Dave Richards AA7EE

May 11, 2012

A 200mW TX and Regen Receiver Make For Some Very Satisfying QSO’s

It’s been almost 10 months since I published the post on my build of N1BYT’s WBR Receiver – a regen with an unusual design that minimizes re-radiation of the local oscillator signal without the need for an RF pre-amp. It’s fairly sensitive, stable, and only draws about 12-13mA. I’m sitting here right now with this great little regen listening to Bill Crane W9ZN calling CQ in his inimitable style.  If Bill’s the guy I think he is, he was a radio DJ that went by the name of Bill “Butterball” Crane in the 1970’s, and his sending is unmistakable – especially his rhythmic and creative CQ calls.

In the time since I published the post on the WBR, it has been far and away the most popular post in this blog. Every now and again, my build of this receiver is featured on another blog or in a forum, and the page views peak for a few days. Currently the Yahoo QRP-tech group are looking for a regen receiver for one of their group builds, and the WBR is one of the designs under consideration.  I hope that at least some of the members choose to build it. Not all regen designs are created equal; I’ve read of some builders having problems with hard-to-control regeneration, or hum issues caused by the local oscillator signal being radiated by the antenna. The WBR doesn’t suffer from these issues.

As if all this attention online isn’t enough, my build of the WBR (Wheatstone Bridge Regenerative) Receiver is about to be featured, along with photographs, in a new edition of an ARRL book to be released soon.  As I mentioned in an earlier post, Daniel N1BYT is either very gratified, or thoroughly fed-up, with all the attention his design is still receiving over 10 years after the date of it’s first publication!

After building it, I spent a month or two happily listening to, and fiddling around with it, then got caught up with building a beta version of NT7S’ CC-series QRP transceivers, and then building a K2.  Since finishing it, most of my other projects, including the WBR, have been boxed away, leaving pride of place at the operating position to the K2.

Then a couple of days ago, I pulled the WBR out of storage and hooked it up. I connected it to a 2 transistor TX powered by a 9V battery that I built based on W1FB’s implementation of the Pixie 2, and this evening called CQ with a whopping 200mW coming from the plastic 2N2222A in the final.  The Reverse Beacon Network showed a 20dB spot from N7TR 180 miles away in Reno and I figured it was worth continuing to call.

Eventually, NY6G in Tracy, CA gave me a 429 and we chatted for about half an hour. Stan lives only 46 miles away from my QTH in Oakland so although it was quite gratifying to know that he was hearing the flea power signal from my little 2 transistor transmitter, the thing that was really satisfying about the QSO was more to do with the fact that it connected me to the world of amateur radio that I remembered from my boyhood in the 1970’s; a world where there seemed to be more camaraderie and gentlemanly behavior.  Stan told me that he was born and grew up in Oakland, where I currently live.  He then moved to Alameda, served in the Air Force and left the immediate area after WW2, but remembers his Mum taking him to Lake Merritt to watch the boats. (I was watching the boats on Lake Merritt just 2 days ago.)  He also remembers when the streets were lit by gas lamps, a job which was performed by a man carrying a long pole.

Sitting at my desk with a separate transmitter and receiver that I had built from schematics Manhattan-style and using them to hear about what the city I live in was like in the 1930’s from a former resident was pure magic.  Stan was getting a kick out of my home-brew separates too:

The Altoids tin on top of the receiver is the N0XAS PicoKeyer.

This is a fun little set-up. The next day, I powered the Pixie 2 TX from 12.8V which allowed it to go QRO and output 500mW. Over the next couple of evenings I worked KI6ON Joe in Santa Clara CA, KE7GKM Bob in Boise ID, W6VJJ Rex in Half Moon Bay CA, N0EK Ed in Bergen ND, KF6RMK Bill in San Rafael CA and Jerome VA7VV in Vancouver, BC

Jerome had a couple of traditional receivers in the shack on which he was having trouble copying my flea-power signal – an FT-950 and a ProIII. However, on his SDR-IQ (a state of the art SDR receiver) with the bandwidth dialed down to 75Hz, he was copying with no problem.  He said it was the first time that he had experienced such a substantial difference between copyability between conventional receivers and SDR receivers. The thought of the signals from that little 2 transistor TX being heard in Vancouver almost 800 miles away was pretty neat.

It was great to QSO with KF6RMK too. Bill lives locally and we run into each other on the air from time to time.  We exchanged e-mails after our QSO and Bill sent me a picture of an old regen that he bought as a kit from Radio Shack many moons ago. He put it into his own case and wound some coils for it to turn it into an all-bander. Neat looking regen Bill! He said that our QSO has inspired him to drag it out and see if he can get it going on 40M  (photo credit Bill KF6RMK):

It’s been fun putting the WBR and Pixie 2 TX back into service for a while.

Now what can I build next……?

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July 4, 2009

Amateur Radio on a World War II Submarine!

This blog is a little out of chronological order.  It happened before Field Day, yet I am writing about it after Field Day.  This kind of thing shouldn’t happen once the blog is well underway, but after making my first entry, I realised I wanted to talk about this, so here we go.

The weekend of June 6th and 7th was the annual Museum Ships On The air event in which historic vessels take to the amateur bands. I met Bill KF6RMK on the Mount Diablo repeater the day before the event began and he invited me to take a look at their event station aboard the USS Pampanito. Well, I had never seen a WWII-era submarine, so the next day, my friend Antoinette and I took Bart to San Francisco to take a look at this sub which is anchored at Pier 45 at Fisherman’s Wharf in the city.

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Bill KF6RMK in the operating position of the radio room aboard the USS Pampanito.

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Dennis K6ZJU in the radio room aboard the USS Pampanito.

At the back of both pictures, you can see the original equipment (all I understand in working order – and it is fired up from time to time).

To the left, hidden away in a cabinet is the more modern amateur radio equipment that is used to put the Pampanito on the amateur bands.

Antoinette was sufficiently interested that she is now thinking about getting her tech license. Go Antoinette – and talking of Antoinette (also known as Mixtress 9 of KALX Berkeley), here she is on the sub as well:

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A most interesting afternoon. Thank you Bill and Dennis – and make sure to look out for the USS Pampanito, NJ6VT. They operate on the second Saturday of every month, and during special events.

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