Number 63 August 1988

Scanned, OCR'ed, and proofed by Bob "Bacon" Bruhns WA3WDR


from W5YI Report, August 1, 1988

"Whether they intend to or not, real estate developers are making communications policy decisions. By prohibiting all outdoor antennas in communities where it is simply not possible to obtain good television reception with an indoor antenna, they are leaving home buyers with no choice but to subscribe to cable television. If builders continue to impose these restrictions, there will eventually be thousands (or more likely millions) of people living in neighborhoods or entire communities where the traditional rooftop television antenna is prohibited. With cable likely to win nearly 100 percent market penetration in these areas -- and with the last vestiges of the 'must carry' rule having disappeared into history, broadcasters will have to rely on the charity of cable operators if they are to keep these new communities in their service areas. Moreover, participation in other federally licensed communication activities such as amateur radio is being effectively prohibited in entire communities, again thwarting federal objectives. In the end, it is quite possible that the nation's real estate developers will do what the FCC has not done by regulatory decree: conclusively tip the scales in the ongoing struggle between over-the-air broadcasters and the cable industry."

[Conclusion of field study by Dr. Wayne Overbeck, N6NB, California State University at Fullerton.]

The American Radio Relay League has filed a massive 12 page response to the FCC's Mass Media Bureau "must carry" inquiry. The proceeding seeks information on the Availability of Broadcast Signals on Cable Television Systems. The primary issue is the ability of the public to receive broadcast television signals over-the-air as an alternative to cable carriage of those signals.

The League said that while it normally does not get involved in matters outside the scope of direct interest to the Amateur Radio Service, it is necessarily very concerned about regulation of outside antennas and their structures. ARRL concludes the broadcast television viewer and amateur radio operator share the same problem.

Restrictive "covenants", deed restrictions and unreasonable regulation by homeowner's associations of radio and television antennas are increasing and serve to preclude effective off-air reception by TV viewers as well as handicapping communications by licensed amateur radio operators.

Dr. Wayne Overbeck (N6NB), a Professor of Communications at California State University (Fullerton) conducted initial research in the area of restrictive covenants in new housing developments in Los Angeles, Dallas/Fort Worth and Chicago at a time when the FCC had proposed the use of "A/B" switches as a means of assuring the availability of local broadcast signals to viewers - even if those viewers were cable subscribers on systems which might not carry all local signals.

Dr. Overbeck's study was first presented at the Western Communications Educators annual conference (San Diego/November 1986) where it won first place as the best research paper, and later published in the Mass Comm Review under the title "A Free-Marketplace Myth: The new 'Must Carry' Rule, A/B Switches and Deed Restrictions."

The field study indicates that outdoor antennas are generally precluded in new, major metropolitan residential tracts. Dr. Overbeck argues that the "A/B" switch option might be meaningless if over-the-air television reception is inhibited by other factors, such as covenants prohibiting outdoor television antennas.

"If outdoor antennas are in fact prohibited in most new housing developments, this would have a profound long-range impact on mass communications in America. It would mean that real-estate developers could eventually limit the television viewing alternatives for a large percentage of the population. In the end, homebuilders, not the FCC or even the free marketplace, might determine the fate of the competing electronic communication technologies by denying some an adequate customer base while providing others a very strong customer base," Overbeck determines in his study.

The League added that " the view of the developer, homeowner's association or architectural control board, there 'is no need' for anyone to have an outdoor antenna. While it is true that the FCC has limited local zoning regulation of both amateur antennas and home satellite dishes, no government action has been taken limiting covenant regulation. The FCC said "[covenants are] private contractual agreements voluntarily entered into by the buyer or tenant when the agreement is executed and do not usually concern this Commission," in their 1985 PRB-1 Amateur Radio Preemption ruling.


Overbeck completed part of his study by examining the Sunday Los Angeles Times Real Estate Section on a given date listing new housing developments advertised in three Los Angeles counties far from Mt. Wilson, the site of most television transmitters in Los Angeles. In these counties, television reception generally requires outdoor television antennas.

The sales office in each development was visited and the Declaration of Covenants (required by California law to be available) was examined. Dr. Overbeck's findings were startling. "Every single new housing development in Orange or Ventura County was found to have a deed restriction prohibiting all outdoor antennas. Only in the more rural and inexpensive areas of Riverside County was there a variation in the pattern."

Many of the deed restrictions examined contained virtually identical language forbidding antennas, suggesting not only that real estate developers have reached a consensus that outdoor antennas should be prohibited, but also that the language has become standardized among the law firms that often draft Declarations of Covenants.

Planned communities consisting of multiple developments are often governed by one master Declaration of Covenants which prohibit antennas in the entire town. Mission Viejo in southern Orange County is one such example.

The 54 new housing developments visited by Dr. Overbeck led him to conclude that by prohibiting outdoor antennas in communities where it is not possible to obtain good television reception with an indoor antenna, home buyers have no choice but to subscribe to cable television. The same study leaves one to conclude that amateur radio can only be conducted in rural areas or in older homes.

How old a home must be in order to escape from anti-antenna covenants is subject to same variation. League studies on the matter reveal that antenna covenants began to proliferate in the early to mid-1970's, during the hey-day of the Citizen's Radio Service, when rooftop antennas for that Service became numerous.

In April of 1987, Dr. Overbeck visited new housing tracts in the Dallas/Fort Worth area. In September and October, 1987, he visited new housing tracts in the San Francisco Bay area. In Dallas/ Fort Worth, having examined 35 Declaration of Covenant documents, it was determined that 11 prohibited outdoor antennas altogether, 10 permitted radio and television receiving antennas (one per lot) while banning all others and 5 imposed severe height limitations on antennas. Their purpose was to permit television antennas while prohibiting amateur or other antennas. The other nine, each rural, large acreage subdivisions distant from Dallas, had no prohibitions.

In San Francisco, 18 new developments were inspected and deed restrictions limiting antennas were present in all but three developments. In a fourth tract, outdoor antennas were available only until cable television service was installed. Outdoor antennas were prohibited thereafter. Among the other 14 developments, 9 prohibited all outdoor antennas, and the remaining 5 required architectural control board approval or homeowner's association approval. In those 5, not a single outdoor antenna had been installed, though all of the homes had been occupied for at least one year.

The League, following Dr. Overbeck's methodology, has examined other areas. In the Baltimore/Washington corridor, for example, antenna covenants are inescapable in all new housing developments, though the tendency is to submit the home buyer to the whims of the homeowner's association rather than to prohibit antennas outright. ARRL says "With the extremely large and growing population in the fringe area of both the Baltimore and Washington television stations, an outdoor antenna is critical for a large number of persons, in order to view UHF and most VHF broadcast television. Cable subscription becomes a powerfully attractive alternative in such circumstances.

The ARRL concludes in its extremely well done submission that "it is apparent that vast numbers of people are unable to erect outdoor antennas. As a result, they cannot receive many broadcast television signals. The proliferation of restrictive covenants makes it impossible to cast the issue aside by calling them "private contractual agreements."

ARRL said they were not suggesting a specific remedy, but only to build a factual record. "...the plight of the television broadcaster in this connection is less than that of the radio amateur, and the ad hoc regulation of interstate communications by covenant is so extensive as to require the Commission's immediate attention, in this proceeding and otherwise."

(Summary of ARRL comments on MM Docket 88-138 dated July 8th and submitted by its counsel, Chris Imlay, N3AKD)

Quiet Hours

The FCC could wind up in federal court if it doesn't back off on unwarranted "quiet hours" imposed on some Hawaiian hams.

It seems that the FCC went out to check on complaints of RFI to stereos and TV sets in Honolulu. In all cases, no fault was found with the ham stations. Rather, it was determined that the entertainment gear was susceptible to RFI from strong RF fields. Instead of simply informing the complaining parties to have their consumer gear modified by the manufacturer to eliminate the problem, these stalwart public servants solved the problem by the imposition of quiet hours, thus restricting the ability of the Hawaiian hams to legally operate.

Hams in Hawaii are outraged. Some feel that this is a definite violation of their civil rights. Reportedly, unless the restrictions are removed and letters of apology are forthcoming, this matter will be settled by a judge and jury.

-Westlink Report

FCC Public Reference Rooms "A Mess"

Apparently the FCC are having some problems in their public reference rooms. The Washington Post and Electronics Media both say they are a mess. A congressional report says many files are not available or are misfiled. Public documents are frequently illegally removed from the crowded, noisy, poorly ventilated reference rooms that are understaffed with rude, abusive employees who fail to provide the public with accurate, timely and convenient access to information. The FCC, which must report by September 30 on corrective action taken, was very unhappy with the report and announced it would seek more funding from Congress to automate its reference facilities to users can call up documents on computer screens. There is little chance they will get it. The Senate Appropriations Committee has approved $101.6 million for the FCC's 1989 fiscal year - 3% more than their current budget but less than needed. Reportedly, the agency had requested $104.7 million, and since they did not get that much, 10% of the agency's 1,770 member staff will have to be cut.

-W5YI Report

Part 97 Rewrite: AM P/X Buys You More Time to Participate!

You will probably receive this issue of AM P/X just days before the August 31 deadline for comments on PR Docket 88-139. However, you may still participate by submitting REPLY comments before October 31, 1988. Reply comments are submitted exactly as regular comments: original plus five photocopies. Mail your comments or reply comments to: Secretary, FCC, Washington, D.C. 20554. The only difference is that REPLY comments must ostensibly be in reply to someone else's comments submitted before the original August 31 deadline.

In reply comments, you should give the name and address of the person(s), whose comments you are replying to. You can state anything from complete agreement to complete disagreement with the person you are replying to, plus (here's the bonus) you can then add your own comments as suggestions. Nothing says you have to confine your suggestions to topics covered by the person you are replying to; you can expand on the original and bring up additional topics in your reply. Putting it another way, if you missed the deadline for comments, you can manipulate the system to get your opinion on the official record after the deadline by simply claiming your comments are in reply to comments already submitted by someone else. As with all comments, your reply comments should contain well thought arguments and suggestions; simply saying you are for or against something with no reasoning or explanation to back it will not make much of an impression an the FCC.

Of course, in order to "reply" to someone's comments, you must know what they stated in the first place. If you know someone who submitted comments on this docket, perhaps you could look over that person's comments. We haven't the space in AM P/X to reprint numerous comments in their entirety, but if you don't have access to any comments submitted, we have included below brief summaries of some comments submitted.

Donald Chester, K4KYV, Route 1 Box 281, Woodlawn, TN 37191: In the docket, the FCC proposes to establish a one-minute time limit on one-way "test" transmissions for the purpose of tuning, adjusting or testing a transmitter. Don opposes any specific time limit on testing, and suggests that the FCC delete the words "(less than one minute)" from proposed section 97.213(b). Don also suggests that the FCC use the proposed rewrite to rescind the 1990 AM power reduction, by rewording proposed section 97.403(b) as follows: "No station may transmit with a transmitter power exceeding 1.5 kw; this power limit notwithstanding, a station may transmit full carrier A3E emission with a transmitter power exceeding 1.5 kw provided the mean carrier power at the antenna terminals of the transmitter does not exceed 0.75 kw."

Fred E. Huntley, W6RNC, P.O. Box 478, Nevada City, CA 95959: Fred similarly proposes to rescind the 1990 power reduction by wording 97.403(b) as follows: "(b) no station may transmit with a transmitter power exceeding 1.5 kw, excepting a station may transmit emission A3E with an unmodulated carrier power not exceeding 0.75 kw." Fred also proposes that amateurs be required to sign portable when operating outside the call district designated by their callsigns. 97.217 would have added to it: "each station identification shall include a designation of the geographic amateur call area being transmitted from, by adding the word or symbol 'slant' (/) plus the actual call area number, when it is not included in the actual call."

"A Reawakening"

The article entitled "A Reawakening" (page 7, AM P/X no. 61) was published without the name of the author, because the manuscript got inadvertently separated from the cover sheet identifying the writer, who forgot to put his name on the actual manuscript. The author dropped us another line to identify himself. This article was written by John W. Morehead, Elk Grove Village, Illinois. John has passed the exam, but has not yet received his ticket. He hopes to work readers of AM P/X when the ticket comes. Congratulations, John.

Society for the Promotion of Amplitude Modulation

S.P.A.M. President dies and a new one is elected

By now most of you have heard the very sad news of the passing of Floyd Dunlap, WA5TWF, the president of SPAM.

Through his hard work, AM is now a growing, viable mode of operation. He recruited Amers and promoted AM through his shortwave broadcasts, classified ads, and over the air. He took great satisfaction and enjoyment in his work.

I remember the first time I talked to Floyd over the phone, just before the ARRL convention in San Diego. His first words were "What can I do to help?" During the convention he called again to find out how we were doing. He was very excited and wanted to know every detail.

Floyd was a man of modest means, but he gave us all he had. AMers now and in the future will be indebted to Floyd. His devotion and dedication is what I will always remember.

Now it is time that I must pay up for some of what I was given. W4CJL, the founder of S.P.A.M., has offered and I have accepted the office of President S.P.A.M. I do so with one reservation, that I haven't paid my dues on AM as many of you have. This only means I will have to work longer and harder. The next two years will be critical, we must set our sights high, and never give up what is rightfully WB6TRQ...

Acknowledgments from SPAM HQ. for Amateurs Who Helped During this Sad Time

I would like to thank W4CJL for his help in getting this off the ground. Thank You John W5MEU who was able to get Floyd's S.P.A.M. records, and provided flowers on behalf of SPAM to his folks. John also made a very generous contribution to help us start SPAM again. I also thank you Chad W5DBA for your contribution, I don't think there are any stamps left in Potrero, HI!

The Society to Set Goals Into The 1990s

During the last week, I have had a chance to look over the records that were saved by Floyd, and ones that Hoisy gave me. I have a better understanding now after reviewing all of the documentation. I also looked over all of the AM Press/Exchanges, it was a great history lesson for me. Floyd had saved all of the letters he received over the years, and there was no question that AM is growing. My wife "Robin" filed each letter by year, each year was larger than the year before. The promotion of AM is working, but will that be all that it will take to keep AM going into the 1990s?

I believe that it is going to take a lot more than just more AMers. As the popularity of AM grows, so will the resistance, and we need to be ready to go into action. Today we see that resistance is coming from two directions, the ARRL and the FCC. Like it or not the ARRL is becoming stronger every day and the FCC just about rubber stamps anything the League puts in front of them. The key is the board of directors of the ARRL, they determine policies and every two years they are elected to office. The election is just like any other election, only a small percentage of ARRL members really do vote. Elections are won or lost in some cases by a very small margin, so the directors are sensitive to groups that may block-vote on one issue.

What is needed is a strong SPAM organization, which runs parallel with the League organization, i.e. 1 President and 16 SPAM board of directors. The directors would be set up and assigned to each of the ARRL divisions. The job of the SPAM director would be to lobby the ARRL director as to the wants and needs of the SPAM membership. SPAM HQ. will monitor the FCC and ARRL agenda items for AM issues. By organizing SPAM in this manner we can be more effective, it is easier to put out a fire if we can stop it before it ever gets started. If we wait until an issue has a docket number on it, the best we can do is a little damage control. A little work up front will pay off in the long run.

So what I need is 16 of the very best arm-twisters we have located in each of 16 ARRL divisions. If you are interested please write or call me today.

I would also like to see an award for the best technical article which appears in the AM Press/Exchange each year. I know I have seen some good candidates so far this year and I would hope that an award would encourage others to take the time to write one of their own.

I have also been kicking around the idea of making another video of showing the complete restoration, from soup to nuts, of an old AM transmitter. It would be something along the lines of the PBS program "This Old House." What do you think?

I would like to have someone who would like to map out one year's worth of AM Jamboree scheduling so we can get it published in other ham radio rags.

We have installed a SPAM 24 hour hot line (618) 478-8347 to help out new and old members alike.

This is the new SPAM address:


PO Box 27

Potrero, CA 92063

Hope we will hear from all of you soon. I am operating on 75 meters Wed. 9:00 PM west coast time, and on 20 meters each night at 7:00 PM west coast time.

Cartoon, "I should have joined SPAM."

Kind Words from Mr. & Mrs. Dunlap

(Houston, TX) Dear John and members of SPAM, your contribution on behalf of Floyd is such a great help. We are so thankful that Floyd had such wonderful friends.

Your friendship to him and love to us means so much more than we can express in words. May God bless you.

Mr. & Mrs. Dunlap,

14113 Stoneshire

Houston, TX 77080


S.P.A.M. AM Questionnaire Mailed out to all ARRL Director Candidates

The ARRL will be having a board of directors election for the following divisions:



New England



Rocky Mountain


West Gulf

Many members of SPAM are also members of the ARRL. This year many of the seats up for election are in AM strongholds. I think it is a good idea if our members know how the candidates stand on the issues of importance to the AM community before the election, and not find out after it's too late. The following is the list of 10 questions each candidate was asked:

  1. Would you support a change in the FCC rules that would let amateurs operate a 1 KW AM transmitter after 1990?
  2. Do you think AM operation of the HF bands should be outlawed?
  3. Would you support a change in the FCC rules which would let Novices operate AM phone in the Novice 10 meter band?
  4. Do you feel that the amateur radio service would be better off if all amateurs operated only commercial equipment?
  5. Would you support an ARRL Worked All States award for AM phone?
  6. Would you support changing the ARRL handbook so that it would again include a chapter on AM phone?
  7. Do you think that the ARRL should provide representation in legislative matters for all radio amateurs?
  8. How would you rate the ARRL's service in dealing with matters of interest to the AM community?
  9. Do you now operate equipment that you have built yourself?
  10. Listed below are activities which take place on amateur radio every day. List the items in your order of importance which you feel contribute the most to the amateur service.


-Emergency Communications



-Building equipment



-Providing tech experts

It should be interesting to see what some of the responses are. We must keep in mind that all candidates are politicians and it is up to all of us to see to it that we have representation. All politicians need to have their feet held to the flames, they don't do the right thing unless they have to. Let's hope they get the message that it's unhealthy to dump on AMer's.

Communications Receivers: Tube vs. Solid State Audio

by David Newkirk, AK7M

What long-time shortwave listener hasn't heard a statement like, "Ah, those old tube receivers had excellent audio -- not like most of this modern, solid-state stuff!" Although the comparison possibilities are many (which old receiver is being compared with which new receiver?), I'm willing to fan the flames of this non-controversy with the statement that this tubes-mean-better audio "fact" is generally not true.

If you do a bit of rooting around through tube textbooks, you can learn that relatively-low-distortion operation of audio-power-amplifier tubes is hard to come by if the amplifier circuit is to be simple and cheap. Harmonic distortion the generation of multiples (harmonics) of the amplified signals for a given output power is the principle specification of interest in "communications"-quality audio-output stages. Until the invention of the beam power tube in the mid-1930s, power triodes and pentodes were "it" for audio power amplification. For ham/SWL purposes, use of a single power pentode types 41, 42, 2A5, 6F6, 6K6 and others; miniatures used in later receivers include the 6AK6, 6AR5, 6EH5, and pentode section of various triode-pentodes, such as the 6EB8 and 6GW8) was normal in most communications receivers of the mid to late 1930s right up until tubed receivers went out with the Collins 75S-3 and the Drake R-4C.

As a matter of fact, power pentodes are quite "distortiony" devices. Even with optimum watching between the tube and its load, total harmonic distortion tends to be at least 4% unless negative feedback is used. It's just about guaranteed that a given tube's load won't be optimum across the "communications audio" range, though, because loudspeakers and headphones usually do not present a constant impedance across their working frequency ranges. (The Radiotron Designer's Handbook [4th edition, 1952, F. Langford Smith, editor] presents a graph of "power output and harmonic distortion of a typical pentode plotted against load resistance" on page 566. The "typical pentode" is a 6AK6 - the same tube type used for the local and line output amplifiers in the R-390A receiver, in fact - and its total harmonic distortion is never less than 5% even with an optimum load! (Writes Langford-Smith on page 566, "A pentode is, unfortunately, critical in its load resistance for both maximum power output and [minimum] distortion.")

Beam power tubes (sometimes called "beam tetrodes") first appeared in 1936. They're generally worse than pentodes in terms of distortion. (Langford-Smith writes of beam power tubes that "the optimum load resistance is more critical than with ordinary power pentodes." [page 567]) Beam power tubes include the 6L6 and 6V6 (octal), the 6AQ5, 50C5 (miniature) and others. Page 570 of the Radiotron Designer's Handbook shows a graph of "power output of type 6L6 beam power amplifier plotted against load resistance..." Operating at a couple of watts of output, the 6L6's total harmonic distortion never drops below 6%, even with an optimum load. The curves confirm that load is critical if distortion is to be minimized.

Think you can't hear 6% distortion? You sure can, especially if you're trying to copy CW signals! True enough, negative feedback can be used to reduce distortion using both power pentode and beam power tubes, but most communications receivers did not use negative feedback with power pentodes; sometimes it was used with beam power tubes.

One difference between beam power tubes and power pentodes is that 2nd harmonic distortion is much worse in beam power tubes than in pentodes. Properly applied, the push-pull amplifier configuration can be used to reduce 2nd harmonic distortion because even-order harmonics tend to cancel in push-pull stages. Push-pull beam-power-tube audio power amplifiers were so used in some communications receivers (National HRO-60 and Hallicrafters SX-62, for instance) and many early "hi-fi" amplifiers. A receiver that uses a single-ended beam-power-tube amplifier can be considered to have been designed more for cheapness and simplicity than performance -- although the audio transducers available when such receivers were new may have been unable to reproduce the distortion in such amplifiers, anyway! Careful communications-receiver designers usually stayed away from single-ended beam-power-tube stages; "All-American Five" (cheap, five-tube "ac/dc") broadcast receivers) used single beam-power tubes as audio power amplifiers. (Because 3rd-harmonic, and not 2nd-harmonic, distortion is the primary source of distortion in pentode power amplifiers, operating pentodes in push-pull is largely a misapplication of technology -- as is the case with the push-pull 6F6s in my Nationals NC-100X and -101X! Push-pull operation actually enhances the 3rd-harmonic distortion that is characteristic of pentodes!)

Modern, solid-state receivers usually leave audio power amplification to a single integrated circuit (IC). It's safe to say that the output portion of most of these chips uses bipolar transistors in a complementary-symmetry configuration -- an analogy of push-pull tubes. Modern audio-power-amplifier ICs have a major advantage over the vacuum-tube amplifiers formerly used in the same situations: they generally don't require the use of a matching transformer between amplifier and load. A over- or underloaded output transformer can cause distortion in addition to that generated in its driving device(s). Also, the transformer(s) in an audio system usually undesirably limit(s) the system power bandwidth -- the range of frequencies over which the amplifier can produce a given power output for a given signal input. Further, inexpensive transformers are excellent hum pickups. (The output transformer in my Hallicrafters SX-24 supplies hum to the headphones even when the '24's audio-output tube is removed! The audio transformer picks up hum directly from the set's power transformer by means of induction.) True enough, most modern communication-equipment manufacturers specify the audio power output of their wares at 10% total harmonic distortion -- gasp! -- but most solid-state output stages are much cleaner -- say, 3% distortion at a half a watt or so, and below 1% at headphone levels. (If you must operate your receiver audio stage at 1 or 2 W output, you're listening in a car or an engine room, are hard of hearing or are using a bag of flour for a speaker! No more than about half a watt is sufficient for use with small, efficient "communications" speakers, and only a few tens of milliwatts are needed for useful headphone operation. I believe that manufacturers use that 10%-distortion figure so they can cite bigger power-output numbers.)

The IC audio output stages in modern communications receivers do tend to exhibit a flaw relatively uncommon in their vacuum-tube equivalents: crossover distortion. Crossover distortion is distortion of an ac waveform at or near its zero crossings -- as it moves from positive to negative or vice versa. The circuit configuration used in many IC audio power amplifiers to reduce no-signal current drain may give rise to crossover distortion; crossover distortion is, by nature, worse at small power outputs than at higher power outputs. Unfortunately, those "low power outputs" are just what the doctor ordered for headphone operation -- and headphone operation is usually what you want to do if you intend to listen to weak signals very close to the noise. Significant crossover distortion can make headphone copy of weak signals annoying to impossible: The crossover distortion causes the noise to intermodulate with the signal and make the signal sound "fuzzy."

Enough theory; here is what I have experienced in comparing "the audio" of tubed receivers with that of solid-state receivers. Especially at output levels appropriate for headphone listening, solid-state output stages seem to be much more tolerant of load mismatch than their vacuum-tube counterparts. (Note: I use high-quality stereo headphones because I feel that selectivity should not be achieved at any point of significant power in a system, and because my experience has shown me that wide-bandwidth transducers generally exhibit less intermodulation distortion than "peaky" transducers. Power unaccepted by a load is reflected back to the generator (the amplifier, in our case), and this can cause distortion in the generator. If you don't want your headphones to reproduce certain parts of the audio spectrum, don't feed that audio to the output stage in the first place! Moral: Expecting a transducer to provide selectivity at the highest-power point in a system-is poor engineering.)

I've used high-quality stereophonic headphones to listen to the following receivers over the past several years: home-built regenerative (6AQ5A beam power tube), National NC-100X (Push-pull 6F6 pentodes), National NC-101X (push-pull 6F6 pentodes), National FB-7 (59 pentode), National HRO (42 pentode), National HRO-60 (push-pull 6V6 beam power tubes), Hallicrafters SX-24 (6F6 pentode), Collins 51J-3 (6AQ5 beam power tube), Collins R-648/ARR-41 (5686 beam power tube), Collins R-390A (6AK6 pentode), Drake R-4B (6EH5 pentode).

None of these receivers "liked" stereo headphones; single audio tones came through with obvious and annoying distortion. Perhaps more accurately, the distortion in their output stages was objectionable when monitored with a good audio transducer. All of them "sounded fine" when a speaker or magnetic headphones were used; with good headphones, all of them sounded less objectionable at wide selectivities and when used for voice reception. (CW reception at narrow bandwidths is the toughest distortion test for a communications receiver: distortion is most audible on single audio tone -- such as received CW signal -- and a narrow IF bandwidth means there's little or no wideband noise to mask distortion products.)

Solid-state receivers I've listened to recently include: home-built 10/18-MHz superheterodyne receiver, Sony ICF-2010, Kenwood R-1000, Kenwood R-5000, Sony ICR-4800, Grundig Satellit International 400, Panasonic RF-2200, Japan Radio Company NRD-525; transceivers: Kenwood TS-130V, TS-830S, TS-440S, Yaesu FT-747GX. Of these, only the Sony ICF-2010 suffers from harmonic distortion akin to that of tube receivers -- and this is mostly noticeable at very low output levels.

The Kenwoods R-5000 and TS-440S seem to have problems with crossover distortion (particularly noticeable during CW reception with a narrow IF bandwidth; the TS-440S, in particular, is almost earsplitting in this regard. I've heard similar reports about the TS-140S transceiver, so the distortion is probably the result of the particular audio output chip[s] chosen by Kenwood for this generation of radio gear). The others are passable to good. All of them are "happy' with my stereo headphones; that's to be expected of transformerless output stages.

True, none of these solid-state receivers can blow me out of the room during speaker operation -- as the push-pull-amplifier tube sets can. (My Nationals NC-100X and NC-101X are supposedly capable of producing 10 watts of audio!) But such house-filling-capability stuff is just as nonsensical now as it was when those sets were released: no one can use that much audio power in most communication situations! And those aren't ten clean watts -- they're just enough to make boomy distortion in speakers incapable of handling low audio frequencies! (Such distortion is what many "hi-fi" enthusiasts of the 1940s, 50s and 60s took to mean "good bass") Note: The headphone outputs on some older receivers are actually intended for use with "high-impedance" magnetic headphones. Such high-impedance outputs can usually drive high-quality stereophonic headphones with reasonable clarity, but only at levels considerably below those afforded by an audio power stage. (A matching transformer is needed to do this, incidentally, and its transformation ratio must be carefully chosen to minimize distortion.) But such high-impedance-output voltage amplifiers generally can't drive headphones as cleanly as a good audio power IC.

Summary. For me, the myth that "tubes generate cleaner, better audio" has no validity, at least where communications receivers are concerned. I know: I've compared tube with solid-state receivers and found the tubed jobs wanting whenever a critical comparison was made. In fact, I've since "solid-stated" the audio output stages of two of the tubed receivers named above (the R-4B and the R-648). In both cases, I used a National Semiconductor LM380N-8 IC (just as I used in that home-built, solid-state 10/18-MHz receiver also mentioned above). The '380N-8 isn't perfect -- it exhibits a bit of crossover distortion -- but it's small, cheap and relatively quiet. Ahh -- you should hear that R-648 audio through the LM380N-8 now (and especially since I replaced its mediocre AGC circuitry with that of the 51J-3 -- but such AGC surgery is another story).

True, an LM380N-8's half watt or so can't fill the apartment courtyard as might my NC-100X's push-pull 6F6s -- but if my neighbors want to listen to shortwave, they'll have to get receivers of their own, anyway!

AM Tips & Techniques

by W3BJZ

The June issue of the AM Press/Exchange carried an article about the dangers of refinishing old equipment. The following tips and techniques should help our readers.

Before applying any solution or cleaner to the surfaces of panels, knobs, and dials, the restorer should "bench test" the chemical on a surface that will not show. Many so-called household cleaners are especially "strong" and will damage the surfaces of plastic or rubber compounds. One of the best cleaning solutions is your wife's dish-washing liquid. Use with a soft bristle toothbrush and warm water. A protective finish such as Liquid Gold can be applied after cleaning.

Try buffing with a soft cloth or a slow-speed buffer. Auto polishes such as Simoniz II do a nice job for the final touch.

For rusty chassis try Naval Jelly obtainable in many K-Marts. Be careful that you don't "over-use." Daub a little aluminum paint on the affected areas.

To replace the white markings on dials and knobs, try a white lacquer stick. If you cannot get these at a local hardware or automotive supply house, try Antique Electronics Supply, 688 W. First St., Tempe, AZ, 85281. Ask for their catalog. Remove the excess with a toothpick, then clean thoroughly, wipe and dry. Next, apply the stick and wipe excess carefully with a soft cloth.

Don't laugh at this next one which appeared in the A.W.A. Bulletin. One of the best methods of obtaining nice shiny aluminum variable condensors, etc., is with the acid from tomatoes. Fill a steel pot with several old tomatoes from the garden (if you have one) plus the skins. Place several variable condensors with aluminum plates in the pot, and water, and stew for a couple of hours. You will be amazed at the results when removed and washed. By the way, some restorers have used a mixture of 1 or 2 oz. of lemon juice with 4 oz. of water.

Incidentally, a good source of manuals for old equipment is Hi-Inc, P.O. Box 864, 1601 Ave. D, Council Bluffs, Iowa, 51501. They carry manuals for most National, Hallicrafters, Hammarlund, or other pieces of equipment.

Refinishing Old Radio Equipment

As K4KYV recently asked in a recent issue of AM P-X, yes, indeed, powerful cleansers such as Fantastic, Formula 409, etc., will not only do a superb job of cleaning old radio cabinets and bakelite parts, but will also totally destroy the finish on many of these old components. Don't ever use this type of cleaner on old radio equipment's painted parts or bakelite panels or knobs! I've had good luck using a mild detergent such as Ivory liquid mixed with water, and applied using an old Windex spray bottle.

If you've had the misfortune of ruining the finish on any old bakelite or hard rubber parts, there is a means of restoring it that I have found extremely effective. Purchase a product called GLAZIT TELEPHONE REFINISHER. This product is specifically designed for the purpose of imparting a new looking shiny finish on old bakelite and hard rubber telephones and equipment. It appears to contain a combination of highly effective waxes and penetrants.

I can personally attest that not only does it do a superb job on old telephones, but also anything else made of bakelite, such as my old Simpson 260 VOM and my Ranger's knobs. Glazit might be a bit tough to find as bakelite phones are getting scarce, and I got my can from an antique shop owner. The can says that it can be ordered from the manufacturer, and here's the info:

Glazit Telephone Refinisher, Product Code M-115

Magnolia Chemical Company, 2646 Rodney Lane, Dallas, TX 75229.

(214) 247-7111 or (800) 527-5038.

Like K4KYV stated, I've tried EVERYTHING to restore the original sheen to old bakelite such as car and floor wax, polishing until my fingers bled, etc. This stuff really works.

Another problem has been matching the original dark maroon color of old Johnson equipment cabinets. My brother is in the business of old auto restoration and has formulated a perfectly matching color.

I can provide the color formula, and if there's enough demand, small quantities of ready mixed paint. Please drop me a SASE for further info.

Bill Kleronomos, KD0HG

P.O. Box 1456

Lyons, Co 80540

EDITOR'S NOTE: Magnolia Chemical Company was contacted by phone, and they indicated that Glazit Telephone Refinisher is a product they have been manufacturing for many years, and is indeed still available. It can be purchased directly from the manufacturer for $5.29 a can, but only in a case of 12 cans for $62.88. However, they will give you a list of retailers in your area who handle the product. A local telephone equipment supply company was given; a phone call indicated that the local supplier has the product in stock for $7.34 per can, and will sell single cans.

Test Of Tactical Low Frequency Transmitting Antenna

The Space and Naval Warfare Systems Command (SPAWAR) under contract with Astron Corporation will conduct tests on an experimental low frequency antenna to determine its electrical performance characteristics and to evaluate its potential for various applications including tactical use aboard naval combatant ships. The antenna is being developed under the Small Business Innovative Research program under a Phase II contract with Astron Corporation, Herndon, VA. A number of radio amateurs are working on the project including: Frank Gentges, AK4R; Steve Shergold, N4QYC; Chris O'Toole, N4SBY; Ed Rathbun, W4ZW and Ed Ray, W4NEZ.

Testing will be conducted on a sporadic basis from August to October 1988 from test sites at Bumpass, VA and Carroll Island, MD. Transmitter output power will be 1 kilowatt. The antenna is a transmitting loop design in the shape of a triangle 65 feet high at the apex and extending 400 feet along the base. The wire is 0 gauge Litz cable and the loop is tuned with a combination of fixed and variable capacitance.

As part of the test program, listening reports from longwave listeners are requested. This qualitative data will augment field strength data taken by project personnel. The objective of collecting the data is to determine the potential coverage of a low frequency system using this type antenna in a naval battle group. The primary operating frequency will be 185 KHz and 175 KHz is available as a secondary frequency.

The signal will consist of alternate periods of steady carrier and on-off keyed 10 word per minute international Morse code with the call sign NWA, the word "TEST", with a single alphabetic character related to the current test condition. Other information related to the test may also be included in the transmission sequence.

Detailed commented logs over a period of time will be especially useful although individual spot reports will also be of value. All reception reports should:

identify the time and date,

the location of the receiver,

a description of the antenna and receiver,

the received signal frequency,

the signal quality (RST) and

the test condition alphabetic character.

Reception reports will be verified with a special QSL card that is only available to participants in this test. Reception reports should be sent to:


NWA Test

Washington D.C. 20363-5100

Current information on the test times and frequencies will be provided on a pre-recorded message at area code (703) 471-1539.

open forum

Editor, AM Press/Exchange:

Regarding proposed Part 97 rules. Under 97.131 reference is made to communications quality AM transmission. Also under 97.201 to "good engineering and amateur practice." Under 97.401 reference is made to "good amateur practice."

Does this mean limiting bandwidth to 500-2500 CPS? This is typical sideband quality. Since AM'ers are outnumbered many times by sideband operators it seems to me AM stations should be given more latitude in establishing bandwidth limits.

Richard Savidge, W3FDE


by Bill Wolf - KA2EEV


Just like the rest of you I was stunned with disbelief when I first received the news about Floyd Dunlap's death. It can't be, I said... he's only 40... my own age! Sadly though, it was true. A friend, a fellow AMer, a fellow correspondent, Floyd Dunlap, WA5TWF, had suddenly passed away ... an untimely death. What do you say??? There are no easy words. I guess this kind of reality was not meant to be easy. The details of how and why are still sketchy as of this writing and I suppose it's not necessarily important at this point anyway. We obviously recognize the tremendous loss here ... the emotional and physical ties to Floyd's immediate loved ones, as well as his direct ties to us, the AM community and the SPAM group in particular. There was a dependency here. Floyd poured an incredible amount of personal energy into the "Society for Promotion of Amplitude Modulation". I very well remember when he first took over as SPAM President just a few short years ago. SPAM had recently been a nearly lifeless and practically inactive "membership" which then hardly did anything to promote AM. An existence by mere name only. Floyd wasted no time in turning SPAM into a vibrantly ACTIVE organization. The first major move with his administration was the selection of state and regional directors who then weaved a network of SPAM affiliates around the country. On-the-air SPAM schedules soon followed which caused interest and activity in AM to prosper. Floyd was soon running ads in major ham publications, raising donations for SPAM, and raising increased awareness of AM as a result. Floyd and I continually exchanged a correspondence of ideas for ways and means to help SPAM and to help AM. There were several times when he and I had strong differences and we made no bones about telling each other. It's part of growth. Ultimately I admired his dedication.

Many have recently been heard asking the obvious natural question ... who will now take over SPAM? Indeed ... who will? More importantly, WHO CAN? All egos and space cadets put aside ... Floyd Dunlap's true dedication, self sacrifice, and dynamic efforts will be hard to match. Realistically no one can expect to fill the void precisely, but, the same spirit of productive dedication can at least be hoped for.

No, there are no easy words ... just to say so long ... we'll all miss you.There's a time to live and there's a time to die ... everything in season. (Ecclesiastes 3:1-2)


In his shack: Ralph Surridge, K4HOL, Winston-Salem, NC


(Names omitted - past copy)

WANTED: Globe Scout Deluxe manual or copy, and one or two good 7027A modulator tubes.

WANTED: Plate xfmr 220 volt primary, 5000-6000 volt secondary, center tapped, rated 1/2 amp or better.

WANTED: Hammarlund transmitter in working condition; 160 metres inclusion preferred.

WANTED: Collins 32V series transmitters. Top prices paid for good condition equipment. Also ART-13 Cable connectors and an "on air" light.

WANTED: UTC LS-49, Chicago BD-2 audio transformers.

FOR SALE: Apache w/ Johnson low pass filter, mint condx pickup only $100. Heath DX-100, pickup only, $70. Eico 730 modulator, excellent condx $50. Zenith Transoceanic H500 w/ book, good shape, collectors item $75.

TUBES WANTED: Good 892's, 833A's, 1000TH'S, 1500TH's, 2000TH's, HK1054's, HK1554's, HK3054's.

FOR SALE OR TRADE: audio patch bays, 52 jacks, normalling, ring-tip-sleeve, for 19" rack mt, like new condx $30 ea. + ship. Mod. xfmr, Kenyon, abt. 1 kw audio, autoformer type, $35 + ship (or u pick up).

FOR SALE: Wired modulator pair 805's with UTC VM4 and PA59AX matching tap transformers. Pickup only; make offer. Also Kenyon 10v and 5.25 v. filament transformers.

WANTED: Manuals for Clegg Thor and Gonset Communicator IV (2 meter version). Will pay for copying, postage, etc.

FOR SALE: Signal generators - URM-25F, 10 khz-50 mhz $125; TS-497B/URR 2-400 mhz $100. All units checked out and are shipped with a schematic. TS-497 & URN-25D, F manual reprints available.

WANTED: PL-172 made by Penta for use in the Hallicrafters HT-33A. Used OK if functional. Also would like to correspond with owners of Hallicrafters amateur equipment of any kind for the purpose of forming a "users' group". Please send equipment model and serial number.

WANTED: Johnson 6N2 xmtr or other six meter AM xmtr & rcvr. FOR SALE: Low freq. converter kit for Drake 2B receiver, new in box w/ instructions. $7.50 postpaid.

FOR TRADE: two R-390A receivers, one working, one for parts, both complete with meters and manual, for a good working R-388 (51J-3) with manual. FOR SALE: Valiant I $75, Hallicrafters S-76 $35, Drake 2NT cw xmtr $40. Will arrange delivery within reasonable distance.

FOR SALE: 814 $10. 828 $10. 813 $20. 6B4G $4. 3B28 $4. Miniatures $1 each. Loctals and octals $2 each. Inquire others. BC-610 modulation transformer $50.

TRADE: Will trade new 3 metre T.V.R.O. system for solid state GENERAL COVERAGE AM/SSB RF transceiver or will sell for $750 plus shipping. M.O. only.

WANTED: Two undamaged Hallicrafter speakers of the R46A or R46B type with 3.2 ohm voice coil.

FOR SALE OR TRADE: SX101A Ec. $150. R46B speaker $25. Eico 720 $30.

WANTED: National HRO parts: 3.5-7, 7-14, 14-30 mc coils, and case.

FOR SALE OR TRADE: Complete Heathkit AM station, two Apache TX-1 transmitters, one for parts; one Mohawk RX-1 receiver, one SB-10 sideband adapter, all cables, excellent condx and looks like new $275 or will trade for Heathkit HW-9 QRP transceiver with HWA-9 bandpack and PSA-9 power supply. Pickup only.


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.