WORLD-WIDE "DX" COMMUNICATIONS VIA AMATEUR RADIO (1st TRUE INTERNET)
THE W7VU / MOBILE :SY'S "HOMEBREW" (SELF-DESIGNED ENGINEERING) FEATURES
*HOMEBREW SOLID-STATE MOBILE AMP:800 WATTS OUTPUT POWER
*HOMEBREW SPEECH CLIPPER: RAISES EFFECTIVE PWR TO ~1.2 KW
*END-FIRED PHASED MOBILE VERTICALS ( 20 METERS ) 4.7 dB GAIN
*HEIL HC-4 DX MIC CARTRIDGE, w BACKGRND NOISE CANCELLATION
*BROWN BROTHERS IAMBIC CW PADDLE, AND "LIL BUGGER" KEYER
*ANTENNA INSTANTLY SWITCHED BETWEEN ANY 4 HF TUNED BANDS
*NORMAL MODES OF OPERATION:BOTH 'MOVING' AND 'STATIONARY'
38,186 CALLSIGN LOOKUP BY OTHERS
SY MOSKOWITZ : W7VU [ JUNE 2011 ]
PREVIOUS CALL : W4IFG [ 2006 - 2011 ]
PREVIOUS CALL : K0SY [ 1998 - 2006 ]
PREVIOUS CALL : N4KEL [ 1985 - 1998 ]
Sy 'Fun In The Sun' @Spring Break In Edgewater Beach, FL
Red Lodge, Montana. '4 Footer' Roof Mag Mount Ascent Up The Bearstooth (WY)
Some Samples Of Thousands Of Sy's Received DX QSL Cards, Confirming Contact - All With A "Mobile" Endorsement
Heard Island Burma North Pole Nepal(Father Moran) Japan(Spuds M.) Japan(M. Mouse) Libya
Tahiti Somalia Pakastan Afghanistan Peter 1st Island Bouvet Island Uganda
Vanatu China Andamans Lacadives Isl. Mongolia,Tadzik India, Chatham Borneo
China China Antartica Iran, Iraq, Israel Qatar, Egypt,UAR Kermadec Isl. Nuie
Laos Vietnam Maldives St. Helena Isl. Chagos Archapel. Reunion Isl. S.Shetland
Thailand Brunei Ascension Tristan D Cunha Tromilin, Crozet Turkey, Mt.Athos Macau
North Korea Cambodia Spratly Kuwait, Saudi Arab. So.Sudan, Yemen Pitcairn Island Siberia(USSR)
SOME REMARKABLE, CONFIRMED MOBILE DX "DEEDS"
1. 351 DXCC countries, all confirmed as either /M or /Mobile.
2. 329 DXCC countries on CW, all confirmed as /M or /Mobile.
3. Mid 1990s only mobile station in the world listed on CQ Magazine DX Honor Roll at 328 confirmed. (N4KEL/M). All QSL cards examined and verified. (CQ Magazine was chosen because QST Magazine does not recognize a "mobile" endorsement).
4. Radio Club Of Moscow Oblast Awards for both SSB and CW, having worked and confirmed at least 150 USSR Oblasts as " / M " in each mode. Sy actually worked and confirmed 283 out of a total 286 original USSR 'oblasts', but the highest endorsement is 150, without having all of them (Basic award requires 100 oblasts). All QSL's were examined, certified, accepted by the Moscow Radio Club as N4KEL/MOBILE, and all with appropriate state-side validation (CQ Magazine, Boeing "Bears" Radio Club). Most likely, this is the only mobile station in the world known to have achieved and received these (2) difficult awards, extraordinarily so, taking into account that a bonafide " /Mobile" endorsemen is certified with the awards, as well.
5. 'Mobile WAZ' [ worked all the world-wide zones ] on each of (3) separate amateur radio bands, and 'Mobile DXCC' [ at least 100 countries confirmed ] on each of (4) separate amateur radio bands...all via mobile operation.
SY IS NOW W7VU. He was formerly W4IFG ("I Feel Good !"), his original call at age 10. He once let W4IFG expire many years ago, while still in graduate school. He became interested and active, again in 1985, as N4KEL / "Mobile", mainly as a result of the urgings of many of his 'ham' colleagues, while he was still with Rockwell/Collins Radio in Cedar Rapids, Iowa. Sy began his operating strictly from his mobile. From 1985 through late 1987, with only 95 watts ('barefoot'), he was able to work and confirm over 270 ARRL listed DXCC countries. However, it became painfully clear that it was' tougher and tougher' in the DX "pile-ups", as just a 'barefoot' mobile station. All of this triggered Sy to design and construct his own HF mobile linear amplifier (about 600 watts output). Starting around 1990, Sy became a highly respected member of the scientific/engineering staff at Bell Laboratories in Whippany, NJ. Also, Sy changed his call from N4KEL to K0SY around 1999. For sentimental reasons, in 2006, he reclaimed his very 1st old original call, W4IFG. All these many years, his mobile operations have been from Ford E-150 vans, all with unique setups (See CQ Magazine Sept 2007, pgs 55, 56). There have been countless mentions, many references, and featured articles about Sy's mobile, and his astounding DX achievements, over the years in magazines, such as QST, CQ, and books like Dave Ingram's (K4TWJ), 'HF Mobile In High Style'. The "SyMobile", as it is often called, draws a bit of attention, curiosity, and interest (especially whenever that big mobile signal is heard amongst all the "big gun" fixed stations, during typical "DX pile-ups"). His actual 'working conditions' with many of the fine details are described further down this page for those really interested in the nuts and bolts of this high-powered mobile operation (there always seems to be a few "inquiring minds that really do want to know"):
RECENT PROFESSIONAL HISTORY + COLLINS RADIO, BELL LABORATORIES, MOTOROLA SEMICONDUCTOR, ETC.
SATURN V MOON PROGRAM
SCIENTIST/ SENIOR PROJECT DESIGN ENGINEERING MEMBER OF TECHNICAL STAFFS WITH THESE COMPANIES:
1) CORNING SCIENCE & TECHNOLOGY DIVISION - RF / Microwave Design Consultant - Sr. Project Engineer(Corning, NY)
5) MOTOROLA - Advanced RF Semiconductor Division - RF Power Applications & Designs - McDowell Street (Phoenix, AZ)
DESIGN, CONSTRUCTION, & INSTALLATION DETAILS OF W7VU / 'SYMOBILE'
A) 'Homebrewed' broadband mobile amplifier' (8) Toshiba 2SC2879 HF transistors on (4) 'Push-Pull' boards with (6) integrated, band switched LP output filters. An external "high-power" RF tuner maintains an extremely tight match and maximum output power into the antennas, during tuning to the desired CW or SSB frequency. Note: Extreme sensitivity of max output power to load VSWR is one of the poorer characteristics of broadband, solid-state amplifiers.Typical output power is 780 watts (a max DC input supply of 85 amps @ 14.0vdc). A 145 ampere van alternator is the power source. Sy's previous van used a very compact 160 amp Leece-Neville alternator and a separate, adjustable,Transppo regulator. This provided slightly better voltage regulation, adding ~ +70 watts of additional output power (insignificant). The van uses just (1) standard 900 CCA 'utility vehicle' battery for a good reason (the total lower Rs with all the extra batteries only acts as an additional load upon the alternator. A popular myth is that more batteries = better 'regulation', but just the opposite is really true). The amplifier DC leads consist of (2) #4 'soft'-stranded copper, super flexible welding cables, each 8' in length, and silver-soldered copper lugs at both ends of each cable.
B) Capacitively-top loaded 5' 8" length, phased verticals on roof of Ford Van ('Birdcage' cylinder top-hats producing extremely large capacitive top-loading, with extremely small wind-load footprints). These verticals are arranged as a 2-element end-fired, phased array for 20 meters, 4.7dB of potential relative gain (true effective gain is 3.9 dBi because of losses). Subtract 2.15 dB as referenced to dipole, and the total realized gain of this array is +1.75 dBd. Comparatively small, but this is actually remarkable as compared to the typical mobile environment (-12 to -25 dB below dipole reference). The antenna system covers (4)) HF bands, instantly switch-able between any of the bands (pre-tuned 'spider' elements atop a common mast). Any band can be put into operation, by switching frequency of the transceiver, and also a bank of low-pass linear output filters.This 'spider' arrangement of Hi-Power / Hi-Q loading coils for each band is attached to a common stainless steel mounting plate atop each antenna mast. Varying amounts of capacitive top-loading is employed above the loading coil for each band.The masts, below the mounting plates, are stainless steel 50" GLA Bugcatcher masts.The bottoms of the masts are inserted into large, heavy-duty, knurled brass "quick- disconnects" from GLA, and are mounted atop the bases of large magnetically-mounted, aluminum frames on both the rear and front roof sections of the Van (8' 6" of separation between vertical elements). These mounting frames are "Van Valzah (4) Footers", but are no longer available. Clear monofilament 100 lb fishing guy lines are attached between the top mounting plates, and the outside edges of gutter rails along the roof, with metal, plastic coated, snap-on 'C' rail clips (these clips are 'off the shelf' items, designed to fit these rails, and are found at several large automotive chains, such as 'Pep Boys'. The clips slide easily along the rails and are positioned for just the right amount of firm tension with no slippage. The guy lines are not totally necessary, but do provide additional insurance against any unforseen accident that might cause a disastrous 'tip over', especially while the Van is moving. The van is easily and safely driven at all legal limit speeds while the antenna system is in place. This is a true 100% mobile operation. A complete antenna mast system, along with it's C-clip guy lines is easily unclipped, lifted from its mag-mount "quick disconnect", and completely removed from the roof, as a totally complete assembly, in typically just under 4-5 minutes.
C) 'Homebrewed' voice speech clipper with integrated "brickwall" Low-Pass filter, installed in Kenwood TS-440/SAT Transceiver. 'Clipper' level adjusted to increase SSB average / peak power ratio such that the linear's SSB average output power is effectively doubled. Normally, SSB average power for a "typical male's" speech components is approximately 40% of the peak value ( 800 watts peak = 320 watts SSB average). Sy's clipper increases this average value to as much as 520 watts. This is effectively the same average as would be obtained from running 1.3 kw from the van, using normal SSB speech characteristics. The beauty of this method is that the peak power of the mobile linear is still actually only 800 watts. This explains why true voice "speech clipping" [analog or digital] is an absolutely extremely effective technique, as compared to other forms of speech processing (such as volume compression, "EQ" graphics, etc...although these have merits, as well). It's important to keep in mind that increasing one's 'effective' power from 800 watts to 1300 watts only makes a very tiny discernable difference on a properly calibrated rcvr's S-Meter. However, when "clipping" is combined with enhanced "EQ" graphics, too, especially above 2KHz, the real effects can be quite startling, and effective, especially in DX pile-ups with the much bigger 'fixed' stations.
D) Heil HC-4 'DX Dream' microphone cartridge tailored installation in the Kenwood TS-440 handheld microphone, with 'baffling' adjusted for both 'noise cancellation' and reduction of 'speech splatter' and road noise that is so typical with handheld mics, while operating 'mobile'.
E) Brown Brothers Iambic CW paddle with tiny, miniature "Lil Bugger" keyer, velcro'ed to the side of paddle (same battery for + 4 years). Ratio of Mobile CW (Morse Code) versus SSB (Voice) operating times is typically split about 60 / 40, respectively.
F) Kenwood SW-2000 Output /SWR Watt Meter & Dual Monitor, mounted horizontally just in front of the dashboard for easy visibility & constant monitoring, while in motion.There is also a metrology calibrated mini-Bird 1000watt broadband HF power meter (no plugin slugs required) between the linear and tuner,there as just a reliable, additional '2nd calibration cross-check' of the true output power and vswr.
G) RG-8X phasing harness, self-designed, 'homebrewed', specifically for 20 meter phased array, using the Al Christman method described in 1980 "Ham Radio" magazine.This method solves the problem of unequal currents due to elements with different driving point input source impedances.This forces currents to divide equally at any desired 'correct' phase displacement (Desired lag: -135 degrees @1/8 Wavelength element spacing (8.5'separation). Actual required cable phase lengths that result (at 14.100 MHz): Front cable: -171 degrees, Rear cable: -19 degrees.This produces the desired equal currents in the antenna elements with the correct -135 deg. desired 'phase lag. The array efficiency is 84% (including all array losses and the equivalent series ground path loss, Rg, too). The result is +3.9 dB true net relative gain, which is very remarkable for very "Hi-Q", extremely short, HF mobile vertical elements.
H) Keys To Mobile "DX'ing" Success - Listening, Patience, Persistence (with all these efforts further enhanced by excellent 'on the air' results, in addition to the satisfaction gathered from the much hard work, painstaking dedication to the assembly and evolution of an effective, competitive, well-engineered mobile DX station at a relatively very modest cost. These activities are a little different and unique from most ham mobile operations, usually encountered. It becomes readily apparent that "Mobile DX'ing" occupies a special niche that is reserved and of special interest to fellow "DX'ers", a term applied to those amateur radio "ham" operators that are interested and primarily engaged in world-wide global communications on the HF (high frequency) amateur radio bands through the science and wonder of multi-layer ionospheric/sunspot phenomena, and long-distance HF radio wave propagation.
7188280 Last modified: 2016-03-24 01:48:54, 31206 bytes
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