Issue No. 71, May 1989

Contemporary America
and the Decline of Interest in Amateur Radio
excerpts from an editorial in WORLDRADIO

A committee of fine gentlemen met to ponder the idea of a codeless entry level Amateur Radio license. They brought to the discussion only the highest of motives. They are in favor of such and their arguments are persuasive. It is obvious that a great deal of thought went into their report.

The report is well-reasoned except for one statement: "The Committee feels that this proposal, in its own way, can help restore the technical viability of the United States."

Tragically, the problems facing the USA are of such massive nature that repair seems beyond any solution. The disaster we are experiencing has nothing to do with CW or a lack of Amateurs.

Here is the problem. About 80 percent of all applicants screened nationally by Motorola Inc. fail an entry-level exam that requires seventh-grade English and fifth-grade math. Not even the 300,000 Archie comic books touting Amateur Radio distributed by Radio Shack will solve that.

Out of 50,000 people taking the basic employment exam at New York Telephone Co., only 2,100 passed.

When 25 percent of Dallas, TX, high school seniors cannot name the nation that borders Texas, they are hardly candidates for a hobby that proclaims "talk to the world."

A Gallup survey on geography given worldwide ranked the United States the lowest among all developed countries surveyed, including Mexico.

At American universities more foreigners receive Ph.Ds in mathematics than Americans. As Thomas Sowell puts it, "The harder the field, the fewer the Americans.

"If you wonder why you see so many foreign doctors, scientists, mathematicians and other high-level people in the United States, it is because so many Americans don't want to study this hard stuff. We now seem to be turning as soft intellectually as we are morally and physically."

Much has been made of the fact that the growth of Amateur licenses has not kept up with the growth of the population. If one goes back and charts the big growth times it will he noticed that such occurred when great masses of discharged servicemen entered civilian life. That was REAL incentive licensing. They knew that if they flunked out of radio school they would be carrying around 8.5 lbs. of gas-operated, clip-fed, semi-automatic.

There are two other factors, also. No longer, as in yesteryear, does practically every radio have "Short-Wave" where Amateurs could be heard, using AM. How many became interested that way?

And we're fast becoming a nation of couch potatoes. The oversold cables and satellites have resulted in "What will I watch?" instead of "What will I do?".

On the subways of the United States our youngsters' heads are bobbing to the Walkman's sounds. On the Japanese subways their kids are READING!

-Armond, N6WR

Dayton Hamvention AM Forum Report

The results of the AM Forum, held on April 29 at the Dayton Hamvention, were very encouraging. The official attendance according to the Hamvention was 75 persons.

The SPAM Update report at the AM Forum included the new membership rules, the new AM Jamboree operating schedule and the new SPAM promotional brochure.

The "Meet the AMers" slide presentation included over 90 photos of AMers and their equipment. It was well received. This slide presentation and narration will be videotaped.

Don Chester's "AM in the 1990's" discussion pointed to the momentum that AM is enjoying and the many facets of AM, from listening pleasure and older equipment operation, to state of the art experimentation and homebrew.

The audience was composed of active AM operators and amateurs that are considering re-activating their AM stations.

The high point of a discussion on operating practice was when Hank, W2IQ asked, "What about the use of bad language on the air?" and several ceiling tiles simultaneously dropped. This occurrence was attributed less to Divine intervention than to recent heavy rain and a leaky roof.

Thanks to all who attended and sent in photos. See you at the Dayton Hamvention AM Forum in 1990!

Dale, KW1I

ARRL Questionnaire Ignores AM

The 1989 Second Meeting of the ARRL board of directors will be held in July. Some of the division directors have sent out opinion survey questionnaires to League members residing in their divisions to "help us better prepare." The questionnaire form asked such questions as the members' age, bands operated, whether or not they are in favor of a no-code license, and what modes they operate. The latter question asked members to circle the appropriate modes from a list which included the following: SSB, CW, FM, RTTY, AMTOR, SSTV, FSTV, OSCAR and EME. Conspicuously absent from this list is AM!

ARRL officials have repeatedly assured the AM community that there is no League bias against AM, and it is sometimes even implied that those who make such accusations are guilty of unfair attacks against the League and League officials.

The League is supposed to represent the interests of all its members. Whether or not any concerted bias against AM indeed exists in Newington, the fact is, a League questionnaire completely ignores the existence of AM, a facet of amateur radio which enjoys substantial popularity and support within the amateur community. This does nothing to dispel the beliefs of many AMers that the League is not looking out for their interests.

The AM Press/Exchange encourages the AM community to join the League and, as members, make our voices heard in Newington. Nevertheless, until the League shows more than lukewarm support at best for AM, many AMers will continue to decline membership and look upon ARRL as inimical to the AM cause.

New High Efficiency Transformer

A power transformer 70% more efficient than current models has been developed by the Electric Power and Research Institute and GE. According to an article in the Wall Street Journal, the key to the new design is the metallurgy of its core. It uses a non-crystalline structure in which the molecules are aligned in random instead of the orderly pattern. With this structure, circulating currents meet less resistance passing through the core.

The secret to achieving the non-crystalline structure is in rapidly cooling the molten iron used in the core material. This freezes the molecules in a random arrangement before they can line up normally. Called an "amorphous metal transformer," the technology is being applied to pole-type distribution transformers. They have already cut power distribution losses by 60% in applications by the Jacksonville Electric Authority in Florida. Tnx LCARA Patch.

Westlink Report

World Radio Closes Retail Stores

World Radio, a Council Bluffs, Iowa, based retailer of consumer electronics has announced that it has closed 15 of its 24 stores located in four states and is seeking protection from its creditors under federal bankruptcy laws. President Malcolm Ballinger said he hopes to reorganize the company around the remaining nine retail stores located in Council Bluffs and Sioux City IA; Omaha and Lincoln, NE; and St. Joseph, MO. Ballinger and a partner, Luke Northwell, bought World Radio from its founders Leo, W0GFQ and Larry Meyerson about a year ago. World Radio opened its first retail store 25 years ago in Omaha, but the company had its beginning in 1921 with 10 year old Leo Meyerson's fascination with wireless. Leo, who built his first radio out of an oatmeal box and a crystal, went on to found Wholesale Radio Labs in Council Bluffs and several other businesses that specialized in supplying equipment to amateurs and manufacturing crystals. Leo was one of the first to supply transmitters in kit form to radio amateurs in the mid 1930's.

Meyerson manufactured crystals for the government during WWII. Afterwards, he resumed operations as World Radio Labs and once again supplied amateur radio equipment. His Globe Scout and Globe King transmitters are ham radio legends. WRL evolved into the World Radio consumer electronics chain. In 1989, World Radio's sales were estimated at $40-$45 million. Leo, a licensed ham for over 60 years, is retired and lives in Omaha during the summer and spends November through May in Cathedral City, California.


DX-60 Audio Modification
And E.F. Johnson Maroon Paint

 (Schematic of modified DX-60 modulator)

This modification changes the type of modulation from controlled carrier to screen grid. It was suggested to me by Tim WALHLR and it has worked out great. The audio reports have been very complimentary. I rely a lot on Pete W1VZR for a critical ear, and he has a scope to monitor audio. He has given this mod his hearty approval.

He sees a full range of audio and 100% modulation. I am using a D104. The work will go easier if you strip all components (except the 100 mmfd. at pin 9) from the 6DE7 socket before starting.

Tune-up is important. Tune-up in "CW" position first for maximum R.F. output. Then switch to "AM". The plate current will be about half that of the "CW" value. DON'T RETUNE in the "AM" position. Check grid current and set at 2ma.

The efficiency of the 6146 at this reduced screen voltage is about 40%. This puts the output at about 15 watts. When the band is open no one will know the difference. I have decided to get my higher power by using an amplifier. My plate current increases 10 ma. on peaks during modulation. Drop me a line if you have any questions.


This is my big moment!!! All of us at one time or another have dreamed about being able to share something special or profound with our fellow man. Something that will put us on top of the world. Something that others will talk about at swap-meets for years to come. Well for me that time has come! (drum roll please). I've found a readily available aerosol spray paint that matches Johnson Dark Maroon paint!!! Boy, do I feel good.

0K, that's over with, now let's talk. I recently acquired a Johnson Challenger that needed a paint job on the cabinet. So I grabbed the cabinet and went to the local Arts and Craft store. I came across a small 3 oz aerosol made by Testors. It is #1803 and called Deep Maroon Metallic. The test patch on the lid looked perfect. The "Metallic" part bothered me, but I decided to buy it anyway.

The old paint on the outside of the cabinet had darkened somewhat, but the original overspray on the inside matched perfectly. I really can't see any metallic in the paint. The paint finish falls between a satin and a high gloss. As far as I'm concerned the color is perfect. I can imagine it would give a really beautiful finish on one of the Viking wrinkle cabinets.

Heathkit Apache Audio Modification
by Ed Bolton, WA3PUN

I've marvelled at the beautiful audio coming from a certain Apache, for many years. The sound emanates from W3YGC, in Hagerstown, Maryland. Each time I talk to Stan over the air, I'm filled with wonder, at how it's possible for a "Scratchy Apache" to sound so wonderful!

So I asked Stan if he would mind sharing his secret of success with all of the A.M. community in general, and the readers of the A.M. Press/Exchange in particular, and he was kind enough to agree to send me the schematic diagram, for all to see.

After making the modifications on the diagram, I'm sure the proud owner will agree that his Apache doesn't necessarily have to sound scratchy.

 (Schematic of modified Apache modulator)

Class C Optimization for Ultra Low Distortion
From the "Kleenex" - Dean, WA1KNX

Most AMers endeavor to improve their audio, at least in the area of distortion. One area which is seldom examined is whether the class C final reproduces an output signal in exact accordance with the modulating waveform.

I examined this carefully a while back, with my then 6146B-powered DX100 final. (it's since been changed to a pair of 813's, another subject!) The trapezoid scope test is invaluable for this test. The modulation waveform is applied to the horizontal, and an RF sample is applied to the vertical. Thus in a perfectly modulated signal, a triangular trapezoid pattern will be produced, with perfectly straight sides.

In the case of 6146's it turned out to have a noticeable slope, which meant the output amplitude was NOT directly proportional to the modulating waveform, and hence there was distortion. Through experiments, I determined that the modulating screen voltage, derived from a dropping resistor from the plate supply, had too much influence on the output signal. In other words, when the modulating waveform was on the negative swing, additional screen voltage is needed, and conversely on the positive side, less voltage is needed.

Using the trapezoid scope pattern for verification, I changed the screen circuit to a network where part of the screen voltage is from the fixed plate supply, and the other part from the normal plate dropping resistor. This achieved the goal of more screen on the negative swing, and less for the positive, and resulted in a perfect waveform, except for a small "bump" that was still present near cutoff or the bottom of the modulation swing. I determined that increasing the grid drive from 2.5MA per tube, to 3MA, removed the "bump" and left an exquisitely perfect modulated waveform!

With proper voltages now on the final, another overlooked source of distortion is the RC setup by the screen dropping resistors, and bypass caps which can cause phase a difference between the plate and screen modulation signals on the higher audio frequencies. A technique I used to eliminate this was to place a proportionally valued capacitor across the plate to screen dropping resistor, thus canceling the effect of the screen bypass capacitor. Distortion from this can be readily seen as a loop effect of the sides of the trapezoid pattern.

In short, for the 6146, I recommend the following...

3MA per tube grid drive.

Derive 60% of the screen voltage from the plate dropping resistor, and 40% from the plate supply.

Place a capacitor of approximately the same value across the Plate to Screen dropping resistor.

~ 73's and Clean signals!!!  Dean ~

 (Schematic and equations)

by the deacon

At 0545Z on 23 May 1989, an AM milestone was achieved when Bill Diggins (WA8LXJ) of Morrow Ohio reported sigs of "S-9/Q4 to Q5" from W6PSS's 16 mW (milliwatt) AM transmission from Chula Vista - a distance of approximately 2,100 miles.

The event occurred on 20 metres (14286 kHz) following a 3-hour old-buzzard marathon. Noting that signals were greater than 40dB over S-9, the idea of a QRP test seemed to be the natural progression of events for this evening.

Test setup consisted of passing the output of a Harvey-Wells Model TBS-50 thru a Hewlett-Packard Model 8498A 30dB Attenuator thus reducing the measured power output of 16 Watts by a factor of one-thousand or 0.016 Watts (16 mW). Power output was measured ahead of the attenuator with a Daiwa Model CN-720B SWR/Power Meter. Although the use of a Hewlett-Packard Model 435A with thermistor mount and appropriate reflectometer would have yielded more accurate measurements (with repeatability), the 16 mW calculation is within ±10% and does not include the 2dB of insertion loss estimated for the transmission line.

The Ohio receiving system consisted of a stacked "ZL Special" with the top array at 93 ft and bottom one at 60 ft, and a Collins 75A3 receiver. Transmitting antenna is a 4-element KT-34A at 98 ft.

Perhaps some of you QRP Buffs are aware of other milestones. This operator would be interested in further statistics for 20 metre AM if such do exist.

In conclusion, please call Bill or myself on the national SPAM frequency when you are prepared to conduct your QRP milestone.



Contributed by
the deacon

A special ad hoc meeting of Westcoast AMers was convened the evening of May 16, 1989, to pay tribute to Dale Gagnon (KW1I) who distinguished himself and honored the AM community with his contributions at the recent Dayton HamVention. This in no way was intended to minimize the outstanding contributions of Don Chester.

This gala event was hosted by Renato and Monica Salcedo at their showcase Torrance QTH. The meeting was attended by Al Levon (WA6MYC), Rich Smith (KF6EA) and the deacon (W6PSS) - all from the San Diego area .... and of course the guest of honor - Mr. Dale Gagnon (KW1I).

Monica was a most gracious hostess providing coffee and assorted beverages and serving ice cream with cake. As though this weren't enough, the treats were served in their formal dining room (which can only be described in gothic terms... but such a description would fill the pages of this issue).

Dale's reason for being in Los Angeles this week was to represent his high-tech firm at various scheduled meetings with client organizations. To Dale, this was a golden opportunity to meet with Southern California AMers and share with us those AM slides shown at Dayton as part of the AM Forum. For this we shall be eternally grateful. Luckily, the event was captured on 8mm home video - but not with studio resolution.

Dale provided notes of interest for each slide with detail and candor. The candor was tempered with humor as demonstrated with the viewing of the "Henry LR" slides (not to worry Tim, Dale didn't tell all).

About the slides, every contributor can be justifiably proud. Each of you assisted Dale and Don earn another prominent slot at next years Dayton HamVention.

Following the slide show and Monica's refreshments, Renato took us upstairs to his fantastic hamshack. There we were amazed to see homebrew equipment rivaling the finest commercial products available - both in size, performance, and appearance. Equipment included a 1-kW (DC) linear amplifier with bias adjustments for class B & C operation. A homebrew modulator of equivalent horsepower was impressively nested with its companion power supply - all homebrew with the same color motif. Among the greatest eye catchers, in my opinion, was Renato's homebrew velocity microphonium (yes, I said velocity, as in ribbon microphonium). Its appearance is reminiscent of a bygone era. This visitor was impressed with Renato's great appreciation for detail and his sense of organization.

Rich Smith conducted an on-camera interview with Dale, just shortly before the gathering ended (around midnight). We apologize, Monica.

Remarks of the interview follow:

Rich: Hello, I'm Rich Smith, KF6EA. This evening we're gathered at Renato's (KG6NH's) home QTH in Torrance, California to see a featured slide presentation that was shown at the Dayton HamVention. I have at my right here, Dale Gagnon, KW1I, who made that presentation. Dale, I first would like to ask if it was your idea to do this?

Dale: I guess it was, but frankly, I was inspired by the fellas who went to the San Diego ARRL Convention a couple of years ago, and I knew that Dayton was an ideal place to get visibility for AM.

Rich: I understand that some people felt that perhaps the AM Forum would be a big failure, but it turned out to be a smashing success.

Dale: Well, we really didn't know how it was going to work out. We got a lot of free publicity, of course, on the AM frequencies. And, I was real pleased to see the number of people who came out. It shows that many people listen as well as operate in the AM mode.

Rich: Tell me, about how many people were in attendance at your seminar?

Dale: Well, we didn't know how many would come, so we got the smallest room available, with a capacity of 50. When we got to the room, I was pleased to see that there were 65 chairs. We actually filled the whole room - leaving people standing. The official count taken by the Forum Coordinator was 75.

Rich: That's wonderful!

Dale: That made us real pleased.

Rich: Tell me, from your feedback from the hams that attended who are not presently active in the AM community, what kind of feeling did you get towards AM operations and the kind of activity that we're presently experiencing on the ham bands?

Dale: Some of the folks that came out have always loved AM and are active in it now and just wanted to meet other AMers. But, we had quite a few who have been off the bands and wondered what was going on with AM. They were thrilled to see that not only was AM alive and well, but there was actually a resurgence going on - and some got excited.

Rich: I understand that you had a gentleman there that had a Collins KW-1 sitting idle in his Seattle home, and that he was very surprised that this kind of activity existed.

Dale: Yes, I believe that Ken Glanzer (uncertain of spelling), who was also making presentations at a couple of sessions, is going to get his KW-1 back on the air from Seattle as a result of seeing what was going on.

Rich: That's wonderful! Well, I think I can express for all of us, our thanks for taking the lead in sponsoring that forum at the Dayton HamVention, and I think its a real positive idea and probably presents the best side of AM to the Amateur Community. ...-.-

Off camera, Dale gave much credit to K4KYV for his contribution. Especially noteworthy was Don's ability to handle all questions in a most tactful and constructive manner. His presentation was well organized and went well. Much praise was also voiced for our SPAM President, Norm Scott, who came through with timely handout information, video tapes, and a new annual AM Jamboree schedule for an entire year. Dale also expressed his heart-felt appreciation to you 150 or so individuals who provided those terrific 35mm slides.

Finally, Dale was very pleased with the response of the Dayton HamVention hierarchy and their very positive attitude in providing an accurate program. Some changes were necessary in the program concerning the AM Forum, and these changes (for the most part) were performed with a minimum of coordination. But it was the positive attitude which seemed to influence the great success of the forum. And, the response of the visitors has earned another reservation next year for Dale and Don. Welldone to you both. CU on 7192.5 kHz late es 73.

 (Photo of New York Times classified ad for UTC auction)

ATTENTION AMers: 40-metre AM group meets on 7192 khz about 0500 GMT, particularly Saturday night (Sunday GMT). Let's join in and help establish another AM frequency on 40!

open forum

Editor, AM P/X:

Answering Bob Dennison, W2HBE, (AM P/X; Apr. 89, p.6) who is confused about how the Bonadio Earth Shunt Wire works. The Shunt is no different from the reflecting element or screen behind the field of an excited antenna on a beam. There is no way to leave the Shunt wire in place and to "switch the BESW in and out," as Bob tried to do. This is like running a "grounding wire" from the center of an excited beam element (equal to a tuner chassis) over to the reflector element screen. Switching it anywhere will have no significant effect. The measurable effect is found by careful "before & after" tests. Bob will see a difference by pulling his wire out of the ground and then removing it from the lot. He will not see an effect with a switch between two neutral points. The effect is from the radiated "field" that induces "ground-currents" largely wasted in the natural resistance of the soil. The ground wire "Shunts" out most of these resistive losses, in the soil which is nearest the elevated wire. A relay, even in the middle of the ground element, is still further shunted by the soil r.f. resistance between the nearby wires on both sides of the relay, and by the very relay wires included. Bob is a good experimenter. He questions why things work. He's learning, as we all do, by trying something new.

- George Bonadio, W2WLR

Editor, AM P/X:

After years of procrastination I have finally subscribed to the AM Press/Exchange. I have only seen two other issues and have never seen anything mentioned on 2 meter AM activity.

I would like to find out if there are any 2 meter AM groups which meet in the Northeast Corridor (Baltimore, Philadelphia, New York). I am curious to find out what frequencies are used. Is there a standard AM calling frequency? What antenna polarization is utilized?

Harry A. Schools, KA3B
1606 South Newkirk Street
Philadelphia, PA 19145

Editor, AM Press Exchange:

I have just completed reading the article on alleged power factor inefficiency problems with the Johnson antenna tuners in the April '89 Press-Exchange, and I have some real problems in accepting the theory Mr. Bonadio presents.

The author suggests that with certain types of reactive loads (i.e., a light bulb at the end of a variable length of feeder) the Johnson tuner fails to efficiently transfer power to the load, and presents as evidence that the bulb fails to brightly light with certain lengths of feedline. Well, if one feeds 100 watts into a tuner, and a light bulb dummy load at the end of some length of feeder fails to light at the other end of the tuner, where is that 100 watts going? Physics laws regarding conservation of energy say that energy can only be transformed (light to heat, RF to light, 60 Hz AC to mechanical motion, etc.), and doesn't disappear into some power factor voodoo land. So therefore, that RF from the transmitter is either heating up something or is being radiated in Mr. Bonadio's tests of the tuner- it is most certainly not being uselessly dissipated due to power factor.

Since the author didn't mention the coils in his tuner melting, which is one theory where the 100 watts went, the only other place that power could have gone was to be radiated by his variable length test feedline at 'some random wavelengths'. All these tests proved with the procedure described is that some lengths of feedline radiate much better than others, especially with a mismatched load and with an unbalance to ground. No feedline of considerable length is ever going to be perfectly balanced to ground in other than a lab environment. Mr. Bonadio should have used a load consisting of his light bulb in series with different amounts of lumped inductance or capacitance, thereby creating varying amounts of leading or lagging reactance, or in his terms, power factor.

And this load should have been placed right at the terminals of the tuner, NOT at 'the end of a considerable length of feedline'. Assuming no I2R losses in this capacitor or inductor, all power being put into the tuner will go to heating (lighting) the load, or heating the internal components of the tuner. IT CANNOT MAGICALLY DISAPPEAR! If the tuner -any brand- can tune out the reactance of the load and present a match to the transmitter (1:1 VSWR), then all the power will go into the load, minus that used in heating up the components of the tuner. As Mr. Bonadio states, the reactances produced by the varying length of his feedline are real, therefore why stick with a feedline, use lumped components. Same difference, right? I suspect Mr. Bonadio unwittingly stuck with using a feedline 'of considerable length' because it produced test results that 'proved' his theory.

As far as I'm concerned, one can use any kind of homebrew antenna tuner circuit or commercially made tuner, and if it maintains proper feeder balance (open wire) and the components don't heat up (resistive losses), and it provides a good match to the transmitter, then it's doing its job. One's power cannot -and will not- be uselessly dissipated in some bizarre fashion. An antenna tuner is just like the transmission in your car. If it takes 50 horsepower to go 50 MPH, then your engine needs to develop 50 horsepower plus a few more to overcome the inefficiency, or losses in the gears. If Mr. Bonadio's theory were true, it would be like your engine developing the 50 horsepower but you car not moving. It would be real easy to see where the power was going (probably burning up your transmission or clutch with heat).

Power is power, mechanical or electrical, and it can only be transformed, it doesn't disappear.

Finally, I don't buy Johnson's discontinuing their antenna tuners as any kind of proof of Mr. Bonadio's conclusions as he states. Johnson also discontinued making a lot of other equipment around the same time! Until someone from Johnson will explain why they discontinued a product - and there are many reasons a company does so, such as profitability, volume of sales, obsolescence, competition, etc - I cannot accept the reason they discontinued the tuners is that one ham didn't like them on the same ham's say-so.

To conclude, let me say that the whole aforementioned story, and the conclusions therein, are largely based on one man's unscientific tests and conjecture held up as irrefutable scientific evidence. To the ham that owns a Johnson antenna tuner let me suggest that you run your own tests by placing a rotary inductor or variable capacitor in series with a light bulb load on the output terminals of your tuner. Try different amounts of reactance (capacitance, inductance, -power factor-) and see if you can tune for a good match to your transmitter while achieving reasonable power transfer to your load. Or, as the author says, do you have a mysterious "Power Factor Problem" where your power mysteriously disappears somewhere?

If you do, let me know. I'd love to buy your 'junk' KW Matchbox for a real cheap price.

Bill Kleronomos KD0HD
P.O. Box 1456
Lyons, CO 80540

West Coast Report

AM activity is out of the doldrums and increasing. 160 meters is heading toward end of season with 5 and 7 station turnouts on 1885 at night. 75 meter SPAM Wed. night sked has had up to 16 check-ins. W60AU on SSB says 32V1 is getting ready to go on AM. He also has KW-1 serial no. 57 to be overhauled and put back on the air. W6VIG, Oak Harbor, WA checked in after a year's absence. So did WB6CRV. WK7U is keeping AM going in Montana with a Viking Valiant. VE7FY is a new check-in from the Vancouver, B.C. area with a Collins 32V. W6HDU continues to come up with big xmtrs. The latest is a USN TDO which is a Collins autotune 6-1/2 ft. tall. He also has a Collins 30K-4 deal cooking. Saturday Night Bash freq. changes to 7160 on account of 2 large nets that have occupied the 7290 area. N5JBT down Texas way says 50.4 mc is the AM calling freq. for 6 meters. KG6NH is working on Tesla coils and also building a retirement QTH/antenna farm. W6RNC is restoring a Hallicrafters BC669B. WA6IPD checks in Sundays with his BC610. KB6YAD of Yuba City checked in on 75 mtrs for the first QSO on his new/old Viking II. XE2UZL checked in from Ensenada, Mexico with his Icom on AM. Jane's Military Communications 1987 edition is available from: Publishers Central Bureau, 1 Champion Ave., Avenel, NJ 07001. Price $39.95 plus $3.95 shipping. 950 pages, 9" X 12-1/2" size, hundreds of photos and info on military radios of all types, world-wide. Also antennas, data, encryption, ECM, satellite, test & measurements etc. Order item no. 68666X (reg. $145).



January 75 Meter AM Jamboree
On the second weekend in January is the 75 meter AM Jamboree. During this time the noise level drops off and signals pick up. A lot of AMers operate during this Jamboree, so make plans early and don't miss out on all of the fun.

March 40 Meter AM Jamboree
On the second weekend in March is the 40 meter AM Jamboree. This is a real test of your operating skill. AM is no stranger to this band, you have a chance to operate with the big boys. The trick here is to find a hole and rack up the points.

May 10 Meter AM Jamboree
On the first weekend in May is the 10 meter AM Jamboree. As the days get longer and things heat up, so does 10 meters. Lots of new AMers operating and it's a great chance to meet folks and still be able to get some sleep at night.

July 20 Meter AM Jamboree
On the first weekend in July is the 20 meter AM Jamboree. Summertime on 20 meters means it's time to break out the HEAVY METAL and join in on the fun.

September 15 meter AM Jamboree
On the third weekend in September is the 15 meter AM Jamboree. This band is new to AM Jamborees, but it should be fun to see what happens. We will have a good chance to start up some AM activity.

November 160/10 Meter AM Jamboree
On Thanksgiving weekend is the 160 and 10 meter AM Jamboree. This is a 4-day marathon, which provides 24 hours of operation. Grab your drum stick and pie, and get set for some great operating in the TOP and BOTTOM Jamboree.


WANTED: Schematic for Heath Sixer HW29.

WANTED: Collins 32V-1 -2-3 for parts. Need transformers. Also new fast tune knob kit for 75A4. Will take used knob. Stancor 10P or Stancor 20P working or not. Have some transmitting tubes to sell. Also wanted hv transformer 2500 or 3000 v. at 400-500 ma.

WANTED: SX-112, DX-100B, Valiant II, Warrior, Courier, all in excellent appearance and working condition.

WANTED: Old bakelite panel Collins xmtr. Will pay top price or swap for 30K-5 Collins AM xmtr. Also want Johnson Navigator.

FOR SALE OR GIVE AWAY: 4 barns full of radio parts and equipment, photography equipment, car parts.

FOR SALE: Various RADIO and ARRL Handbooks 1939 to present. SASE or call for list.

COLLINS SALE: DX Engineering speech processor for Collins 32S-3 transmitter, $90. Collins 75S3-B 800 hz CW filter $90. 75A4 500 hz CW filter $90. All items postpaid.

HAVE FUN ON 20 METER AM! Convert a Radio Shack TRC-218 AM CB handheld to 14286 khz, the 20 metre S.P.A.M. frequency. RF output 1-2 watts, receive sensitivity 0.8 uv. Just plug in 2 crystals, change capacitors only, and tune up. $79.95 cheque or m.o.

WANTED: Meissner Signal Shifter, model 9-1077/80 (plug-in coil type) and a Hallicrafters S-19R Sky Buddy receiver, both units in good physical condition. B&W 75 watt plug-in coils (5 prongs) model 80JEL and 40JEL (end link) or equiv.

WANTED: Audio transformers Chicago BD-2 and UTC LS-49.

WANTED: "Allbander" converter for Clegg Interceptor receiver.

WANTED: Collins 180S-1 antenna tuner, any condition.

WANTED: Heath HW-19 "Tener", back issues AM Press/Exchange.

WANTED: Top cover for R388/51J receiver; schematic/instructions for converting 51J3 to a 51J4 (addition of mechanical filters).

FOR SALE: Transmitting tubes 872A $10 ea. 805 $20 ea. 803 $20 ea. Miniature 7 & 9 pin tubes $1 each. Octals and loctals $2 each. Variacs Powerstat 15 amp 110 volt $50. Power transformers, modulation transformers, components, inquire.

ALSO FOR SALE: Morrow Twins, clean tx and rx $100.

This is the AM PRESS:
An amateur radio publication dedicated to Amplitude Modulation.
This is the AM EXCHANGE:
Offering FREE ADVERTISING to enhance the availability of AM equipment and parts.
DISPLAY ADVERTISING: Rates upon request.
Edited and published by Donald Chester, K4KYV
NOTICE: The purpose of this publication is the advancement of Amplitude Modulation in the Amateur Radio Service, and there is no pecuniary Interest. Therefore, permission is hereby expressed for the use of material contained herein without permission of the publisher, with the exception of specifically copyrighted articles, provided that The AM Press/Exchange is properly credited.