K7JEB AM Log: 01 Sept 2006 - 15 Oct 2006 09/02/Sat/3855kcs W7PLR, Len down in Tucson, checks in with his "mystery antenna" which, upon further inquiry, turns out to be a longwire fed against a mobile home counterpoise. Very good signal here in Phoenix. Maybe there is something to the "throw a wire out the window" approach to antenna system development. Ken, K6CJA, decides against attending a NASCAR race down in Riverside "live" and opts instead for the electronic version without the withering heat and ear-splitting noise. Extended discussion with Ted, WA6TJN, about IC's for an audio distribution amplifier to pipe the outputs of my computer sound cards around the shack. Those crummy little LM386's keep popping up as the most cost-effective solution although there are a huge number of higher-powered stereo chips out there. I'm left with the notion of this being yet another example of how computers are infiltrating both ham radio and everyday living. It's just that it would be so nice to be able to listen to, and re-transmit, the audio outputs (off-the-air recordings, Skype, Echolink, etc) from the various computers around the house. Question arises whether those big wind turbines alongside the highway are AC or DC and how much power they each generate. I think they are AC synchronous machines because they all turn in step with each other. I get from someone that they have an output of 1.3 megawatts each. Hear from Ted, WA8ULG, that his SX-28 muting isn't working and that he has one foot out the door heading for Manhattan on business. Must be nice. All of my business-trip possibilities seem to be to Haifa, Israel at the height of the rocket season. Talk with WA7LYO, Greg in Phoenix, about his various boat- anchor repair activities, his '74 Super Beetle and selling stuff on E-Bay. I try to talk him into being my E-Bay broker (with me as the brokee) but he encourages me to start my own account there. 09/03/Sun/3855kcs Shep, W5EOE, observes an influx of motorcyclists into his normally quiet SE Colorado area this weekend. Shep very carefully selected his QTH to be as far from the freeway system as he could get, but, paradoxically, this is exactly what makes good motorcycle-riding territory. Throw in some winding roads and funky, out-of-the-way bars in old mining towns and the picture is complete. Sorry about that Shep, but they will be leaving soon to go back to their day jobs. Along those same lines, Ted, WA6TJN, wonders why all these people are moving to his little town of Hemet, CA. I speculate that it may have something to do with the baby boomers hitting retirement age. I'm starting to hear "spitting", aka splatter, from the 50 kW xmtr on 1360 down the street from me. I dunno what's with that, but the last time this happened, their nice, new Harris DX-50 burned up its backplane. But not until it had provided me with 6 months of QRM on 75 meters. George, W8QBG, reports that all his AM transmitters are "looking at him", presumably with the meters on their front panels. George might be in the running for a guest appearance on the Art Bell show with that kind of thing. Anyway, he also reports on his latest hardware endeavor, building up a set of "ears" for a KWM-2 power supply. A previous owner committed blasphemy by sawing them off. I'm beginning to think that, when it comes to boatanchor hardware, George is like the Energizer Bunny -- he just keeps going and going and going. Some discussion about past glories and adventures in AM broadcasting: the perennial problem of preventing theft of ground-radial wires and trying to load up a TV tower on top of a mountain on 1380 kcs. With a feedpoint impedance of 50+j2500, what we ended with was a 5kW Tesla coil. 09/05/Tues/7293 Hear from semi-famous ER author Jim Hanlon, W8KGI, in Sandia Park, NM. Jim is preparing for Classic Exchange weekend and is on the air with a Collins 32RA. This rig was originally designed in 1938 and was used extensively in WWII. It transmits on four, fixed-tuned channels and puts out about 50 watts over a frequency range of 5 - 15 Mcs. Other stations heard this day: W6JEO in Santa Barbara and WB7CAM out in Mesa, AZ. AL0F stayed up all night and worked W2ZM, Bob, up in New York State and WA0ZHH, Chuck, in Midland on 3880. Chuck was using the KC9VF transmitter in Oklahoma and pounding into Arizona. 09/06/Wed/7293/rec-only Heard Ken, K6CJA, declare he would never own an electric Corvette automobile. Good thing, actually, since a 500hp engine would require a 373 kW power supply, a bit of a stretch for battery technology. 09/08/Fri/7293 Rough copy today. Attempted to talk with QBG about CCD antennas he had heard about at the CADXA meeting. Also had some comments about cloud-warmers from Tom, AE8O, in Rio Rancho, NM. I disclosed my "secret sauce" -- a buried power conduit directly under my dipole that serves as a reflector to push the power on 80 and 40 straight up. Great for local contacts via NVIS, poor for DX work. I also put up a web page for KE7ASK on www.arizona-am.net in the Phoenix section. Nice classic Hallicrafters station. 09/09/Sat/3855kcs Usual stuff on 3855. Ken, K6CJA, having an intermittent HV arc-over somewhere. Max, K7CAX, bypasses Kingman hamfest for lack of overnight RV parking. Ken advises a 'Route 66' special event station, K6J, will be on 7266 this weekend from Barstow ("Kingman, Barstow.... Saan Bernardino - get your kicks - on Route 66"). Ken is also having a problem with a neighborhood cat tracking up the Corvette inside his garage. John, WA6JUS, has a busy time participating in ARES, attending the funeral for Jackie Porter, KG6PRO's XYL, and attending to various boat-building and classic-Mustang- restoration projects. Max is working on getting a 12-volt T/R relay going for his Ameco 6/2 Xmtr and Converter setup. 09/10/Sun/3855 W5EOE lives in a log cabin up there in Delores, CO. So it's a good thing he has an ART-13 with that masterpiece of Collins Radio engineering, an ultra stable PTO. Shep set it on 3855 months ago and it comes up within 200 cycles of net frequency. W8QBG is on 3855 with the Bauer. I aircheck him and find him clean +/- 10 kcs from 3855 with the 3 kc filter in the old 'Divine Wind' transceiver. It's panic time at K7JEB. A number of severe power bumps due to a passing thunderstorm has my Internet computer attempting to reboot and getting bounced up and down. After the fifth or sixth glitch, the BIOS comes up with the 'Blue Screen of Death' and says the boot sector on the hard disk is corrupted. After thinking hard and fast, I boot off of the Windows 2000 CD-ROM, discover a utility to reload the boot sector and, Voila!, back in business. Whew! A passing thunderstorm also knocks WA6TJN's mast down and he is off 80 and 40 for the time being. This info comes to me from Ted via e-mail and I relay it to the group. What's this about a mode that gets through when nothing else can? AL0F is planning a motorcycle trip up into Colorado before the cold sets in and might drop in on W5EOE. W5EOE's XYL departs for the Philippines for medical tests and to visit relatives there. George cremates a Heathkit power meter and overheats his Cantenna testing the Bauer in high-power mode. Yikes! WA7LYO, Greg in Phoenix, sends me some pictures of a nice little go-anywhere linear amplifier he has built that runs 3-811's and has a massive roller inductor in the final tank. Greg comments about some of the strange circumstances in his life due to his involvement with home-brewing everything. This naturally leads into a Jeff-Foxworthy-like riff that begins "You might be a home-brewer if.... ". A few of the lines we came up with were: (1) You might be a home-brewer if your xyl is constantly digging small items of electronic hardware out of her washing machine. (2) You might be a home-brewer if all of your cars are parked on the street in front of your two-car garage. (3) You might be a home-brewer if you can't tell where the workbench ends and the operating position begins. (4) You might be a home-brewer if your wardrobe has that "extra sparkle" due to embedded metal shards. (5) You might be a home-brewer if certain rooms in your house have the same phenolic-and-potting-tar aroma as the old Radio Row places did, pre-WTC. Well, that's a start, more later.... 09/15/Fri/7293kcs Hear K6KSG, Dick, on from Colorado with his 100V plus amplifier. Nice signal under lousy band condx. Also in there, W8KGI, Jim, in New Mexico with a Globe Scout. Can't copy W8QBG across the Valley running legal limit though. I gather that George is looking at replacing 4D32 in a Viking I with an 829 or some other more modern tube. W7HB recounts a sad day in his Air Force career seeing stacks and stacks of R390's out in the rain in a dump in Turkey. 09/16/Sat/3855kcs Spinach scare starts and spacewalk is in progress aboard the ISS. Hoover Dam has massive traffic pileup due to construction crane collapse at bridge site. This trivia courtesy of various SSB nets. AE8O working on getting acoustic "EQ" right on Mouser microphone element in D104 stand. The K7JEB experience with these little jewels is to back them with foam rubber or closely packed cotton and then to place a single sheet of polyethylene cut from a Glad freezer bag in front of the element. These measures knock down the excessive audio response at the higher audio frequencies (3-5kc) that the Mouser elements have. They also only put out about half the voltage of a stock D104 element, those now priced out of the market due to excessive unobtainium content. Max continues to have antenna relay problems with the Ameco 6/2m transmitter. Internal power supply can't swing a large relay. George is monitoring the Bauer's spectral content with an R-390 and panadaptor. Seems to be working. Both AE8O and W5EOE are amazed at the development taking place in their somewhat rural environs due to the real estate boom. 09/17/Sun/3855kc W8QYT returns from "Yupper Land" and promptly breaks 40M dipole raising crank-up tower. Oh... Well.... Big discussion on cars, gas mileage, hybrid vehicles, etc. Didn't know we had so many car nuts on frequency. John, K7JWA, and I have an extended conversation about top hats on mobile antennas. I don't believe in top hats from a mechanical standpoint, but if you have to have them, they should be away from the coil and as far up the whip as possible, including being at the very end. Right?? I download a scanned-in image of an article from QST for Oct. 1956 from the AM section of the ARRL website. The article's title is "The Ultra Modulation System" and now I finally understand the rationale behind negative peak clipping and loading and the relatively simple 3-diode, 1-resistor circuit that produces it. Tnx to NA7RH for the link. 09/19/Tues/7293kc Bad band condx, can only copy W7HB near Provo Utah. Is there something about N-S propagation being different than E-W propagation when the band is this lousy? 09/20/Wed/7293kc AE8O explores an extinct volcano in NM. George says Picacho Peak is also one, something I didn't know. 09/23/Sat/3855kc Damon, W7MD, continues to be plagued by miswired rotators on his beams but is making progress otherwise. Henry amp now has 220V line in and is running. Ken, K6CJA, marries up a command-set transmitter with his AL-80B linear amplifier for a very nice-sounding 80-meter AM signal with a lot of 'Moxie'. Other news in CJA-land: refurbished top for Corvette and surgery on other eye for cataracts. W8QBG is 'critter-proofing' the Bauer by sealing door and bottom opening of box with screen. He is also constructing a balanced 'U' tuner for his ladder-line feed system that will handle the high average power of the Bauer. 09/24/Sun/3855kc Some discussion with CJA about running AM with a linear amp. I mail him yet another article from ARRL AM page about how one is really only modulating the efficiency of the amplifier when going from carrier level to peak envelope power. Basically, whatever the peak-power efficiency of the linear amp is (typically 67%), that efficiency is halved when transmitting an unmodulated carrier. *That's* why there is color on those plates in the linear. It's brutal. Speaking of command sets, WA6JUS advises that they now have one installed in the Veterans Museum in San Diego. Ted, WA8ULG, reports touring the Naval Observatory interferometer out from Flagstaff. Didn't know they gave tours. Should be interesting if you're an astronomy buff. 09/26/Tues/144.45Mcs AM At the behest of Scott Johnson, W7SVJ, I send out an e-mail outlining his activities to build and put on the air a 2-meter, AM repeater for the Phoenix area. I get a number of replies from the local 2M-AM community. And then, this Tuesday, we have an on-air discussion of the various issues surrounding the project. That e-mail can be found at: http://groups.yahoo.com/group/Arizona-AM/message/97 and some of the replies at: http://groups.yahoo.com/group/Arizona-AM/message/98 The over-the air comments centered around finding a location for the machine, getting the necessary frequency coordination, wondering if a cross-band machine (50.4 -> 144.45) might be a better option. J.D., N6IME, checks in, mentions that he has had some experience putting AM repeaters on the air and a lot of experience with FM ones and volunteers to help Scott with technical and political problems. Other, non-repeater news was that George, W8QBG, has acquired yet another BC-610, another 'I' model. That makes three for him. Preliminary diagnosis: shorted turns in the modulation transformer, crude modifications everywhere. Max, K7CAX, has ironed out the problems with his Ameco 6N2 and checks in with decent signal that isn't toooo far off frequency. Great to have Max back on 144.45. The University of Phoenix has acquired the right to rename Cardinal Stadium in their honor. All they need now is a football team to play in it. The imagination leaps at what that team could be called: The Fighting MBA's, The Nightschool Marauders, etc. 9/26/Sat/3855kc Damon, W7MD, is working 6-meter sporadic-E propagation and is building a J-pole for that band for local QSO's on AM with the Tucson bunch. He also has sad news; his Henry 8K burned up something while on the air on 40-meter AM. No diagnosis or prognosis at this point. Ken, K6CJA, continues to sound very good with his command set and amplifier combo but is worried a bit about 2nd harmonic stuff out of the command set being passed by the amplifier and will perform some measurements to evaluate the problem. He also cleaned out his stove pipe/chimney without benefit of a chimney sweep or even a top hat. WA6JUS, John in San Diego, attends the ARRL Convention there and reports that a good time was had by all. John also finds himself the recipient of a software-defined radio made by ComerCom. This ought to be interesting. Speaking of SDR's, W7CPA continues to be very pleased and impressed with his FlexRadio SDR-1000 and on-the-air listening shows it to be clean and free from distortion and other artifacts. It definitely *does not* sound like the AM from "riceboxes". Randy is now moving on to resume his work on his Sonar transmitter -- which has real vacuum tubes in it and is no longer made. He is also having fun driving his Hummer3 around with good gas mileage and performance. 10/01/Sun/3855kc Shep, W5EOE, shares his 75th birthday with us on the air and reports this autumn in Colorado is living up to expectations. We are getting a great signal this morning from Shep's partially famous, 3-element wire beam pointed down here to the southwest. Shep's XYL is still over in the Philippines and he is a bit concerned given a typhoon swept over the islands in the last few days. 10/03/Tues nite/144.45 Mcs I retrieve the schematics for Max's B&W 5100 from BAMA for him. Actually, I get them from the mirror site, which is much better behaved (http://bama.edebris.com/manuals/). Max also reports Mouser microphone element tamed with cotton baffling in back of it in D-104 mount. Ameco 6N2 is sounding good. Scott, W7SVJ, is on and thinks he will need a 6-cavity, bandpass/band-reject duplexer for the AM repeater. Quite a bit of discussion about this with JD, N6IME. Lock, W1ZD, is back from his vacation in France and reports visiting the Normandy beaches and memorials, something he has wanted to do for a long time. ------------------------------------------------------ Sidebar on AM through Linear Amplifiers ------------------------------------------------------ | |Suppose you had a linear amplifier capable of 1500 watts |PEP output with an efficiency of 67% (at that peak output). | |Typical plate constants would be: | |Plate Voltage = 3000 volts |Plate Current = 0.746 amps (peak) |Plate Power Input = 2238 watts (peak) |Efficiency = 1500/2238 = 0.67 | |These are the conditions that would attain at 100% positive |modulation peaks. | |Now, the RF output voltage across the antenna is reduced to |1/2 the peak modulation value to get the carrier wave |amplitude. By the P = I squared times R formula, this gives |an output power of 1/4 the peak power, or 375 watts, a |number universally despised by AMers. | |However, the plate voltage doesn't change. The only thing |that changes is the plate current. It drops to 1/2 its |peak value -- to 0.373 amps. | |Now the plate constants are: | |Plate Voltage = 3000 volts |Plate Current = 0.373 amps |Plate Power Input = Ep x Ip = 3000 x 0.373 = 1119 watts | |But power output at carrier is only 375 watts (doncha hate |it?) | |So the efficiency is: | |Eff = Output Power / Input Power = 375 / 1119 = 0.335 |or 33.5%. | |And that, my friend, is why those 3-500 plates glow |orangish-red when you crank AM through the LoudenBoomer. | --------------------------------------------------------- 10/07/Sat/3855kc To my dismay, I find a very obnoxious signal on 3860 this morning. It sounds like some kind of phase/amplitude modulated data and extends +/- 10 kcs from that center frequency, clobbering 3860 and giving me a fit down at 3855 and even up at 3870. I hope it goes away but it sure sounds like it is here for good. I'm also recovering from a financial blow; the indoor blower motor in my air conditioner seized up early Thursday morning. I caught it in time to keep it from cremating itself, but the damage was done. And when the repairman came out, he announced that the plenum in the gas furnace had also developed a crack, thereby posing a carbon-monoxide poisoning risk. Bottom line: $1500 for repairs, completed today. So I am cool as a cucumber and poor as a church mouse. On to more interesting matters. George, W8QBG, is still working on locating the HV glitch in his latest BC-610. He has replaced the mod transformer from his "stock on-hand". Another "You might be a homebrewer" caption here for sure. One more incident like that and W8QBG becomes depot-level maintenance for 610's. Ken, K6CJA, has two new eyes now, all the better to see through the sham and hypocrisy of ham radio. Or maybe just to keep from running over little old ladies with his Corvette. With dismay the AM group learns that Damon, W7MD, has been involved in a rear-end collision that injured him. Details are sketchy at this point, but everyone is hoping for the best for him. Some conversation about being able to make it to both the Tucson hamfest on Oct.21 and the 'Caliche Caper' at K7POF's place in Chino Valley on the 23rd. AL0F bemoans the latter happening on a Monday which is a workday for him at Cox Cable. 10/08/Sun/3855kc Understandably, Damon, W7MD, is not on the air today. AL0F reports that he was knocked around a bit, has a bad headache, but is not in immediate distress. More later.... I'm in late and out early on this go-around. 3860 noise is pretty bad - wipes out weak signals on 3855 almost completely. 10/10/Tues afternoon/147.22 FM That's right, FM. I happen to hear WA8ULG mobile on the Mingus Mtn. machine. He is coming back from somewhere east of Flagstaff with a Collins 820-D2 in tow, headed for his bat cave outside Parks, AZ. Now an 820 is some serious iron and although ULG isn't disclosing the source of said transmitter, it is obvious he is mighty pleased with his acquisition, as well he should be. Interesting side note: the 820 uses 5-500's rather than 4-400's in finals and modulators. 10/10/Tues nite/144.45 AM Nice roundtable discussion. Jim, K7SC, is concerned about the BPL trial scheduled to begin in El Mirage, just up the road from Sun City. General agreement all around that this thing will have to be watched closely, and that the economics of BPL just don't make any sense. Community WiFi seems to be a better all-around solution. Discussion drifts to issue of the 'dark fiber' left over from the telecom meltdown in 2000. Hopefully that will eventually see use, but as a busted telecom investor, I can say it would be too little way too late. Also some hopeful speculation about the presence of "flipped" sunspots signaling the beginning of the next solar cycle. 10/14/Sat/3855kc Data noise still present at K7JEB, but signals are strong on both 3860 and 3855 and override it for the most part, although it takes the Clearspeech DSP box to knock it down below annoyance. And when the band starts going out, the weak signals get clobbered. Oh, well.... Ted, WA6TJN, has a nice signal from Hemet this morning. Don't know what the antenna configuration is, but band conditions are excellent and he is good copy and great to have back on the air. WA6JUS misses AL0F on the roundtable. John wants to talk to Tim about sailing and fishing. Maybe next time, guys, or make a sked. CJA is heading down to the Colorado River on a fishing quest, but first has to get licenses from California, Arizona and Nevada. It's sad how modern bureaucracy thwarts man's inner drives for primal fulfillment. 10/14/Sat/7293kc Good band condx persist! AE8O, Tom out in NM, sees a weird transient problem in his Ranger/Amplifier setup - Ranger plate current momentarily pegs the meter. Can't replicate it. Rats. George, W8QBG, decides to turn his attention to the speech amplifier that came with his latest BC-610. This would be the BC-614. It is full of mods and George is carefully backing those out one at a time. The unit is a disaster area. I ask about documentation on the mods and am answered with a loud guffaw from all present. We hear from Damon, W7MD. He is still suffering some ill effects from the accident but is coping. His current project is to get the 6-meter and 2-meter J-pole antennas up so that he can get on VHF-AM. W7CCC is asking if anyone knows where one can find an old BC-375 tuning unit. He just wants the vernier dials off of it for a friend's project. Nice roundtable until 1130 MST and then the band went away in a flash. Had an even dozen participants. 10/15/Sun/3855kc Latest FCC Report and Order "refarming" the 80-, 40- and 15-meter Novice CW bands into Extra-class 'phone bands is a major topic of discussion this morning. Some confusion about exactly what is what, so here's what I saw on a chart on the ARRL website: 75/80 meters: Extra Phone ........ 3600 - 4000 kcs Advanced Phone ..... 3700 - 4000 General Phone ...... 3800 - 4000 40 meters: Extra Phone ....... 7125 - 7300 Advanced Phone .... 7125 - 7300 General Phone ..... 7175 - 7300 15 meters: Extra Phone ....... 21200 - 21450 Advanced Phone .... 21225 - 21450 General Phone ..... 21275 - 21450 By relay, N0BD reports that VOA is no longer programming on 7290 at night, opening the possibility of coast-to-coast nighttime AM QSO's there. K7CAX, Max, comments that he is tickled pink to find a "new" control in a switch coupled to the RF Gain control on his NC-300 receiver. This switch reconfigures the AGC control on the RF and IF amplifier stages for best phone or CW operation. Hope to be more prompt in getting this thing out next month. Letting things pile up and get stale is not the way to go. AM HONOR ROLL... (stations logged this period) W7PLR _______ WA6TJN ______ K6CJA _______ WA8ULG WA6JUS ______ W0OGH _______ WA7LYO ______ W5EOE W8QBG _______ W8KGI _______ W6JEO _______ AE8O WB7CAM ______ W7HB ________ K7CAX _______ WA6JUS AL0F ________ K7SC ________ KO6SM _______ WA6HCX VE5NT _______ K6IRD _______ W0ZUS _______ K6KSG W8QYT _______ K7JWA _______ W6BCN _______ K7BDY NA7RH _______ W7MD ________ N6IME _______ N6PY K6JEK _______ K7CF ________ W7CPA _______ W7IXA W1ZD _______ W7SVJ _______ N6PPO _______ W7CCC W9FGJ _______ W0NW ________ K6KOI _______ W6OM WA6WRF ______ XE2/W7ISJ