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LPY2 

 6  

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7.  From the bottom side, slide the center conductor of the coax through the 
open via at the front of the circuit board. 

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8.  Gently bend the remaining cable to mount flush along the tinned center 
ground strip. 

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9.  Look closely at the ground 
conductor and make sure there are 
no stray braid wires hanging 
around. They can short out the 
coax near the via when you solder 
it in place rendering your antenna 
useless! 

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10.  Solder the length of the ground 
conductor to the circuit board along 
the tinned center ground strip. Be 
careful at this point not to overheat 
the ground conductor and melt the 
dielectric layer. Spot soldering the 
ground braid at the element junctions works well to avoid overheating the 
coax. 

ˆ

11. It’s time for the last connection! Solder the center lead of the coax in 
place on the top side of the circuit board where it passes through the via. 

ˆ

12. Visually examine the junction you just soldered and again make sure 
the center feed of the coax is not shorted to ground. 

 
Note that using an ohmeter to check you LPY915 antenna for shorts will not 
work. By default, the top and bottom layers are connected together by small 
traces near the end of the board. Normal operation requires these traces to be 
left intact. An optional low frequency modification for improved performance 
near 825 MHz will be discussed next. 
Time to start playing! Interface the other end of the coax feed with your radio 
and enjoy the benefits of a broadband 
directional antenna! 

LOGI LOW FREQUENCY MODIFICATION 

If your radio system requires DC isolation 
or you plan to use your Logi below 900 
MHz, the small connecting traces near the 
rear of the antenna should be cut. By 
removing these traces you can extend the 
effective frequency range down to 825 
MHz. You will however wind up with some 
‘lumps’ in the matching response on the 

Soldered Coax Positioning 

Final Installation View 

Содержание The `Logi' Log Periodic Antenna LPY915

Страница 1: ...signal into a powerful beam that is 4 times more powerful in the direction you desire Easy hookup to your Receiver or Transmitter Small thin size with excellent broadband performance Solid 6 dB gain...

Страница 2: ...C1 Inductance Capacitance Meter RAMSEY AMATEUR RADIO KITS DDF1 Doppler Direction Finder HR Series HF All Mode Receivers QRP Series HF CW Transmitters CW7 CW Keyer CPO3 Code Practice Oscillator QRP Pow...

Страница 3: ...y Modification 7 Building a Corner Reflector 7 Building a Reflector Grid 9 LPY915 Return Loss Plot 10 Return Loss vs VSWR Chart 10 Warranty 11 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR RAMSEY ELECTRONIC...

Страница 4: ...put impedances and good VSWR characteristics While the log periodic design has been around since the late 1950 s it has now been discovered to be at the cutting edge of antenna development Looking at...

Страница 5: ...the protective solder mask coating on the bottom side center ground trace with a razor Only remove the mask along the center trace not the perpendicular elements Be careful not to accidentally cut the...

Страница 6: ...it passes through the via 12 Visually examine the junction you just soldered and again make sure the center feed of the coax is not shorted to ground Note that using an ohmeter to check you LPY915 an...

Страница 7: ...as the main element versus a simple dipole The following diagram gives a few basic dimensions for an experimental corner reflector The main points to key in on are the base reflector size and the ele...

Страница 8: ...e vertex of the reflector to allow you to slide the boom in and out while testing Once the optimal position of the Logi is set tighten the coupler and your ready to go BUILDING A REFLECTOR GRID Buildi...

Страница 9: ...nylon wire tie at the end of the boom to squeeze the slotted pipe like a vise Wow Simple to make and highly effective If you plan to do the same here is a quick shopping list 1 Ramsey ISM19R or ISM24...

Страница 10: ...0 1 377 30 0 1 065 7 0 2 615 17 0 1 329 35 0 1 036 8 0 2 323 18 0 1 288 40 0 1 020 9 0 2 100 19 0 1 253 50 0 1 006 10 0 1 925 20 0 1 222 60 0 1 002 RETURN LOSS VERSUS VSWR CONVERSION CHART The LPY2 o...

Страница 11: ...be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I guess the red band really does look orange Ramsey Electronics project kits are packed with pride in the USA If you b...

Страница 12: ...amsey RTS05 Small Diagonal Cutters Ramsey RTS04 OR Complete Soldering Tool Set RS64 2801 ADDITIONAL SUGGESTED ITEMS Optivisor Magnifier Headband Ramsey OPMAG Holder for PC Board Parts Ramsey RTS13 Des...

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