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Friday, October 31, 2025
Dale Parfitt, W4OP, Inducted into the QRP Hall of Fame
Wednesday, March 11, 2020
QSO Today Interview with Dale Parfitt W4OP
Eric Guth 4Z1UG interviewed Homebrew Hero Dale Parfitt W4OP on the QSO Today podcast. The interview is really great. Listen here:
https://www.qsotoday.com/podcasts/W4OP
Wow, libration fading. Who knew?
Dale has appeared in many SolderSmoke bolg posts and podcasts. He is definitely in the Homebrew Hero category.
Check out some of those blog posts here:
https://soldersmoke.blogspot.com/search?q=Parfitt
and here:
https://soldersmoke.blogspot.com/search/label/Parfitt--%20Dale
Thanks to Eric and Dale.
Friday, July 29, 2011
Amateur radio at PAR (W4OP)
 An e-mail exchange on QRP-L this morning about using ceramic resonators in 455 kHz filter circuits (great idea Grayson!) led me to the ham radio corner of the PAR electronics web site.  PAR is the company run by Dale Parfitt, W4OP.
An e-mail exchange on QRP-L this morning about using ceramic resonators in 455 kHz filter circuits (great idea Grayson!) led me to the ham radio corner of the PAR electronics web site.  PAR is the company run by Dale Parfitt, W4OP.  http://www.parelectronics.com/par-amateur-radio.php.
That's a nice looking 2-B Dale! Please send us the serial number! Even more impressive is Dale's award-wining homebrew solid state version of the 2-B (on the far right). Visit his web site for more info (on his site you can hover your mouse above the pieces of gear for more info).
I'm proud to say that I have a piece of gear in my shack that was built by Dale Parfitt. The story is told in SolderSmoke The Book: I'd built my own version of Doug DeMaw's Barebones Superhet and had liked it a lot. When I saw another one (this one built on a FAR circuits board) for sale on e-bay, I bought it. It stayed on the shelf for a while. Years later when I started working on it, I turned to QRP-L for help and this fellow named Dale Parfitt came to my rescue. It was only after a long series of e-mail exchanges did we realize that the receiver we were discussing had been built (and sold to me) by... Dale Parfitt.
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Saturday, December 12, 2009
Dale Parfitt, W4OP, Homebrew Hero
 Yesterday,  in my search for pictures of the Drake 2B, I came across VE3MPG's excellent interview with Dale Parfitt, W4OP.   Dale and I crossed paths years ago:  After I built my first version of Doug DeMaw's Barebones Superhet, I went out on the net and found a couple of kit versions of this receiver for sale.  A few years later, I was working on one of them, and turned (as you do) to QRP-L for some advice.  Dale came to the rescue and we started exchanging e-mails.  After a while he told me that the version I was working on sounded familiar.  Sure enough, he was the original builder!  The story appears in SolderSmoke -- The Book.
Yesterday,  in my search for pictures of the Drake 2B, I came across VE3MPG's excellent interview with Dale Parfitt, W4OP.   Dale and I crossed paths years ago:  After I built my first version of Doug DeMaw's Barebones Superhet, I went out on the net and found a couple of kit versions of this receiver for sale.  A few years later, I was working on one of them, and turned (as you do) to QRP-L for some advice.  Dale came to the rescue and we started exchanging e-mails.  After a while he told me that the version I was working on sounded familiar.  Sure enough, he was the original builder!  The story appears in SolderSmoke -- The Book.Here is further evidence that Dale and I have similar tastes in receivers: Pictured above is his solid state version of the Drake 2-B. FB! I note that the dial scales are the same as the hollow-state version.
Here is the VE3MPG interview:
http://ve3mpg.blogspot.com/2008/10/interview-with-dale-parfitt-par.html
Thursday, February 26, 2015
Video on W4OP's Progressive Receiver (Solid State Drake 2-B)
This is so great. I saw pictures of Dale's receiver a few years ago, but somehow missed the video. I am the proud owner of a W4OP-built Barebones Superhet. And, of course, of a Drake 2B (mine has tubes!)
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Thursday, December 5, 2013
W4OP -- Earth-Moon-Earth and Another Barebones Superhet
And his vintage projects here: http://www.parelectronics.com/vintage-radio-restoration.php
And here's what Dale has been doing with the Moon (that's his 15 foot dish in the picture):
for PAR Electronics, Inc.
http://www.parelectronics.com
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Wednesday, July 4, 2012
AA1TJ -- As always, in the Vanguard
----------------------------------------------------
From AA1TJ:
Wahoo...Dale, you amazing!
You are my first QSO with the Vanguard 1 reproduction satellite beacon transmitter. My circuit is a fairly close copy of the one shown on the lower left-hand corner of the 1959 CQ Magazine article (notice the output signal pick-off shown in this schematic is incorrect, or at least incomplete). My circuit uses link-coupled output impedance matching, which is similar to the only other documentation that I was able to dig up. The attached image "Early_Microlock_Bcn.jpg" was snipped from an original NASA report on the transmitter used in early airborne and sub-orbital tests leading up to the Vanguard flights.

Yes, you heard correctly. I'm using a Philco 2N504 surface-barrier transistor, but please let me back up a bit.
Roger Easton (a native Vermonter...and still resides here!) was at the helm of the communications development for the Vanguard/Minitrack project. Of the Vanguard "grapefruit" satellite beacon transmitters, he wrote in the May 2008 issue of High Frontier magazine
"We tried subminiature tube transmitters first. They worked marginally. Finally, Bell Telephone/Western Electric developed a very nice transistor for the task, and the problem was solved."
However, that leaves out a small detail. They first tried Philco surface-barrier transistors, which worked fine on the bench, however two problems were discovered. They were found to be too temperature sensitive; the RF output power from the one-stage transmitter dropped excessively at elevated temps. Secondly, there was some issue with the packaging that produced erratic operation when the transistor was rotated positionally. The Western Electric devices proved better on both counts.
The WE transistor appears to be "unobtainium" these days. That, plus the fact that my circuit won't be flying up to space anytime soon, prompted me to settle on a Philco 2N504. Although my device was manufactured in September of 1959 (Vanguard TV-4 - re-Christened "Vanguard 1" - first orbited on March 17, 1958), the 2N504 was an off-the-shelf item on the launch-date.
The only other obvious difference is the Vanguard 1 beacon circuit operated on 108MHz, whereas mine is presently working on 14.0596MHz. I recently had it running as a beacon on 10m for 48 hours but I had no luck given present band conditions.
The receiver is a simple, 0-V-0 regenerative set using a single Raytheon QF721 (fabricated in February 1953). I heard little activity on 20m when I started up my auto-keyer this morning. I had it looping 3X1 CQs whilst I worked on another project. To make matters more difficult, the exhaust fan was running in my shop and it happened to be raining heavily when you called. Worse yet, the receiver had drifted off my calling frequency by the time you called. I barely discerned a high-pitched CW "1" or "J"...which prompted me to quickly switch off the fan and re-tune. You were subsequently a solid 579.
Of course my heart jumped when I heard you calling me...how I love that feeling! And it was a fabulous QSO so far as I'm concerned. Following our contact I opened my metal index card file box and pulled out the QSL that you sent to me following our "Code Talker" QSO. To think I now have another happy memory to add to that one! Thank you once again, Dale. It figures you'd be the one to pick-off my unannounced presence on the 20m QRP calling frequency with 25mW. Well done, OM.
Also, you might enjoy this video of the actual launch, including some interesting control room audio banter. It may be found here: http://www.nrl.navy.mil/vanguard50/index.php. The way at least one of them nervously repeats, "Keep going baby!" gives some indication of the pressure these guys were under...having failed so spectacularly on two previous occasions.
All the best,
Mike, AA1TJ
Hi Michael,That was fun!I first heard you on my SG-2020 rig, but did not have a paddle handy, so I fired up the K3. I don't ever recall having QRN on 20M, but it was bad. Without it, you were 579 and even with it, 569 towards the end of the QSO.I just happened to be QRV on 060 listening when I heard your CQ's. Not bad for a 25mW signal from (I think you said) a Philco transistor.73,Dale W4OP
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Friday, November 18, 2022
The 2Q -- A Homebrew Solid-State Drake 2-B from 1967
This is really an amazing project. Way back in 1967 (that's 55 years ago) John Aggers W5ETT of Ponca City, Oklahoma decided to homebrew a solid state version of our beloved Drake 2-B receiver. Triple conversion. No crystal filters. Twenty two discrete transistors and no ICs. Tuned circuits at 50 kHz to provide most of the selectivity. And he did it. Just look at the picture above. It even LOOKS like a Drake 2-B.
I sent this to our friend Dale Parfitt, W4OP who more recently built a receiver like this. He too was amazed by this project.
The article by John Aggers is very clear and provides a lot of good information on how he designed and built this receiver using the technology of 1967 and junk box parts. I was struck by the lack of diode ring mixers. And I was somewhat taken aback by his use of plug-in socketed transistors. The AF amplifier is our still-familiar transformer-less push-pull complementary pair design. John did a wonderful job on the mechanical tuning and slide rule mechanism.
Three cheers for John Aggers W5ETT. This article is a reminder of the great benefit to the hobby of writing up a project and putting out there in the world. Here we are, more than half a century later, reading John's article and learning from it. FB OM.
Page 8
Saturday, January 2, 2010
SolderSmoke Podcast #120
http://www.soldersmoke.com
January 2, 2010
Olive harvest in Sabina, Christmas and New Years in Rome.
"What, no Klingon?"
How's my whistling SSSS problem?
DX on 20, HW8 QSO with KZ1H
Auroral flutter on US stations
W4OP: Homebrew Hero
Softrock progress
Linux woes
72 Part Challenge: "Stuck between best wishes and hugs and kisses!"
Chinese Hamsat in orbit, with CW telemetry
AA1TJ in CQ, and using diodes as audio amplifiers.
Stradavari and Julia Child:  inspirational late starters!
Billy's RC plane
QRSS:  telemetry next?
WSPR:  150K reports per day
New issue of Hot Iron
MAILBAG
Monday, November 9, 2009
Transatlantic Team Heads to the Coast!
 When it comes time to cross the pond, it seems only natural to head to the beach.  That's what Marconi did (above we see his team struggling with a kite at Newfoundland). And that is what AA1TJ, W1REX, AA1MY and W1PID are doing today and tomorrow.  Here is Michael's message to QRP-L describing the expedition.  Good luck guys!
When it comes time to cross the pond, it seems only natural to head to the beach.  That's what Marconi did (above we see his team struggling with a kite at Newfoundland). And that is what AA1TJ, W1REX, AA1MY and W1PID are doing today and tomorrow.  Here is Michael's message to QRP-L describing the expedition.  Good luck guys!  Some of the lads are heading over to the Maine seacoast on Monday
morning for what we're calling a "Rexpedition." W1REX was kind enough
to secure the use of his family's beachfront camp for us for a couple
of days. He explained the urgency to them, saying, "...a bunch of
radio-heads want to talk to Europe with the equivalent of a cellphone
with a dead battery."
Rex, Seab, AA1MY and Jim, W1PID, are going to arrive early on Monday
to begin putting up the antennas. I plan to show up in time for lunch;
hopefully after all the hard work is done. Seab wants to erect a pair
of half-wave phased verticals on 20m. I think the plan is to lift a
160m antenna using one of Seab's big kites.
Our hope is to cross the pond on both 160m QRP and with my
voice-powered 20m transmitter. The weather forecast looks great at
least through Tuesday. My "Code Talker" will be rockbound on
14.055MHz; same as last Thursday. We'll begin the voice-powered 20m CW
attempt the first thing on Tuesday morning (11/10/09). Again, the goal
is to span the Atlantic, but as always, I'll be very pleased to work
anyone that hears me.
By the way, last Thursday's voice-powered operation on 20m was a great
success. Altogether, I worked four stations and received one SWL
report. The best DX was W4FOA in Chickamauga, GA; a distance of
923miles. Tony reported that my 15mW signal was "an honest 579". W4OP
- located one hundred miles to the north of Tony - handed me the same
report and followed up with an amazing recording (you can hear it on
my website). Later in the day I received an email from AD5VC. Dana
reported that he clearly copied my callsign while listening on the LSU
club station (K5LSU) in Baton Rouge; a distance of 1375miles (nearly
half the distance between the Maine coast and London, England).
I thought these were remarkable results for 15mW into an endfed wire
at 35 feet. It makes next week's attempt from a saltwater QTH, coupled
with the low-angle of radiation with a spot of directional gain all
the more exciting.
So please keep us in mind come next Tuesday morning. I'm guessing Seab
will be operating 160m QRP on both Monday and Tuesday evenings.
Thank you,
Mike, AA1TJ
Wednesday, February 9, 2022
Video of SolderSmoke Podcast #235
One contact on uBITX. More SW listening.
Repaired my Chrome Book in Santo Domingo!
Christmas Present for All: James Web Space Telescope launch
Saturday, September 7, 2013
BITX Build Update #6: Rock Steady
So, having given up on the VFO, this week I built a VXO. The IF in my W4OP-built Barbones Superhet is at 5 MHz. That receiver has a VXO running at 23.133-23.168 MHz with two crystals switchable from the front panel. My plan is to build a 5 MHz filter for the BITX 17. So I just plucked one of the crystals in the Barebones RX and used it to test and tweak the VXO. Trying different values for the series inductor, I got wide variations in freq swing. With .7uH I could only pull the rock 9 kHz (too little). With 5.6 uH, it was pulling 434 KHz (way too much -- it was acting like a VFO). 3.213 uH was just right: With my 19-148 pF variable cap (with 53pF in series) I got a swing of 22 kHz, with crystal-oscillator stability.
I know, I know: I could have done this with a DDS chip, or with an SI570. But simplicity is a virtue, and the BITX is all about simplicity, right? Having recently built a DDS RF generator, and now this simple three transistor device, I must say that I like the simple analog circuit better. But hey, that's just me. I'll talk about this in the next podcast.
Today I built the mic amp circuit. You can see it off to the right of the VXO.
One of these days I'm going to have to actually troubleshoot and fix my Tek 465. But I'm
afraid of that thing! The voltages in there are HIGH, and so is the circuit complexity.
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Saturday, August 6, 2016
SolderSmoke Podcast #189: Juliano Blue, FET Amp, Si5351 QSK, Bill LC VFO, QSOs
SolderSmoke Podcast #189 is available:
http://soldersmoke.com/soldersmoke189.mp3
Billy in Europe. Bill in Virtual Reality.
Great News: Little Gonzalo is "all clear." Thanks for the help.
BENCH REPORTS:
Pete paints the rigs blue.
Pete's FET amplifier project with FET switching and key pad
Using an Si5351 for CW offset and QSK.
Bill working on VFO for a rig built around HRO dial and gear box.
HRO gears seem a bit loose. What should I do?
The search for an Imperial Whitworth.
For variable caps, brass is better, but two bearings beats brass.
QSO REPORTS
Pete having fun with homebrew rigs.
Bill works K3MRK, WA3O, W4OP, W1VLF and N6ORS
MAILBAG:
Dallas CBLA
Conventional Current Flow Controversy
"I regret ever listening to your podcast!"
LCR recommendations
Sunday, January 18, 2015
Digitizing the Barebones Superhet
I did this for Pete. And I did it to start out the new year with something different. And because I needed the crystal for my beloved BITX and didn't want to buy more crystals.
After successfully broadening the filter in my Barebones Barbados Superhet (originally built by Dale Parfiit W4OP) I decided to replace the VXO with an outboard Arduino/DDS device. Nothing new in that (I was playing with this back in October), but in what I think is a symbolically significant twist, I pulled out the tuning cap for the VXO and, in the hole left by the tuning control, replaced the knob with a BNC connector. That connector now carries DDS signals into the receiver. The crystal was at around 23.125 MHz -- that's why the LCD display is showing 23 MHz.
It works great. I was listening to the DX station in Iran this morning.
Here is a video of the October 2014 experiments:
Saturday, July 16, 2016
Preserving Vanguard 1
Ira Flatow of "Science Friday" was recently talking about how best to preserve important bits of the history of mankind's exploration of space. Our old friend Vanguard 1 was mentioned several times. It is now the oldest satellite still in space.
You can listen to the Science Friday show here:
http://www.sciencefriday.com/segments/protecting-the-historic-human-record-in-space/
They also have a transcript of the show on the same page.
SolderSmoke fans will remember the Vanguard adventures of Mike Rainey AA1TJ:
http://soldersmoke.blogspot.com/search?q=Vanguard
This seems to be the month for Vanguard: just a couple of weeks ago, on 40 meters I spoke to Dale Parfitt W4OP. Dale was one of the first people to pick up Mike Rainey's Vanguard replica signals (see link above).
AND...
The Vanguard reproduction project came up during Eric Guth 4Z1UG's "QSO Today" interview with Graham Firth G3MFJ of the G-QRP Club:
http://www.qsotoday.com/podcasts/g3mfj
(Graham has such a great voice. He definitely SHOULD build a phone rig!)
VIVA VANGUARD!
Wednesday, October 19, 2016
The Last Hallicrafters Transceiver...REBORN! TWICE!
Pete Juliano and his colleague Giovanni Manzoni led me this morning to the happy land of Hallicrafters hybrid nostalgia.
It all started with Pete's latest blog post:
http://n6qw.blogspot.com/2016/10/more-junk-box-rigs.html
I admit that I had never even heard of the Hallicrafters FPM rigs. Pete's (uh, I mean Giovanni's) video show's Pete's junk-box rebuild of the old rig. Very nice. Note the presence of the Si5351...
I needed more background info, so I turned to YouTube. This led me to more old friends: Dale Parfitt W4OP has a really nice video of his rebuild of the Halli FPM rig (see above). From his video we learn why Dr. Juliano prescribed a dose of Si5351 for the patient: Dale tells us that VFO instability was a major problem with this rig. Dale fixed his with the addition of an X-Lock board from yet another friend of SolderSmoke: Ron G4GXO of Cumbria Designs.
Dale really out-did himself by building an add-on accessory box for the FPM. Very nice. I especially liked the addition of the W3NQN passive audio filter for CW. I always have misgivings about adding audio filters to Direct Conversion receivers -- this will reduce QRM, but you are still listening to both sides of zero beat. But when you add a sharp CW audio filter to an SSB superhet you will end up with true "single signal reception." FB Dale.
Friday, December 30, 2011
Back to the Barebones (Receiver)
I converted it to a 17 meter receiver. I put in a VXO, using two crystals controlled by a panel switch. I also changed the caps in the filter so as to broaden the response for SSB.
As I was going through all these modifications, I turned to the USENET for help and advice. Dale, W4OP, came to my assistance. Little did we know how DETAILED his familiarity with my RX was:
"Bill N2CQR MOHBR"
 news:22f6e3ee.0503292244.1b9a1481@posting.google.com...
> superhet project. I now have the one I built (still on 20), and this
> morning
> I got another one (the one built by someone else on a factory-made
> board)going on 17 with a VXO. I have a THIRD partially built Barbados
> RX board. If this
> keeps up, I'll soon have a BBRX museum.
>Hi Bill,
varicap in a shielded enclosure for main tuning. It was done on a factory
board. Or was that a 6M xverter I sold?
Dale
| Newsgroups: rec.radio.amateur.homebrew From: meara.lon...@virgin.net (Bill N2CQR MOHBR) Date: 30 Mar 2005 22:33:57 -0800 Local: Thurs, Mar 31 2005 1:33 am  Subject: Re: Homebrew projects Dale: Wow, small world!  Yea I think that is the one I'm working on. I think you also had a DC-DC converter to bring the voltage to the varicaps up. Very nice enclosure for the oscillator. I now have it percolating nicely as a VXO around 23 Mhz (for the 17 meter band). Bill | 
Sunday, January 29, 2012
Putting 17 Meter SSB Station On the Air
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
 





