AD 5 X Antenna Hints Kinks u Short

AD 5 X Antenna Hints & Kinks u. Short HF Antenna Efficiency u. Mobile/Portable Antenna Construction u. Antenna Accessories/Tools/Hints Phil Salas – AD 5 X ad 5 x@arrl. net www. ad 5 x. com Richardson, Texas Phil Salas – AD 5 X

AD 5 X Short Antenna Efficiency Search for the Ideal Antenna u. Unobtrusive u. Very Small u. Cheap u 100% Efficient TANSTAAFL u. There Ain’t No Such Thing As A Free Lunch u. Everything is a Tradeoff Richardson, Texas Phil Salas – AD 5 X

AD 5 X Short Antenna Trade-offs Positive u. Small u. Light u. Easy to Transport u. Less Expensive u. Spouse-Friendly (Maybe most important!) l I. e. , not as much of an eye-sore Negative u. Efficiency Richardson, Texas Phil Salas – AD 5 X

AD 5 X Why an Efficiency Penalty? Radiation Resistance is what you want to get your power into to get it radiated. However… u. Radiation Resistance Height 2 u. Radiation Resistance Frequency 2 Therefore, as Height and Frequency are reduced, the Radiation Resistance Plummets! u. So Who Cares – Just match to the lower radiation resistance, right? Richardson, Texas Phil Salas – AD 5 X

AD 5 X Efficiency Loss u. Theoretically, matching to a low impedance is no problem. u. But, if there are other losses in low impedance systems, your efficiency will suffer. u. And there ARE other losses. l Coil Losses n l matching and loading coils Ground Losses n Because you won’t have a perfect ground system Richardson, Texas Phil Salas – AD 5 X

AD 5 X Simple Antenna Equations Let’s consider some simple equations. u. Capacitance of a short antenna l l Cb = 3. 75 pf/ft (base loading) Cc = 1/2 Cb (center loading) u. Radiation Resistance of a short antenna (< 1/8λ) l l Base Loading: Center Loading: RRb = 2. 73 X 10 -6 (hf)2 RRc = 6. 7 X 10 -6 (hf)2 Where: h = height in inches, f = frequency in MHz Richardson, Texas Phil Salas – AD 5 X

AD 5 X Simple Equations (Cont. ) u. Antenna Q = 360 f. MHZ/(2: 1 VSWR BWKHZ) u. Inductance L = 1/[(2 f)2 C] l l Not totally accurate for calculating loading coil. But very close. Tends to give a slightly greater inductance value than necessary. u. Coil Q = 2 f. L/RL u. Coil Loss = RL = 2 f. L/Q Richardson, Texas Phil Salas – AD 5 X

AD 5 X Simple Equations (Cont. ) u. RT = Total System Resistance (RR + RL + RG) = 2 f. L/Antenna Q u. Ant. Efficiency (%) = [RR/(RR + RL + RG)] x 100 = [RR/(Total System Resistance)] x 100 u. Power Loss (d. B) = 10 LOG [RR/(RR + RL + RG)] = 10 LOG [RR/(Total System Resistance)] Richardson, Texas Phil Salas – AD 5 X

AD 5 X Simple Example 8 -Foot Base-Loaded 40 Meter Antenna, Coil Q = 300 u Cb = 3. 75 pf/ft x 8 ft = 30 pf u L = 1/[(2 f)2 C] = 1/[(2 7. 2 X 106)2 (30 X 10 -12)] = 16. 3 uhy u RL = 2 f. L/Q = 2 (7. 2)(16. 3)/300 = 2. 5 u RRb = 2. 73 X 10 -6 (hf)2 = 2. 73 X 10 -6 (96 x 7. 2)2 = 1. 3 u High-Q Coil Loss is Almost TWICE the Radiation Resistance. With a PERFECT ground, you still lose 2/3 rds of your power do to the coil loss! Your antenna is 34% efficient! u With 10 of ground loss, your efficiency is only 9%! Richardson, Texas Phil Salas – AD 5 X

AD 5 X Simple Example (Cont. ) What Does Center Loading Buy You? u RC = 6. 7 X 10 -6 (hf)2 = 6. 7 X 10 -6 (96 x 7. 2)2 = 3. 2 u RL = 2 f. L/Q = 2 (7. 2)(32)/300 = 5 u Radiation Resistance increases 2. 5 times, but your coil losses double (twice the inductance). l l With no ground losses, your efficiency is now 39%. With 10 ground loss, your efficiency becomes 17. 5%. u In the real world with finite ground losses, center loading generally doubles your antenna efficiency. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Loss vs Freq. vs Efficiency u. Losses get worse fast if ground losses and/or coil losses increase because of low antenna radiation resistance. u. Things get much better as you go higher in frequency because the radiation resistance increases as frequency 2 and so the other losses don't hurt you as much. u. Conversely, efficiency can get much worse when you go lower in frequency. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Determining Efficiency u Measure the 2: 1 SWR bandwidth of your antenna l Typically 30 -80 k. Hz for a 7 -foot long antenna. u From the above, determine the antenna Q. u Measure the antenna length and calculate the antenna capacitance l Using 3. 75 pf/ft for base loading, 1. 9 pf/ft for center loading. u Calculate the inductance needed for resonating the antenna. u Calculate the radiation resistance (base loaded or center loaded). u Determine the Total System Resistance. u Calculate the antenna efficiency. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Mobile Antenna Comparisons u Lets look at the efficiency of some short antennas (i. e. mobile antennas). Richardson, Texas Phil Salas – AD 5 X

AD 5 X Mobile Antenna Comparisons Type Carolina Bug. Katcher Hustler “Standard” Hamstick Outbacker Big DK 3 Hustler “Super” 2: 1 SWR BW (40 m) 30 k. Hz 40 -50 k. Hz* 50 k. Hz 50 -80 k. Hz* * From Data Sheets Richardson, Texas Phil Salas – AD 5 X

AD 5 X Ex: Carolina Bug. Katcher u Measure the 2: 1 VSWR bandwidth of your antenna l 30 k. Hz u From the above, determine the antenna Q. l Antenna Q = 360 f. MHZ/(2: 1 VSWR BWKHZ) = 360(7. 2)/30 = 86. 4 u Measure the antenna length and calculate the antenna capacitance using 1. 9 pf/ft (antenna is center loaded). l 7 ft x 1. 9 pf = 13. 3 pf u Calculate the inductance needed for resonating the antenna. l L = 1/[(2 f)2 C] = 1/[(2 7. 2 x 106)2(13. 3 x 10 -12)] = 36. 74 μHy Richardson, Texas Phil Salas – AD 5 X

AD 5 X Carolina Bug. Katcher (Cont. ) u. Calculate the radiation resistance (center loaded). l RRc = 6. 7 x 10 -6 (hf)2 = 6. 7 x 10 -6 (84 x 7. 2)2 = 2. 45 Ω u. Determine the Total System Resistance. l RT = 2 f. L/Antenna Q = 2 (7. 2)(36. 74)/86. 4 = 19. 24 u. Calculate the antenna efficiency. l Power Loss (d. B) = 10 LOG [RR/(RR + RL + RG)] = 10 LOG(2. 45/19. 24) = -9 d. B Richardson, Texas Phil Salas – AD 5 X

AD 5 X Other Antennas 40 m 2: 1 Antenna VSWR BW/Q Length C(pf) L(uhy) RR(Ω) Eff. % Loss CBKatcher 30 k. Hz/86 7’(84”) 13. 3 36. 74 2. 45 12. 7 -9 d. B Antenna B 50 k. Hz/52 7’(84”) 13. 3 36. 74 2. 45 7. 7 -11 d. B Antenna C 80 k. Hz/32 7’(84”) 13. 3 36. 74 2. 45 4. 7 -13 d. B What are the actual ground losses? u Carolina Bug. Katcher Coil Q Measured: 210 RL = 2 f. L/Q = 2 (7. 2)(36. 7)/210 = 7. 9 Ω RRc = 6. 7 X 10 -6 (hf)2 = 6. 7 x 10 -6 (84 x 7. 2)2 = 2. 45 Ω RT = 2 f. L/Antenna Q = 2 (7. 2)(36. 74)/86. 4 = 19. 24 Ω RG = RT - RR - RL = 19. 24 – 2. 45 – 7. 9 = 8. 9 Ω (typically 7 -15 ohms) Richardson, Texas Phil Salas – AD 5 X Q

AD 5 X Auto-Tuners & Short Antennas u. Auto-tuners provide flexibility l You don’t have to re-tune antenna every few KHz. u. Auto-tuner must be located directly at the base of a non-resonant antenna for best operation. l The auto-tuner is now the loading coil of a baseloaded short antenna. u. Auto-tuner should be connected to the base of a non-resonant antenna with a very short piece of wire – NOT COAX. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Auto-tuners (Cont. ) u. Unfortunately, most auto-tuners do not have hi-Q inductors. l l Auto-tuner inductors are typically close-wound inductors with much lower Q than the air-wound inductors often used as the base loading coil. Your losses will be higher due to the low-Q auto-tuner inductors. u. So again, TANSTAFFL l You are trading off efficiency for QSY convenience. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Auto-tuners (Cont. ) u Coax interconnects from an antenna tuner to a nonresonant antenna lead to very poor efficiency. l l A short antenna capacitance ~ 30 pf (depends on length). A one-foot length of coax cable has about the same capacitance. u So you will shunt the antenna capacitance plus radiation/loss resistances with a similar amount of capacitance and loss resistance. u This loss resistance could be even lower than the lossplus-radiation resistance of the antenna l You could be throwing away half of your power or more, just by putting a 1 -foot section of coax between the tuner and nonresonant antenna! Richardson, Texas Phil Salas – AD 5 X

AD 5 X Auto-tuners (Cont. ) Wire Radio 30 pf Tuner RR + RL + RG (10 -20 ) Tuner with short wire interconnect 30 pf Radio Tuner Coax Equiv. RR + RL + RG (10 -20 ) 27 pf/ft Loss resistance Tuner with 1 -ft coax interconnect Richardson, Texas Phil Salas – AD 5 X

AD 5 X Efficiency Summary u Use center loading l Typically doubles the efficiency of base loading n 3 d. B or ½ S-Unit improvement u Use high-Q coils l l Large wire (with at least 1 -turn wire separation) Air wound u High-Q means reduced operating bandwidth! l But more power is radiated u Use the highest frequency HF band available l Doubling the frequency (7 14 Mhz) quadruples the radiation resistance. u Make your antenna as long as possible. l Increases radiation resistance. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Efficiency Summary (Cont. ) u. In mobile applications, mount the antenna as high as possible. l Reduces Ground losses. u. Keep capacitive hats well-above loading coil. l Hat-to-coil capacitance reduces coil Q. u. If you don’t need some sort of base matching to achieve a good VSWR with a short antenna, you probably have high coil and/or ground losses. l The better the antenna/ground is, the worse the VSWR at resonance becomes for an efficient antenna. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Efficiency Summary (Cont. ) u. If you use an auto-tuner with a non-resonant antenna, use a short wire interconnect to the base of the antenna. l For reasonable VSWR conditions (< 5: 1 VSWR) coax losses will be minimal if the antenna tuner is located away from the antenna. n Coax losses are not too bad at these VSWR levels if the coax run is reasonably short. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Antenna Construction Hints & Kinks u. Mobile/Portable Antenna Construction u. Antenna Accessories/Tools/Hints Richardson, Texas Phil Salas – AD 5 X

AD 5 X Build Efficient Short Antennas u Use 3/8” diameter brass rods from your local hardware Store. u Or 3/8” or ½” diameter aluminum tubing from Texas Towers or your local hardware store. l You can solder to aluminum with aluminum solder paste from www. solder-it. com. u Make brass coupling interconnects for the rods and coils. l l l Use 1/8 NPT brass nipples and couplings. Thread 3/8” wood/fiberglass rods to screw into 1/8 NPT couplings. Non-preferred: Ream out couplings (use 3/8” drill bit) to fit over 3/8” diameter brass rods and wood/fiberglass insulators. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Joining Shorter Tubes #6 SS screws 5/32”D hole ½”OD tube 3/32”D hole 3/8”OD tube Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas Nipples, Couplings, 3/8 x 24 Studs Phil Salas – AD 5 X

AD 5 X 1/8 NPT Nipple & Coupling Male/Female 1/8 NPT Assemblies Richardson, Texas Reaming: Non-preferred Be Careful!! Phil Salas – AD 5 X

AD 5 X 3/8” Diameter Mast Details 0. 7” nipple 3/8” 2’OD fiberglass brass orrod AL rod 1/8 NPT Brass Coupling Mast Sections 1/8 NPT Brass Coupling Soldered with Solder-It torch and aluminum solder paste. Soldered with Solder-It torch and silver solder paste. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas Alternative Attachments Phil Salas – AD 5 X

AD 5 X ½”D Mast Details (Base) ¾”x#8 ss screw, nut & lockwasher 3/8 x 24 ss stud ½”D AL Tubing Richardson, Texas Phil Salas – AD 5 X

AD 5 X ½”D Mast Details (Top) Harbor Freight 39391 -0 VGA Tap & Die Kit @ $12. 99 Sizes: 4 -40, 6 -32, 8 -32, 10 -24, 12 -24, 1/4 -20, 1/4 -28, 5/16 -18, 5/1624, 3/8 -16, 3/8 -24, 7/16 -14, 7/16 -20, 1/2 -13, 1/2 -20, 1/8'' NPT pipe tap. 1/8 NPT Tap Richardson, Texas Phil Salas – AD 5 X

AD 5 X ½” Diameter Mast Interfaces Parts for Female End Richardson, Texas Assembled – With & Without Heat-Shrink Tubing Phil Salas – AD 5 X

AD 5 X Parts for Male End Richardson, Texas ½” Diameter Mast Interfaces Assembled – With & Without Heat-Shrink Tubing Phil Salas – AD 5 X

AD 5 X Butane Torches Solder. Pro 50/70/100/120 • Solder-It Company • ACE Hardware • Radio Shack • Fry’s Electronics Silver Solder Paste • Solder-It Company • Radio Shack Aluminum Solder Paste • Solder-It Company Richardson, Texas Phil Salas – AD 5 X

AD 5 X Loading Coils u Use 3/8” diameter wood dowel or fiberglass rod for the coil support. u 1/4”D fiberglass Bicycle Flags also make good supports. l l Use ¼” compression-to-1/8 NPT Male/Female brass adapters Be careful when working with fiberglass! u B&W 3027 Coil (~60 u. Hy) l l l 2”D x 10”L Surplus Sales of Nebraska (www. surplussales. com) $15 ea u MFJ-404 -008 (~60 u. Hy) 2. 5”D x 5”L l $15 ea. Note: Reinforce ends of coils with Home Depot 2 -part quick setting clear epoxy. l Richardson, Texas Phil Salas – AD 5 X

AD 5 X 3/8”Dia. Rod Coil Support 3”L x 1/8”D brass rod 0. 7” nipple 3/8”D wood/fiberglass 1/8 NPT Brass Coupling Coil Support Section Richardson, Texas Phil Salas – AD 5 X

AD 5 X Coil Details Coil: MFJ-404 -008 @ $14. 95 2. 5”D x 5”L Richardson, Texas Phil Salas – AD 5 X

AD 5 X ¼” Fiberglass Rod Coil Support 3”L x 1/8”D brass rod 0. 7” nipple 1/4”D fiberglass rod ¼ compressionto-1/8 NPT M ¼ compressionto-1/8 NPT F Coil Support Section Bicycle fiberglass rod Richardson, Texas Phil Salas – AD 5 X

AD 5 X ¼” Fiberglass Coil Support ¼ Compression-to 1/8 NPT Male ¼ Compression-to 1/8 NPT Female ¼”Fiberglass Bicycle Flag Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas ¼” Fiberglass Support Coil Phil Salas – AD 5 X

AD 5 X Find the Tap Point Radio Shack RS 270 -373 Micro Clip Richardson, Texas Phil Salas – AD 5 X

AD 5 X Final Tap Point MFJ-605 -4001 Silver-plated coil clip Richardson, Texas Phil Salas – AD 5 X

AD 5 X Build your Own Coil u. Items needed: l l Desired PVC pipe form (OD and length) Nylon Edge Trim (8 -TPI) n l 14 Gauge bare copper wire n l Mc. Master-Carr 8873 K 51, $10. 20 for 80 -feet Tie Wraps n l Mc. Master-Carr 85085 K 8, $10. 29 for 25 x 12 -3/4” strips To hold ends of Nylon Edge Trim to PVC pipe Hot Glue Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas Build Your Own Coil Phil Salas – AD 5 X

AD 5 X Build Your Own Coil L(uhy) = d 2 n 2/(18 d + 14 l) where: d = diameter (wire center to wire center in inches) n = number of turns l = length of coil (inches) Richardson, Texas Phil Salas – AD 5 X

AD 5 X Top Whips or Dipole Elements u 1/8 NPT Nipple has a 1/4” ID l l Will take a 1/4” OD fiberglass bicycle flag pole Or a Radio Shack 72” telescoping whip (RS 270 -1408) n May need to ream nipple with 9/32” drill bit u 1/8 NPT Nipple will screw solidly into a 0. 5” OD aluminum tube. l Thread the 1/2” diameter tube for 1/8 NPT. u. To make a 3/8 X 24 stud, screw a 3/8 X 24 stainless steel bolt firmly into a 1/8 NPT coupling. Then cut off the head of the SS bolt. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Top Whips or Dipole Elements 3/8 x 24 Stud 1/8 NPT x 3” Nipple 6’ Bicycle Fiberglass Rod or Radio Shack 72” whip 1/8 NPT Brass Coupling OR 3/8 x 24 Stud 1/8 NPT x 3” Nipple 1/8 NPT Brass Coupling Richardson, Texas 0. 5” OD Aluminum Tube Phil Salas – AD 5 X

AD 5 X Richardson, Texas Radio Shack 72” Whip Interface Phil Salas – AD 5 X

AD 5 X Richardson, Texas RS whip and 3/8 x 24 thread Phil Salas – AD 5 X

AD 5 X Fixed and Sliding Whips u Top whips can be made with 1/8” rods l l l 3 -feet brass rod @ Home Depot for $2. 29 each 4 -feet steel rod @ Home Depot for $1. 19 each 12 -feet stainless steel rod from Jacob Schmidt n n www. jschmidtstainless. com 12 -feet for $2, but shipping ~$10. u Couplers made with 1/8 Compression-to-1/8 NPT Male brass adapter l l l Drill out center hole to 1/8” diameter Use compression collar for fixed whip Throw away compression collar for sliding whip n n Drill and tap brass adapter for #6 thumbscrew And/or solder on #6 nut over tapped hole for extra support Richardson, Texas Phil Salas – AD 5 X

AD 5 X 1/8” Steel or Brass Whip Intfc 1/8 Compression-to-1/8 NPT Male Adapter Richardson, Texas Phil Salas – AD 5 X

AD 5 X 1/8 Compression-to-1/8 NPT Adapter Drilled & tapped for #6 thumb screw Richardson, Texas Sliding Whip Adapter Sliding whip & shaft Phil Salas – AD 5 X

AD 5 X More Robust Whip Adjust #6 brass nut soldered on brass adapter for additional thread length Richardson, Texas Phil Salas – AD 5 X

AD 5 X More Robust Adjust & Shaft Whip/Adapter/Tube Assembly Richardson, Texas Phil Salas – AD 5 X

AD 5 X Corona Ball u. Corona Discharge effectively gives you a varying antenna length, with a varying VSWR. u. To eliminate corona discharge, you need to eliminate any sharp points at the antenna end. l Also keeps you from poking your eye!! u. Taper the end of the 1/8” rod with a file. u. Screw on a #6 nut just enough so that it is firm on the end of the whip. u. Solder it in place. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Corona Ball Stainless Steel and Brass “Corona Ball” Richardson, Texas Phil Salas – AD 5 X

AD 5 X Short Antenna Matching u. Short antennas have low radiation resistance. u. Sum of radiation resistance, coil loss and ground loss typically less than 25 ohms. u. Inductive, capacitive, or transformer matching will give you a good VSWR. u. If you don’t need base matching on your short antenna, you probably have excessive losses! Richardson, Texas Phil Salas – AD 5 X

AD 5 X In-Line Capacitive Base Match 1/2 x 1/8 NPT Brass 1 -1/4 x 1/2” PVC Adapter IN #8 x 1” brass machine screw, lockwasher, nut, wingnut. #6 x 3/8” SS sheet metal screws (4 plcs) OUT GND 1 -1/4 PVC Coupler etc. 1 -1/4” PVC plug 3/8 x 24 x 1 -1/4” hex head stainless steel, nut, lockwasher. In-Line Capacitor Matching Assembly (Not all internal capacitors shown) Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas In-Line Capacitive Base Match Phil Salas – AD 5 X

AD 5 X SO-239 Capacitive Base Match 1/2 x 1/8 NPT Brass Adapter 1 -1/4 x 1/2” PVC Adapter SO-239 #8 x 1” brass machine screw, lockwasher, nut, wingnut. 1 P 12 POS Rotary Switch GND 1 -1/4 PVC Coupler #6 x 3/8” SS sheet metal screws (4 plcs) 1 -1/4” PVC plug Richardson, Texas 3/8 x 16 x 1 -1/4” hex head stainless steel, nut, lockwasher. Phil Salas – AD 5 X

AD 5 X Richardson, Texas SO-239 Capacitive Base Match Phil Salas – AD 5 X

AD 5 X Richardson, Texas SO-239 Capacitive Base Match Phil Salas – AD 5 X

AD 5 X Inductive Base Mount 1/2 x 1/8 NPT Brass Adapter 1 -1/4 x 1/2” PVC Adapter 3 turns # 18 enameled wire SO-239 #8 x 1” brass machine screw, lockwasher, solder lug. Screw threads into #8 tapped hole in brass adapter. #8 x 1” brass machine screw, lockwasher, nut, wingnut. 1 -1/4 PVC Coupler 1 -1/4” PVC plug 3/8 x 16 x 1 -1/4” hex head stainless steel, nut, lockwasher. Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas Inductive Base Mount Phil Salas – AD 5 X

AD 5 X XFMR Base Matching 1/2 x 1/8 NPT Brass 1 -1/4 x 1/2” PVC Adapter 22Ω 22 ohms #8 x 1” brass machine screw, lockwasher, nut, wingnut. 50Ω 1 -1/4 PVC Coupler GND #6 x 3/8” SS sheet metal screws (4 plcs) 5 6 3 4 1 2 50 ohms 2. 25: 1 Broadband Matching Transformer. 8 -turns triple #16 enameled wires on FT-114 A-61 1 -1/4” PVC plug 3/8 x 24 x 1 -1/4” hex head stainless steel, nut, lockwasher. XFMR Matching Assembly Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas XFMR Base Matching Phil Salas – AD 5 X

AD 5 X Richardson, Texas X- and C-Match Phil Salas – AD 5 X

AD 5 X Portable Antenna Base 1/2 x 1/8 NPT Brass 3/4 x 1/2” PVC Adapter #8 x 1” brass machine screw, lockwasher, nut, wingnut (2 plcs). #6 x 3/8” SS sheet metal screws (4 plcs) 3/4” PVC threaded plug Richardson, Texas 3/8 x 16 coupler 3/4 x 1/2 PVC “T” SO-239 3/8 x 16 x 2 -1/2” hex head carriage bolt, nut, lockwasher. 3/8 x 16 nut, lockwasher. 3/8 x 16 x 12” hex head carriage bolt with head cut off. Phil Salas – AD 5 X

AD 5 X Richardson, Texas Portable Antenna Mount Phil Salas – AD 5 X

AD 5 X Richardson, Texas Portable Mount “in-action” Phil Salas – AD 5 X

AD 5 X Richardson, Texas Capacitive Matching Phil Salas – AD 5 X

AD 5 X New 40 -10 M Portable Dipole Update to 20 -10 meter dipole in Dec. 2000 QST u. Use switches instead of clip-leads u. Added Balun l 10 T RG-174 on FT-114 -43 ferrite torroid u. Add loading coils for 40/30 meters l 40 M: 18. 5 uhy across open 10 -meter switches n l 36 T #20 enameled wire on T 106 -2 torroid 30 M: 6. 5 uhy across open 10 -meter switches n 22 T #20 enameled wire on T 106 -2 torroid Richardson, Texas Phil Salas – AD 5 X

AD 5 X New 40 -10 M Portable Dipole Optional 30/40 meter coils 41. 5” (20 m) 20. 5” (17 m) 18. 5” (15 m) 11” (12 M) 7’ 11” (10 m) Coax 11” (12 M) 18. 5” (15 m) 20. 5” (17 m) 41. 5” (20 m) Figure 5: 40 -10 meter Switched Dipole FT 114 -43 Ferrite Core Figure 1: Balun Winding Details 5 Turns/Side (Not all turns shown) 10 turns RG 174 coax Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas Balun & 30/40 M Loading Coils Phil Salas – AD 5 X

AD 5 X Packed Portable Station In MFJ-6404 Case Richardson, Texas Portable Station Unpacked Portable Station Phil Salas – AD 5 X

AD 5 X Tuning The Antenna u. Most radios have internal SWR metering. u. My preference is a simple external SWR meter that also protects the radio during tune-up. u. A resistive SWR bridge using an LED indicator works great. u. Limits worst case SWR to 2: 1 during tuning l l Use Caddock power resistors MP 915 -50: 15 -watt, 50 ohm, TO-126 n l $2. 78 each – Mouser Electronics 684 -MP 915 -50 MP 930 -50: 30 -watt, 50 ohm, TO-220 n $3. 58 each – Mouser Electronics 684 -MP 930 -50 Richardson, Texas Phil Salas – AD 5 X

AD 5 X The Tenna-Tune Transmit TX ANT Tune/SWR 50 50 0. 01 uf 1 N 4454 Pin 1: key 10 K Pin 2: start 10 K IC 706 Tune 50 Pin 3: +12 V Ultrabright Red LED 0. 01 uf Pin 4: gnd RS 274 -224 IC 706 INTFC Tenna-Tune Schematic Richardson, Texas Phil Salas – AD 5 X

AD 5 X Richardson, Texas The Tenna-Tune (Cont. ) Phil Salas – AD 5 X

AD 5 X Richardson, Texas MFJ-902 & Tenna-Tune Phil Salas – AD 5 X

AD 5 X Richardson, Texas MFJ-935 B & Tenna-Tune Phil Salas – AD 5 X

AD 5 X Richardson, Texas MFJ-932 & Tenna-Tune Phil Salas – AD 5 X

AD 5 X Screwdriver Control/Indicator + 12 VDC IN (Powerpole) - Motor control (4 -pin socket/2 used) Motor control + 10 Ω 2 W 2 XUltrabright Red LEDs Hi-freq limit Lo-freq limit 150 Ω Schematic - Direction control and limit indicator QTY 1 1 2 1 1 1 2 Richardson, Texas Description Rocker Switch (Mouser 629 -GRS 4023 C 13) 4 -pin Receptacle (Mouser 538 -03 -06 -1044) Female sockets (Mouser 538 -02 -06 -1103) 1. 97 x 1. 38 x 67 box (Mouser 546 -1551 GB) 10 - 3 -watt resistor (Mouser 71 -CW 2 B-10) 150 - ¼-watt resistor (Mouser 71 -CCF 07 -J-150/R) Ultra-bright red 5 mm LED (All Elctronics LED-94) Phil Salas – AD 5 X Price $1. 41 $0. 77 $0. 19 ea. $1. 03 $0. 40 $0. 02 $0. 75 ea Q

AD 5 X Parts Suppliers u Aluminum tubing – Texas Towers, ACE, Home Depot, Mc. Master. Carr (www. mcmaster. com). u Fiberglass rods/tubes l l l The Deer Shock Depot: http: //electric-deer-fence. com/ Max-Gain Systems: http: //www. mgs 4 u. com/ Walmart/Bicycle shops: ¼” diameter fiberglass bicycle flag u PVC, brass plumbing parts, tubing, stainless steel hardware l ACE/True Value/Home Depot/Elliott’s/Mc. Master-Carr u Air-wound coil & coil taps l l l MFJ-404 -008 coil, MFJ-605 -4001 coil tap B&W coils (Surplus Sales of Nebraska) Make your own!! Richardson, Texas Phil Salas – AD 5 X

AD 5 X Parts Suppliers (Cont. ) u Tools: Solder-It Company: http: //www. solder-it. com/ l l l Solder. Pro torches (Solder. Pro 50 is $19. 95 @ Radio Shack) Aluminum Solder Paste Silver Solder Paste (Silver Solder Paste is $4 @ Radio Shack) u Hand Tools l l Harbor Freight 39391 -0 VGA Tap & Die Kit @ $12. 99 11/64” cobalt drill bit (for drilling #8 clearance hole in stainless steel): ACE Hardware Store u Stainless Steel hardware l l l Jacob Schmidt & Son (www. jschmidtstainless. com) ACE Hardware store Mc. Master-Carr (www. mcmaster. com) Richardson, Texas Phil Salas – AD 5 X

AD 5 X Conclusion Covered u. Short Antenna Efficiency u. Mobile Antenna Comparisons u. Short and Portable Antenna Building u. Antenna Tuning Accessories u. Parts Sources for Antenna Construction u. It’s fun to design antennas while standing in the plumbing area of your local hardware store. l Though you may confuse the store employees! Richardson, Texas Phil Salas – AD 5 X