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CHECKOUT AND ADJUSTMENT

4. Check VSWR on 20 meters.  Tuning is quite broad on this band because the

antenna is physically much taller than a quarter wavelength.  To raise the

frequency of the lowest VSWR, reposition the 30 meter assembly so that the

coil support tube 30 meter L bracket (O1) can be replaced on the next lower

turn of the 40 meter coil.  Alternatively, to lower the frequency of lowest

SWR, reconnect the coil support tube 30 meter L bracket (O1) to the next

higher turn of the 40 meter coil.  In some cases moving the tap point a full turn

up or down may cause more of a frequency shift than is desired, in which

case the entire 30 meter assembly may be rotated around tube (E) to permit

adjustments of less than one full turn.

5. Check VSWR on 15 meters.  The VSWR curve may be shifted upward or

downward by changing the length of the stranded wire between wire clamp

0.500" 15 M w/wire (L) and wire clamp 0.875" 15 M w/insulator (K). To raise

the frequency, simply shorten the wire by wrapping a longer 

tail

 back on itself

and sliding the lower clamp upward to maintain tension.  To lower frequency,

feed more of the 

tail

 back through the hole in the insulator to increase the

length of the wire between wire clamp 0.500" 15 M w/wire (L) and wire

clamp 0.875" 15 M w/insulator (K).  A change of 2 in (5.1 cm.) will shift the

VSWR curve approximately 300 kHz.

6. Check VSWR on 10 meters.  To raise the resonant frequency loosen the small

hose clamp over the slotted end of tube (I) and slide tube (J) farther into tube

(I); to lower the frequency, slide tube (J) farther out of tube (I) and retighten

the hose clamp.  A length change of 3 in (7.6 cm) should move the VSWR

curve approximately 200 kHz.

7. Check  VSWR on 30 meters.  To raise frequency, loosen the wing nut on the

bottom coil clamp of coil/capacitor assembly 30 meter (P), stretch the coil and

retighten the wing nut.  To lower frequency, compress the coil.  A change of

only 1/4 in (6.4 mm) will shift the VSWR curve approximately 100 kHz.  Large

changes in the setting of coil/capacitor assembly 30 meter (P) may affect 20

and 40 meter tuning, in which case it may be necessary to repeat steps 3 and

4.  In general, the point at which the 30 meter coil taps on to the 40 meter coil

will be the major factor in 20 meter tuning.

8. Check VSWR on 17 meters.  To move the SWR curve to a higher frequency

loosen the wing nut on the upper coil clamp and STRETCH the coil about 1/4 in

(6.4 mm) at a time.  To move the SWR curve to a lower frequency range

COMPRESS the coil a like amount.

9. Check VSWR on 12 meters.  Stretch the 12 meter coil in increments of 1/4 in

(6.4 mm) or so to raise the resonant frequency, or compress the coil a like

amount to lower the resonant frequency.

Содержание HF9V

Страница 1: ...GROUND IT IS ALSO RECOMMENDED THAT ALL STATION EQUIPMENT BE DISCONNECTED FROM THE POWER MAINS BEFORE CONNECTING THE FEEDLINE TO THE ANTENNA PLEASE CONSULT THE A R R L HANDBOOK OR OTHER REFERENCE MANU...

Страница 2: ...he end of the tube Pass a 8 x 1 1 2 screw through both parts and secure with a lock washer and hex nut 4 From the center of the insulator measure downward to a point that is 13 in 33 cm along tube B a...

Страница 3: ...t 40 meter D2 and install on the smaller 67 pF capacitor as above 12 Install the above assembly onto the 10 screw protruding from the tab of the center clamp on the coil assembly 80 40 meter C Align c...

Страница 4: ...et O1 around the fourth turn of the 40 meter coil on coil assembly 80 40 meter C Secure with a 8 x 3 4 screw lock washer and hex nut 24 Attach strip 17 meter X to the bolt that fastens the coil to the...

Страница 5: ...so the top edge is 33 1 4 in 84 5 cm from the upper end of the tube 38 Pass the free end of the stranded wire from wire clamp 0 625 6 M w wire T through the small hole in wire clamp 0 750 6 M w insula...

Страница 6: ...he uncapped end of tube J into the slotted end of tube I until only 25 in 63 5 cm extends and secure with compression clamp small adjustable NOTE In the following steps the antenna will be assembled a...

Страница 7: ...and may be as much as 100 kHz at the high end of the band depending on the efficiency of the ground system used greater bandwidth being associated with lossy ground systems It should be remembered th...

Страница 8: ...e and lowest VSWR NOTE To minimize interference to other stations and to avoid erroneous reading use only enough power to produce full scale deflection of the meter in the forward or r f out position...

Страница 9: ...re clamp 0 875 15 M w insulator K A change of 2 in 5 1 cm will shift the VSWR curve approximately 300 kHz 6 Check VSWR on 10 meters To raise the resonant frequency loosen the small hose clamp over the...

Страница 10: ...equency in all installations In the preceding steps it has been assumed that the antenna has been installed in a more or less clear spot away from other vertical conductors such as TV antenna feedline...

Страница 11: ...nnas an electrical 1 4 8 section of 75 ohm coax is used as a geometric mean transformer to match the 100 odd S of feedpoint impedance on that band to a 50 S main transmission line of any convenient le...

Страница 12: ...ylene rope may be used but because some grades tend to deteriorate fairly rapidly periodic inspection should be made A single set of guys placed just above the 30 meter circuit will contribute greatly...

Страница 13: ...ter L Bracket P 00249SZV Coil Capacitor Assembly 30 Meter Q 00137SZV Coil Q Base Matching R 290 08 Coax 75 Ohm Matching S 00228GZV Connector PL 258 T 00331RZV Wire Clamp 5 8 6 M W Wire U 00332RZV Wire...

Страница 14: ...14 Feedline Detail PICTORIAL...

Страница 15: ...G AND WEAKEN THE INSTALLATION If U bolts must be used place a larger diameter metal such as the MPS Mounting Post Sleeve over tube w insulator A Similar precautions should be observed when using TV st...

Страница 16: ...cken wire may be used as a substitute for radial wires and or a ground connection the mesh or screen acting as one plate of a capacitor to provide coupling to the earth beneath the antenna It should b...

Страница 17: ...verticals for reasonable efficiency If the ground loss of resistance of 15 ohms from the preceding example could be reduced to zero ohms it is easy to show that the efficiency of our one eighth wavele...

Страница 18: ...that band It s important to note that cutting each conductor of rotator cable to a specific frequency will not work unless you separate it angling each conductor away for most of its length because t...

Страница 19: ...a supporting metal structure for antenna currents that might otherwise flow on the structure and thus turn the vertical antenna system into a vertical long wire with unwanted high angle radiation OTHE...

Страница 20: ...but it is generally considered that the best possible location for a mobile antenna is in the middle of the roof of the vehicle i e at the center of the vehicle s ground plane and at a point where the...

Страница 21: ...building Steel TV mast sections are readily available in lengths of ten feet and the mounting posts of Butternut HF verticals will slide into those which have an outside diameter of 1 1 4 inches and...

Страница 22: ...tion 6 in or less Symptom High SWR on one band when antenna is roof mounted Radials are in place but antenna will just not tune Look for Radials of wrong length or running close to metal rain gutters...

Страница 23: ...ged or damaged Build up of salt or pollution deposits on insulators and capacitors Radial system corroded or rotted away Owner must do routine maintenance at intervals according to local conditions Sy...

Страница 24: ...ure of an antenna to wind or weather c from improper assembly installation or use of an antenna or d from failure periodically to inspect and maintain an antenna and its installation The Customer is r...

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