8-Band HF Vertical 80 thru 10 Meters Model DX-88 Instruction Manual
Please record the following information for your records: Date of Purchase: _____________________________________________ Purchased From:______________________________________________ Price Paid:__________ Please retain your copy of the Bill-of-sale for warranty claims. TABLE OF CONTENTS Chapter 1..........................................................................................................................................1-1 General Description .………...........…..................................
LIST OF ILLUSTRATIONS Figure 1 2 Detail A Detail B Detail C 3 Detail A Detail B 4 Detail A Detail B 5 Detail A Detail A 6 Detail B Detail C 7 Detail A Detail B 8 9 10 11 12 13 14 15 Base Assembly 80/40 Meter Assembly 45” Capacitor Assembly 1 1/8” x 1” Mast/Capacitor Clamp 1 1/8” x 7/16” Mast/Capacitor Clamp 10/12/15 Meter Capacitor Assemblies 13” Capacitor Assembly 16” Capacitor Assembly 10/12/15 Meter Trap Assembly 1 1/8” x 1” Mast/Capacitor Clamp 1 1/8” x 7/16” Mast/Capacitor Clamp 17/20 Meter Capacitor
CHAPTER I GENERAL DESCRIPTION ELECTRICAL DESIGN The Hy-Gain DX-88 is an omnidirectional, unity gain, self supporting vertical antenna that operates in the Amateur 10, 12, 15, 17, 20, 30, 40, and 80 meter bands. This vertical antenna may also be tuned to provide outstanding reception in the SWL 11, 13, 16, 19, 22, 25, 31, 41, 49, 74, and 90 meter bands. The DX-88 will work against an earth ground and a set of ground radials or a resonant radial system when mounted above ground.
SPEC IFIC ATIONS Elect rical Frequency: Transmit .............................……….................... 80, 40, 30, 20, 17, 15, 12, 10 meter A m a t e u r Bands Receive...............................……………..................... 3-30 MHz, tunable in 8 International SWL Bands. Input impedance . ...................…………………………………………………………………….50 ohms VSWR at resonance..................................………………l e s s than 1.5:1 if using recommended' radial' system Maximum Power* ...... ................... ... .....
TYPICAL VSWR CURVES Cont.
CHAPTER 2 PREPARATION FOR ASSEMBLY FOR OVERSEAS CUSTOMERS: If you use the Metric System, see the American-ToMetric conversion table in the rear of the manual. The illustrations in this manual will provide both American and Metric Dimensions. Choose a table-top or similarly sized clear area to assemble the Omni DX-88 vertical antenna. A bench-vise may be used to hold the tubing during assembly.
CHAPTER 8 BASE ASSEMBLY Select the DX-88 base assembly and assemble as shown in Figure 1. 80/40 METER ASSEMBLY Capacitor Assembly Construct the two 45" capacitors for the 80/40 meter assembly. Select a 1" x 45" tube (Item 3), 7/16" x 48" tube (Item 1), 3 spacers (Item 35), 1 rain cap (Item 36), and 1 caplug (Item 34) for each capacitor assembly. Refer to Figure 2.
Detail B 11/8" x 7/16" Mast/Capacitor Clamp Detail C 1 1/8" x 1" Mast/Capacitor Clamp Detail A Ite No. 1 3 14 17 18 26 Description Tube, 7/16" x 48" Tube, 1" x 45" Coil Assembly, 80/40 Meters Clamp, Mast/Capacitor, 11/8" x 1" Clamp, Mast/Capacitor, 1 1/8" x 7/16" Bolt, #10-24 x 1/2", hex head, stainless steel Item No.
/12/15 METER TRAP Capacitor There is one 16 inch capacitor and two 13 inch capacitors used in the 10, 12, and 15 meter trap assembly. Select one 1" x 16" tube (Item 4), 7/16" x 19" tube (Item 8), 3 spacers (Item 35), 1 rain ap (Item 36), and 1 caplug (Item 34). Push the spacers onto the 7/16" x 19" tube and adjust so that the top spacer is approximately 10 inches from the top end of the tube, and the bottom spacer is near the bottom end of the tube.
Attaching Capacitors to Coil Assembly Loosely assemble three pairs of 11/8" x 1" clamps and three pairs of 11/8" x 7/16" clamps as shown in Details A and B of Figure 4. Select the 10/12/15 meter coil assembly (Item 13) and attach the capacitors onto the coil assembly using the clamps as shown in Figure 4. Dimensions C, D, and E will be set later on in the instructions. NOTE: The edge of each 11/8" x 1" clamp should be flush with the edge of each coil form.
17/20 METER ASSEMBLY Capacitor Assembly There is one 16 inch capacitor and one 13 inch capacitor used in the 17/20 meter trap assembly. Select one 1" x 16" tube (Item 4), 7/16" x 19" tube (Item 8), 3 spacers (Item 35), 1 rain cap (Item 36), and 1 caplug (Item 34). Push the spacers onto the 7/16" x 19" tube and adjust so that the top spacer is approximately 10 inches from the top end of the tube, and the bottom spacer is near the bottom end of the tube.
Attaching Capacitors to Coil Assembly Loosely assemble two pairs of 1 1/8" x 1" clamps and two pairs of 1 1/8" x 7/16" clamps as shown in Details A and B of Figure 6. Select the 17/20 meter coil assembly (Item 12) and attach the capacitors onto the coil assembly using the clamps as shown in Figure 6. Dimensions G, and F will be set later on in the instructions. NOTE: The edge of each 11/8" x 1" clamp should be flush with the bottom edge of each coil form.
30 METER TRAP ASSEMBLY Attaching Capacitors to Coil Loosely assemble a pair of 1" clamps and a pair of 3/8" x 1" x 3/8" clamps as shown in Details A and B of Figure 7. Select the 30 meter coil assembly (Item 15) and attach the capacitors onto the coil assembly using the clamps as shown in Figure 7. NOTE: The edge of each clamp assembly should be flush with each edge of the coil form. Tighten the hardware on these two clamp assemblies.
ATTACHING UPPER RADIATOR TUBES TO 30 METER TRAP ASSEMBLY Select the 30 meter trap assembly, 7/8" x 36" tube (Item 11), 5/8" x 48" tube (Item 10), 7/16" x 55" tube (Item 2), and the two #6 tubing clamps (Item 21). Assemble as shown in Figure 8. Dimensions H and I will be set later on in the instructions. Tighten all hardware and clamps except for the middle tubing clamp. Push a caplug (Item 34) on the top end of the 55" x 7/16" tube (Item 2).
INSTALLATION OF TUBING CLAMPS Select the proper size tubing clamp as shown in the chart. When installing the clamps, place the clamp near the tube end with the top of the clamp over the slot in the tube as shown in Figure 9. Part No. 358756 After adjustment of the tubing lengths, tighten the clamp with a 5/16 inch nut driver, socket, or open end wrench until the tubing will not twist or telescope.
ATTACHING THE TRAP ASSEMBLIES Slide the bottom end of the 30 meter trap into the top end of the 17/20 meter trap assembly. Dimension H will be set later on in the instructions. DO NOT tighten now. Select the 11/4" x 61/4" slotted tube splice (Item 6), and the two #16 tubing clamps (Item 23) . Assemble as shown in Figure 8. The bottom of the 17/20 meter trap assembly and the top of the 10/12/15 meter trap assembly should meet within this tube. Tighten both tubing clamps securely.
Figure 11 Connecting Trap Assemblies
TUNING THE DX-88 VERTICAL ANTENNA Decide if you want to tune the DX-88 vertical for the 8 HF amateur bands or whether you wish to tune it for reception on the international shortwave broadcasting bands. Also, if you choose the amateur band settings, you must also choose a setting for either 80 meter CW (3500 - 3800 KHz) or 75 meter "phone" (3700 - 4000 KHz).
Graph 1 Sum of Dimension A and B 80/40 Meter Trap for 6.9-7.4 MHz Graph 2 Sum of Dimension A and B 80/40 Meter Trap for 3.5-4.0 MHz Graph 3 Dimension C 10 Meter Trap for 27-29.7 MHz Graph 4 Dimension D 12 Meter Trap for 245-26.
Graph 5 Dimension E 15 Meter Trap for 20.5-22 MHz Graph 6 Dimension F 17 Meter Trap for 17.5-18.5 MHz Graph 8 Dimension H 30 Meter Trap for 9.5-10.5 MHz Graph 7 Dimension G 20 Meter Trap for 13.5-15.
SETTING HAM - CW DIMENSION DIMENSION "H" "I" 16 in. 18 in. 19 in. 28 in. 25 in. 46 in.
TOP VIEW TOP VIEW Figure 12 DX-88 Overall View
CHAPTER 4 MOUNTING THE ANTENNA The Omni DX-88 vertical can be mounted on the ground, on a rooftop or on a mast. For best performance, it should be mounted in the clear, at least 20 feet from buildings, metal fences, metal masts or flag poles and other metallic structures. WARNING DO NOT install this antenna near any power lines. Not only is it dangerous to put up and take down, the power lines could cause excessive noise to be received by the radio connected to this antenna.
Since the radials of a ground-mounted vertical are actually on, if not in, the ground, they are coupled by capacitance or conduction to the ground, and thus resonance effects are not important. Basically, the function of ground radials is to provide a lowloss return path for ground currents. Longer radials and more radials will reduce the ground losses and effectively increase the gain of the antenna.
RESONANT RADIAL LENGTHS AMATEUR BAND WIRE LENGTH SWL BAND WIRE LENGTH (METERS) U.S. METRIC (METERS) U.S. METRIC 41/40 30 20 17 15 12 34'2" 23'9" 17'1" 13'8" 11,111, 10'3" 10.41 m 7.24 m 5.21 m 4.17 m 3.63 m 3.12 m 31 22 19 16 13 11 25'1" 17'10" 16'0" 13' 10" 11'5" 9'7" 7.65 m 5.43 m 4.87 m 4.23 m 3.47 m 2.92 m 10 9' 1" 2.
WARNING Keep this antenna away from the reach of children or pets. When transmitting, the antenna and antenna radials are hot with RF proportional to the operating power. If you mount your antenna on a roof and find the roof space is too small for the radial system, you can droop the radials over the edge of the roof at almost any angle without seriously changing the p-Irformance of the antenna. The radial system must be insulated from the roof and connected to a good ground for lightning protection.
VSWR RECORD Type of VSWR Meter Date_____________ Date______________ Date____________ Frequency 3. 7.000 7.150 7.300 10.100 10.150 14.000 14.200 14.350 18.068 18.168 21.000 21.250 21.450 24.890 24.990 28.000 28.400 28.800 29.
CHAPTER 5 PARTS LIST Item 1 2 3 4 5 6 7 8 9 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 174865 174939 179764 179767 179768 179771 179772 179782 179783 190000 190210 878202 878204 878532 878536 878537 878539 179734 179735 179736 179737 358756 358757 358758 543792 878541 500321 500158 505266 554071 554099 555747 562961 564792 565697 878542 455644 460367 460368 878548 Tube, 7/16" x 48".................................................................................. 2 Tube, 7/16" x 55"...........
LIMITED WARRANTY Hy-Gain Warrants to the original owner of this product, if manufactured by Hy-Gain and purchased from an authorized dealer or directly from Hy-Gain to be free from defects in material and workmanship for a period of 12 months for rotator products and 24 months for antenna products from date of purchase provided the following terms of this warranty are satisfied. 1. The purchaser must retain the dated proof-of-purchase (bill of sale, canceled check, credit card or money order receipt, etc.
