AmateurRadio.com

Well ... my new 1930's style MOPA transmitter is finally finished after several months of construction. I have also put together a page on my website describing the project.

For many years, December's high winds here on the coast, have always arrived coincidentally with the start of the annual 1929 QSO Party, making my signal dance around even more than usual! With the new MOPA, I'll no longer have to worry about high winds upsetting signal stabilty ... although many of us do enjoy hearing these musical sounds of '29!

By the way, there's still plenty of time for you also, to put something together for this annual fun event. You can see a whole page-full of inspiring '29 homebrew magic here (scroll to the bottom half) ... and there is plenty of help available for your project in the AWA Yahoo Builders Group ... we are always looking for more new activity, particularly here out west.

courtesy: natubes.com/

The new MOPA uses two type '10 tubes (like many, I use the war-time type '10 equivalent, the more affordable VT-25), one as a Hartley oscillator and the other as a Class-C final amplifier.

I'm looking forward to working many of you in the next '29 QSO Party ... in the meantime, I'm thinking hard about what my next project might be!

This morning I completed the wiring of the test-bed MOPA's Hartley oscillator circuit. I was using the 80m tank at the time, wound with 3/16" copper tubing. Oscillator keying is about what I expected ... stable but with some ripple on the note. Even with DC on the filaments, many of these open-breadboard oscillators suffer from RF-modulated notes. Sometime wrapping the power supply or keying leads in a ferrite toroid help or eliminate the slight rasp. On the other hand, some builders prefer to have a note that sounds more '29-like, as in all likelihood, not many notes sounded like pure DC back in the day.
I'm really having second thoughts about my construction method and may just jump to the next (final) construction phase rather than slog through completion of the test-bed model. I've already learned much about the layout by getting to this stage and the extra work involved in completing the test-bed model may not tell me anything new.



I'm using a VT-25 version of the somewhat pricey and hard-to-find type '10' tube. The final version will be built in a similar fashion to my Tri-Tet-Ten, on an aluminum sheet atop the breadboard. Hopefully having the groundplane and shorter leads, will lead to a cleaner note in the final version.

I'm rather dreading this next final phase as there is little room for error. The aluminum sheet must be precisely pre-drilled, as well as the breadboard, and protected at all times (especially when making soldered connections) to prevent any finger marks or scratching on the aluminum sheet. There are still several drilling details to be worked out before I can move forward.

Courtesy: http://www.arrl.org/

I've now completed a set of tank coils for the new'29 MOPA project. These were wound with 3/16" copper tubing which has become very difficult to source. Luckily, after much searching, I was fortunate enough to find several rolls locally at a very attractive price. Although I do see it quite often on e-bay, sellers either refuse to ship to Canada or their shipping charges are far too high to make it worthwhile. The larger 1/4" rolls are still readily available, but for any given inductance, will take up a lot more room on the breadboard if space is an issue.

These coils cover the amplifier tank, the Hartley oscillator's tank, and the antenna coupling link. Respectively, the coils measure 4.9uH, 4.0uH and 1.9uH.

Winding these is always fun but the method used requires that the needed length be predetermined and cut from the roll beforehand. The first time I did this, when building my TNT transmitter, I learned the hard way to always add at least another foot to cover the additional length eaten-up by turn-spacing and for coil end flattening and mounting.


While visiting Vancouver for a few days I was able to find a couple of pieces needed for my non-line of sight (NLOS) lightwave experiments.

I purchased a nice 4.25" magnifier lens, with suitable focal length, as well as an inexpensive page-size fresnel magnifying lens. What is particularly pleasing is that the fresnel is a rigid lens, about 2 mm thick, unlike most page magnifiers that are thin and floppy. I have yet to test its blur circle or determine its focal length.

I plan to use one or the other of these lenses in a small, portable lightwave receiver module that I can carry to the other side of the island to listen for the main large transmitter, aimed slightly above the horizon, in beacon-mode. If the smaller fresnel does the job, it will be an inexpensive source for anyone else needing a simple lens for either transmitting or receiving.

If the deep-red light tests prove successful, I'll switch the system to IR light but at this stage I'm not sure how focusing and optimizing receivers and transmitters can be done with a light source that is essentially invisible? Perhaps using an IR source that is right on the edge of deep-red will still have enough visible light to allow finding the optimum focus more easily.



More information on NLOS experiments can be found in Yahoo's Optical DX Group as well is in G3XBM' s 481thz blogs.

As well, anyone in the Vancouver lower mainland (as far as the northern Sunshine Coast area) that might be considering lightwave ... I'd love to work you! Pretty well any high spot in this region is direct LOS for me.

'29 MOPA Plan

I have completed manufacture of the three RF chokes required for my new MOPA project. Two of the chokes (the ones in the amplifier) are broken into three sections, presumably to reduce stray capacitance or unwanted resonances while the choke for the Hartley oscillator section is one single winding.


The choke forms were first turned on the wood lathe, using Mahogany hardwood scrap, to a diameter of 3/4", and then stepped down slightly, for the space occupied by the windings. The windings, using single silk enamel #31, were then done, still on the lathe, while rotating the spindle manually.





I've always been surprised at how little inductance is really needed for effective choking on HF and it would seem that the 'standard' 2.5mH is much more than is actually required. The single-ended version is just 190uH, while the three-section chokes measure just 240uH, about 10% of what normally might be specified today.

With headphones clamped to my ears, the past two Saturday nights have been spent in the Bruce Kelley 1929 QSO Party. Before I was hit with the '29-bug, these two weekends were usually taken up with the ARRL 160 CW Contest, and then with the ARRL 10m Contest the following weekend. Perhaps it's just as well that the BK has taken priority as I'm not sure if I could hang-in until 0100 or so anymore for the topband affair....or sit all weekend for the 10m fracas. At least the BK action finishes up early here out west, as by the time 10pm rolls around, most of the guys further east have hit the sack...my kind of contest!

Courtesy: http://www.spaceweatherlive.com

This year's conditions were rather dismal, on both weekends, as...once again...the planet was whacked with more coronal hole streaming. These things are ionospheric-killers from what I can see, as the level of signal absorption shoots way up, and quickly...not as much however, the further you get from the auroral zone.


Not to disappoint, the usual BK winds came up, right on schedule as well, almost coincidental with the start of the Party. Thankfully, weekend number two saw no wind whatsoever....a rare event in December....but, from the sound of many other notes, I wasn't the only one having windy weather.
  
More information on '29 building may be found here in previous "'29-style blogs" and good project discussions always abound at the Yahoo "AWA Group" builder's site.

It's really not too early to start building for next year's BK!

QST Feb 1931 Courtesy: http://www.arrl.org/

In addition to the new frequency allocations, amateurs heading into 1929 faced several other changes.
For North American hams, many of these had already been in place, but for much of the DX, this was all new.

Some of the more important changes are ones that we have come to recognize as "everyday practice" for the past several decades.

Like our friend below, and for all new amateurs worldwide, mastering CW would now be mandatory.



Courtesy: http://www.arrl.org/

" Article {6} (3) ...any person operating the apparatus...must have proved his ability to transmit passages in the Morse Code and to read...passages thus transmitted."



Licencing was also mandated.

" Article {2} (1) No radioelectric sending station shall be established or worked by a ...person...without a special licence issued by the Government..."

And hams would need to earn their tickets.



Courtesy: http://www.arrl.org/

Article 6 (4) Administrations...take such measures to verify the qualifications, from the technical point of view, of all persons operating the apparatus."





No longer would hams have the luxury of making up their own call signs, although not an issue in North America since the end of WW1.  All calls would now be assigned by the government.

"Article {14} (13) ...private experimental stations must have a call sign taken from the international series assigned to each country."



Courtesy: http://www.steveirwinstamps.co.uk

Courtesy: http://hamgallery.com

The system of Q signals, as we know them today, were to be implemented for all users, both commercial and amateur. As noted in the September, 1928 QST, the signal for "QST" had been removed.

"The prefix for a general call to all stations has been changed from "QST" to "CQ" and the former is now blank in the international list of "Q" signals. That doesn't mean that QST is going to change its name though. If some uncomplimentary meaning has been assigned the letters "QST", such as "You interfere with me -- get out," we might have to." [QST September, 1928]

And no, the list did not include "QLF".

Although chiefly aimed at the commercial ops working mobile stations, such as maritime or aeronautical traffic, many of these new operating procedures filtered-down to amateurs very quickly and are still used today:

" Article {9} (6) When a station is uncertain of the call sign of the station calling...reply...using the signal .. _ _ .. "

" Article {9} (7-1) When it is necessary to make test signals...such signals...must be composed by a series of  V's followed by the call letters of the station working. "

" Article {9} (3-1a) The station calling makes the call...not more than three times...and the word DE, followed...by its own call sign. "
 
" Article {9} (3-3) If the station called is not ready...it replaces the letter K by the signal  . _ ...  (wait)... "


Courtesy: http://www.arrl.org/

" Article {9} (3-9a) The transmission...is terminated by the signal . _ . _ . (end of transmission)... "

 " Article {9} (10a) The acknowledgement of receipt...is given by the means of the letter R."

" Article {9} (11) The end of work between two stations is indicated by each of them, by means of the signal ... _ . _ "
 
" Article {10} (1-1) Stations desiring to enter into communications...may use the signal of inquiry CQ...followed by the letter K... "

Although they had already been operating from Washington, DC, on a limited schedule, Jan 1st, 1929, marked the expansion of WWV, which began a regular schedule, cycling through 40 different precise frequencies during a two-hour period. All transmissions were in CW. This would allow for all users, worldwide, to calibrate their receiving equipment to 1929 standards.

Compiled in November 1928, the January 1929 edition of QST carried these last hopeful words before the big day arrived:

"January 1st, 1929, magic date, is upon us...the dividing line between the old and the new in amateur radio...when we look back...we are going to wonder how we ever got along in 1927 and 1928 with those crude methods which we once employed...It is the duty of every amateur to prepare himself for the new life which exists on the other side of January 1st." [QST January, 1929]

The following month's editorial described the early days of 1929 activity and was somewhat surprsing, considering all of the hard work that had gone into preparing radio amateurs for the new era.

Courtesy: http://www.arrl.org/

"We write in the early days of January. January 1st, another tremendous hurdle, has been safely crossed, and somewhat to the surprise of some of us we seem to be still alive and kicking. The air seems very much the same as it was before; in fact, too much so...in the width of our bands...every amateur knows that these widths were changed. We cannot feel that there is excusable reason for an amateur operating outside the new frequency bands -- our preparation for success...has been thorough. All of us must realize...he who gets on the wrong side of the fence is very liable to be jerked up without warning for trespass...lets play the game. [QST February, 1929]


And so, finally, the long anticipated day came and went, but it seemed the ARRL's task was far from over. Not everyone had gotten the message or, at least, the entire message. VE4GU was all prepared for 1929 with new QSL's for his Jan 22, 1929 QSO with W9DYV on 40m CW but apparently missed the 'other' announcement...his card reports using '500V' of raw AC on his 210 Hartley!

Courtesy: http://www.arrl.org/

QSL cards from 1929 and later still, show many one-tube oscillators and simple receivers yet being used...it was a hard-sell to move hams from what they were comfortable with...but...things were looking up and there would be no turning back.


Without question our cherished hobby was shaped forever by those well-considered pronouncements and the timely leadership of the ARRL during those tumultuous days, so long ago. We owe them a lot.

Drum Dial Rx Tuning Courtesy: http://www.arrl.org/

As the leader of the ARRL's Technical Development Program and its assault on 1929 preparedness, Hull continued his relentless pace of construction and publication in the November 1928 issue of QST...turning now to receivers. The detailed article analyzed three receivers of varying complexity to see how they might fare in the busy "international bands" of 1929...and where improvements might be gleaned.

In "High-Frequency Receivers for the Coming Year / Incorporating Thoroughly Practical and Satisfying Selectivity, Open Scales, and a New Ease in Handling", editors proudly announced that,

 "...practical selectivity for 1929 has been secured; it is within the reach of every amateur." [QST November, 1928]

QST Oct '28 Courtesy: http://www.arrl.org/

Another equally important issue was addressed in QST's October 1928 edition, once again by Ross Hull.

"In view of the present off-band operation, it is not surprising that amateurs have been wondering how it will be possible for them to stay within the relatively narrow confines of the 1929 bands and to know definitely and at all times that the frequency of their transmitters is legal." [QST October, 1928]





"The Frequency Measurement Problem / Applications of the Monitor in Transmitter Setting and Signal Checking" described, in exacting detail, the construction and calibration of a combined monitor and frequency meter that would fulfill the new rules regarding frequency allocations...but only if hams used them regularly.

QST Sept '28 Courtesy: http://www.arrl.org/

 
With the ARRL's reliance on QST's significant advertising revenue as a major source of income, the urgent 'need' to rebuild was not overlooked by the ad-men, as more building would mean that more parts had to be purchased. A skeptic might even suggest that the possibility of increased advertising revenue may have been just as much of a driving-force for the need of new construction than the new rules themselves!

QST  1929 Courtesy: http://www.arrl.org/

Advertisers in QST were not shy about reminding amateurs of the coming deadline as well as promising easy solutions to compliance.









In early 1928, QST published several of the Convention articles that would apply to amateurs. Chief amongst them were the frequency allocations. North American amateurs lost about 40% of the spectrum space that they had previously enjoyed but...the harmonically-related bands, although slimmed-down, were retained along with exclusive access to the new and largely unwanted territory of 28-30mc.

Many amateurs at the time complained about the loss of older frequencies and that the League representatives had dropped the ball. In light of the times, and in view of the commercial feeding-frenzy for new broadcasting allotments, they fared very well.

1929 Band Plan - QST Jan '28 Courtesy: http://www.arrl.org/

With the steady growth of Solar Cycle 17 over the next decade, the exploration of 10m would lead to significant progress in the field of transmitters, receivers, antennas and propagation, driving experimenters to push the "state of technical development" in all four areas. It was, in hindsight, possibly the greatest gift of 1929.

But it wasn't just frequency assignments that were changing...1929 operators would need to change their crummy old operating habits as well! ....(cont'd)