter for 40m along with a microprocessor-based T/R switch, which has been dubbed the "Magig Box.".

I'm looking forward to building this kit and getting on the air because it will be the first time I've run a separate rcvr / xmtr since my Novice days back in the 1960's. Back then I was running a Hallicrafters SX-130 receiver and a Heathkit DX-40 transmitter. A 60w incandescent lightbulb was my dummy load and a simple copper knife switch was a T/R switch. Simple and effective. I worked a lot of stations (and even some DX) with that setup. My antenna was a longwire.

If the "Magic Box" works as well I expect I hope to build additional transmitters, especially one for 10m now that the sunspot cycle has become more active. The Magic Box effectively makes running a separate rcvr and xmtr almost like running a xcvr according to the guys at Four State QRP.

This new station ensemble first appeared at the 2010 OzarkCon held in Branson, MO.

I'm also considering running separate xmit/rcv antennas to see whether that is a more effective approach than my current dipole cut for 40m.

John Kraus - W8JK

One of the things I enjoy most about my work as a Research Librarian at an engineering company is my exposure to all kinds of technology and related books and online resources. I recently skimmed through John Kraus' classic, Antennas and, although I am not an engineer, found several sections of the book very valuable to my understanding of simple wire antennas. John himself was a ham, W8JK, who is well know for his innovative antenna designs.

While reading through the chapter on dipole antennas, I came across a Beetle Bailey cartoon which, for me, captured part of the essence and mystery of antennas. Beetle is up on the roof holding an antenna while his buddy inside is telling him when it is positioned just right for a good signal. In the next frame, Beetle slips and begins falling off the roof. In the final frame Beetle is shown hanging upside down off the roof still clutching the antenna, as his buddy shouts out, That's perfect right there!

So often, that's what happens in antenna work. You read about all the theory behind an antenna, but when it comes down to making it work, reality sets in and the concept of "free space" goes out the window. Thanks John!

Final thoughts on the 2011 CQ WW DX contest

This was my personal best result yet for a contest. Band conditions on 20m, at least here in northern Idaho, were excellent. The last hour was a mad rush to the finish.

I logged almost as many contacts in the last hour of the contest than I did all the other hours. I finished with 38 contacts. All were made on 20m.

I was impressed that the QRP signal from my OHR-100A was able to punch through several times under messy pile-up conditions. I was amazed at how many times I simply dove in amongst a crowd of signals and still managed to be heard.

Can't wait for next year's contest...and perhaps I'll be active on 15m by then!

2011 CQ WW DX contest

Really enjoying the 2011 CQ WW DX contest. Last year I was only active on 40m since I only had my NorCal 40A. This year, so glad for my Oak Hills Research 100A for 20m. Still, the NorCal 40A is a superior contesting rig as its keyer speed and auto send controls are all on the front panel. The same controls on the OHR 100A are located on the rear of the XCVR making quick use of them awkward. I do like the bandwidth tuning on the OHR 100A, it came in handy on several pileups during the contest.

Not sure why, but even though there was activity on 40m, I have had no luck making any contacts there, yet. Lots of QRN.

20m has been hot and cold, but when it's been hot, activity has been phenomenal! Signals so loud they practically blew the headphones off my head. ...and that was with the AF turned down quite a bit. Stations such as KH7X, N6WM and WX0B were blasting through like gangbusters. I could consistently hear them with the AF almost off.

I've worked about 25 stations so far, not bad for my 1-2 watts out to my wrap-around 40m dipole. Made contact with stations in Russia, Japan, the Bahamas, Alaska and most parts of the US, including, Texas, Georgia, and Pennsylvania to name a few.

Still plan to get on for a few more hours if propagation continues to be favorable. Would have liked to get on 15m, as that band has seen some strong activity at times this weekend. But, not 15m gear this year. Maybe next year.

Gearing up for the 2011 CQ WW DX contest

I'll be running single operator low power

Last year I only had my NorCal 40 rig which pretty much limited me to night time operating. Really looking to operating on 40m and 20m now that I've added my OHR 100A. Hope propagation cooperates but it will be fun no matter what happens.

The Novice Historical Society

If you have not seen it yet, be sure to visit the Novice Historical Society web site created by Cliff Cheng, PhD, AC6C and former WN6JPA (1975). The site is dedicated to preserving unique history of the Novice era in Amateur Radio (1951-2000). And what a wonderful time it was for us all back then!

If you were a novice during that time period please visit the site and add your story to the many that have already been published. I contributed my story, which began in 1969 when I was a young teenager.

The site has a full timeline of events from that period.

Cliff is still looking for Novice stories from the 1970s - 2001. He and many others have dedicated significant time to making this a very well-done site. If you can help, please contact Cliff.

Antennas: Theory vs. Practice

One of the things I enjoy most about amateur radio is the fun of experimenting. I've always enjoyed trying new things with antennas to see whether I can improve signal reception and transmission. Recently I purchased an Icom 2m monobander and, along with it, an Arrow yagi antenna. I really like the antenna as it is very light, easily to assemble and disassemble and comes pre-tuned.

My QTH presents several challenges as it is located in a fairly deep "bowl" out of eyesight of local repeaters. On top of that there are significant restrictions on putting antennas up so I need to bear that in mind when considering installation. For my new 2m antenna I decided to try it inside the house initially to see what reception would be like. I was able to just barely get a signal from the repeater with the antenna mounted on a 5 foot pole and then lashed to a five foot ladder.

Last evening I decided to put the antenna up in the attic to see whether the additional height might improve reception. I crawled up into the attic amongst the beams and suspended the yagi, orienting it about the same as it had been downstairs - making it about 30 feet in the air. To my dismay, reception was worse regardless of the antennas' orientation! The most challenging part of this work was not having the radio up with me in the attic to be able to observe the S-meter as I changed orientation.

After my XYL returned home I asked her to watch the S-meter on the Icom as I rotated the antenna up in the attic. Same result. no matter how I changed orientation, there was no signal. I should note that the antenna was oriented horizontally, I was only rotating it in a horizontal plane.

So, back to the drawing board.

Next, I decided to try holding the antenna out on the small porch to see if having it outside might improve reception. Again, no signal as I held it away from the porch but in the same horizontal orientation that would be optimum for a yago antenna. As I brought the antenna in to the porch my XYL yelled out, "Good signal now!" Strange, considering the antenna was practically in a vertical orientation.

So, back inside, I decided to throw antenna theory out the window and go with what was actually working. I stood near the radio with the antenna positioned vertically. The S-meter moved to nearly S5! As soon as I oriented it horizontally the signal dropped to S0. Although I do not understand how this is possible, it does remind me of old days when my Dad would climb into the attic with a new TV antenna in an effort to help us get the ABC channel back in Binghamton, NY. He would tell us to yell out to him after he was up in the attic if the signal improved. Invariably, we would start to call out, even before he got all the way into the attic, that the picture looked great. He would always get so exasperated.

Here I was, 50 years later, in the same situation. Which just goes to show that theory only goes so far. At some point you need to trust what experience tells you.

Christmas Island DXpedition!

Patience and persistence paid off! After nearly an hour of calling the T32C DXpedition on CW on 20m I finally made contact. What a thrill to have done it with my OHR-100A QRP XCVR and my simple dipole wrapped around the house. The Great Circle distance is 3929.2 miles. I doubt my signal was more than 1 or 2 watts. Very exciting!

2011 RSGB IOTA CW contest

At around 1700 hours local time I set up my S9 31 foot vertical in the back yard with 16 radials. Had my station set up up outside on the patio about 50 feet from the antenna. My original plan was just to test out the OHR 100A on the vertical after having no success on the dipoles wrapped around my house.

Propagation was strong on 20 meters with lots of contest calls. Checked the contest calendars and discovered that this was the weekend of the RSGB 2011 IOTA! Decided to jump in to road test the new rig and keyer.

The OHR 100A was putting out about 3 watts. I spent the first few hours trying vainly to make a contact. Then finally made an IOTA contact with KU8E in Georgia! Followed that up with an IOTA contact with KL2AX in Alaska. Notched 12 other contest contacts including ZL1TM, EA8URL (Canary Ialands), W4S (Special Station in Florida) and W6UX on Anacapa Island off the coast of California.

By around 2300 local time, 20 meters had pretty closed down for me in Idaho.

Really enjoyed the contest and it was great to return to 20 meters after many years!

OHR 100A PK4 Keyer

Built and installed the PK4 keyer for the OHR 100A. Product works well. Many ways to customize and personalize it by programming it. The primary downside is that controls for the unit are located on the back side of the OHR 100A forcing the operator to grope around the back side of the xcvr to adjust the keyer speed and press the function button.

Fortunately, the unit works pretty well right out of the box. Looking forward to putting the keyer and xcvr to the test on the 2011 IOTA contest.

OHR 100A is completed

I completed the OHR 100A last week. The receive side of the rig worked fine right out of the gate, all I had to do was tweak the VFO (L114) to get it in range for the low end of 20m (14.020). Having no main station XCVR I used my trusty Hallicrafters SX-130 to find a station near the low end that I could also find on the OHR 100A.

On the transmit side, there appears to be a problem with either the wiring on my straight or with the straight key jack itself. May possibly have a cold solder joint on the key jack. I'll troubleshoot and resolve the issue this week.

I still need to build and install the OHR 100A keyer unit. Hope to get that done this week.

Can't wait to get active on 20m again. Propagation last night was very good. Heard stations from Russia, Estonia and Ukraine as well as Hawaii, Virginia and Cuba, all with just my simple dipole wrapped tightly around my house.

Also looking forward to seeing how my S9 tunes up on 20m.

OHR 100A progress update

Here's a look at my progress so far building the OHR 100A 20m xcvr.  Component placement has gone smoothly. 

Next phase is toroid winding, there are 9 toroids but most are simple. I don't anticipate any problems. 

My main concern is that the kit provides no interim testing along the way. So identifying issues after the entire board has been populated could be challenging. The kit simply instructs the builder to install all resistors first, then capacitors, then transistors, etc. 

There are two other build phases to this lit: 

   - component placement for the 20 meter band pack

   - the build for the electronic keyer option

The photo below shows progress to-date installing components. 

   OHR 100A PCB partially populated

OHR 100A kit build report

Started installing components on the circuit board. Unfortunately, the kitting provides no information as to placement of components. Other kits I've done indicate where, for example, R105 is located. Having to individually identify the location each component is quite time-consuming.

Except for that, the build has gone smoothly so far. All resistors are installed.

I'm really looking forward to getting this rig on the air.

Next kit project: OHR 100A 20m QRP CW XCVR

Although I really enjoy my NorCal 40A 40m CW QRP XCVR, I've been wanting to expand my operating horizons and be able to operate during more than night time hours. So I decided to build the Oak Hills Research 100A 20M QRP CW transceiver.

I opted for the the memory keyer as well as the 10-turn pot for finer tuning.

I had been considering the NorCal Sierra, and really liked its ability to accommodate multiple bands, but decided to go with the OHR 100A for a different kit building experience.

The rig operates in the 12-13.8V range which is perfect for the power sources I use.

Not sure if I will add the frequency counter, although it might be a good piece of gear to own since it serves as test gear too.

I'm hoping to receive the OHR 100A by June 25 and complete it by mid-July or so. Looking forward to operating 20M again, not to mention working with my S9 and trying other smaller antennas that I really can't erect at the house due to space restrictions.

S9 v31 vs. a dipole at 20 feet

I set up the S9 for a nighttime test comparison with one of my dipoles mounted about 20 feet up and touching my house. I was running my NorCal 40a on battery power. Skies were clear at about 65 degrees F. There was a fair amount of activity on 40 meters, conditions were good for a test.

The result? The vertical was, at least this time out, a superior performer. There was no comparison. The ground-mounted S9 v31 was significantly quieter and heard more signals as well. The other thing about the S9 is that signals are so strong I typically have to reduce my RF gain by 25-50% so my eardrums don't get blown out. It's amazing how much louder many signals are on the vertical vs. the dipole.

While comparing the two antennas,I worked Kevin, K7KHC, in Aberdeen, Washington using the vertical. Had a nice QSO but discovered that trying to use my key mounted on a clipboard was a bit awkward. Still need to optimize that set-up.

After that experiment I moved my NorCal 40, power supply and cables up to my second floor outside porch to enjoy the night sky and see if I could catch any DX. Right around 0500Z I chanced on ZL2AGY, Tony in New Zealand! He was in a QSO so I waited till they finished, but was unable to contact him. Not sure if my signal was not getting out strongly enough or whether he had gone QRT. Anyway it was great to hear propagation working so well into Moscow, Idaho for my S9.

I hope to receive my new radial plate this coming week and am interested to learn whether it will improve the strength of my transmissions. My current radial plate is nothing more than a plumbing fixture with some paint scraped off so the screws and wires all make good contact. Not optimal.

It was great sitting out under the stars, tuning around just by feel. The NorCal 40a has no display so I was able to sit in total darkness, watch up at the sky and tune quietly around the CW portion of 40m. Any time I needed to write, I just clicked on my Petzl headlamp with the red filter on to minimize getting blinded. Worked great.

Looking forward to many more evening sessions like this.